If the ... element type contained no pointers,
then the escape analysis did not track the ... itself.
This manifested in an escaping ...byte being treated
as non-escaping.
Fixes#7934.
LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/100310043
The register allocator decides which variables should be placed into registers by charging for each load/store and crediting for each use, and then selecting an allocation with minimal cost. NOPs will be eliminated, however, so using a variable in a NOP should not generate credit.
Issue 7867 arises from attempted registerization of multi-word variables because they are used in NOPs. By not crediting for that use, they will no longer be considered for registerization.
This fix could theoretically lead to better register allocation, but NOPs are rare relative to other instructions.
Fixes#7867.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/94810044
Variables declared with 'var' have no sym->def.
Fixes#7794.
LGTM=rsc
R=golang-codereviews, bradfitz, rsc
CC=golang-codereviews
https://golang.org/cl/88360043
The new code is adapted from the Go 1.2 nosplit code,
but it does not have the bug reported in issue 7623:
g% go run nosplit.go
g% go1.2 run nosplit.go
BUG
rejected incorrectly:
main 0 call f; f 120
linker output:
# _/tmp/go-test-nosplit021064539
main.main: nosplit stack overflow
120 guaranteed after split check in main.main
112 on entry to main.f
-8 after main.f uses 120
g%
Fixes#6931.
Fixes#7623.
LGTM=iant
R=golang-codereviews, iant, ality
CC=golang-codereviews, r
https://golang.org/cl/88190043
Trying to make GODEBUG=gcdead=1 work with liveness
and in particular ambiguously live variables.
1. In the liveness computation, mark all ambiguously live
variables as live for the entire function, except the entry.
They are zeroed directly after entry, and we need them not
to be poisoned thereafter.
2. In the liveness computation, compute liveness (and deadness)
for all parameters, not just pointer-containing parameters.
Otherwise gcdead poisons untracked scalar parameters and results.
3. Fix liveness debugging print for -live=2 to use correct bitmaps.
(Was not updated for compaction during compaction CL.)
4. Correct varkill during map literal initialization.
Was killing the map itself instead of the inserted value temp.
5. Disable aggressive varkill cleanup for call arguments if
the call appears in a defer or go statement.
6. In the garbage collector, avoid bug scanning empty
strings. An empty string is two zeros. The multiword
code only looked at the first zero and then interpreted
the next two bits in the bitmap as an ordinary word bitmap.
For a string the bits are 11 00, so if a live string was zero
length with a 0 base pointer, the poisoning code treated
the length as an ordinary word with code 00, meaning it
needed poisoning, turning the string into a poison-length
string with base pointer 0. By the same logic I believe that
a live nil slice (bits 11 01 00) will have its cap poisoned.
Always scan full multiword struct.
7. In the runtime, treat both poison words (PoisonGC and
PoisonStack) as invalid pointers that warrant crashes.
Manual testing as follows:
- Create a script called gcdead on your PATH containing:
#!/bin/bash
GODEBUG=gcdead=1 GOGC=10 GOTRACEBACK=2 exec "$@"
- Now you can build a test and then run 'gcdead ./foo.test'.
- More importantly, you can run 'go test -short -exec gcdead std'
to run all the tests.
Fixes#7676.
While here, enable the precise scanning of slices, since that was
disabled due to bugs like these. That now works, both with and
without gcdead.
Fixes#7549.
LGTM=khr
R=khr
CC=golang-codereviews
https://golang.org/cl/83410044
1. Use n->alloc, not n->left, to hold the allocated temp being
passed from orderstmt/orderexpr to walk.
2. Treat method values the same as closures.
3. Use killed temporary for composite literal passed to
non-escaping function argument.
4. Clean temporaries promptly in if and for statements.
5. Clean temporaries promptly in select statements.
As part of this, move all the temporary-generating logic
out of select.c into order.c, so that the temporaries can
be reclaimed.
With the new temporaries, can re-enable the 1-entry
select optimization. Fixes issue 7672.
While we're here, fix a 1-line bug in select processing
turned up by the new liveness test (but unrelated; select.c:72).
Fixes#7686.
6. Clean temporaries (but not particularly promptly) in switch
and range statements.
7. Clean temporary used during convT2E/convT2I.
8. Clean temporaries promptly during && and || expressions.
---
CL 81940043 reduced the number of ambiguously live temps
in the godoc binary from 860 to 711.
CL 83090046 reduced the number from 711 to 121.
This CL reduces the number from 121 to 23.
15 the 23 that remain are in fact ambiguously live.
The final 8 could be fixed but are not trivial and
not common enough to warrant work at this point
in the release cycle.
These numbers only count ambiguously live temps,
not ambiguously live user-declared variables.
There are 18 such variables in the godoc binary after this CL,
so a total of 41 ambiguously live temps or user-declared
variables.
The net effect is that zeroing anything on entry to a function
should now be a rare event, whereas earlier it was the
common case.
This is good enough for Go 1.3, and probably good
enough for future releases too.
Fixes#7345.
LGTM=khr
R=khr
CC=golang-codereviews
https://golang.org/cl/83000048
1. In functions with heap-allocated result variables or with
defer statements, the return sequence requires more than
just a single RET instruction. There is an optimization that
arranges for all returns to jump to a single copy of the return
epilogue in this case. Unfortunately, that optimization is
fundamentally incompatible with PC-based liveness information:
it takes PCs at many different points in the function and makes
them all land at one PC, making the combined liveness information
at that target PC a mess. Disable this optimization, so that each
return site gets its own copy of the 'call deferreturn' and the
copying of result variables back from the heap.
This removes quite a few spurious 'ambiguously live' variables.
2. Let orderexpr allocate temporaries that are passed by address
to a function call and then die on return, so that we can arrange
an appropriate VARKILL.
2a. Do this for ... slices.
2b. Do this for closure structs.
2c. Do this for runtime.concatstring, which is the implementation
of large string additions. Change representation of OADDSTR to
an explicit list in typecheck to avoid reconstructing list in both
walk and order.
3. Let orderexpr allocate the temporary variable copies used for
range loops, so that they can be killed when the loop is over.
Similarly, let it allocate the temporary holding the map iterator.
CL 81940043 reduced the number of ambiguously live temps
in the godoc binary from 860 to 711.
This CL reduces the number to 121. Still more to do, but another
good checkpoint.
Update #7345
LGTM=khr
R=khr
CC=golang-codereviews
https://golang.org/cl/83090046
The new channel and map runtime routines take pointers
to values, typically temporaries. Without help, the compiler
cannot tell when those temporaries stop being needed,
because it isn't sure what happened to the pointer.
Arrange to insert explicit VARKILL instructions for these
temporaries so that the liveness analysis can avoid seeing
them as "ambiguously live".
The change is made in order.c, which was already in charge of
introducing temporaries to preserve the order-of-evaluation
guarantees. Now its job has expanded to include introducing
temporaries as needed by runtime routines, and then also
inserting the VARKILL annotations for all these temporaries,
so that their lifetimes can be shortened.
In order to do its job for the map runtime routines, order.c arranges
that all map lookups or map assignments have the form:
x = m[k]
x, y = m[k]
m[k] = x
where x, y, and k are simple variables (often temporaries).
Likewise, receiving from a channel is now always:
x = <-c
In order to provide the map guarantee, order.c is responsible for
rewriting x op= y into x = x op y, so that m[k] += z becomes
t = m[k]
t2 = t + z
m[k] = t2
While here, fix a few bugs in order.c's traversal: it was failing to
walk into select and switch case bodies, so order of evaluation
guarantees were not preserved in those situations.
Added tests to test/reorder2.go.
Fixes#7671.
In gc/popt's temporary-merging optimization, allow merging
of temporaries with their address taken as long as the liveness
ranges do not intersect. (There is a good chance of that now
that we have VARKILL annotations to limit the liveness range.)
Explicitly killing temporaries cuts the number of ambiguously
live temporaries that must be zeroed in the godoc binary from
860 to 711, or -17%. There is more work to be done, but this
is a good checkpoint.
Update #7345
LGTM=khr
R=khr
CC=golang-codereviews
https://golang.org/cl/81940043
1. On entry to a function, only zero the ambiguously live stack variables.
Before, we were zeroing all stack variables containing pointers.
The zeroing is pretty inefficient right now (issue 7624), but there are also
too many stack variables detected as ambiguously live (issue 7345),
and that must be addressed before deciding how to improve the zeroing code.
(Changes in 5g/ggen.c, 6g/ggen.c, 8g/ggen.c, gc/pgen.c)
Fixes#7647.
2. Make the regopt word-based liveness analysis preserve the
whole-variable liveness property expected by the garbage collection
bitmap liveness analysis. That is, if the regopt liveness decides that
one word in a struct needs to be preserved, make sure it preserves
the entire struct. This is particularly important for multiword values
such as strings, slices, and interfaces, in which all the words need
to be present in order to understand the meaning.
(Changes in 5g/reg.c, 6g/reg.c, 8g/reg.c.)
Fixes#7591.
3. Make the regopt word-based liveness analysis treat a variable
as having its address taken - which makes it preserved across
all future calls - whenever n->addrtaken is set, for consistency
with the gc bitmap liveness analysis, even if there is no machine
instruction actually taking the address. In this case n->addrtaken
is incorrect (a nicer way to put it is overconservative), and ideally
there would be no such cases, but they can happen and the two
analyses need to agree.
(Changes in 5g/reg.c, 6g/reg.c, 8g/reg.c; test in bug484.go.)
Fixes crashes found by turning off "zero everything" in step 1.
4. Remove spurious VARDEF annotations. As the comment in
gc/pgen.c explains, the VARDEF must immediately precede
the initialization. It cannot be too early, and it cannot be too late.
In particular, if a function call sits between the VARDEF and the
actual machine instructions doing the initialization, the variable
will be treated as live during that function call even though it is
uninitialized, leading to problems.
(Changes in gc/gen.c; test in live.go.)
Fixes crashes found by turning off "zero everything" in step 1.
5. Do not treat loading the address of a wide value as a signal
that the value must be initialized. Instead depend on the existence
of a VARDEF or the first actual read/write of a word in the value.
If the load is in order to pass the address to a function that does
the actual initialization, treating the load as an implicit VARDEF
causes the same problems as described in step 4.
The alternative is to arrange to zero every such value before
passing it to the real initialization function, but this is a much
easier and more efficient change.
(Changes in gc/plive.c.)
Fixes crashes found by turning off "zero everything" in step 1.
6. Treat wide input parameters with their address taken as
initialized on entry to the function. Otherwise they look
"ambiguously live" and we will try to emit code to zero them.
(Changes in gc/plive.c.)
Fixes crashes found by turning off "zero everything" in step 1.
7. An array of length 0 has no pointers, even if the element type does.
Without this change, the zeroing code complains when asked to
clear a 0-length array.
(Changes in gc/reflect.c.)
LGTM=khr
R=khr
CC=golang-codereviews
https://golang.org/cl/80160044
Revision 3ae4607a43ff introduced CONVNOP layers
to fix type checking issues arising from comparisons.
The added complexity made 8g run out of registers
when compiling an equality function in go.net/ipv6.
A similar issue occurred in test/sizeof.go on
amd64p32 with 6g.
Fixes#7405.
LGTM=khr
R=rsc, dave, iant, khr
CC=golang-codereviews
https://golang.org/cl/78100044
A too large float constant is an error.
A too small float constant is rounded to zero.
Fixes#7419
Update #6902
LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/76730046
The lowering to runtime calls introduces hidden pointers to the
arguments of select clauses. When implicit conversions were
involved it could end up with incompatible pointers. Since the
pointed-to types have the same representation, we can introduce a
forced conversion.
Fixes#6847.
LGTM=rsc
R=rsc, iant, khr
CC=golang-codereviews
https://golang.org/cl/72380043
The garbage collector uses type information to guide the
traversal of the heap. If it sees a field that should be a string,
it marks the object pointed at by the string data pointer as
visited but does not bother to look at the data, because
strings contain bytes, not pointers.
If you save s[len(s):] somewhere, though, the string data pointer
actually points just beyond the string data; if the string data
were exactly the size of an allocated block, the string data
pointer would actually point at the next block. It is incorrect
to mark that next block as visited and not bother to look at
the data, because the next block may be some other type
entirely.
