fanzha02
6efd51c6b7
cmd/compile: change the condition flags of floating-point comparisons in arm64 backend
...
Current compiler reverses operands to work around NaN in
"less than" and "less equal than" comparisons. But if we
want to use "FCMPD/FCMPS $(0.0), Fn" to do some optimization,
the workaround way does not work. Because assembler does
not support instruction "FCMPD/FCMPS Fn, $(0.0)".
This CL sets condition flags for floating-point comparisons
to resolve this problem.
Change-Id: Ia48076a1da95da64596d6e68304018cb301ebe33
Reviewed-on: https://go-review.googlesource.com/c/go/+/164718
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-03-07 21:23:52 +00:00
Keith Randall
0b79dde112
cmd/compile: don't use CMOV ops to compute load addresses
...
We want to issue loads as soon as possible, especially when they
are going to miss in the cache. Using a conditional move (CMOV) here:
i := ...
if cond {
i++
}
... = a[i]
means that we have to wait for cond to be computed before the load
is issued. Without a CMOV, if the branch is predicted correctly the
load can be issued in parallel with computing cond.
Even if the branch is predicted incorrectly, maybe the speculative
load is close to the real load, and we get a prefetch for free.
In the worst case, when the prediction is wrong and the address is
way off, we only lose by the time difference between the CMOV
latency (~2 cycles) and the mispredict restart latency (~15 cycles).
We only squash CMOVs that affect load addresses. Results of CMOVs
that are used for other things (store addresses, store values) we
use as before.
Fixes #26306
Change-Id: I82ca14b664bf05e1d45e58de8c4d9c775a127ca1
Reviewed-on: https://go-review.googlesource.com/c/145717
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
2018-11-27 17:22:37 +00:00
Giovanni Bajo
e7b1d0a9cf
test: add missing copyright header
...
Change-Id: Ia64535492515f725fe3c4b59ea300363a0c4ce10
Reviewed-on: https://go-review.googlesource.com/107136
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-04-15 21:17:54 +00:00
Giovanni Bajo
a35ec9a59e
cmd/compile: implement CMOV on amd64
...
This builds upon the branchelim pass, activating it for amd64 and
lowering CondSelect. Special care is made to FPU instructions for
NaN handling.
Benchmark results on Xeon E5630 (Westmere EP):
name old time/op new time/op delta
BinaryTree17-16 4.99s ± 9% 4.66s ± 2% ~ (p=0.095 n=5+5)
Fannkuch11-16 4.93s ± 3% 5.04s ± 2% ~ (p=0.548 n=5+5)
FmtFprintfEmpty-16 58.8ns ± 7% 61.4ns ±14% ~ (p=0.579 n=5+5)
FmtFprintfString-16 114ns ± 2% 114ns ± 4% ~ (p=0.603 n=5+5)
FmtFprintfInt-16 181ns ± 4% 125ns ± 3% -30.90% (p=0.008 n=5+5)
FmtFprintfIntInt-16 263ns ± 2% 217ns ± 2% -17.34% (p=0.008 n=5+5)
FmtFprintfPrefixedInt-16 230ns ± 1% 212ns ± 1% -7.99% (p=0.008 n=5+5)
FmtFprintfFloat-16 411ns ± 3% 344ns ± 5% -16.43% (p=0.008 n=5+5)
FmtManyArgs-16 828ns ± 4% 790ns ± 2% -4.59% (p=0.032 n=5+5)
GobDecode-16 10.9ms ± 4% 10.8ms ± 5% ~ (p=0.548 n=5+5)
