If I change a rule in ARM64.rules to use the variable name "b" in a
conflicting way, rulegen would previously not complain, and the compiler
would later give a confusing error:
$ go run *.go && go build cmd/compile/internal/ssa
# cmd/compile/internal/ssa
../rewriteARM64.go:24236:10: b.NewValue0 undefined (type int64 has no field or method NewValue0)
Make rulegen complain early about those cases. Sometimes they might
happen to be harmless, but in general they can easily cause confusion or
unintended effect due to shadowing.
After the change, with the same conflicting rule:
$ go run *.go && go build cmd/compile/internal/ssa
2021/03/22 11:31:49 rule ARM64.rules:495 uses the reserved name b
exit status 1
Note that 24 existing rules were using reserved names. It seems like the
shadowing was harmless, as it wasn't causing typechecking issues nor did
it seem to cause unintended behavior when the rule rewrite code ran.
The bool values "b" were renamed "t", since that seems to have a
precedent in other rules and in the fmt package.
Sequential values like "a b c" were renamed to "x y z", since "b" is
reserved.
Finally, "typ" was renamed to "_typ", since there doesn't seem to be an
obviously better answer.
Passes all three of:
$ GOARCH=amd64 go build -toolexec 'toolstash -cmp' -a std
$ GOARCH=arm64 go build -toolexec 'toolstash -cmp' -a std
$ GOARCH=mips64 go build -toolexec 'toolstash -cmp' -a std
Fixes#45154.
Change-Id: I1cce194dc7b477886a9c218c17973e996bcedccf
Reviewed-on: https://go-review.googlesource.com/c/go/+/303549
Trust: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Add generic rule to rewrite the single-precision square root expression
with one single-precision instruction. The optimization will reduce two
times of precision converting between double-precision and single-precision.
On arm64 flatform.
previous:
FCVTSD F0, F0
FSQRTD F0, F0
FCVTDS F0, F0
optimized:
FSQRTS S0, S0
And this patch adds the test case to check the correctness.
This patch refers to CL 241877, contributed by Alice Xu
(dianhong.xu@arm.com)
Change-Id: I6de5d02281c693017ac4bd4c10963dd55989bd7e
Reviewed-on: https://go-review.googlesource.com/c/go/+/276873
Trust: fannie zhang <Fannie.Zhang@arm.com>
Run-TryBot: fannie zhang <Fannie.Zhang@arm.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
MOV*nop and MOV*reg seem superfluous. They are there to keep type
information around that would otherwise get thrown away. Not sure
what we need it for. I think our compiler needs a normalization of
how types are represented in SSA, especially after lowering.
MOV*nop gets in the way of some optimization rules firing, like for
load combining.
For now, just fold MOV*nop and MOV*const. It's certainly safe to
do that, as the type info on the MOV*const isn't ever useful.
R=go1.17
Change-Id: I3630a80afc2455a8e9cd9fde10c7abe05ddc3767
Reviewed-on: https://go-review.googlesource.com/c/go/+/276792
Trust: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Current many architectures use a rule along the lines of
// Canonicalize the order of arguments to comparisons - helps with CSE.
((CMP|CMPW) x y) && x.ID > y.ID => (InvertFlags ((CMP|CMPW) y x))
to normalize comparisons as much as possible for CSE. Replace the
ID comparison with something less variable across compiler changes.
This helps avoid spurious failures in some of the codegen-comparison
tests (though the current choice of comparison is sensitive to Op
ordering).
Two tests changed to accommodate modified instruction choice.
Change-Id: Ib35f450bd2bae9d4f9f7838ceaf7ec682bcf1e1a
Reviewed-on: https://go-review.googlesource.com/c/go/+/280155
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
It just makes the compiler crash. Oops.