The fix is to ignore strings with zero length during collection:
they are empty and can never become non-empty: the base
pointer will never be used again. The handling of slices already
does this (but using cap instead of len).
This was not a bug in Go 1.2, because until January all string
allocations included a trailing NUL byte not included in the
length, so s[len(s):] still pointed inside the string allocation
(at the NUL).
This bug was causing the crashes in test/run.go. Specifically,
the parsing of a regexp in package regexp/syntax allocated a
[]syntax.Inst with rounded size 1152 bytes. In fact it
allocated many such slices, because during the processing of
test/index2.go it creates thousands of regexps that are all
approximately the same complexity. That takes a long time, and
test/run works on other tests in other goroutines. One such
other test is chan/perm.go, which uses an 1152-byte source
file. test/run reads that file into a []byte and then calls
strings.Split(string(src), "\n"). The string(src) creates an
1152-byte string - and there's a very good chance of it
landing next to one of the many many regexp slices already
allocated - and then because the file ends in a \n,
strings.Split records the tail empty string as the final
element in the slice. A garbage collection happens at this
point, the collection finds that string before encountering
the []syntax.Inst data it now inadvertently points to, and the
[]syntax.Inst data is not scanned for the pointers that it
contains. Each syntax.Inst contains a []rune, those are
missed, and the backing rune arrays are freed for reuse. When
the regexp is later executed, the runes being searched for are
no longer runes at all, and there is no match, even on text
that should match.
On 64-bit machines the pointer in the []rune inside the
syntax.Inst is larger (along with a few other pointers),
pushing the []syntax.Inst backing array into a larger size
class, avoiding the collision with chan/perm.go's
inadvertently sized file.
I expect this was more prevalent on OS X than on Linux or
Windows because those managed to run faster or slower and
didn't overlap index2.go with chan/perm.go as often. On the
ARM systems, we only run one errorcheck test at a time, so
index2 and chan/perm would never overlap.
It is possible that this bug is the root cause of other crashes
as well. For now we only know it is the cause of the test/run crash.
Many thanks to Dmitriy for help debugging.
Fixes#7344.
Fixes#7455.
LGTM=r, dvyukov, dave, iant
R=golang-codereviews, dave, r, dvyukov, delpontej, iant
CC=golang-codereviews, khr
https://golang.org/cl/74250043
Some of the errorcheck tests have many many identical regexps.
Use a map to avoid storing the compiled form many many times
in memory. Change the filterRe to a simple string to avoid
the expense of those regexps as well.
Cuts the time for run.go on index2.go by almost 50x.
Noticed during debugging of issue 7344.
LGTM=bradfitz
R=bradfitz, josharian
CC=golang-codereviews
https://golang.org/cl/74380043
The byte that r is or'd into is already 0x7, so the failure to zero r only
impacts the generated machine code if the register is > 7.
Fixes#7044.
LGTM=dave, minux.ma, rsc
R=dave, minux.ma, bradfitz, rsc
CC=golang-codereviews
https://golang.org/cl/73730043
The cached computed interface tables are indexed by the interface
types, not by the unnamed underlying interfaces
To preserve the invariants expected by interface comparison, an
itab generated for an interface type must not be used for a value
of a different interface type even if the representation is identical.
Fixes#7207.
LGTM=rsc
R=rsc, iant, khr
CC=golang-codereviews
https://golang.org/cl/69210044
See golang.org/s/go13nacl for design overview.
This CL is the mostly mechanical changes from rsc's Go 1.2 based NaCl branch, specifically 39cb35750369 to 500771b477cf from https://code.google.com/r/rsc-go13nacl. This CL does not include working NaCl support, there are probably two or three more large merges to come.
CL 15750044 is not included as it involves more invasive changes to the linker which will need to be merged separately.
The exact change lists included are
15050047: syscall: support for Native Client
15360044: syscall: unzip implementation for Native Client
15370044: syscall: Native Client SRPC implementation
15400047: cmd/dist, cmd/go, go/build, test: support for Native Client
15410048: runtime: support for Native Client
15410049: syscall: file descriptor table for Native Client
15410050: syscall: in-memory file system for Native Client
15440048: all: update +build lines for Native Client port
15540045: cmd/6g, cmd/8g, cmd/gc: support for Native Client
15570045: os: support for Native Client
15680044: crypto/..., hash/crc32, reflect, sync/atomic: support for amd64p32
15690044: net: support for Native Client
15690048: runtime: support for fake time like on Go Playground
15690051: build: disable various tests on Native Client
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/68150047
Revision c0e0467635ec (cmd/gc: return canonical Node* from temp)
exposed original nodes of temporaries, allowing callers to mutate
their types.
In walkcompare a temporary could be typed as ideal because of
this. Additionnally, assignment of a comparison result to
a custom boolean type was broken.
Fixes#7366.
LGTM=rsc
R=rsc, iant, khr
CC=golang-codereviews
https://golang.org/cl/66930044
The error message was previously off by one in all cases.
Fixes#7150.
LGTM=r
R=golang-codereviews, r
CC=golang-codereviews
https://golang.org/cl/65850043
Update #6853
For an ephemeral binary - one created, run, and then deleted -
there is no need to write dwarf debug information, since the
binary will not be used with gdb. In this case, instruct the linker
not to spend time and disk space generating the debug information
by passing the -w flag to the linker.
Omitting dwarf information reduces the size of most binaries by 25%.
We may be more aggressive about this in the future.
LGTM=bradfitz, r
R=r, bradfitz
CC=golang-codereviews
https://golang.org/cl/65890043
Not recording the address being taken was causing
the liveness analysis not to preserve x in the absence
of direct references to x, which in turn was making the
net test fail with GOGC=0.
In addition to the test, this fixes a bug wherein
GOGC=0 go test -short net
crashed if liveness analysis was in use (like at tip, not like Go 1.2).
TBR=ken2
CC=golang-codereviews
https://golang.org/cl/64470043
The VARDEF placement must be before the initialization
but after any final use. If you have something like s = ... using s ...
the rhs must be evaluated, then the VARDEF, then the lhs
assigned.
There is a large comment in pgen.c on gvardef explaining
this in more detail.
This CL also includes Ian's suggestions from earlier CLs,
namely commenting the use of mode in link.h and fixing
the precedence of the ~r check in dcl.c.
This CL enables the check that if liveness analysis decides
a variable is live on entry to the function, that variable must
be a function parameter (not a result, and not a local variable).
If this check fails, it indicates a bug in the liveness analysis or
in the generated code being analyzed.
The race detector generates invalid code for append(x, y...).
The code declares a temporary t and then uses cap(t) before
initializing t. The new liveness check catches this bug and
stops the compiler from writing out the buggy code.
Consequently, this CL disables the race detector tests in
run.bash until the race detector bug can be fixed
(golang.org/issue/7334).
Except for the race detector bug, the liveness analysis check
does not detect any problems (this CL and the previous CLs
fixed all the detected problems).
The net test still fails with GOGC=0 but the rest of the tests
now pass or time out (because GOGC=0 is so slow).
TBR=iant
CC=golang-codereviews
https://golang.org/cl/64170043
The existing tests issue4463.go and issue4654.go had failures at
typechecking and did not test walking the AST.
Fixes#7272.
LGTM=khr
R=khr, rsc, iant
CC=golang-codereviews
https://golang.org/cl/60550044
When the liveness code doesn't know a function doesn't return
(but the generated code understands that), the liveness analysis
invents a control flow edge that is not really there, which can cause
variables to seem spuriously live. This is particularly bad when the
variables are uninitialized.
TBR=iant
CC=golang-codereviews
https://golang.org/cl/63720043
The registerization code needs the function to end in a RET,
even if that RET is actually unreachable.
The liveness code needs to avoid such unreachable RETs.
It had a special case for final RET after JMP, but no case
for final RET after UNDEF. Instead of expanding the special
cases, let fixjmp - which already knows what is and is not
reachable definitively - mark the unreachable RET so that
the liveness code can identify it.
TBR=iant
CC=golang-codereviews
https://golang.org/cl/63680043
A normal RET is treated as using the return values,
but a tail jump RET does not - it is jumping to the
function that is going to fill in the return values.
If a tail jump RET is recorded as using the return values,
since nothing initializes them they will be marked as
live on entry to the function, which is clearly wrong.
Found and tested by the new code in plive.c that looks
for variables that are incorrectly live on entry.
That code is disabled for now because there are other
cases remaining to be fixed. But once it is enabled,
test/live1.go becomes a real test of this CL.
TBR=iant
CC=golang-codereviews
https://golang.org/cl/63570045
Any initialization of a variable by a block copy or block zeroing
or by multiple assignments (componentwise copying or zeroing
of a multiword variable) needs to emit a VARDEF. These cases were not.
Fixes#7205.
TBR=iant
CC=golang-codereviews
https://golang.org/cl/63650044
Before, an unnamed return value turned into an ONAME node n with n->sym
named ~anon%d, and n->orig == n.
A blank-named return value turned into an ONAME node n with n->sym
named ~anon%d but n->orig == the original blank n. Code generation and
printing uses n->orig, so that this node formatted as _.
But some code does not use n->orig. In particular the liveness code does
not know about the n->orig convention and so mishandles blank identifiers.
It is possible to fix but seemed better to avoid the confusion entirely.
Now the first kind of node is named ~r%d and the second ~b%d; both have
n->orig == n, so that it doesn't matter whether code uses n or n->orig.
After this change the ->orig field is only used for other kinds of expressions,
not for ONAME nodes.
This requires distinguishing ~b from ~r names in a few places that care.
It fixes a liveness analysis bug without actually changing the liveness code.
TBR=ken2
CC=golang-codereviews
https://golang.org/cl/63630043
Make the loop nesting depth of &x depend on where x is declared,
not on where the &x appears. The latter is only a conservative
estimate of the former. Being more careful can avoid some
variables escaping, and it is easier to reason about.
It would have avoided issue 7313, although that was still a bug
worth fixing.
Not much effect in the tree: one variable in the whole tree
is saved from a heap allocation (something in x509 parsing).
LGTM=daniel.morsing
R=daniel.morsing
CC=golang-codereviews
https://golang.org/cl/62380043
Logically, the init statement is in the enclosing scopes loopdepth, not inside the for loop.
Fixes#7313.
LGTM=rsc
R=golang-codereviews, gobot, rsc
CC=golang-codereviews
https://golang.org/cl/62430043
Array values are comparable if values of the array element type
are comparable.
Fixes#6526.
LGTM=khr
R=rsc, bradfitz, khr
CC=golang-codereviews
https://golang.org/cl/58580043
This CL makes the bitmaps a little more precise about variables
that have their address taken but for which the address does not
escape to the heap, so that the variables are kept in the stack frame
rather than allocated on the heap.
The code before this CL handled these variables by treating every
return statement as using every such variable and depending on
liveness analysis to essentially treat the variable as live during the
entire function. That approach has false positives and (worse) false
negatives. That is, it's both sloppy and buggy:
func f(b1, b2 bool) { // x live here! (sloppy)
if b2 {
print(0) // x live here! (sloppy)
return
}
var z **int
x := new(int)
*x = 42
z = &x
print(**z) // x live here (conservative)
if b2 {
print(1) // x live here (conservative)
return
}
for {
print(**z) // x not live here (buggy)
}
}
The first two liveness annotations (marked sloppy) are clearly
wrong: x cannot be live if it has not yet been declared.
The last liveness annotation (marked buggy) is also wrong:
x is live here as *z, but because there is no return statement
reachable from this point in the code, the analysis treats x as dead.
This CL changes the liveness calculation to mark such variables
live exactly at points in the code reachable from the variable
declaration. This keeps the conservative decisions but fixes
the sloppy and buggy ones.
The CL also detects ambiguously live variables, those that are
being marked live but may not actually have been initialized,
such as in this example:
func f(b1 bool) {
var z **int
if b1 {
x := new(int)
*x = 42
z = &x
} else {
y := new(int)
*y = 54
z = &y
}
print(**z) // x, y live here (conservative)
}
Since the print statement is reachable from the declaration of x,
x must conservatively be marked live. The same goes for y.
Although both x and y are marked live at the print statement,
clearly only one of them has been initialized. They are both
"ambiguously live".
These ambiguously live variables cause problems for garbage
collection: the collector cannot ignore them but also cannot
depend on them to be initialized to valid pointer values.