GobEncode-16 9.52ms ± 5% 9.46ms ± 2% ~ (p=1.000 n=5+5)
Gzip-16 334ms ± 2% 337ms ± 2% ~ (p=0.548 n=5+5)
Gunzip-16 64.4ms ± 1% 65.0ms ± 1% +1.00% (p=0.008 n=5+5)
HTTPClientServer-16 156µs ± 3% 155µs ± 3% ~ (p=0.690 n=5+5)
JSONEncode-16 21.0ms ± 1% 21.8ms ± 0% +3.76% (p=0.016 n=5+4)
JSONDecode-16 95.1ms ± 0% 95.7ms ± 1% ~ (p=0.151 n=5+5)
Mandelbrot200-16 6.38ms ± 1% 6.42ms ± 1% ~ (p=0.095 n=5+5)
GoParse-16 5.47ms ± 2% 5.36ms ± 1% -1.95% (p=0.016 n=5+5)
RegexpMatchEasy0_32-16 111ns ± 1% 111ns ± 1% ~ (p=0.635 n=5+4)
RegexpMatchEasy0_1K-16 408ns ± 1% 411ns ± 2% ~ (p=0.087 n=5+5)
RegexpMatchEasy1_32-16 103ns ± 1% 104ns ± 1% ~ (p=0.484 n=5+5)
RegexpMatchEasy1_1K-16 659ns ± 2% 652ns ± 1% ~ (p=0.571 n=5+5)
RegexpMatchMedium_32-16 176ns ± 2% 174ns ± 1% ~ (p=0.476 n=5+5)
RegexpMatchMedium_1K-16 58.6µs ± 4% 57.7µs ± 4% ~ (p=0.548 n=5+5)
RegexpMatchHard_32-16 3.07µs ± 3% 3.04µs ± 4% ~ (p=0.421 n=5+5)
RegexpMatchHard_1K-16 89.2µs ± 1% 87.9µs ± 2% -1.52% (p=0.032 n=5+5)
Revcomp-16 575ms ± 0% 587ms ± 2% +2.12% (p=0.032 n=4+5)
Template-16 110ms ± 1% 107ms ± 3% -3.00% (p=0.032 n=5+5)
TimeParse-16 463ns ± 0% 462ns ± 0% ~ (p=0.810 n=5+4)
TimeFormat-16 538ns ± 0% 535ns ± 0% -0.63% (p=0.024 n=5+5)
name old speed new speed delta
GobDecode-16 70.7MB/s ± 4% 71.4MB/s ± 5% ~ (p=0.452 n=5+5)
GobEncode-16 80.7MB/s ± 5% 81.2MB/s ± 2% ~ (p=1.000 n=5+5)
Gzip-16 58.2MB/s ± 2% 57.7MB/s ± 2% ~ (p=0.452 n=5+5)
Gunzip-16 302MB/s ± 1% 299MB/s ± 1% -0.99% (p=0.008 n=5+5)
JSONEncode-16 92.4MB/s ± 1% 89.1MB/s ± 0% -3.63% (p=0.016 n=5+4)
JSONDecode-16 20.4MB/s ± 0% 20.3MB/s ± 1% ~ (p=0.135 n=5+5)
GoParse-16 10.6MB/s ± 2% 10.8MB/s ± 1% +2.00% (p=0.016 n=5+5)
RegexpMatchEasy0_32-16 286MB/s ± 1% 285MB/s ± 3% ~ (p=1.000 n=5+5)
RegexpMatchEasy0_1K-16 2.51GB/s ± 1% 2.49GB/s ± 2% ~ (p=0.095 n=5+5)
RegexpMatchEasy1_32-16 309MB/s ± 1% 307MB/s ± 1% ~ (p=0.548 n=5+5)
RegexpMatchEasy1_1K-16 1.55GB/s ± 2% 1.57GB/s ± 1% ~ (p=0.690 n=5+5)
RegexpMatchMedium_32-16 5.68MB/s ± 2% 5.73MB/s ± 1% ~ (p=0.579 n=5+5)
RegexpMatchMedium_1K-16 17.5MB/s ± 4% 17.8MB/s ± 4% ~ (p=0.500 n=5+5)
RegexpMatchHard_32-16 10.4MB/s ± 3% 10.5MB/s ± 4% ~ (p=0.460 n=5+5)
RegexpMatchHard_1K-16 11.5MB/s ± 1% 11.7MB/s ± 2% +1.57% (p=0.032 n=5+5)
Revcomp-16 442MB/s ± 0% 433MB/s ± 2% -2.05% (p=0.032 n=4+5)
Template-16 17.7MB/s ± 1% 18.2MB/s ± 3% +3.12% (p=0.032 n=5+5)
Change-Id: I6972e8f35f2b31f9a42ac473a6bf419a18022558
Reviewed-on: https://go-review.googlesource.com/100935
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-15 16:41:59 +00:00
Ilya Tocar
644d14ea0f
Revert "cmd/compile: implement CMOV on amd64"
...
This reverts commit 080187f4f7https://go-review.googlesource.com/100755
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2018-03-14 21:21:23 +00:00
Giovanni Bajo
080187f4f7
cmd/compile: implement CMOV on amd64
...
This builds upon the branchelim pass, activating it for amd64 and
lowering CondSelect. Special care is made to FPU instructions for
NaN handling.