Fixes#43099
Change-Id: Id996c14799c1a5d0063ecae3b8770568161c2440
Reviewed-on: https://go-review.googlesource.com/c/go/+/276652
Trust: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
These replacement rules assume that TST and TEQ set V. But TST and
TEQ do not set V. This is a problem because instructions like LT are
actually checking for N!=V. But with TST and TEQ not setting V, LT
doesn't do anything meaningful. It's possible to construct trivial
miscompilations from this, such as:
package main
var x = [4]int32{-0x7fffffff, 0x7fffffff, 2, 4}
func main() {
if x[0] > x[1] {
panic("fail 1")
}
if x[2]&x[3] < 0 {
panic("fail 2") // Fails here
}
}
That first comparison sets V, via the CMP that subtracts the values
causing the overflow. Then the second comparison operation thinks that
it uses the result of TST, when it actually uses the V from CMP.
Before this fix:
TST R0, R1
BLT loc_6C164
After this fix:
TST R0, R1
BMI loc_6C164
The BMI instruction checks the N flag, which TST sets. This commit
fixes the issue by using [LG][TE]noov instead of vanilla [LG][TE], and
also adds a test case for the direct issue.
Fixes#42876.
Change-Id: I13c62c88d18574247ad002b671b38d2d0b0fc6fa
Reviewed-on: https://go-review.googlesource.com/c/go/+/274026
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Also make canMergeSym take Syms instead of interface{}
Change-Id: I4926a1fc586aa90e198249d67e5b520404b40869
Reviewed-on: https://go-review.googlesource.com/c/go/+/265817
Trust: Alberto Donizetti <alb.donizetti@gmail.com>
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Add type casting to offset.
L246-L247
L1473-L1475
toolstash-check successful.
Change-Id: I816c7556609ca6dd67bff8007c2d006cab89ee2b
Reviewed-on: https://go-review.googlesource.com/c/go/+/257639
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Trust: Alberto Donizetti <alb.donizetti@gmail.com>
Toolstash-check successful for remaining rules using GOARM value.
Change-Id: I254f80d17839ef4957c1b7afbdb4db363a3b9367
Reviewed-on: https://go-review.googlesource.com/c/go/+/240997
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Trust: Giovanni Bajo <rasky@develer.com>
add type casting to int32: L148-L156, L774-L778
Toolstash-check successful
Change-Id: Ib6544c1d7853c2811def5b18786e1fc5c18086ca
Reviewed-on: https://go-review.googlesource.com/c/go/+/256097
Reviewed-by: Keith Randall <khr@golang.org>
Trust: Giovanni Bajo <rasky@develer.com>
"mul by constant" until "div by constant"
L547-L609
Change-Id: I19ebb5694e383878f505d34df2591a51fe38431a
Reviewed-on: https://go-review.googlesource.com/c/go/+/254662
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Alberto Donizetti <alb.donizetti@gmail.com>
End of "constant folding in *shift ops" until EOF
(L1070-)
Toolstash-check is successful.
Change-Id: I55846a459aca5238f831750f04132e13a0baeed7
Reviewed-on: https://go-review.googlesource.com/c/go/+/234198
Reviewed-by: Giovanni Bajo <rasky@develer.com>
Reviewed-by: Keith Randall <khr@golang.org>
Trust: Giovanni Bajo <rasky@develer.com>
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Go Bot <gobot@golang.org>
From "absorb InvertFlags" until "constant folding in *shift ops"
L666-L1011
Toolstash-check is successful.
Change-Id: Ieed7d4643dc3dc2b3649477e87aebd22c81d1322
Reviewed-on: https://go-review.googlesource.com/c/go/+/234197
Reviewed-by: Giovanni Bajo <rasky@develer.com>
Reviewed-by: Keith Randall <khr@golang.org>
Trust: Giovanni Bajo <rasky@develer.com>
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Go Bot <gobot@golang.org>
Toolstash-check successful from L270 until L543.