Ambiguously live variables do not come up too often in real code,
but recent changes to the way map and interface runtime functions
are invoked has created a large number of ambiguously live
compiler-generated temporary variables. The next CL will adjust
the analysis to understand these temporaries better, to make
ambiguously live variables fairly rare.
Once ambiguously live variables are rare enough, another CL will
introduce code at the beginning of a function to zero those
slots on the stack. At that point the garbage collector and the
stack copying routines will be able to depend on the guarantee that
if a slot is marked as live in a liveness bitmap, it is initialized.
R=khr
CC=golang-codereviews, iant
https://golang.org/cl/51810043
For historical reasons, temp was returning a copy
of the created Node*, not the original Node*.
This meant that if analysis recorded information in the
returned node (for example, n->addrtaken = 1), the
analysis would not show up on the original Node*, the
one kept in fn->dcl and consulted during liveness
bitmap creation.
Correct this, and watch for it when setting addrtaken.
Fixes#7083.
R=khr, dave, minux.ma
CC=golang-codereviews
https://golang.org/cl/51010045
Nodes of goto statements were corrupted when written
to export data.
Fixes#7023.
R=rsc, dave, minux.ma
CC=golang-codereviews
https://golang.org/cl/46190043
Gccgo doesn't have the same equivalent of file name and
package as the gc compiler, so the error messages are
necessarily different.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/40510048
fixedbugs/issue4510.dir/f2.go:7: error: 'fmt' defined as both imported name and global name
f1.go:7: note: 'fmt' imported here
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/41530044
const1.go:33: error: integer constant overflow
<similar errors omitted>
const1.go:64: error: division by zero
const1.go:67: error: floating point constant overflow
const1.go:68: error: floating point constant overflow
const1.go:69: error: floating point constant overflow
const1.go:70: error: division by zero
const1.go:71: error: expected integer type
const1.go:77: error: argument 1 has incompatible type (cannot use type int8 as type int)
const1.go:78: error: argument 1 has incompatible type (cannot use type int8 as type int)
const1.go:79: error: argument 1 has incompatible type (cannot use type uint8 as type int)
const1.go:81: error: argument 1 has incompatible type (cannot use type float32 as type int)
const1.go:82: error: argument 1 has incompatible type (cannot use type float64 as type int)
const1.go:83: error: floating point constant truncated to integer
const1.go:85: error: argument 1 has incompatible type (cannot use type float64 as type int)
const1.go:86: error: argument 1 has incompatible type (cannot use type string as type int)
const1.go:87: error: argument 1 has incompatible type (cannot use type bool as type int)
const1.go:90: error: const initializer cannot be nil
const1.go:91: error: expression is not constant
const1.go:92: error: expression is not constant
const1.go:93: error: invalid constant type
const1.go:94: error: invalid constant type
fixedbugs/bug462.go:17: error: unknown field 'os.File' in 'T'
fixedbugs/issue3705.go:9: error: cannot declare init - must be func
fixedbugs/issue4251.go:12: error: inverted slice range
fixedbugs/issue4251.go:16: error: inverted slice range
fixedbugs/issue4251.go:20: error: inverted slice range
fixedbugs/issue4405.go:11: error: invalid character 0x7 in identifier
fixedbugs/issue4405.go:12: error: invalid character 0x8 in identifier
fixedbugs/issue4405.go:13: error: invalid character 0xb in identifier
fixedbugs/issue4405.go:14: error: invalid character 0xc in identifier
fixedbugs/issue4429.go:15: error: expected pointer
fixedbugs/issue4517d.go:9: error: cannot import package as init
fixedbugs/issue4545.go:17: error: invalid context-determined non-integer type for left operand of shift
fixedbugs/issue4545.go:16: error: incompatible types in binary expression
fixedbugs/issue4610.go:15: error: expected ';' or '}' or newline
fixedbugs/issue4610.go:16: error: expected declaration
fixedbugs/issue4654.go:15: error: value computed is not used
<similar errors omitted>
fixedbugs/issue4776.go:9: error: program must start with package clause
fixedbugs/issue4776.go:9: error: expected ';' or newline after package clause
fixedbugs/issue4813.go:31: error: index must be integer
<similar errors omitted>
fixedbugs/issue4847.go:22: error: initialization expression for 'matchAny' depends upon itself
fixedbugs/issue5089.go:13: error: redefinition of 'bufio.Buffered': receiver name changed
fixedbugs/issue5089.go:11: note: previous definition of 'bufio.Buffered' was here
fixedbugs/issue5172.go:17: error: reference to undefined field or method 'bar'
fixedbugs/issue5172.go:18: error: reference to undefined field or method 'bar'
fixedbugs/issue5172.go:12: error: use of undefined type 'bar'
fixedbugs/issue5358.go:16: error: argument 2 has incompatible type
fixedbugs/issue5581.go:29: error: use of undefined type 'Blah'
funcdup.go:10: error: redefinition of 'i'
funcdup.go:10: note: previous definition of 'i' was here
<similar errors omitted>
funcdup2.go:10: error: redefinition of 'i'
funcdup2.go:10: note: previous definition of 'i' was here
<similar errors omitted>
slice3err.go:20: error: middle index required in 3-index slice
<similar errors omitted>
slice3err.go:20: error: final index required in 3-index slice
<similar errors omitted>
slice3err.go:21: error: final index required in 3-index slice
slice3err.go:46: error: invalid 3-index slice of string
<similar errors omitted>
slice3err.go:57: error: inverted slice range
<similar errors omitted>
slice3err.go:62: error: invalid slice index: capacity less than length
slice3err.go:64: error: invalid slice index: capacity less than start
slice3err.go:65: error: invalid slice index: capacity less than start
slice3err.go:66: error: invalid slice index: capacity less than start
slice3err.go:68: error: invalid slice index: capacity less than length
slice3err.go:70: error: invalid slice index: capacity less than start
slice3err.go:80: error: invalid slice index: capacity less than length
slice3err.go:82: error: invalid slice index: capacity less than start
slice3err.go:83: error: invalid slice index: capacity less than start
slice3err.go:84: error: invalid slice index: capacity less than start
slice3err.go:86: error: invalid slice index: capacity less than length
slice3err.go:88: error: invalid slice index: capacity less than start
slice3err.go:99: error: array index out of bounds
<similar errors omitted>
slice3err.go:106: error: invalid slice index: capacity less than length
slice3err.go:107: error: invalid slice index: capacity less than start
slice3err.go:118: error: invalid slice index: capacity less than length
slice3err.go:119: error: invalid slice index: capacity less than start
syntax/semi1.go:10: error: missing '{' after if clause
syntax/semi1.go:10: error: reference to undefined name 'x'
syntax/semi1.go:10: error: reference to undefined name 'y'
syntax/semi1.go:12: error: reference to undefined name 'z'
syntax/semi2.go:10: error: missing '{' after switch clause
syntax/semi2.go:10: error: reference to undefined name 'x'
syntax/semi3.go:10: error: missing '{' after for clause
syntax/semi3.go:10: error: reference to undefined name 'x'
syntax/semi3.go:10: error: reference to undefined name 'y'
syntax/semi3.go:10: error: reference to undefined name 'z'
syntax/semi3.go:12: error: reference to undefined name 'z'
syntax/semi4.go:11: error: missing '{' after for clause
syntax/semi4.go:10: error: reference to undefined name 'x'
syntax/semi4.go:12: error: reference to undefined name 'z'
typecheck.go:12: error: reference to undefined name 'b'
typecheck.go:17: error: reference to undefined name 'c'
typecheck.go:11: error: use of undefined type 'b'
typecheck.go:16: error: not enough arguments
typecheck.go:17: error: not enough arguments
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/41520044
There is no necessary relationship between the imports of the
packages a and b, and gccgo happens to import them in a
different order, leading to different output. This ordering
is not the purpose of the test in any case.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/40400043
blank1.go:10:9: error: invalid package name _
blank1.go:17:2: error: cannot use _ as value
blank1.go:18:7: error: cannot use _ as value
blank1.go:20:8: error: invalid use of ‘_’
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/14088044
When a floating point constant is used as an array/slice
index, gccgo prints "error: index must be integer"; gc prints
"constant 2.1 truncated to integer".
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/14044044
The select2.go test assumed that the memory allocated between
its two samplings of runtime.ReadMemStats is strictly
increasing. To avoid failing the tests when this is not true,
a greater-than check is introduced before computing the
difference in allocated memory.
R=golang-dev, r, cshapiro
CC=golang-dev
https://golang.org/cl/13701046
This eliminates ~75% of the nil checks being emitted,
on all architectures. We can do better, but we need
a bit more general support from the compiler, and
I don't want to do that so close to Go 1.2.
What's here is simple but effective and safe.
A few small code generation cleanups were required
to make the analysis consistent on all systems about
which nil checks are omitted, at least in the test.
Fixes#6019.
R=ken2
CC=golang-dev
https://golang.org/cl/13334052
The implementation of division in the 5 toolchain is a bit too magical.
Hide the magic from the traceback routines.
Also add a test for the results of the software divide routine.
Fixes#5805.
R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/13239052
Bug #1:
Issue 5406 identified an interesting case:
defer iface.M()
may end up calling a wrapper that copies an indirect receiver
from the iface value and then calls the real M method. That's
two calls down, not just one, and so recover() == nil always
in the real M method, even during a panic.
[For the purposes of this entire discussion, a wrapper's
implementation is a function containing an ordinary call, not
the optimized tail call form that is somtimes possible. The
tail call does not create a second frame, so it is already
handled correctly.]
Fix this bug by introducing g->panicwrap, which counts the
number of bytes on current stack segment that are due to
wrapper calls that should not count against the recover
check. All wrapper functions must now adjust g->panicwrap up
on entry and back down on exit. This adds slightly to their
expense; on the x86 it is a single instruction at entry and
exit; on the ARM it is three. However, the alternative is to
make a call to recover depend on being able to walk the stack,
which I very much want to avoid. We have enough problems
walking the stack for garbage collection and profiling.
Also, if performance is critical in a specific case, it is already
faster to use a pointer receiver and avoid this kind of wrapper
entirely.
Bug #2:
The old code, which did not consider the possibility of two
calls, already contained a check to see if the call had split
its stack and so the panic-created segment was one behind the
current segment. In the wrapper case, both of the two calls
might split their stacks, so the panic-created segment can be
two behind the current segment.
Fix this by propagating the Stktop.panic flag forward during
stack splits instead of looking backward during recover.
Fixes#5406.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/13367052
These tests were suggested in golang.org/issue/6080.
They were fixed as part of the new nil pointer checks
that I added a few weeks ago.
Recording the tests as part of marking the issue closed.
Fixes#6080.
R=golang-dev, r, bradfitz
CC=golang-dev
https://golang.org/cl/13255049
Types in function scope can have methods on them if they embed another type, but we didn't make the name unique, meaning that 2 identically named types in different functions would conflict with eachother.
Fixes#6269.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13326045
The compiler computes initialization order by finding
a spanning tree between a package's global variables.
But it does so by walking both variables and functions
and stops detecting cycles between variables when they
mix with a cycle of mutually recursive functions.
Fixes#4847.
R=golang-dev, daniel.morsing, rsc
CC=golang-dev
https://golang.org/cl/9663047
syntax/*: update messages
sliceerr3.go: bizarre new error fixed by deleting a space.
I could have sworn I ran all.bash before submitting the CL that triggered these.
TBR=golang-dev@googlegroups.com
R=golang-dev
CC=golang-dev
https://golang.org/cl/12812044
See golang.org/s/go12nil.
This CL is about getting all the right checks inserted.
A followup CL will add an optimization pass to
remove redundant checks.
R=ken2
CC=golang-dev
https://golang.org/cl/12970043
Individual variables bigger than 10 MB are now
moved to the heap, as if they had escaped on
their own.
This avoids ridiculous stacks for programs that
do things like
x := [1<<30]byte{}
... use x ...
If 10 MB is too small, we can raise the limit.
Fixes#6077.
R=ken2
CC=golang-dev
https://golang.org/cl/12650045
The gc compiler only gives an error about an unused label if
it has not given any errors in an earlier pass. Remove all
unused labels in this test because they don't test anything
useful and they cause gccgo to give unexpected errors.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12580044
The gc compiler only gives an error about fallthrough in a
type switch if it has not given any errors in an earlier pass.
