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https://github.com/golang/go
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815509ae31
This change includes the following: - Generate LXV/STXV sequences instead of LXVD2X/STXVD2X on power9. These instructions do not require an index register, which allows more loads and stores within a loop without initializing multiple index registers. The LoweredQuadXXX generate LXV/STXV. - Create LoweredMoveXXXShort and LoweredZeroXXXShort for short moves that don't generate loops, and therefore don't clobber the address registers or flags. - Use registers other than R3 and R4 to avoid conflicting with registers that have already been allocated to avoid unnecessary register moves. - Eliminate the use of R14 as scratch register and use R31 instead. - Add PCALIGN when the LoweredMoveXXX or LoweredZeroXXX generates a loop with more than 3 iterations. This performance opportunity was noticed in github.com/golang/snappy benchmarks. Results on power9: WordsDecode1e1 54.1ns ± 0% 53.8ns ± 0% -0.51% (p=0.029 n=4+4) WordsDecode1e2 287ns ± 0% 282ns ± 1% -1.83% (p=0.029 n=4+4) WordsDecode1e3 3.98µs ± 0% 3.64µs ± 0% -8.52% (p=0.029 n=4+4) WordsDecode1e4 66.9µs ± 0% 67.0µs ± 0% +0.20% (p=0.029 n=4+4) WordsDecode1e5 723µs ± 0% 723µs ± 0% -0.01% (p=0.200 n=4+4) WordsDecode1e6 7.21ms ± 0% 7.21ms ± 0% -0.02% (p=1.000 n=4+4) WordsEncode1e1 29.9ns ± 0% 29.4ns ± 0% -1.51% (p=0.029 n=4+4) WordsEncode1e2 2.12µs ± 0% 1.75µs ± 0% -17.70% (p=0.029 n=4+4) WordsEncode1e3 11.7µs ± 0% 11.2µs ± 0% -4.61% (p=0.029 n=4+4) WordsEncode1e4 119µs ± 0% 120µs ± 0% +0.36% (p=0.029 n=4+4) WordsEncode1e5 1.21ms ± 0% 1.22ms ± 0% +0.41% (p=0.029 n=4+4) WordsEncode1e6 12.0ms ± 0% 12.0ms ± 0% +0.57% (p=0.029 n=4+4) RandomEncode 286µs ± 0% 203µs ± 0% -28.82% (p=0.029 n=4+4) ExtendMatch 47.4µs ± 0% 47.0µs ± 0% -0.85% (p=0.029 n=4+4) Change-Id: Iecad3a39ae55280286e42760a5c9d5c1168f5858 Reviewed-on: https://go-review.googlesource.com/c/go/+/226539 Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
125 lines
2.6 KiB
Go
125 lines
2.6 KiB
Go
// asmcheck
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// Copyright 2018 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package codegen
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import "runtime"
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// Check small copies are replaced with moves.
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func movesmall4() {
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x := [...]byte{1, 2, 3, 4}
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// 386:-".*memmove"
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// amd64:-".*memmove"
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// arm:-".*memmove"
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// arm64:-".*memmove"
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// ppc64:-".*memmove"
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// ppc64le:-".*memmove"
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copy(x[1:], x[:])
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}
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func movesmall7() {
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x := [...]byte{1, 2, 3, 4, 5, 6, 7}
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// 386:-".*memmove"
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// amd64:-".*memmove"
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// arm64:-".*memmove"
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// ppc64:-".*memmove"
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// ppc64le:-".*memmove"
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copy(x[1:], x[:])
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}
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func movesmall16() {
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x := [...]byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}
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// amd64:-".*memmove"
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// ppc64:".*memmove"
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// ppc64le:".*memmove"
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copy(x[1:], x[:])
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}
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var x [256]byte
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// Check that large disjoint copies are replaced with moves.
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func moveDisjointStack32() {
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var s [32]byte
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// ppc64:-".*memmove"
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// ppc64le:-".*memmove"
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// ppc64le/power8:"LXVD2X",-"ADD",-"BC"
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// ppc64le/power9:"LXV",-"LXVD2X",-"ADD",-"BC"
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copy(s[:], x[:32])
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runtime.KeepAlive(&s)
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}
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func moveDisjointStack64() {
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var s [96]byte
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// ppc64:-".*memmove"
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// ppc64le:-".*memmove"
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// ppc64le/power8:"LXVD2X","ADD","BC"
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// ppc64le/power9:"LXV",-"LXVD2X",-"ADD",-"BC"
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copy(s[:], x[:96])
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runtime.KeepAlive(&s)
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}
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func moveDisjointStack() {
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var s [256]byte
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// s390x:-".*memmove"
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// amd64:-".*memmove"
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// ppc64:-".*memmove"
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// ppc64le:-".*memmove"
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// ppc64le/power8:"LXVD2X"
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// ppc64le/power9:"LXV",-"LXVD2X"
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copy(s[:], x[:])
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runtime.KeepAlive(&s)
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}
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func moveDisjointArg(b *[256]byte) {
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var s [256]byte
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// s390x:-".*memmove"
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// amd64:-".*memmove"
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// ppc64:-".*memmove"
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// ppc64le:-".*memmove"
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// ppc64le/power8:"LXVD2X"
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// ppc64le/power9:"LXV",-"LXVD2X"
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copy(s[:], b[:])
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runtime.KeepAlive(&s)
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}
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func moveDisjointNoOverlap(a *[256]byte) {
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// s390x:-".*memmove"
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// amd64:-".*memmove"
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// ppc64:-".*memmove"
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// ppc64le:-".*memmove"
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// ppc64le/power8:"LXVD2X"
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// ppc64le/power9:"LXV",-"LXVD2X"
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copy(a[:], a[128:])
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}
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// Check that no branches are generated when the pointers are [not] equal.
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func ptrEqual() {
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// amd64:-"JEQ",-"JNE"
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// ppc64:-"BEQ",-"BNE"
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// ppc64le:-"BEQ",-"BNE"
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// s390x:-"BEQ",-"BNE"
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copy(x[:], x[:])
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}
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func ptrOneOffset() {
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// amd64:-"JEQ",-"JNE"
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// ppc64:-"BEQ",-"BNE"
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// ppc64le:-"BEQ",-"BNE"
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// s390x:-"BEQ",-"BNE"
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copy(x[1:], x[:])
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}
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func ptrBothOffset() {
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// amd64:-"JEQ",-"JNE"
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// ppc64:-"BEQ",-"BNE"
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// ppc64le:-"BEQ",-"BNE"
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// s390x:-"BEQ",-"BNE"
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copy(x[1:], x[2:])
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}
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