Not recognized in any instructions yet, but this lets the
assembler parse them at least.
For #14068.
Change-Id: Id4f7329a969b747a867ce261b20165fab2cdcab8
Reviewed-on: https://go-review.googlesource.com/18846
Reviewed-by: Rob Pike <r@golang.org>
Also, remove output file if there are encoding errors.
The extra reports are convenient.
Removing the output file is very important.
Noticed while testing.
Change-Id: I0fab17d4078f93c5a0d6d1217d8d9a63ac789696
Reviewed-on: https://go-review.googlesource.com/18845
Reviewed-by: Rob Pike <r@golang.org>
Instead of two parallel files that look almost identical,
mark the expected differences in the original file.
The annotations being added here keep the tests passing,
but they also make clear a number of printing or parsing
errors that were not as easily seen when the data was
split across two files.
Fix a few diagnostic problems in cmd/internal/obj as well.
A step toward #13822.
Change-Id: I997172681ea6fa7da915ff0f0ab93d2b76f8dce2
Reviewed-on: https://go-review.googlesource.com/18823
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Fixes build on those systems.
Also fix printing of AVARLIVE.
Change-Id: I1b38cca0125689bc08e4e1bdd0d0c140b1ea079a
Reviewed-on: https://go-review.googlesource.com/18641
Reviewed-by: Russ Cox <rsc@golang.org>
This will allow the compiler to crunch Prog lists down to code as each
function is compiled, instead of waiting until the end, which should
reduce the working set of the compiler. But not until Go 1.7.
This also makes it easier to write some machine code output tests
for the assembler, which is why it's being done now.
For #13822.
Change-Id: I0811123bc6e5717cebb8948f9cea18e1b9baf6f7
Reviewed-on: https://go-review.googlesource.com/18311
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Consider this code:
func f(*int)
func g() {
p := new(int)
f(p)
}
where f is an assembly function.
In general liveness analysis assumes that during the call to f, p is dead
in this frame. If f has retained p, p will be found alive in f's frame and keep
the new(int) from being garbage collected. This is all correct and works.
We use the Go func declaration for f to give the assembly function
liveness information (the arguments are assumed live for the entire call).
Now consider this code:
func h1() {
p := new(int)
syscall.Syscall(1, 2, 3, uintptr(unsafe.Pointer(p)))
}
Here syscall.Syscall is taking the place of f, but because its arguments
are uintptr, the liveness analysis and the garbage collector ignore them.
Since p is no longer live in h once the call starts, if the garbage collector
scans the stack while the system call is blocked, it will find no reference
to the new(int) and reclaim it. If the kernel is going to write to *p once
the call finishes, reclaiming the memory is a mistake.
We can't change the arguments or the liveness information for
syscall.Syscall itself, both for compatibility and because sometimes the
arguments really are integers, and the garbage collector will get quite upset
if it finds an integer where it expects a pointer. The problem is that
these arguments are fundamentally untyped.
The solution we have taken in the syscall package's wrappers in past
releases is to insert a call to a dummy function named "use", to make
it look like the argument is live during the call to syscall.Syscall:
func h2() {
p := new(int)
syscall.Syscall(1, 2, 3, uintptr(unsafe.Pointer(p)))
use(unsafe.Pointer(p))
}
Keeping p alive during the call means that if the garbage collector
scans the stack during the system call now, it will find the reference to p.
Unfortunately, this approach is not available to users outside syscall,
because 'use' is unexported, and people also have to realize they need
to use it and do so. There is much existing code using syscall.Syscall
without a 'use'-like function. That code will fail very occasionally in
mysterious ways (see #13372).
This CL fixes all that existing code by making the compiler do the right
thing automatically, without any code modifications. That is, it takes h1
above, which is incorrect code today, and makes it correct code.
Specifically, if the compiler sees a foreign func definition (one
without a body) that has uintptr arguments, it marks those arguments
as "unsafe uintptrs". If it later sees the function being called
with uintptr(unsafe.Pointer(x)) as an argument, it arranges to mark x
as having escaped, and it makes sure to hold x in a live temporary
variable until the call returns, so that the garbage collector cannot
reclaim whatever heap memory x points to.