Remove all functions in this test that use fallthrough in a
type switch because they don't test anything useful and they
cause gccgo to give unexpected errors.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12614043
Backends do not exactly expect receiving binary operators with
constant operands or use workarounds to move them to
register/stack in order to handle them.
Fixes#5841.
R=golang-dev, daniel.morsing, rsc
CC=golang-dev
https://golang.org/cl/11107044
clearfat (used to zero initialize structures) will use AX for x86 block ops. If we write to AX while calculating the dest pointer, we will fill the structure with incorrect values.
Since 64-bit arithmetic uses AX to synthesize a 64-bit register, getting an adress by indexing with 64-bit ops can clobber the register.
Fixes#5820.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/11383043
Deferred functions are not run by a call instruction. They are run by
the runtime editing registers to make the call start with a caller PC
returning to a
CALL deferreturn
instruction.
That instruction has always had the line number of the function's
closing brace, but that instruction's line number is irrelevant.
Stack traces show the line number of the instruction before the
return PC, because normally that's what started the call. Not so here.
The instruction before the CALL deferreturn could be almost anywhere
in the function; it's unrelated and its line number is incorrect to show.
Fix the line number by inserting a true hardware no-op with the right
line number before the returned-to CALL instruction. That is, the deferred
calls now appear to start with a caller PC returning to the second instruction
in this sequence:
NOP
CALL deferreturn
The traceback will show the line number of the NOP, which we've set
to be the line number of the function's closing brace.
The NOP here is not the usual pseudo-instruction, which would be
elided by the linker. Instead it is the real hardware instruction:
XCHG AX, AX on 386 and amd64, and AND.EQ R0, R0, R0 on ARM.
Fixes#5856.
R=ken2, ken
CC=golang-dev
https://golang.org/cl/11223043
Escape analysis needs the right curfn value on a dclfunc node, otherwise it will not analyze the function.
When generating method value wrappers, we forgot to set the curfn correctly.
Fixes#5753.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/10383048
A struct with a single field was considered as equivalent to the
field type, which is incorrect is the field is blank.
Fields with padding could make the compiler think some
types are comparable when they are not.
Fixes#5698.
R=rsc, golang-dev, daniel.morsing, bradfitz, gri, r
CC=golang-dev
https://golang.org/cl/10271046
Design doc at golang.org/s/go12slice.
This is an experimental feature and may not be included in the release.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/10743046
fn can clearly hold a closure in memory.
argp/pc point into stack and so can hold
in memory a block that was previously
a large stack serment.
R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/10784043
Exported inlined functions that perform a string conversion
using a non-exported named type may miss it in export data.
Fixes#5755.
R=rsc, golang-dev, ality, r
CC=golang-dev
https://golang.org/cl/10464043
Functions without bodies were excluded from the ordering logic,
because when I wrote the ordering logic there was no reason to
analyze them.
But then we added //go:noescape tags that need analysis, and we
didn't update the ordering logic.
So in the absence of good ordering, //go:noescape only worked
if it appeared before the use in the source code.
Fixes#5773.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/10570043
The existing compilers convert empty strings to empty
but non-nil byte and rune slices. The spec required
a nil byte and rune slice in those cases. That seems
an odd additional requirement. Adjust the spec to
match the reality.
Also, removed over-specification for conversions of
nil []byte and []rune: such nil slices already act
like empty slices and thus don't need extra language.
Added extra examples instead.
Fixes#5704.
R=rsc, r, iant
CC=golang-dev
https://golang.org/cl/10440045
This avoids problems with inlining in genwrappers, which
occurs after functions have been compiled. Compiling a
function may cause some unused local vars to be removed from
the list. Since a local var may be unused due to
optimization, it is possible that a removed local var winds up
beingused in the inlined version, in which case hilarity
ensues.
Fixes#5515.
R=golang-dev, khr, dave
CC=golang-dev
https://golang.org/cl/10210043
It was never tested and also breaks Windows.
run.go doesn't yet support the proper !windows,!plan9 syntax.
««« original CL description
test: do not run SIGCHLD test on Plan 9
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/10017045
»»»
R=golang-dev, dave
CC=golang-dev
https://golang.org/cl/10024044
It works on i386, but fails on amd64 and arm.
««« original CL description
runtime: prevent the GC from seeing the content of a frame in runfinq()
Fixes#5348.
R=golang-dev, dvyukov
CC=golang-dev
https://golang.org/cl/8954044
»»»
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/8695051
They caused internal compiler errors and they're expensive enough that inlining them doesn't make sense.
Fixes#5259.
R=golang-dev, r, iant, remyoudompheng
CC=golang-dev
https://golang.org/cl/8636043
Don't measure wall time in map.go. Keep it portable
and only test NaN, but not time.
Move time tests to mapnan.go and only measure user CPU time,
not wall time. It builds on Darwin and Linux, the primary
platforms where people hack on the runtime & in particular
maps. The runtime is shared, though, so we don't need it to
run on all of the platforms.
Fixes flaky build failures like:
http://build.golang.org/log/ba67eceefdeaa1142cb6c990a62fa3ffd8fd73f8
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/8479043
The offset of an embedded field s.X must be relative to s
and not to the implicit s.Field of which X is a direct field.
Moreover, no indirections may happen on the path.
Fixes#4909.
R=nigeltao, ality, daniel.morsing, iant, gri, r
CC=golang-dev
https://golang.org/cl/8287043
Reusing it when multiple comparisons occurred in the same
function call led to bad overwriting.
Fixes#5162.
R=golang-dev, daniel.morsing
CC=golang-dev
https://golang.org/cl/8174047
Usually, there is no esc info when inlining, but there will be when generating inlined wrapper functions.
If we don't use this information, we get invalid addresses on the stack.
Fixes#5056.
R=golang-dev, rsc
CC=golang-dev, remyoudompheng
https://golang.org/cl/7850045
It used to not mark parameters as escaping if only one of the
fields it points to leaks out of the function. This causes
problems when importing from another package.
Fixes#4964.
R=rsc, lvd, dvyukov, daniel.morsing
CC=golang-dev
https://golang.org/cl/7648045
Also rename the go parser test to GoParse so it doesn't grab the globally useful Parse name.
R=golang-dev, dave
CC=golang-dev
https://golang.org/cl/7732044
Composite literals using the &T{} form were incorrectly
exported, leading to weird errors at import time.
Fixes#4879.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7395054
The interpreter's os.Exit now triggers a special panic rather
than kill the test process. (It's semantically dubious, since
it will run deferred routines.) Interpret now returns its
exit code rather than calling os.Exit.
Also:
- disabled parts of a few $GOROOT/tests via os.Getenv("GOSSAINTERP").
- remove unnecessary 'slots' param to external functions; they
are never closures.
Most of the tests are disabled until go/types supports shifts.
They can be reenabled if you patch this workaround:
https://golang.org/cl/7312068
R=iant, bradfitz
CC=golang-dev, gri
https://golang.org/cl/7313062
The commands being run are 'go tool this' and 'go tool that',
and the go command will call Getwd during its init.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/7336045
Previously merely printing an error would cause the golden
file comparison (in 'bash run') to fail, but that is no longer
the case with the new run.go driver.
R=iant
CC=golang-dev
https://golang.org/cl/7310087
Details:
- reorder.go: delete p8.
(Once expectation is changed per b/4627 it is identical to p1.)
- switch.go: added some more (degenerate) switches.
- range.go: improved error messages in a few cases.
- method.go: added tests of calls to promoted methods.
R=iant
CC=golang-dev
https://golang.org/cl/7306087
A new comment directive //go:noescape instructs the compiler
that the following external (no body) func declaration should be
treated as if none of its arguments escape to the heap.
Fixes#4099.
R=golang-dev, dave, minux.ma, daniel.morsing, remyoudompheng, adg, agl, iant
CC=golang-dev
https://golang.org/cl/7289048
If the analysis reached a node twice, then the analysis was cut off.
However, if the second arrival is at a lower depth (closer to escaping)
then it is important to repeat the traversal.
The repeating must be cut off at some point to avoid the occasional
infinite recursion. This CL cuts it off as soon as possible while still
passing all tests.
Fixes#4751.
R=ken2
CC=golang-dev, lvd
https://golang.org/cl/7303043
Was not re-walking the new AND node, so that its ullman
count was wrong, so that the code generator attempted to
store values in registers across the call.
Fixes#4752.
R=ken2
CC=golang-dev
https://golang.org/cl/7288054
For consistency with conversions that look like function calls,
conversions that don't look like function calls now allow an
optional trailing comma.
That is, int(x,) has always been syntactically valid.
Now []int(x,) is valid too.
Fixes#4162.
R=ken2
CC=golang-dev
https://golang.org/cl/7288045
Expressions involving nil, even if they can be evaluated
at compile time, do not count as Go constants and cannot
be used in const initializers.
Fixes#4673.
Fixes#4680.
R=ken2
CC=golang-dev
https://golang.org/cl/7278043
The test case of issue 4585 was not passing due to
miscalculation of memequal args, and the previous fix
does not handle padding at the end of a struct.
Handling of padding at end of structs also fixes the case
of [n]T where T is such a padded struct.
Fixes#4585.
(again)
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7133059
runoutput styles tests generally consume a lot of memory. On arm platforms rotate?.go consume around 200mb each to compile, and as tests are sorted alphabetically, they all tend to run at once.
This change limits the number of runoutput jobs to 2 on arm platforms.
R=minux.ma, remyoudompheng, bradfitz, lucio.dere
CC=golang-dev
https://golang.org/cl/7099047
The linker split PKGDEF into (prefix, name, def) pairs,
and defines def to begin after a space following the identifier.
This is totally wrong for the following export data:
func "".FunctionName()
var SomethingCompletelyUnrelated int
The linker would parse
name=`"".FunctionName()\n\tvar`
def=`SomethingCompletelyUnrelated int`
since there is no space after FunctionName.
R=minux.ma, rsc
CC=golang-dev
https://golang.org/cl/7068051
A constant node of type uintptr with a nil literal could
happen in two cases: []int(nil)[1:] and
uintptr(unsafe.Pointer(nil)).
Fixes#4614.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7059043
Unnamed types like structs with embedded fields can have methods.
These methods are generated on-the-fly by the compiler and
it may happen for identical types in different packages.
The linker must accept these multiple definitions.
Fixes#4590.
R=golang-dev, rsc
CC=golang-dev, remy
https://golang.org/cl/7030051
Before this CL, defining the variable worked fine, but then when
the implicit package-level init func was created, that caused a
name collision and a confusing error about the redeclaration.
Also add a test for issue 3705 (func init() needs body).
Fixes#4517.
R=ken2
CC=golang-dev
https://golang.org/cl/7008045
Ordinary variable load was assumed to be not worth saving,
but not if one of the function calls later might change
its value.
Fixes#4313.
R=ken2
CC=golang-dev
https://golang.org/cl/6997047
The patch makes the compile user an ordinary package-local
symbol for the name of embedded fields of builtin type.
This is incompatible with the fix delivered for issue 2687
(revision 3c060add43fb) but fixes it in a different way, because
the explicit symbol on the field makes the typechecker able to
find it in lookdot.
Fixes#3552.
R=lvd, rsc, daniel.morsing
CC=golang-dev
https://golang.org/cl/6866047
The typechecking code was doing an extra, unnecessary
indirection.
Fixes#4458.
R=golang-dev, daniel.morsing, rsc
CC=golang-dev
https://golang.org/cl/6998051
A fatal error used to happen when escassign-ing a multiple
function return to a single node. However, the situation
naturally appears when using "go f(g())" or "defer f(g())",
because g() is escassign-ed to sink.
Fixes#4529.
R=golang-dev, lvd, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6920060
I just committed a patch to gccgo that notices that float was
never defined, causing an additional unmatched error message.
Rename the type to avoid that message.
R=golang-dev, minux.ma
CC=golang-dev
https://golang.org/cl/6947049
This check for BADWIDTH might happen while in defercheckwidth, making it raise errors for non-erroneous situations.
Fixes#4495.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6927043
Used to say:
issue4251.go:12: inverted slice range
issue4251.go:12: constant -1 overflows uint64
issue4251.go:16: inverted slice range
issue4251.go:16: constant -1 overflows uint64
issue4251.go:20: inverted slice range
issue4251.go:20: constant -1 overflows uint64
With this patch, only gives the "inverted slice range" errors.