Change-Id: Ic39ab86c80f970bfb21e318284f6bb3e8a994220
Reviewed-on: https://go-review.googlesource.com/c/go/+/233439
Reviewed-by: Giovanni Bajo <rasky@develer.com>
Reviewed-by: Keith Randall <khr@golang.org>
Trust: Giovanni Bajo <rasky@develer.com>
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Go Bot <gobot@golang.org>
Toolstash-check successful from L0 until L268
Change-Id: Ifc55ea1e4177c21107c521fc72da2da7b507b8ba
Reviewed-on: https://go-review.googlesource.com/c/go/+/232811
Reviewed-by: Keith Randall <khr@golang.org>
Trust: Giovanni Bajo <rasky@develer.com>
This patch adds the ARM6464Bitfield auxInt to auxIntType() and
returns its Go type as "arm64Bitfield" type, which is defined
as int16 type.
And the Go type of SymOff auxInt is int32, but some functions
(such as min(), areAdjacentOffsets() and read16/32/64(),etc.)
use SymOff as an input parameter and treat its type as int64,
this patch adds the type conversion for these rules.
Passes toolstash-check -all.
Change-Id: Ib234b48d0a97ef244dd37878e06b5825316dd782
Reviewed-on: https://go-review.googlesource.com/c/go/+/234378
Reviewed-by: Keith Randall <khr@golang.org>
Encode the flag results in an auxint field instead of having
one opcode per flag state. This helps us handle the new *noov
branches in a unified manner.
This is only for arm, arm64 is in a subsequent CL.
We could extend to other architectures as well, athough it would
only be cleanup, no behavioral change.
Update #39505
Change-Id: Ia46cea596faad540d1496c5915ab1274571543f0
Reviewed-on: https://go-review.googlesource.com/c/go/+/238077
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Keep track of all expressions encountered while
generating a rewrite result, and re-use them whenever possible.
Named expressions may still be used for clarity when desired.
Change-Id: I640dca108763eb8baeff8f9a4169300af3445b82
Reviewed-on: https://go-review.googlesource.com/c/go/+/229800
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Extend CL 220417 (which removed the integer Greater and Geq ops) to
floating point comparisons. Greater and Geq can always be
implemented using Less and Leq.
Fixes#37316.
Change-Id: Ieaddb4877dd0ff9037a1dd11d0a9a9e45ced71e7
Reviewed-on: https://go-review.googlesource.com/c/go/+/222397
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
For 1.15, unless someone really wants it in 1.14.
A performance-sensitive user thought this would be useful,
though "large" was not well-defined. If 128 is large,
there are 139 static instances of "large" copies in the compiler
itself.
Includes test.
Change-Id: I81f20c62da59d37072429f3a22c1809e6fb2946d
Reviewed-on: https://go-review.googlesource.com/c/go/+/205066
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
In cases in which we had a named value whose args were all _,
like this rule from ARM.rules:
(MOVBUreg x:(MOVBUload _ _)) -> (MOVWreg x)
We previously inserted
_ = x.Args[1]
even though it is unnecessary.
This change eliminates this pointless bounds check.
And in other cases, we now check bounds just as far as strictly necessary.
No significant movement on any compiler metrics.
Just nicer (and less) code.
Passes toolstash-check -all.
Change-Id: I075dfe9f926cc561cdc705e9ddaab563164bed3a
Reviewed-on: https://go-review.googlesource.com/c/go/+/221781
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
This:
* Simplifies and shortens the generated code for rewrite rules.
* Shrinks cmd/compile by 86k (0.4%) and makes it easier to compile.
* Removes the stmt boundary code wrangling from Value.reset,
in favor of doing it in the one place where it actually does some work,
namely the writebarrier pass. (This was ascertained by inspecting the
code for cases in which notStmtBoundary values were generated.)
Passes toolstash-check -all.
Change-Id: I25671d4c4bbd772f235195d11da090878ea2cc07
Reviewed-on: https://go-review.googlesource.com/c/go/+/221421
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
The SSA backend has rules to read the contents of readonly Lsyms.