For now I am leaving the explicit calls to use in package syscall,
but they can be removed early in a future cycle (likely Go 1.7).
The rule has no effect on escape analysis, only on liveness analysis.
Fixes#13372.
Change-Id: I2addb83f70d08db08c64d394f9d06ff0a063c500
Reviewed-on: https://go-review.googlesource.com/18584
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Add several instructions that were used via BYTE and use them.
Instructions added: PEXTRB, PEXTRD, PEXTRQ, PINSRB, XGETBV, POPCNT.
Change-Id: I5a80cd390dc01f3555dbbe856a475f74b5e6df65
Reviewed-on: https://go-review.googlesource.com/18593
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Added a format option to inhibit output of .Note field in
printing, and enabled that option during export.
Added test.
Fixes#13777.
Change-Id: I739f9785eb040f2fecbeb96d5a9ceb8c1ca0f772
Reviewed-on: https://go-review.googlesource.com/18217
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: David Chase <drchase@google.com>
This CL changes the source file information in the
standard library's .a files to say "$GOROOT/src/runtime/chan.go"
(with a literal "$GOROOT") instead of spelling out the actual directory.
The linker then substitutes the actual $GOROOT (or $GOROOT_FINAL)
as appropriate.
If people download a binary distribution to an alternate location,
following the instructions at https://golang.org/doc/install#install,
the code before this CL would end up with source paths pointing to
/usr/local/go no matter where the actual sources were.
Now the source paths for built binaries will point to the actual sources
(hopefully).
The source line information in distributed binaries is not affected:
those will still say /usr/local/go. But binaries people build themselves
(their own programs, not the go distribution programs) will be correct.
Fixing this path also fixes the lookup of the runtime-gdb.py file.
Fixes#5533.
Change-Id: I03729baae3fbd8cd636e016275ee5ad2606e4663
Reviewed-on: https://go-review.googlesource.com/18200
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
These three files contain only code written for Go
(and trivial amounts at that), not any code ported
from Inferno or Plan 9.
Remove the incorrect Inferno/Plan 9 notices.
Fixes#13576.
Change-Id: Ib9901fb360232282aae5ee0f4aa527bd6f4eaaed
Reviewed-on: https://go-review.googlesource.com/17779
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
When using GOEXPERIMENT=fieldtrack, we can see AUSEFIELD instructions.
We generally want to ignore them.
No tests because as far as I can tell there are no tests for
GOEXPERIMENT=fieldtrack.
Change-Id: Iee26f25592158e5db691a36cf8d77fc54d051314
Reviewed-on: https://go-review.googlesource.com/17610
Reviewed-by: David Symonds <dsymonds@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
runtime.stackBarrier is a strange function: it is only ever "called" by
smashing its address into a LR slot on the stack. Calling it like this
certainly does not adhere to the rule that r12 is set to the global entry point
before calling it and the prologue instrutions that compute r2 from r12 in fact
just corrupt r2, which is bad because the function that stackBarrier returns to
probably uses r2 to access global data.
Fortunately stackBarrier itself does not access any global data and so does not
depend on the value of r2, meaning we can ignore the ABI rules and simply skip
inserting the prologue instructions into this specific function.
Fixes 64bit.go, append.go and fixedbugs/issue13169.go from "cd test; go run
run.go -linkshared".
Change-Id: I606864133a83935899398e2d42edd08a946aab24
Reviewed-on: https://go-review.googlesource.com/17281
Reviewed-by: Austin Clements <austin@google.com>
Transactional memory, will later be used for semaphore implementation.
Nacl not supported yet.
Change-Id: Ic18453dcaa08d07bb217c0b95461584f007d518b
Reviewed-on: https://go-review.googlesource.com/16479
Reviewed-by: Russ Cox <rsc@golang.org>
golang.org/cl/16383 broke android/386 because by a sort of confluence of hacks
no TLS relocations were emitted at all when Flag_shared != 0. The hack in
runtime/cgo works as well in a PIE executable as it does with a position
dependent one, so the simplest fix is to still emit a R_TLS_LE reloc when goos
== "android".