R=golang-dev, daniel.morsing
CC=golang-dev
https://golang.org/cl/6871058
Fixes#4396.
For fixed arrays larger than the unmapped page, agenr would general a nil check by loading the first word of the array. However there is no requirement for the first element of a byte array to be word aligned, so this check causes a trap on ARMv5 hardware (ARMv6 since relaxed that restriction, but it probably still comes at a cost).
Switching the check to MOVB ensures alignment is not an issue. This check is only invoked in a few places in the code where large fixed arrays are embedded into structs, compress/lzw is the biggest offender, and switching to MOVB has no observable performance penalty.
Thanks to Rémy and Daniel Morsing for helping me debug this on IRC last night.
R=remyoudompheng, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6854063
The current spec says that when calling make, if both len and
cap are constant, it is an error if len > cap. The gc
compiler does not yet implement that, but when it does this
will need to change. Changing it now for the benefit of
gccgo.
R=gri
CC=golang-dev
https://golang.org/cl/6867064
The compiler was confused when inlining a T.Method(f()) call
where f returns multiple values: support for this was marked
as TODO.
Variadic calls are not supported but are not inlined either.
Add a test preventively for that case.
Fixes#4167.
R=golang-dev, rsc, lvd
CC=golang-dev
https://golang.org/cl/6871043
Bools from comparisons can be assigned to all bool types, but this idealness would propagate through logical operators when the result should have been lowered to a non-ideal form.
Fixes#3924.
R=golang-dev, remyoudompheng, r, rsc, mtj
CC=golang-dev
https://golang.org/cl/6855061
The stack overflow checker in the linker uses the spadj field
to determine whether stack space will be large enough or not.
When spadj=0, the checker treats the function as a nosplit
and emits an error although the program is correct.
Also enable the stack checker in 8l.
Fixes#4316.
R=rsc, golang-dev
CC=golang-dev
https://golang.org/cl/6855088
The patch adds more cases to agenr to allocate registers later,
and makes 6g generate addresses for sgen in something else than
SI and DI. It avoids a complex save/restore sequence that
amounts to allocate a register before descending in subtrees.
Fixes#4207.
R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/6817080
When exporting a body containing
x, ok := v.(Type)
the definition for Type was not being included, so when the body
was actually used, it would cause an "unknown type" compiler error.
Fixes#4370.
R=ken2
CC=golang-dev
https://golang.org/cl/6827064
Running this test via "bash run" uncovered three different
bugs (4344, 4348, 4353). We need to run it by default.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6832043
The code assumed that the only choices were EscNone, EscScope, and EscHeap,
so that it makes sense to set EscScope only if the current setting is EscNone.
Now that we have the many variants of EscReturn, this logic is false, and it was
causing important EscScopes to be ignored in favor of EscReturn.
Fixes#4360.
R=ken2
CC=golang-dev, lvd
https://golang.org/cl/6816103
The old code worked with gc, I assume because the linker
unified identical strings, but it failed with gccgo.
R=rsc
CC=gobot, golang-dev
https://golang.org/cl/6826063
Avoids problems with local declarations shadowing other names.
We write a more explicit form than the incoming program, so there
may be additional type annotations. For example:
int := "hello"
j := 2
would normally turn into
var int string = "hello"
var j int = 2
but the int variable shadows the int type in the second line.
This CL marks all local variables with a per-function sequence number,
so that this would instead be:
var int·1 string = "hello"
var j·2 int = 2
Fixes#4326.
R=ken2
CC=golang-dev
https://golang.org/cl/6816100
The compiler now gives an error for out of bounds constant
indexes for arrays, and for negative constant indexes for both
arrays and slices.
With this change the index.go test passes if CLs 6815085,
6815088, and 6812089 are committed.
R=golang-dev, remyoudompheng, rsc
CC=golang-dev
https://golang.org/cl/6810085
Compiling expressions like:
s[s[s[s[s[s[s[s[s[s[s[s[i]]]]]]]]]]]]
make 5g and 6g run out of registers. Such expressions can arise
if a slice is used to represent a permutation and the user wants
to iterate it.
This is due to the usual problem of allocating registers before
going down the expression tree, instead of allocating them in a
postfix way.
The functions cgenr and agenr (that generate a value to a newly
allocated register instead of an existing location), are either
introduced or modified when they already existed to allocate
the new register as late as possible, and sudoaddable is disabled
for OINDEX nodes so that igen/agenr is used instead.
Update #4207.
R=dave, daniel.morsing, rsc
CC=golang-dev
https://golang.org/cl/6733055
When local declarations needed unexported types, these could
be missing in the export data.
Fixes build with -gcflags -lll, except for exp/gotype.
R=golang-dev, rsc, lvd
CC=golang-dev
https://golang.org/cl/6813067
I fixed a bug in gccgo that was causing it to only give an
error for the first package that was imported and not used.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6813058
includes step 0: synthesize outparams, from 6600044
includes step 1,2: give outparams loopdepth 0 and verify unchanged results
generate esc:$mask tags, but still tie to sink if a param has mask != 0
from 6610054
adds final steps:
- have esccall generate n->escretval, a list of nodes the function results flow to
- use these in esccall and ORETURN/OAS2FUNC/and f(g())
- only tie parameters to sink if tag is absent, otherwise according to mask, tie them to escretval
R=rsc, bradfitz
CC=dave, gobot, golang-dev, iant, rsc
https://golang.org/cl/6741044
Someone new to the language may not know the connection between ints and arrays, which was the only thing that the previous error told you anything about.
Fixes#4256.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6739048
Since this patch changes the way complex literals are written
in export data, there are a few other glitches.
Fixes#4159.
R=golang-dev, rsc
CC=golang-dev, remy
https://golang.org/cl/6674047
This patch is enough to fix compilation of
exp/types tests but only passes a stripped down
version of the appripriate torture test.
Update #4207.
R=dave, nigeltao, rsc, golang-dev
CC=golang-dev
https://golang.org/cl/6621061
The other tests either need a complex procedure
or are architecture- or OS-dependent.
Update #4139.
R=golang-dev, daniel.morsing, iant
CC=golang-dev
https://golang.org/cl/6618062
testlib will complain about any unmatched errors left in errorchecks while run.go will not.
Fixes#4141.
R=golang-dev, minux.ma, remyoudompheng, rsc
CC=golang-dev
https://golang.org/cl/6614060
If we're benchmarking 8g, use gcc -m32.
If we're benchmarking 6g, use gcc -m64.
R=golang-dev, bradfitz, minux.ma, remyoudompheng
CC=golang-dev
https://golang.org/cl/6625061
The nil dereference in the next few lines doesn't seem
to cause a segmentation fault on Unix, but does seem
to halt the Go compiler.
The following is a test case:
>>>
package main
func mine(int b) int {
return b + 2
}
func main() {
mine()
c = mine()
}
<<<
Without this change only the following is caught:
typecheck.go:3: undefined: b
typecheck.go:4: undefined: b
with it, we catch all the errors:
typecheck.go:3: undefined: b
typecheck.go:4: undefined: b
typecheck.go:10: undefined: c
typecheck.go:10: cannot assign to c .
R=rsc, minux.ma
CC=golang-dev
https://golang.org/cl/6542060
rundir will compile each file in the directory in lexicographic order, link the last file as the main package and run the resulting program. rundircmpout is an related command, that will compare the output of the program to an corresponding .out file
errorcheckdir will compile each file in a directory in lexicographic order, running errorcheck on each file as it compiles. All compilations are assumed to be successful except for the last file. However, If a -0 flag is present on the command, the last compilation will also be assumed successful
This CL also includes a small refactoring of run.go. It was getting unwieldy and the meaning of the run commands was hidden behind argument line formatting.
Fixes#4058.
R=rsc, minux.ma, remyoudompheng, iant
CC=golang-dev
https://golang.org/cl/6554071
Also mention that ignoring second blank identifier of range is required by the spec in the code.
Fixes#4173.
R=daniel.morsing, remyoudompheng, r
CC=golang-dev
https://golang.org/cl/6594043
const1.go:31:12: error: integer constant overflow
const1.go:31:12: error: integer constant overflow
const1.go:33:12: error: integer constant overflow
const1.go:33:12: error: integer constant overflow
const1.go:34:14: error: integer constant overflow
const1.go:35:17: error: integer constant overflow
const1.go:35:17: error: integer constant overflow
const1.go:35:17: error: integer constant overflow
const1.go:35:17: error: integer constant overflow
const1.go:35:17: error: integer constant overflow
const1.go:36:19: error: integer constant overflow
const1.go:37:15: error: integer constant overflow
const1.go:37:15: error: integer constant overflow
const1.go:37:24: error: integer constant overflow
const1.go:37:15: error: integer constant overflow
const1.go:37:15: error: integer constant overflow
const1.go:37:15: error: integer constant overflow
const1.go:37:24: error: integer constant overflow
const1.go:37:15: error: integer constant overflow
const1.go:38:12: error: integer constant overflow
const1.go:38:12: error: integer constant overflow
const1.go:38:12: error: integer constant overflow
const1.go:38:12: error: integer constant overflow
const1.go:41:20: error: integer constant overflow
const1.go:41:20: error: integer constant overflow
const1.go:42:20: error: integer constant overflow
const1.go:42:20: error: integer constant overflow
const1.go:44:28: error: integer constant overflow
const1.go:44:28: error: integer constant overflow
const1.go:45:14: error: integer constant overflow
const1.go:49:14: error: integer constant overflow
const1.go:50:14: error: integer constant overflow
const1.go:51:14: error: integer constant overflow
const1.go:54:23: error: integer constant overflow
const1.go:54:23: error: integer constant overflow
const1.go:54:23: error: integer constant overflow
const1.go:54:23: error: integer constant overflow
const1.go:56:14: error: integer constant overflow
const1.go:57:24: error: integer constant overflow
const1.go:57:24: error: integer constant overflow
const1.go:58:24: error: integer constant overflow
const1.go:58:24: error: integer constant overflow
const1.go:59:22: error: integer constant overflow
const1.go:59:22: error: integer constant overflow
const1.go:61:24: error: integer constant overflow
const1.go:62:20: error: division by zero
const1.go:65:19: error: floating point constant overflow
const1.go:65:19: error: floating point constant overflow
const1.go:66:28: error: floating point constant overflow
const1.go:66:28: error: floating point constant overflow
const1.go:67:19: error: floating point constant overflow
const1.go:67:19: error: floating point constant overflow
const1.go:68:19: error: division by zero
const1.go:33:14: error: integer constant overflow
const1.go:35:19: error: integer constant overflow
const1.go:42:22: error: integer constant overflow
const1.go:53:17: error: integer constant overflow
const1.go:55:14: error: integer constant overflow
const1.go:59:24: error: integer constant overflow
const1.go:69:20: error: expected integer type
const1.go:75:4: error: argument 1 has incompatible type (cannot use type int8 as type int)
const1.go:76:4: error: argument 1 has incompatible type (cannot use type int8 as type int)
const1.go:77:4: error: argument 1 has incompatible type (cannot use type uint8 as type int)
const1.go:79:4: error: argument 1 has incompatible type (cannot use type float32 as type int)
const1.go:80:4: error: argument 1 has incompatible type (cannot use type float64 as type int)
const1.go:81:4: error: floating point constant truncated to integer
const1.go:83:4: error: argument 1 has incompatible type (cannot use type float64 as type int)
const1.go:84:4: error: argument 1 has incompatible type (cannot use type string as type int)
const1.go:85:4: error: argument 1 has incompatible type (cannot use type bool as type int)
const1.go:88:7: error: const initializer cannot be nil
const2.go:14:8: error: expected ‘=’
const5.go:27:7: error: expression is not constant
const5.go:28:7: error: expression is not constant
const5.go:30:7: error: expression is not constant
const5.go:31:7: error: expression is not constant
ddd1.go:57:23: error: invalid use of ‘...’ in type conversion
ddd1.go:59:6: error: invalid use of ‘...’ in type conversion
ddd1.go:60:12: error: use of ‘[...]’ outside of array literal
ddd1.go:21:15: error: argument 1 has incompatible type
ddd1.go:22:10: error: argument 1 has incompatible type
ddd1.go:30:6: error: invalid use of ‘...’ with non-slice
ddd1.go:30:6: error: invalid use of ‘...’ with non-slice
ddd1.go:46:2: error: invalid use of %<...%> with builtin function
ddd1.go:47:2: error: invalid use of %<...%> with builtin function
ddd1.go:49:2: error: invalid use of %<...%> with builtin function
ddd1.go:50:6: error: invalid use of %<...%> with builtin function
ddd1.go:51:6: error: invalid use of %<...%> with builtin function
ddd1.go:53:6: error: invalid use of %<...%> with builtin function
ddd1.go:58:13: error: invalid use of %<...%> with builtin function
ddd1.go:20:10: error: floating point constant truncated to integer
ddd1.go:32:6: error: invalid use of ‘...’ calling non-variadic function
declbad.go:20:3: error: variables redeclared but no variable is new
declbad.go:38:3: error: variables redeclared but no variable is new
declbad.go:44:3: error: variables redeclared but no variable is new
declbad.go:51:3: error: variables redeclared but no variable is new
declbad.go:57:3: error: variables redeclared but no variable is new
declbad.go:63:3: error: variables redeclared but no variable is new
declbad.go:26:3: error: incompatible types in assignment (cannot use type float32 as type int)
declbad.go:32:3: error: incompatible types in assignment (cannot use type int as type float32)
declbad.go:44:3: error: incompatible types in assignment (different number of results)
fixedbugs/bug223.go:21:5: error: initialization expression for ‘m’ depends upon itself
fixedbugs/bug412.go:10:2: error: duplicate field name ‘x’
fixedbugs/bug413.go:11:5: error: initialization expression for ‘i’ depends upon itself
fixedbugs/bug416.go:13:1: error: method ‘X’ redeclares struct field name
fixedbugs/bug435.go:15:49: error: missing ‘)’
fixedbugs/bug435.go:15:2: error: reference to undefined name ‘bar’
fixedbugs/bug451.go:9:9: error: expected package
typeswitch3.go:39:9: error: no new variables on left side of ‘:=’
typeswitch3.go:24:2: error: impossible type switch case (type has no methods)
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6560063
The assembly offsets were converted mechanically using
code.google.com/p/rsc/cmd/asmlint. The instruction
changes were done by hand.