However, this rule was failing to trigger for many readonly Lsyms.
This is because the readonly attribute that was set on the Node.Name
was not propagated to its Lsym until the dump globals phase, after SSA runs.
To work around this phase ordering problem, introduce Node.SetReadonly,
which sets Node.Name.Readonly and also configures the Lsym
enough that SSA can use it.
This change also fixes a latent problem in the rewrite rule function,
namely that reads past the end of lsym.P were treated as entirely zero,
instead of merely requiring padding with trailing zeros.
This change also adds an amd64 rule needed to fully optimize
the results of this change. It would be better not to need this,
but the zero extension that should handle this for us
gets optimized away too soon (see #36897 for a similar problem).
I have not investigated whether other platforms also need new
rules to take full advantage of the new optimizations.
Compiled code for (interface{})(true) on amd64 goes from:
LEAQ type.bool(SB), AX
MOVBLZX ""..stmp_0(SB), BX
LEAQ runtime.staticbytes(SB), CX
ADDQ CX, BX
to
LEAQ type.bool(SB), AX
LEAQ runtime.staticbytes+1(SB), BX
Prior to this change, the readonly symbol rewrite rules
fired a total of 884 times during make.bash.
Afterwards they fire 1807 times.
file before after Δ %
cgo 4827832 4823736 -4096 -0.085%
compile 24907768 24895656 -12112 -0.049%
fix 3376952 3368760 -8192 -0.243%
pprof 14751700 14747604 -4096 -0.028%
total 120343528 120315032 -28496 -0.024%
Change-Id: I59ea52138276c37840f69e30fb109fd376d579ec
Reviewed-on: https://go-review.googlesource.com/c/go/+/220499
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
The generic Greater and Geq ops can always be replaced with the Less and
Leq ops. This CL therefore removes them. This simplifies the compiler since
it reduces the number of operations that need handling in both code and in
rewrite rules. This will be especially true when adding control flow
optimizations such as the integer-in-range optimizations in CL 165998.
Change-Id: If0648b2b19998ac1bddccbf251283f3be4ec3040
Reviewed-on: https://go-review.googlesource.com/c/go/+/220417
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Ensure that any comparison between two values has the same argument
order. This helps ensure that they can be eliminated during the
lowered CSE pass which will be particularly important if we eliminate
the Greater and Geq ops (see #37316).
Example:
CMP R0, R1
BLT L1
CMP R1, R0 // different order, cannot eliminate
BEQ L2
CMP R0, R1
BLT L1
CMP R0, R1 // same order, can eliminate
BEQ L2
This does have some drawbacks. Notably comparisons might 'flip'
direction in the assembly output after even small changes to the
code or compiler. It should help make optimizations more reliable
however.
compilecmp master -> HEAD
master (218f4572f5): text/template: make reflect.Value indirections more robust
HEAD (f1661fef3e): cmd/compile: canonicalize comparison argument order
platform: linux/amd64
file before after Δ %
api 6063927 6068023 +4096 +0.068%
asm 5191757 5183565 -8192 -0.158%
cgo 4893518 4901710 +8192 +0.167%
cover 5330345 5326249 -4096 -0.077%
fix 3417778 3421874 +4096 +0.120%
pprof 14889456 14885360 -4096 -0.028%
test2json 2848138 2844042 -4096 -0.144%
trace 11746239 11733951 -12288 -0.105%
total 132739173 132722789 -16384 -0.012%
Change-Id: I11736b3fe2a4553f6fc65018f475e88217fa22f9
Reviewed-on: https://go-review.googlesource.com/c/go/+/220425
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
CL 213703 converted generated rewrite rules for commutative ops
to use loops instead of duplicated code.
However, it loaded args using expressions like
v.Args[i] and v.Args[i^1], which the compiler could
not eliminate bounds for (including with all outstanding
prove CLs).