A real fix is to use something more like the IE model code but loading the
offset from %gs to the thread local storage from a global variable rather than
from a location chosen by the system linker (this is how android/arm works).
Issue #9327.
Change-Id: I9fbfc890ec7fe191f80a595b6cf8e2a1fcbe3034
Reviewed-on: https://go-review.googlesource.com/17049
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
This works by adding a call to __x86.get_pc_thunk.cx immediately before any
instruction that accesses global data and then assembling the instruction to
use the appropriate offset from CX instead of the absolute address. Some forms
cannot be assembled that way and are rewritten to load the address into CX
first.
-buildmode=pie works now, but is not yet tested.
Fixes#13201 (I think)
Change-Id: I32a8561e7fc9dd4ca6ae3b0e57ad78a6c50bf1f5
Reviewed-on: https://go-review.googlesource.com/17014
Reviewed-by: Ian Lance Taylor <iant@golang.org>
I was prodded into doing this in review comments for the ARM version, and it's
going to make shared libs for 386 easier.
Change-Id: Id12de801b1425b8c6b5736fe91b418fc123a4e40
Reviewed-on: https://go-review.googlesource.com/17012
Reviewed-by: David Crawshaw <crawshaw@golang.org>
This includes the first parts of the general approach to PIC: load PC into CX
whenever it is needed. This is going to lead to large binaries and poor
performance but it's a start and easy to get right.
Change-Id: Ic8bf1d0a74284cca0d94a68cf75024e8ab063b4e
Reviewed-on: https://go-review.googlesource.com/16383
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This requires changing the tls access code to match the patterns documented in
the ABI documentation or the system linker will "optimize" it into ridiculousness.
With this change, -buildmode=pie works, although as it is tested in testshared,
the tests are not run yet.
Change-Id: I1efa6687af0a5b8db3385b10f6542a49056b2eb3
Reviewed-on: https://go-review.googlesource.com/15971
Reviewed-by: Russ Cox <rsc@golang.org>
The PowerPC ISA does not have a PC-relative load instruction, which poses
obvious challenges when generating position-independent code. The way the ELFv2
ABI addresses this is to specify that r2 points to a per "module" (shared
library or executable) TOC pointer. Maintaining this pointer requires
cooperation between codegen and the system linker:
* Non-leaf functions leave space on the stack at r1+24 to save the TOC pointer.
* A call to a function that *might* have to go via a PLT stub must be followed
by a nop instruction that the system linker can replace with "ld r1, 24(r1)"
to restore the TOC pointer (only when dynamically linking Go code).
* When calling a function via a function pointer, the address of the function
must be in r12, and the first couple of instructions (the "global entry
point") of the called function use this to derive the address of the TOC
for the module it is in.
* When calling a function that is implemented in the same module, the system
linker adjusts the call to skip over the instructions mentioned above (the
"local entry point"), assuming that r2 is already correctly set.
So this changeset adds the global entry point instructions, sets the metadata so
the system linker knows where the local entry point is, inserts code to save the
TOC pointer at 24(r1), adds a nop after any call not known to be local and copes
with the odd non-local code transfer in the runtime (e.g. the stuff around
jmpdefer). It does not actually compile PIC yet.
Change-Id: I7522e22bdfd2f891745a900c60254fe9e372c854
Reviewed-on: https://go-review.googlesource.com/15967
Reviewed-by: Russ Cox <rsc@golang.org>
The larger stack frames causes the nosplit stack to overflow so the next change
increases the stackguard.
Change-Id: Ib2b4f24f0649eb1d13e3a58d265f13d1b6cc9bf9
Reviewed-on: https://go-review.googlesource.com/15964
Reviewed-by: Russ Cox <rsc@golang.org>
Larger stack frames mean nosplit functions use more stack and so the limit
needs to increase.