Fixes#2188.
R=iant, r, bradfitz, remyoudompheng
CC=golang-dev
https://golang.org/cl/6550058
Was not handling &x.y[0] and &x.y.z correctly where
y is an array or struct-valued field (not a pointer).
R=ken2
CC=golang-dev
https://golang.org/cl/6551059
Can tell this doesn't get run very often, but it is still important
for when you've broken everything else.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6547065
Today, if run.go doesn't understand a test header line it just ignores
the test, making it too easy to write or edit tests that are not actually
being run.
- expand errorcheck to accept flags, so that bounds.go and escape*.go can run.
- create a whitelist of skippable tests in run.go; skipping others is an error.
- mark all skipped tests at top of file.
Update #4139.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6549054
Revision 63f7abcae015 introduced a bug caused by
code assuming registers started at X5, not X0.
Fixes#4138.
R=rsc
CC=golang-dev, remy
https://golang.org/cl/6558043
use a function to get stdout and stderr, instead of depending
on a specific libc implementation.
also make test/run.go replace \r\n by \n before comparing
output.
Fixes#2121.
Part of issue 1741.
R=alex.brainman, rsc, r, remyoudompheng
CC=golang-dev
https://golang.org/cl/5847068
In switches without an expression, the compiler would not convert the implicit true to an interface, causing codegen errors.
Fixes#3980.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6497147
Broke tests on 386.
««« original CL description
6l/8l: emit correct opcodes to F(SUB|DIV)R?D.
When the destination was not F0, 6l and 8l swapped FSUBD/FSUBRD and
FDIVD/FDIVRD.
R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/6498092
»»»
R=golang-dev
CC=golang-dev
https://golang.org/cl/6492100
Accomplished by synchronizing the formatting of conversion errors between typecheck.c and subr.c
Fixes#3984.
R=golang-dev, remyoudompheng, rsc
CC=golang-dev
https://golang.org/cl/6500064
This fixes a spurious 'invalid recursive type' error, and stops the compiler from emitting errors on uses of the invalid type.
Fixes#3766.
R=golang-dev, dave, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6443100
This is required by the spec to produce the replacement char.
The fix lies in lib9's rune code.
R=golang-dev, nigeltao, rsc
CC=golang-dev
https://golang.org/cl/6443109
CVTSS2SQ's rounding mode is controlled by the RC field of MXCSR;
as we specifically need truncate semantic, we should use CVTTSS2SQ.
Fixes#3804.
R=rsc, r
CC=golang-dev
https://golang.org/cl/6352079
Surrogate halves are part of UTF-16 and should never appear in UTF-8.
(The rune that two combined halves represent in UTF-16 should
be encoded directly.)
Encoding: encode as RuneError.
Decoding: convert to RuneError, consume one byte.
This requires changing:
package unicode/utf8
runtime for range over string
Also added utf8.ValidRune and fixed bug in utf.RuneLen.
Fixes#3927.
R=golang-dev, rsc, bsiegert
CC=golang-dev
https://golang.org/cl/6458099
Enhances test/run.go to support testing other directories
Will enable stdio tests on Windows in a follow-up CL.
R=golang-dev, alex.brainman, rsc
CC=golang-dev
https://golang.org/cl/6220049
The compiler is incorrectly rejecting switches on arrays of
comparable types. It also doesn't catch incomparable structs
when typechecking the switch, leading to unreadable errors
during typechecking of the generated code.
Fixes#3894.
R=rsc
CC=gobot, golang-dev, r, remy
https://golang.org/cl/6442074
we can't import "./bug0" on windows, as it will trigger
"import path contains invalid character ':'" error.
instead, we pass "-D." and "-I." to gc to override this
behavior. this idea is due to remyoudompheng.
R=golang-dev, r, alex.brainman, remyoudompheng
CC=golang-dev
https://golang.org/cl/6441074
The receive operator was given incorrect precedence
resulting in incorrect deletion of parentheses.
Fixes#3843.
R=rsc
CC=golang-dev, remy
https://golang.org/cl/6442049
The compiledir pattern compiles all files xxx.dir/*.go
in lexicographic order (which is assumed to coincide with
the topological order of dependencies).
R=rsc
CC=golang-dev, remy
https://golang.org/cl/6440048
They were previously ignored when deciding order and
detecting dependency loops.
Fixes#3824.
R=rsc, golang-dev
CC=golang-dev, remy
https://golang.org/cl/6455055
There may be further savings if convT2I can avoid the function call
if the cache is good and T is uintptr-shaped, a la convT2E, but that
will be a follow-up CL.
src/pkg/runtime:
benchmark old ns/op new ns/op delta
BenchmarkConvT2ISmall 43 15 -64.01%
BenchmarkConvT2IUintptr 45 14 -67.48%
BenchmarkConvT2ILarge 130 101 -22.31%
test/bench/go1:
benchmark old ns/op new ns/op delta
BenchmarkBinaryTree17 8588997000 8499058000 -1.05%
BenchmarkFannkuch11 5300392000 5358093000 +1.09%
BenchmarkGobDecode 30295580 31040190 +2.46%
BenchmarkGobEncode 18102070 17675650 -2.36%
BenchmarkGzip 774191400 771591400 -0.34%
BenchmarkGunzip 245915100 247464100 +0.63%
BenchmarkJSONEncode 123577000 121423050 -1.74%
BenchmarkJSONDecode 451969800 596256200 +31.92%
BenchmarkMandelbrot200 10060050 10072880 +0.13%
BenchmarkParse 10989840 11037710 +0.44%
BenchmarkRevcomp 1782666000 1716864000 -3.69%
BenchmarkTemplate 798286600 723234400 -9.40%
R=rsc, bradfitz, go.peter.90, daniel.morsing, dave, uriel
CC=golang-dev
https://golang.org/cl/6337058
otherwise it fails spuriously with "newfunc allocated unexpectedly" message
when run with GOMAXPROCS>1 (other goroutine allocates).
R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/6347056
-lm must come after the source file, versions of gcc insist this strict order.
On standard compliant systems, we no longer need malloc.h for malloc.
Use pkg-config(1) to get correct glib cflags and libs.
Fix compiler warning in threadring.c and k-nucleotide.c.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6198076
CL 4313064 fixed its test case but did not address a
general enough problem:
type T1 struct { F *T2 }
type T2 T1
type T3 T2
could still end up copying the definition of T1 for T2
before T1 was done being evaluated, or T3 before T2
was done.
In order to propagate the updates correctly,
record a copy of an incomplete type for re-execution
once the type is completed. Roll back CL 4313064.
Fixes#3709.
R=ken2
CC=golang-dev, lstoakes
https://golang.org/cl/6301059
As discussed in
https://groups.google.com/d/msg/golang-dev/Na9XE6mcQyY/zbeBI7R-vnoJ
Here is a static copy of the go/parser benchmark. I ended up using
fancy encodings because the original parser.go had a number of `s
scattered throughout which made it hard to embed the source directly.
Curiously on my laptop this benchmark always scores roughly 10% higher
than the standalone benchmark. This may be down to the generation of
the fasta data set triggering the cpu governor to raise the cpu speed.
However the benchmark is consistent with itself across multiple runs.
R=golang-dev, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6305055
As discussed on golang-dev, reduce the size of the fasta
dataset to make it possible to run the go1 benchmarks on
small ARM systems.
Also, remove the 25m suffix from fasta data and Revcomp.
linux/arm: pandaboard OMAP4
BenchmarkBinaryTree17 1 70892426000 ns/op
BenchmarkFannkuch11 1 35712066000 ns/op
BenchmarkGobDecode 10 137146000 ns/op 5.60 MB/s
BenchmarkGobEncode 50 64953000 ns/op 11.82 MB/s
BenchmarkGzip 1 5675690000 ns/op 3.42 MB/s
BenchmarkGunzip 1 1207001000 ns/op 16.08 MB/s
BenchmarkJSONEncode 5 860424800 ns/op 2.26 MB/s
BenchmarkJSONDecode 1 3321839000 ns/op 0.58 MB/s
BenchmarkMandelbrot200 50 45893560 ns/op
BenchmarkRevcomp 10 135220300 ns/op 18.80 MB/s
BenchmarkTemplate 1 6385681000 ns/op 0.30 MB/s
R=rsc, minux.ma, dsymonds
CC=golang-dev
https://golang.org/cl/6278048
It is not necessary for the test to be effective and uses a
lot of resources in the compiler. Memory usage is halved and
compilation around 8x faster.
R=golang-dev, r, rsc, r
CC=golang-dev
https://golang.org/cl/6290044
We can't depend on init() order, and certainly we don't want to
register all future benchmarks that use jsonbytes or jsondata to init()
in json_test.go, so we use a more general solution: make generation of
jsonbytes and jsondata their own function so that the compiler will take
care of the order.
R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/6282046
Most significant in mandelbrot, from avoiding MOVSD between registers,
but there are others.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6258063
Surprise! The C code is using floating point values for its counters.
Its off the critical path, but the Go code and C code are supposed to
be as similar as possible to make comparisons meaningful.
It doesn't have a significant effect.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6260058
Moving panic out of line speeds up fannkuch almost a factor of two.
Changes to bitwhacking code affect mandelbrot badly.
R=golang-dev, bradfitz, rsc, r
CC=golang-dev
https://golang.org/cl/6258056
for expr1, expr2 = range slice
was assigning to expr1 and expr2 in sequence
instead of in parallel. Now it assigns in parallel,
as it should. This matters for things like
for i, x[i] = range slice.
Fixes#3464.
R=ken2
CC=golang-dev
https://golang.org/cl/6252048
This is from CL 5451105 but was dropped from that CL.
See also CL 6137051.
The only change compared to 5451105 is to check for
h != nil in reflect·mapiterinit; allowing use of nil maps
must have happened after that original CL.
Fixes#3573.
R=golang-dev, dave, r
CC=golang-dev
https://golang.org/cl/6215078
* Eliminate bounds check on known small shifts.
* Rewrite x<<s | x>>(32-s) as a rotate (constant s).
* More aggressive (but still minimal) range analysis.