Benchmark results on Xeon E5630 (Westmere EP):
name old time/op new time/op delta
BinaryTree17-16 4.99s ± 9% 4.66s ± 2% ~ (p=0.095 n=5+5)
Fannkuch11-16 4.93s ± 3% 5.04s ± 2% ~ (p=0.548 n=5+5)
FmtFprintfEmpty-16 58.8ns ± 7% 61.4ns ±14% ~ (p=0.579 n=5+5)
FmtFprintfString-16 114ns ± 2% 114ns ± 4% ~ (p=0.603 n=5+5)
FmtFprintfInt-16 181ns ± 4% 125ns ± 3% -30.90% (p=0.008 n=5+5)
FmtFprintfIntInt-16 263ns ± 2% 217ns ± 2% -17.34% (p=0.008 n=5+5)
FmtFprintfPrefixedInt-16 230ns ± 1% 212ns ± 1% -7.99% (p=0.008 n=5+5)
FmtFprintfFloat-16 411ns ± 3% 344ns ± 5% -16.43% (p=0.008 n=5+5)
FmtManyArgs-16 828ns ± 4% 790ns ± 2% -4.59% (p=0.032 n=5+5)
GobDecode-16 10.9ms ± 4% 10.8ms ± 5% ~ (p=0.548 n=5+5)
GobEncode-16 9.52ms ± 5% 9.46ms ± 2% ~ (p=1.000 n=5+5)
Gzip-16 334ms ± 2% 337ms ± 2% ~ (p=0.548 n=5+5)
Gunzip-16 64.4ms ± 1% 65.0ms ± 1% +1.00% (p=0.008 n=5+5)
HTTPClientServer-16 156µs ± 3% 155µs ± 3% ~ (p=0.690 n=5+5)
JSONEncode-16 21.0ms ± 1% 21.8ms ± 0% +3.76% (p=0.016 n=5+4)
JSONDecode-16 95.1ms ± 0% 95.7ms ± 1% ~ (p=0.151 n=5+5)
Mandelbrot200-16 6.38ms ± 1% 6.42ms ± 1% ~ (p=0.095 n=5+5)
GoParse-16 5.47ms ± 2% 5.36ms ± 1% -1.95% (p=0.016 n=5+5)
RegexpMatchEasy0_32-16 111ns ± 1% 111ns ± 1% ~ (p=0.635 n=5+4)
RegexpMatchEasy0_1K-16 408ns ± 1% 411ns ± 2% ~ (p=0.087 n=5+5)
RegexpMatchEasy1_32-16 103ns ± 1% 104ns ± 1% ~ (p=0.484 n=5+5)
RegexpMatchEasy1_1K-16 659ns ± 2% 652ns ± 1% ~ (p=0.571 n=5+5)
RegexpMatchMedium_32-16 176ns ± 2% 174ns ± 1% ~ (p=0.476 n=5+5)
RegexpMatchMedium_1K-16 58.6µs ± 4% 57.7µs ± 4% ~ (p=0.548 n=5+5)
RegexpMatchHard_32-16 3.07µs ± 3% 3.04µs ± 4% ~ (p=0.421 n=5+5)
RegexpMatchHard_1K-16 89.2µs ± 1% 87.9µs ± 2% -1.52% (p=0.032 n=5+5)
Revcomp-16 575ms ± 0% 587ms ± 2% +2.12% (p=0.032 n=4+5)
Template-16 110ms ± 1% 107ms ± 3% -3.00% (p=0.032 n=5+5)
TimeParse-16 463ns ± 0% 462ns ± 0% ~ (p=0.810 n=5+4)
TimeFormat-16 538ns ± 0% 535ns ± 0% -0.63% (p=0.024 n=5+5)
name old speed new speed delta
GobDecode-16 70.7MB/s ± 4% 71.4MB/s ± 5% ~ (p=0.452 n=5+5)
GobEncode-16 80.7MB/s ± 5% 81.2MB/s ± 2% ~ (p=1.000 n=5+5)
Gzip-16 58.2MB/s ± 2% 57.7MB/s ± 2% ~ (p=0.452 n=5+5)
Gunzip-16 302MB/s ± 1% 299MB/s ± 1% -0.99% (p=0.008 n=5+5)
JSONEncode-16 92.4MB/s ± 1% 89.1MB/s ± 0% -3.63% (p=0.016 n=5+4)
JSONDecode-16 20.4MB/s ± 0% 20.3MB/s ± 1% ~ (p=0.135 n=5+5)
GoParse-16 10.6MB/s ± 2% 10.8MB/s ± 1% +2.00% (p=0.016 n=5+5)
RegexpMatchEasy0_32-16 286MB/s ± 1% 285MB/s ± 3% ~ (p=1.000 n=5+5)
RegexpMatchEasy0_1K-16 2.51GB/s ± 1% 2.49GB/s ± 2% ~ (p=0.095 n=5+5)
RegexpMatchEasy1_32-16 309MB/s ± 1% 307MB/s ± 1% ~ (p=0.548 n=5+5)
RegexpMatchEasy1_1K-16 1.55GB/s ± 2% 1.57GB/s ± 1% ~ (p=0.690 n=5+5)
RegexpMatchMedium_32-16 5.68MB/s ± 2% 5.73MB/s ± 1% ~ (p=0.579 n=5+5)
RegexpMatchMedium_1K-16 17.5MB/s ± 4% 17.8MB/s ± 4% ~ (p=0.500 n=5+5)
RegexpMatchHard_32-16 10.4MB/s ± 3% 10.5MB/s ± 4% ~ (p=0.460 n=5+5)
RegexpMatchHard_1K-16 11.5MB/s ± 1% 11.7MB/s ± 2% +1.57% (p=0.032 n=5+5)
Revcomp-16 442MB/s ± 0% 433MB/s ± 2% -2.05% (p=0.032 n=4+5)
Template-16 17.7MB/s ± 1% 18.2MB/s ± 3% +3.12% (p=0.032 n=5+5)
Change-Id: Ic7cb7374d07da031e771bdcbfdd832fd1b17159c
Reviewed-on: https://go-review.googlesource.com/98695
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
2018-03-12 18:01:33 +00:00