Also, given a series of separate rewrite rules for the same op,
we generated bounds checks for every rewrite rule, even though
we were repeatedly loading the same set of args.
This change reduces both sets of bounds checks.
Instead of loading v.Args[i] and v.Args[i^1] for commutative loops,
we now preload v.Args[0] and v.Args[1] into local variables,
and then swap them (as needed) in the commutative loop post statement.
And we now load all top level v.Args into local variables
at the beginning of every rewrite rule function.
The second optimization is the more significant,
but the first helps a little, and they play together
nicely from the perspective of generating the code.
This does increase register pressure, but the reduced bounds
checks more than compensate.
Note that the vast majority of rewrite rules evaluated
are not applied, so the prologue is the most important
part of the rewrite rules.
There is one subtle aspect to the new generated code.
Because the top level v.Args are shared across rewrite rules,
and rule evaluation can swap v_0 and v_1, v_0 and v_1
can end up being swapped from one rule to the next.
That is OK, because any time a rule does not get applied,
they will have been swapped exactly twice.
Passes toolstash-check -all.
name old time/op new time/op delta
Template 213ms ± 2% 211ms ± 2% -0.85% (p=0.000 n=92+96)
Unicode 83.5ms ± 2% 83.2ms ± 2% -0.41% (p=0.004 n=95+90)
GoTypes 737ms ± 2% 733ms ± 2% -0.51% (p=0.000 n=91+94)
Compiler 3.45s ± 2% 3.43s ± 2% -0.44% (p=0.000 n=99+100)
SSA 8.54s ± 1% 8.32s ± 2% -2.56% (p=0.000 n=96+99)
Flate 136ms ± 2% 135ms ± 1% -0.47% (p=0.000 n=96+96)
GoParser 169ms ± 1% 168ms ± 1% -0.33% (p=0.000 n=96+93)
Reflect 456ms ± 3% 455ms ± 3% ~ (p=0.261 n=95+94)
Tar 186ms ± 2% 185ms ± 2% -0.48% (p=0.000 n=94+95)
XML 251ms ± 1% 250ms ± 1% -0.51% (p=0.000 n=91+94)
[Geo mean] 424ms 421ms -0.68%
name old user-time/op new user-time/op delta
Template 275ms ± 1% 274ms ± 2% -0.55% (p=0.000 n=95+98)
Unicode 118ms ± 4% 118ms ± 4% ~ (p=0.642 n=98+90)
GoTypes 983ms ± 1% 980ms ± 1% -0.30% (p=0.000 n=93+93)
Compiler 4.56s ± 6% 4.52s ± 6% -0.72% (p=0.003 n=100+100)
SSA 11.4s ± 1% 11.1s ± 1% -2.50% (p=0.000 n=96+97)
Flate 168ms ± 1% 167ms ± 1% -0.49% (p=0.000 n=92+92)
GoParser 204ms ± 1% 204ms ± 2% -0.27% (p=0.003 n=99+96)
Reflect 599ms ± 2% 598ms ± 2% ~ (p=0.116 n=95+92)
Tar 227ms ± 2% 225ms ± 2% -0.57% (p=0.000 n=95+98)
XML 313ms ± 2% 312ms ± 1% -0.37% (p=0.000 n=89+95)
[Geo mean] 547ms 544ms -0.61%
file before after Δ %
compile 21113112 21109016 -4096 -0.019%
total 131704940 131700844 -4096 -0.003%
Change-Id: Id6c39e0367e597c0c75b8a4b1eb14cc3cbd11956
Reviewed-on: https://go-review.googlesource.com/c/go/+/216218
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Prior to this change, we generated additional rules at rulegen time
for all possible combinations of args to commutative ops.
This is simple and works well, but leads to lots of generated rules.
This in turn has increased the size of the compiler,
made it hard to compile package ssa on small machines,
and provided a disincentive to mark some ops as commutative.