R=ken, dave, iant
CC=golang-dev
https://golang.org/cl/6209077
There's no need for the 16-bit arithmetic here,
and it tickles a long-standing compiler bug.
Fix the exp code not to use 16-bit math and
create an explicit test for the compiler bug.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6256048
Not a complete fix for issue 3342, but fixes the trivial case.
There may still be a race in the instants before and after
a scavenger-induced garbage collection.
Intended to be "obviously safe": a call to runtime·gosched
before main.main is no different than a call to runtime.Gosched
at the beginning of main.main, and it is (or had better be)
safe to call runtime.Gosched at any point during main.
Update #3342.
R=iant
CC=golang-dev
https://golang.org/cl/5919052
Breaks closure test when GOMAXPROCS=2 or more.
««« original CL description
runtime: restore deadlock detection in the simplest case.
Fixes#3342.
R=iant, r, dave, rsc
CC=golang-dev, remy
https://golang.org/cl/5844051
»»»
R=rsc
CC=golang-dev
https://golang.org/cl/5924045
The two optimizations for small structs and arrays
were missing the implicit cast from ideal bool.
Fixes#3351.
R=rsc, lvd
CC=golang-dev
https://golang.org/cl/5848062
The spec is looser than the current implementation.
The spec edit was made in CL 4444050 (May 2011)
but I never implemented it.
Fixes#3244.
R=ken2
CC=golang-dev
https://golang.org/cl/5785049
This change is necessary to make the run shell script work
again, but it is not sufficient as bug424.go's execution line
does not name the package that it imports.
R=golang-dev, gri, rsc
CC=golang-dev
https://golang.org/cl/5771043
Also, tweak run.go to use no more than 2x the
number of CPUs, and only one on ARM.
53.85u 13.33s 53.69r ./run
50.68u 12.13s 18.85r go run run.go
Fixes#2833.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5754047
As runtime.UintType is no longer defined, the gccgo error
messages have changed.
bug388.go:12:10: error: reference to undefined identifier ‘runtime.UintType’
bug388.go:12:10: error: invalid named/anonymous mix
bug388.go:13:21: error: reference to undefined identifier ‘runtime.UintType’
bug388.go:17:10: error: reference to undefined identifier ‘runtime.UintType’
bug388.go:18:18: error: reference to undefined identifier ‘runtime.UintType’
bug388.go:22:9: error: non-name on left side of ‘:=’
bug388.go:27:10: error: expected type
bug388.go:32:9: error: expected type
bug388.go:23:14: error: reference to field ‘i’ in object which has no fields or methods
R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/5755044
GOROOT_FINAL is a build parameter that means "eventually
the Go tree will be installed here". Make the file name information
match that eventual location.
Fixes#3180.
R=ken, ken
CC=golang-dev
https://golang.org/cl/5742043
The two string comparison optimizations were
missing the implicit cast from ideal bool.
Fixes#3119.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5696071
They are broken and hard to make work.
They have never worked: if you import "/tmp/x"
from "/home/rsc/p.c" then the compiler rewrites
this into import "/home/rsc/tmp/x", which is
clearly wrong.
Also we just disallowed the : character in import
paths, so import "c:/foo" is already not allowed.
Finally, in order to support absolute paths well in
a build tool we'd have to provide a mechanism to
instruct the compiler to resolve absolute imports
by looking in some other tree (where the binaries live)
and provide a mapping from absolute path to location
in that tree. This CL avoids adding that complexity.
This is not part of the language spec (and should not be),
so no spec change is needed.
If we need to make them work later, we can.
R=ken2
CC=golang-dev
https://golang.org/cl/5712043
Also allow multiple invalid import statements in a
single file.
Fixes#3021. The changes to go/parser and the
language specifcation have already been committed.
R=rsc, gri
CC=golang-dev
https://golang.org/cl/5672084
To find test files with legacy headers.
We can remove this flag once everything is converted.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5694060
This is a manual undo of CL 5674098.
It does not implement the even less strict spec
that we just agreed on, but it gets us back where
we were at the last weekly.
R=ken2
CC=golang-dev
https://golang.org/cl/5683069
Such variables would be put at 0(SP), leading to serious
corruptions at zero initialization.
Fixes#3084.
R=golang-dev, r
CC=golang-dev, remy
https://golang.org/cl/5683052
It's in an odd style and it's unclear what true purpose it serves as
a test other than to be another Go program.
R=gri
CC=golang-dev
https://golang.org/cl/5674111
Very few of the compiler regression tests include a comment
saying waht they do. Many are obvious, some are anything but.
I've started with a-c in the top directory. More will follow once
we agree on the approach, correctness, and thoroughness here.
zerodivide.go sneaked in too.
R=rsc, r
CC=golang-dev
https://golang.org/cl/5656100
Because bug040.go was ignoring all error messages, the fact
that it got an error about fuction main was being ignored.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5675085
The set of errors forwarded by the os package varied with system and
was therefore non-portable.
Three helpers added for portable error checking: IsExist, IsNotExist, and IsPermission.
One or two more may need to come, but let's keep the set very small to discourage
thinking about errors that way.
R=mikioh.mikioh, gustavo, r, rsc
CC=golang-dev
https://golang.org/cl/5672047
This CL makes it possible to run make.bash with
GOOS and GOARCH set to something other than
the native host GOOS and GOARCH.
As part of the CL, the tool directory moves from bin/tool/
to pkg/tool/goos_goarch where goos and goarch are
the values for the host system (running the build), not
the target. pkg/ is not technically appropriate, but C objects
are there now tool (pkg/obj/) so this puts all the generated
binaries in one place (rm -rf $GOROOT/pkg cleans everything).
Including goos_goarch in the name allows different systems
to share a single $GOROOT on a shared file system.
Fixes#2920.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5645093
Fix it twice: reuse registers more aggressively in cgen abop,
and also release R14 and R15, which are no longer m and g.
Fixes#2669.
R=ken2
CC=golang-dev
https://golang.org/cl/5655056
Should be obviously correct. Includes minimal test case.
A future CL should clear up the logic around typecheckok and importpkg != nil someday.
R=rsc, dsymonds, rsc
CC=golang-dev
https://golang.org/cl/5652057
This changes makes constant propagation compare 'from' values using node
pointers rather than symbol names when checking to see whether a set
operation is redundant. When a function is inlined multiple times in a
calling function its arguments will share symbol names even though the values
are different. Prior to this fix the bug409 test would hit a case with 6g
where an LEAQ instruction was incorrectly eliminated from the second inlined
function call. 8g appears to have had the same bug, but the test did not fail
there.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5646044
Unexports runtime.MemStats and rename MemStatsType to MemStats.
The new accessor requires passing a pointer to a user-allocated
MemStats structure.
Fixes#2572.
R=bradfitz, rsc, bradfitz, gustavo
CC=golang-dev, remy
https://golang.org/cl/5616072
When slicing a slice, the bounds may be > len as long as they
are <= cap. Interestingly, gccgo got that wrong and still
passed the testsuite and all the library tests.
R=golang-dev, rsc, iant
CC=golang-dev
https://golang.org/cl/5622053
The go- is redundant now that the directory is required
to be inside $GOROOT. Rob LGTMed the idea.
R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/5618044
gccgo currently fails this test:
fixedbugs/bug402.go:12:9: error: floating point constant truncated to integer
fixedbugs/bug402.go:13:8: error: floating point constant truncated to integer
R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/5600050
Consequently, remove many package Makefiles,
and shorten the few that remain.
gomake becomes 'go tool make'.
Turn off test phases of run.bash that do not work,
flagged with $BROKEN. Future CLs will restore these,
but this seemed like a big enough CL already.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5601057
A current theory is that this test is too fast for the
time resolution on the VMs where our builders run.
R=rsc
CC=golang-dev
https://golang.org/cl/5581056
Also delete gotest, since it's messy to fix and slated for deletion anyway.
A couple of things outside src can't be tested any more. "go test" will be
fixed and these tests will be re-enabled. They're noisy for now.
Fixes#284.
R=rsc
CC=golang-dev
https://golang.org/cl/5598049
complit1.go:37:34: error: may only omit types within composite literals of slice, array, or map type
complit1.go:38:19: error: may only omit types within composite literals of slice, array, or map type
complit1.go:18:21: error: slice of unaddressable value
complit1.go:19:10: error: slice of unaddressable value
complit1.go:20:9: error: slice of unaddressable value
convert1.go:28:13: error: invalid type conversion
convert1.go:32:12: error: invalid type conversion (cannot use type string as type Tint64)
convert1.go:36:12: error: invalid type conversion
convert1.go:37:13: error: invalid type conversion
convert1.go:40:11: error: invalid type conversion
convert1.go:41:12: error: invalid type conversion
convert1.go:44:12: error: invalid type conversion
convert1.go:46:13: error: invalid type conversion
convert1.go:48:11: error: invalid type conversion
convert1.go:50:12: error: invalid type conversion
convert1.go:52:6: error: invalid type conversion
convert1.go:53:12: error: invalid type conversion
convert1.go:54:12: error: invalid type conversion
convert1.go:56:13: error: invalid type conversion
convert1.go:57:11: error: invalid type conversion
convert1.go:58:11: error: invalid type conversion
convert1.go:64:13: error: invalid type conversion
convert1.go:68:12: error: invalid type conversion (cannot use type Tstring as type Tint64)
convert1.go:72:12: error: invalid type conversion
convert1.go:73:13: error: invalid type conversion
convert1.go:76:11: error: invalid type conversion (cannot use type Tbyte as type Trune)
convert1.go:77:12: error: invalid type conversion (cannot use type Tbyte as type Tint64)
convert1.go:80:12: error: invalid type conversion
convert1.go:82:13: error: invalid type conversion
convert1.go:84:11: error: invalid type conversion (cannot use type Trune as type Tbyte)
convert1.go:86:12: error: invalid type conversion (cannot use type Trune as type Tint64)
convert1.go:88:6: error: invalid type conversion (cannot use type Tint64 as type string)
convert1.go:89:12: error: invalid type conversion
convert1.go:90:12: error: invalid type conversion
convert1.go:92:13: error: invalid type conversion (cannot use type Tint64 as type Tstring)
convert1.go:93:11: error: invalid type conversion (cannot use type Tint64 as type Tbyte)
convert1.go:94:11: error: invalid type conversion (cannot use type Tint64 as type Trune)
fixedbugs/bug195.go:9:21: error: interface contains embedded non-interface
fixedbugs/bug195.go:12:21: error: interface contains embedded non-interface
fixedbugs/bug195.go:15:15: error: interface contains embedded non-interface
fixedbugs/bug195.go:18:2: error: invalid recursive interface
fixedbugs/bug195.go:26:2: error: invalid recursive interface
fixedbugs/bug195.go:22:2: error: invalid recursive interface
fixedbugs/bug251.go:15:2: error: invalid recursive interface
fixedbugs/bug251.go:11:2: error: invalid recursive interface
fixedbugs/bug374.go:18:34: error: use of undefined type ‘xxxx’
fixedbugs/bug374.go:16:5: error: incompatible type in initialization (incompatible type for method ‘m’ (different number of parameters))
fixedbugs/bug383.go:11:2: error: expected boolean expression
fixedbugs/bug383.go:12:2: error: expected boolean expression
fixedbugs/bug386.go:10:25: error: incompatible type for return value 1 (type has no methods)
fixedbugs/bug386.go:12:25: error: incompatible type for return value 1 (type has no methods)
fixedbugs/bug388.go:12:10: error: invalid named/anonymous mix
fixedbugs/bug388.go:17:19: error: non-name on left side of ‘:=’
fixedbugs/bug388.go:22:9: error: non-name on left side of ‘:=’
fixedbugs/bug388.go:27:10: error: expected type
fixedbugs/bug388.go:32:9: error: expected type
fixedbugs/bug388.go:23:14: error: reference to field ‘i’ in object which has no fields or methods
fixedbugs/bug388.go:18:18: error: invalid use of type
fixedbugs/bug389.go:12:5: error: incompatible type in initialization (different parameter types)
fixedbugs/bug390.go:15:24: error: expected integer, floating, or complex type
fixedbugs/bug394.go:10:1: error: expected declaration
fixedbugs/bug397.go:12:2: error: incompatible type for element 2 key in map construction
switch3.go:18:2: error: incompatible types in binary expression
switch3.go:22:2: error: incompatible types in binary expression
switch3.go:28:2: error: map can only be compared to nil
switch3.go:35:2: error: slice can only be compared to nil
switch3.go:42:2: error: func can only be compared to nil
syntax/else.go:11:9: error: expected ‘if’ or ‘{’
typeswitch2.go:15:2: error: duplicate type in switch
typeswitch2.go:19:2: error: duplicate type in switch
typeswitch2.go:26:2: error: duplicate type in switch
typeswitch2.go:40:9: error: ‘t’ declared and not used
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5573073
Pulling function calls out to happen before the
expression being evaluated was causing illegal
reorderings even without inlining; with inlining
it got worse. This CL adds a separate ordering pass
to move things with a fixed order out of expressions
and into the statement sequence, where they will
not be reordered by walk.