The change to test/nosplit.go is a bit ugly but I can't really think of a
way to make it nicer.
Change-Id: I2616b58015f0b62abbd62951575fcd0d2d8643c2
Reviewed-on: https://go-review.googlesource.com/16504
Reviewed-by: Russ Cox <rsc@golang.org>
MIPS64 has 32 general purpose 64-bit integer registers (R0-R31), 32
64-bit floating point registers (F0-F31). Instructions are fixed-width,
and are 32-bit wide. Instructions are all in standard 1-, 2-, 3-operand
forms.
MIPS64-specific relocations are added. For this reason, test data of
cmd/newlink are regenerated.
No other changes are made to portable structures.
Branch delay slots are current filled with NOP instructions. The function
for instruction scheduling (try to fill the delay slot with a useful
instruction) is implemented but disabled for now.
Change-Id: Ic364999c7a33245260c1381fc26a2fa8972d38b3
Reviewed-on: https://go-review.googlesource.com/14442
Reviewed-by: Minux Ma <minux@golang.org>
sradi and sradi. hide the top bit of their immediate argument apart from the
rest of it, but the code only handled the sradi case.
I'm pretty sure this is the only instruction missing (a couple of the rotate
instructions encode their immediate the same way but their handling looks OK).
This fixes the failure of "GOARCH=amd64 ~/go/bin/go install -v runtime" as
reported in the bug.
Fixes#11987
Change-Id: I0cdefcd7a04e0e8fce45827e7054ffde9a83f589
Reviewed-on: https://go-review.googlesource.com/16710
Reviewed-by: Minux Ma <minux@golang.org>
On ppc64x, the thread pointer, held in R13, points 0x7000 bytes past where
thread-local storage begins (presumably to maximize the amount of storage that
can be accessed with a 16-bit signed displacement). The relocations used to
indicate thread-local storage to the platform linker account for this, so to be
able to support external linking we need to change things so the linker applies
this offset instead of the runtime assembly.
Change-Id: I2556c249ab2d802cae62c44b2b4c5b44787d7059
Reviewed-on: https://go-review.googlesource.com/14233
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
And get rid of the stupid game of encoding the instruction in the addend.
Change-Id: Ib4de7515196cbc1e63b4261b01931cf02a44c1e6
Reviewed-on: https://go-review.googlesource.com/14055
Reviewed-by: Russ Cox <rsc@golang.org>
Android linker does not handle TLS for us. We set up the TLS slot
for g, as darwin/386,amd64 handle instead. This is disgusting and
fragile. We will eventually fix this ugly hack by taking advantage
of the recent TLS IE model implementation. (Instead of referencing
an GOT entry, make the code sequence look into the TLS variable that
holds the offset.)
The TLS slot for g in android/amd64 assumes a fixed offset from %fs.
See runtime/cgo/gcc_android_amd64.c for details.
For golang/go#10743
Change-Id: I1a3fc207946c665515f79026a56ea19134ede2dd
Reviewed-on: https://go-review.googlesource.com/15991
Reviewed-by: David Crawshaw <crawshaw@golang.org>
The reg-reg version compiled to PSRAW, not PSRLW (arithmetic
instead of logical shift right).
Fixes#13010.
Change-Id: I69a47bd83c8bbe66c7f8d82442ab45e9bf3b94fb
Reviewed-on: https://go-review.googlesource.com/16168
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Shared libraries on ppc64le will require a larger minimum stack frame (because
the ABI mandates that the TOC pointer is available at 24(R1)). Part 2a of
preparing for that is to have all bits of arch-independent and ppc64-specific
codegen that need to know call a function to find out.
Change-Id: I55899f73037e92227813c491049a3bd6f30bd41f
Reviewed-on: https://go-review.googlesource.com/15524
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Russ Cox
Shenghou Ma
Ilya Tocar
David Chase
Matthew Dempsky
Ian Lance Taylor
Michael Hudson-Doyle
sergey.arseev
David Crawshaw
Yao Zhang
Hyang-Ah Hana Kim
Robert Griesemer
Keith Randall