This change reworks how we handle commutative ops.
Instead of generating a rule per argument permutation,
we generate a series of nested loops, one for each commutative op.
Each loop tries both possible argument orderings.
I also considered attempting to canonicalize the inputs to the
rewrite rules. However, because either or both arguments might be
nothing more than an identifier, and because there can be arbitrary
conditions to evaluate during matching, I did not see how to proceed.
The duplicate rule detection now sorts arguments to commutative ops,
so that it can detect commutative-only duplicates.
There may be further optimizations to the new generated code.
In particular, we may not be removing as many bounds checks as before;
I have not investigated deeply. If more work here is needed,
we could do it with more hints or with improvements to the prove pass.
This change has almost no impact on the generated code.
It does not pass toolstash-check, however. In a handful of functions,
for reasons I do not understand, there are minor position changes.
For the entire series ending at this change,
there is negligible compiler performance impact.
The compiler binary shrinks by about 15%,
and package ssa shrinks by about 25%.
Package ssa also compiles ~25% faster with ~25% less memory.
Change-Id: Ia2ee9ceae7be08a17342319d4e31b0bb238a2ee4
Reviewed-on: https://go-review.googlesource.com/c/go/+/213703
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
This API was added for #25819, where it was discussed as math.FMA.
The commit adding it used math.Fma, presumably for consistency
with the rest of the unusual names in package math
(Sincos, Acosh, Erfcinv, Float32bits, etc).
I believe that using an idiomatic Go name is more important here
than consistency with these other names, most of which are historical
baggage from C's standard library.
Early additions like Float32frombits happened before "uppercase for export"
(so they were originally like "float32frombits") and they were not properly
reconsidered when we uppercased the symbols to export them.
That's a mistake we live with.
The names of functions we have added since then, and even a few
that were legacy, are more properly Go-cased, such as IsNaN, IsInf,
and RoundToEven, rather than Isnan, Isinf, and Roundtoeven.
And also constants like MaxFloat32.
For new API, we should keep using proper Go-cased symbols
instead of minimally-upper-cased-C symbols.
So math.FMA, not math.Fma.
This API has not yet been released, so this change does not break
the compatibility promise.
This CL also modifies cmd/compile, since the compiler knows
the name of the function. I could have stopped at changing the
string constants, but it seemed to make more sense to use a
consistent casing everywhere.
Change-Id: I0f6f3407f41e99bfa8239467345c33945088896e
Reviewed-on: https://go-review.googlesource.com/c/go/+/205317
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Slight differences existed due to a change in rulegen after the
FMA intrinsic code was generated.
Change-Id: Ieb6b3ec1b29985a18d1bbbc5a820ffea699306fd
Reviewed-on: https://go-review.googlesource.com/c/go/+/202443
Run-TryBot: Michael Munday <mike.munday@ibm.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This change introduces an arm intrinsic that generates the FMULAD
instruction for the fused-multiply-add operation on systems that
support it. System support is detected via cpu.ARM.HasVFPv4. A rewrite
rule translates the generic intrinsic to FMULAD.
Updates #25819.
Change-Id: I8459e5dd1cdbdca35f88a78dbeb7d387f1e20efa
Reviewed-on: https://go-review.googlesource.com/c/go/+/142117
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
This is part two if the nacl removal. Part 1 was CL 199499.
This CL removes amd64p32 support, which might be useful in the future
if we implement the x32 ABI. It also removes the nacl bits in the
toolchain, and some remaining nacl bits.
Updates #30439
Change-Id: I2475d5bb066d1b474e00e40d95b520e7c2e286e1
Reviewed-on: https://go-review.googlesource.com/c/go/+/200077
Reviewed-by: Ian Lance Taylor <iant@golang.org>
First, renove unnecessary "// cond:" lines from the generated files.
This shaves off about ~7k lines.
Second, join "if cond { break }" statements via "||", which allows us to
deduplicate a large number of them. This shaves off another ~25k lines.