Replaces lvd's CL 5534079.
Fixes#2740.
R=lvd
CC=golang-dev
https://golang.org/cl/5569062
I haven't looked at the source, but the gc compiler appears to
omit "not used" errors when there is an error in the
initializer. This is harder to do in gccgo, and frankly I
think the "not used" error is still useful even if the
initializer has a problem. This CL tweaks some tests to avoid
the error, which is not the point of these tests in any case.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5561059
Preserve test.
changeset: 11593:f1deaf35e1d1
user: Luuk van Dijk <lvd@golang.org>
date: Tue Jan 17 10:00:57 2012 +0100
summary: gc: fix infinite recursion for embedded interfaces
This is causing 'interface type loop' errors during compilation
of a complex program. I don't understand what's happening
well enough to boil it down to a simple test case, but undoing
this change fixes the problem.
The change being undone is fixing a corner case (uses of
pointer to interface in an interface definition) that basically
only comes up in erroneous Go programs. Let's not try to
fix this again until after Go 1.
Unfixes issue 1909.
TBR=lvd
CC=golang-dev
https://golang.org/cl/5555063
This will make these tests more meaningful for gccgo, which
runs tests in parallel and has no equivalent to golden.out.
Remove ken/simpprint.go since it duplicates helloworld.go.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5536058
I'm planning to change these tests, but the gofmt changes are
fairly extensive, so I'm separating the gofmt changes from the
substantive changes.
R=golang-dev, rsc, r
CC=golang-dev
https://golang.org/cl/5557052
The escape analysis code does not make a distinction between
scalar and pointers fields in structs. Non-pointer fields
that escape should not make the whole struct escape.
R=lvd, rsc
CC=golang-dev, remy
https://golang.org/cl/5489128
This fixes issue 2444.
A big cleanup of all 31/32bit size boundaries i'll leave for another cl though. (see also issue 1700).
R=rsc
CC=golang-dev
https://golang.org/cl/5484058
Refactors the benchmarks and test code.
Now benchmarks can call Errorf, Fail, etc.,
and the runner will act accordingly.
Because functionality has been folded into an
embedded type, a number of methods' docs
no longer appear in godoc output. A fix is
underway; if it doesn't happen fast enough,
I'll add wrapper methods to restore the
documentation.
R=bradfitz, adg, rsc
CC=golang-dev
https://golang.org/cl/5492060
I have included a few important microbenchmarks,
but the overall intent is to have mostly end-to-end
benchmarks timing real world operations.
The jsondata.go file is a summary of agl's
activity in various open source repositories.
It gets used as test data for many of the benchmarks.
Everything links into one binary (even the test data)
so that it is easy to run the benchmarks on many
computers: there is just one file to copy around.
R=golang-dev, r, bradfitz, adg, r
CC=golang-dev
https://golang.org/cl/5484071
This avoids degraded performance caused by extra labels
emitted by inlining (breaking strconv ftoa alloc count unittest) and is better in any case.
R=rsc
CC=golang-dev
https://golang.org/cl/5483071
To allow these types as map keys, we must fill in
equal and hash functions in their algorithm tables.
Structs or arrays that are "just memory", like [2]int,
can and do continue to use the AMEM algorithm.
Structs or arrays that contain special values like
strings or interface values use generated functions
for both equal and hash.
The runtime helper func runtime.equal(t, x, y) bool handles
the general equality case for x == y and calls out to
the equal implementation in the algorithm table.
For short values (<= 4 struct fields or array elements),
the sequence of elementwise comparisons is inlined
instead of calling runtime.equal.
R=ken, mpimenov
CC=golang-dev
https://golang.org/cl/5451105
All but 3 cases (in gcimporter.go and hixie.go)
are automatic conversions using gofix.
No attempt is made to use the new Append functions
even though there are definitely opportunities.
R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/5447069
This is the result of running `gofix -r hashsum` over the tree, changing
the hash function implementations by hand and then fixing a couple of
instances where gofix didn't catch something.
The changed implementations are as simple as possible while still
working: I'm not trying to optimise in this CL.
R=rsc, cw, rogpeppe
CC=golang-dev
https://golang.org/cl/5448065
The wrong value made Nconv() show "1" for node "-1", and "2" from
node "2+3".
Fixes#2452.
R=gri, lvd, rsc
CC=golang-dev, remy
https://golang.org/cl/5435064
The allowed conversions before and after are:
type Tstring string
type Tbyte []byte
type Trune []rune
string <-> string // ok
string <-> []byte // ok
string <-> []rune // ok
string <-> Tstring // ok
string <-> Tbyte // was illegal, now ok
string <-> Trune // was illegal, now ok
Tstring <-> string // ok
Tstring <-> []byte // ok
Tstring <-> []rune // ok
Tstring <-> Tstring // ok
Tstring <-> Tbyte // was illegal, now ok
Tstring <-> Trune // was illegal, now ok
Update spec, compiler, tests. Use in a few packages.
We agreed on this a few months ago but never implemented it.
Fixes#1707.
R=golang-dev, gri, r
CC=golang-dev
https://golang.org/cl/5421057
An experiment: allow structs to be copied even if they
contain unexported fields. This gives packages the
ability to return opaque values in their APIs, like reflect
does for reflect.Value but without the kludgy hacks reflect
resorts to.
In general, we trust programmers not to do silly things
like *x = *y on a package's struct pointers, just as we trust
programmers not to do unicode.Letter = unicode.Digit,
but packages that want a harder guarantee can introduce
an extra level of indirection, like in the changes to os.File
in this CL or by using an interface type.
All in one CL so that it can be rolled back more easily if
we decide this is a bad idea.
Originally discussed in March 2011.
https://groups.google.com/group/golang-dev/t/3f5d30938c7c45ef
R=golang-dev, adg, dvyukov, r, bradfitz, jan.mercl, gri
CC=golang-dev
https://golang.org/cl/5372095
Allow any type in switch on interface value.
Statically check typeswitch early.
Fixes#2423.
Fixes#2424.
R=rsc, dsymonds
CC=golang-dev
https://golang.org/cl/5339045
This contains the files that required handiwork, mostly
Makefiles with updated TARGs, plus the two packages
with modified package names.
html/template/doc.go needs a separate edit pass.
test/fixedbugs/bug358.go is not legal go so gofix fails on it.
R=rsc
CC=golang-dev
https://golang.org/cl/5340050
Fixes#2355.
I have a test, but not sure if it's worth adding. Instead i've made
the patching-over in reflect.c methods more fatal and more descriptive.
R=rsc
CC=golang-dev
https://golang.org/cl/5302082
mark OADDR inserted by typecheck as implicit
OCOPY takes ->left and ->right, not ->list
OMAKE*'s can all have arguments
precedence for OIND was initalized twice
fixes#2414
R=rsc, dave
CC=golang-dev
https://golang.org/cl/5319065
Got rid of all the magic mystery globals. Now
for %N, %T, and %S, the flags +,- and # set a sticky
debug, sym and export mode, only visible in the new fmt.c.
Default is error mode. Handle h and l flags consistently with
the least side effects, so we can now change
things without worrying about unrelated things
breaking.
fixes#2361
R=rsc
CC=golang-dev
https://golang.org/cl/5316043
There is no semantic change here, just better errors.
If a function says it takes a byte, and you pass it an int,
the compiler error now says that you need a byte, not
that you need a uint8.
Groundwork for rune.
R=ken2
CC=golang-dev
https://golang.org/cl/5300042
For example, if you are debugging an optimization
problem you can now run
GCFLAGS=-N gotest
This is a convention for make, not for the general build,
so it may go away or be done differently in the eventual
'go' command.
The plan is that people will be able to test their code for
rune safety by doing GCFLAGS=-r.
R=golang-dev, bradfitz, lvd
CC=golang-dev
https://golang.org/cl/5294042
Had been allowing it for use by fmt, but it is too hard to lock down.
Fix other packages not to depend on it.
R=r, r
CC=golang-dev
https://golang.org/cl/5266054
string literals used as package qualifiers are now prefixed with '@'
which obviates the need for the extra ':' before tags.
R=rsc, gri, lvd
CC=golang-dev
https://golang.org/cl/5129057
Fixes#2337.
Unfortunate sequence of events is:
1. maxcpu=2, mcpu=1, grunning=1
2. starttheworld creates an extra M:
maxcpu=2, mcpu=2, grunning=1
4. the goroutine calls runtime.GOMAXPROCS(1)
maxcpu=1, mcpu=2, grunning=1
5. since it sees mcpu>maxcpu, it calls gosched()
6. schedule() deschedules the goroutine:
maxcpu=1, mcpu=1, grunning=0
7. schedule() call getnextandunlock() which
fails to pick up the goroutine again,
because canaddcpu() fails, because mcpu==maxcpu
8. then it sees that grunning==0,
reports deadlock and terminates
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5191044
My previous CL:
changeset: 9645:ce2e5f44b310
user: Russ Cox <rsc@golang.org>
date: Tue Sep 06 10:24:21 2011 -0400
summary: gc: unify stack frame layout
introduced a bug wherein no variables were
being registerized, making Go programs 2-3x
slower than they had been before.
This CL fixes that bug (along with some others
it was hiding) and adds a test that optimization
makes at least one test case faster.
R=ken2
CC=golang-dev
https://golang.org/cl/5174045
Running test/garbage/parser.out.
On a 4-core Lenovo X201s (Linux):
31.12u 0.60s 31.74r 1 cpu, no atomics
32.27u 0.58s 32.86r 1 cpu, atomic instructions
33.04u 0.83s 27.47r 2 cpu
On a 16-core Xeon (Linux):
33.08u 0.65s 33.80r 1 cpu, no atomics
34.87u 1.12s 29.60r 2 cpu
36.00u 1.87s 28.43r 3 cpu
36.46u 2.34s 27.10r 4 cpu
38.28u 3.85s 26.92r 5 cpu
37.72u 5.25s 26.73r 6 cpu
39.63u 7.11s 26.95r 7 cpu
39.67u 8.10s 26.68r 8 cpu
On a 2-core MacBook Pro Core 2 Duo 2.26 (circa 2009, MacBookPro5,5):
39.43u 1.45s 41.27r 1 cpu, no atomics
43.98u 2.95s 38.69r 2 cpu
On a 2-core Mac Mini Core 2 Duo 1.83 (circa 2008; Macmini2,1):
48.81u 2.12s 51.76r 1 cpu, no atomics
57.15u 4.72s 51.54r 2 cpu
The handoff algorithm is really only good for two cores.
Beyond that we will need to so something more sophisticated,
like have each core hand off to the next one, around a circle.
Even so, the code is a good checkpoint; for now we'll limit the
number of gc procs to at most 2.
R=dvyukov
CC=golang-dev
https://golang.org/cl/4641082
ChaiShushan
Russ Cox
Josh Bleecher Snyder
Ian Lance Taylor
Shenghou Ma
Jan Ziak
Keith Randall
Dave Cheney
Rémy Oudompheng
Chris Manghane
Brad Fitzpatrick
Rick Arnold
Daniel Morsing
David du Colombier
Dmitriy Vyukov
Dominik Honnef
Martin Olsson
Carl Shapiro
Alan Donovan
Robert Griesemer
Rob Pike
Anthony Martin
Robert Obryk
Volker Dobler
Tyler Bunnell
Luuk van Dijk
David Symonds
Akshat Kumar
Adam Langley
Nigel Tao
Alex Brainman
Ryan Hitchman
Mikio Hara
Jamie Gennis
Olivier Duperray
Jeff R. Allen
Scott Lawrence
Maxim Pimenov