This change is not for readability or simplicity; but rather, to avoid
unnecessary verbosity that makes the generated files larger. All in all,
git reports that the generated files overall weigh ~200KiB less, or
about 2.7% less.
While at it, add a -trace flag to rulegen.
Updates #33644.
Change-Id: I3fac0290a6066070cc62400bf970a4ae0929470a
Reviewed-on: https://go-review.googlesource.com/c/go/+/196498
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
First, add cpu and memory profiling flags, as these are useful to see
where rulegen is spending its time. It now takes many seconds to run on
a recent laptop, so we have to keep an eye on what it's doing.
Second, stop writing '_ = var' lines to keep imports and variables used
at all times. Now that rulegen removes all such unused names, they're
unnecessary.
To perform the removal, lean on go/types to first detect what names are
unused. We can configure it to give us all the type-checking errors in a
file, so we can collect all "declared but not used" errors in a single
pass.
We then use astutil.Apply to remove the relevant nodes based on the line
information from each unused error. This allows us to apply the changes
without having to do extra parser+printer roundtrips to plaintext, which
are far too expensive.
We need to do multiple such passes, as removing an unused variable
declaration might then make another declaration unused. Two passes are
enough to clean every file at the moment, so add a limit of three passes
for now to avoid eating cpu uncontrollably by accident.
The resulting performance of the changes above is a ~30% loss across the
table, since go/types is fairly expensive. The numbers were obtained
with 'benchcmd Rulegen go run *.go', which involves compiling rulegen
itself, but that seems reflective of how the program is used.
name old time/op new time/op delta
Rulegen 5.61s ± 0% 7.36s ± 0% +31.17% (p=0.016 n=5+4)
name old user-time/op new user-time/op delta
Rulegen 7.20s ± 1% 9.92s ± 1% +37.76% (p=0.016 n=5+4)
name old sys-time/op new sys-time/op delta
Rulegen 135ms ±19% 169ms ±17% +25.66% (p=0.032 n=5+5)
name old peak-RSS-bytes new peak-RSS-bytes delta
Rulegen 71.0MB ± 2% 85.6MB ± 2% +20.56% (p=0.008 n=5+5)
We can live with a bit more resource usage, but the time/op getting
close to 10s isn't good. To win that back, introduce concurrency in
main.go. This further increases resource usage a bit, but the real time
on this quad-core laptop is greatly reduced. The final benchstat is as
follows:
name old time/op new time/op delta
Rulegen 5.61s ± 0% 3.97s ± 1% -29.26% (p=0.008 n=5+5)
name old user-time/op new user-time/op delta
Rulegen 7.20s ± 1% 13.91s ± 1% +93.09% (p=0.008 n=5+5)
name old sys-time/op new sys-time/op delta
Rulegen 135ms ±19% 269ms ± 9% +99.17% (p=0.008 n=5+5)
name old peak-RSS-bytes new peak-RSS-bytes delta
Rulegen 71.0MB ± 2% 226.3MB ± 1% +218.72% (p=0.008 n=5+5)
It might be possible to reduce the cpu or memory usage in the future,
such as configuring go/types to do less work, or taking shortcuts to
avoid having to run it many times. For now, ~2x cpu and ~4x memory usage
seems like a fair trade for a faster and better rulegen.
Finally, we can remove the old code that tried to remove some unused
variables in a hacky and unmaintainable way.
Change-Id: Iff9e83e3f253babf5a1bd48cc993033b8550cee6
Reviewed-on: https://go-review.googlesource.com/c/go/+/189798
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Daniel Martí
fanzha02
Keith Randall
David Chase
Jason A. Donenfeld
Alberto Donizetti
Constantin Konstantinidis
Xiangdong Ji
Josh Bleecher Snyder
Michael Munday
Russ Cox
smasher164
Brad Fitzpatrick
Ben Shi