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5c67ebbb31
With GOAMD64=V3 the canonical isPowerOfTwo function:
func isPowerOfTwo(x uintptr) bool {
return x&(x-1) == 0
}
Used to compile to:
temp := BLSR(x) // x&(x-1)
flags = TEST(temp, temp)
return flags.zf
However the blsr instruction already set ZF according to the result.
So we can remove the TEST instruction if we are just checking ZF.
Such as in multiple pieces of code around memory allocations.
This make the code smaller and faster.
Change-Id: Ia12d5a73aa3cb49188c0b647b1eff7b56c5a7b58
Reviewed-on: https://go-review.googlesource.com/c/go/+/448255
Run-TryBot: Jakub Ciolek <jakub@ciolek.dev>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
210 lines
4.2 KiB
Go
210 lines
4.2 KiB
Go
// asmcheck
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// Copyright 2021 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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func andn64(x, y int64) int64 {
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// amd64/v3:"ANDNQ"
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return x &^ y
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}
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func andn32(x, y int32) int32 {
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// amd64/v3:"ANDNL"
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return x &^ y
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}
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func blsi64(x int64) int64 {
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// amd64/v3:"BLSIQ"
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return x & -x
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}
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func blsi32(x int32) int32 {
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// amd64/v3:"BLSIL"
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return x & -x
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}
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func blsmsk64(x int64) int64 {
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// amd64/v3:"BLSMSKQ"
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return x ^ (x - 1)
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}
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func blsmsk32(x int32) int32 {
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// amd64/v3:"BLSMSKL"
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return x ^ (x - 1)
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}
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func blsr64(x int64) int64 {
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// amd64/v3:"BLSRQ"
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return x & (x - 1)
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}
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func blsr32(x int32) int32 {
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// amd64/v3:"BLSRL"
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return x & (x - 1)
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}
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func isPowerOfTwo64(x int64) bool {
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// amd64/v3:"BLSRQ",-"TESTQ",-"CALL"
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return blsr64(x) == 0
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}
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func isPowerOfTwo32(x int32) bool {
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// amd64/v3:"BLSRL",-"TESTL",-"CALL"
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return blsr32(x) == 0
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}
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func isPowerOfTwoSelect64(x, a, b int64) int64 {
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var r int64
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// amd64/v3:"BLSRQ",-"TESTQ",-"CALL"
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if isPowerOfTwo64(x) {
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r = a
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} else {
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r = b
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}
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// amd64/v3:"CMOVQEQ",-"TESTQ",-"CALL"
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return r * 2 // force return blocks joining
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}
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func isPowerOfTwoSelect32(x, a, b int32) int32 {
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var r int32
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// amd64/v3:"BLSRL",-"TESTL",-"CALL"
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if isPowerOfTwo32(x) {
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r = a
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} else {
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r = b
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}
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// amd64/v3:"CMOVLEQ",-"TESTL",-"CALL"
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return r * 2 // force return blocks joining
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}
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func isPowerOfTwoBranch64(x int64, a func(bool), b func(string)) {
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// amd64/v3:"BLSRQ",-"TESTQ",-"CALL"
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if isPowerOfTwo64(x) {
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a(true)
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} else {
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b("false")
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}
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}
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func isPowerOfTwoBranch32(x int32, a func(bool), b func(string)) {
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// amd64/v3:"BLSRL",-"TESTL",-"CALL"
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if isPowerOfTwo32(x) {
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a(true)
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} else {
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b("false")
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}
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}
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func isNotPowerOfTwo64(x int64) bool {
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// amd64/v3:"BLSRQ",-"TESTQ",-"CALL"
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return blsr64(x) != 0
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}
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func isNotPowerOfTwo32(x int32) bool {
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// amd64/v3:"BLSRL",-"TESTL",-"CALL"
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return blsr32(x) != 0
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}
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func isNotPowerOfTwoSelect64(x, a, b int64) int64 {
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var r int64
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// amd64/v3:"BLSRQ",-"TESTQ",-"CALL"
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if isNotPowerOfTwo64(x) {
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r = a
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} else {
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r = b
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}
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// amd64/v3:"CMOVQNE",-"TESTQ",-"CALL"
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return r * 2 // force return blocks joining
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}
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func isNotPowerOfTwoSelect32(x, a, b int32) int32 {
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var r int32
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// amd64/v3:"BLSRL",-"TESTL",-"CALL"
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if isNotPowerOfTwo32(x) {
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r = a
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} else {
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r = b
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}
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// amd64/v3:"CMOVLNE",-"TESTL",-"CALL"
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return r * 2 // force return blocks joining
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}
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func isNotPowerOfTwoBranch64(x int64, a func(bool), b func(string)) {
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// amd64/v3:"BLSRQ",-"TESTQ",-"CALL"
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if isNotPowerOfTwo64(x) {
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a(true)
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} else {
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b("false")
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}
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}
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func isNotPowerOfTwoBranch32(x int32, a func(bool), b func(string)) {
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// amd64/v3:"BLSRL",-"TESTL",-"CALL"
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if isNotPowerOfTwo32(x) {
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a(true)
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} else {
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b("false")
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}
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}
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func sarx64(x, y int64) int64 {
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// amd64/v3:"SARXQ"
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return x >> y
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}
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func sarx32(x, y int32) int32 {
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// amd64/v3:"SARXL"
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return x >> y
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}
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func sarx64_load(x []int64, i int) int64 {
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// amd64/v3: `SARXQ\t[A-Z]+[0-9]*, \([A-Z]+[0-9]*\)\([A-Z]+[0-9]*\*8\), [A-Z]+[0-9]*`
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s := x[i] >> (i & 63)
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// amd64/v3: `SARXQ\t[A-Z]+[0-9]*, 8\([A-Z]+[0-9]*\)\([A-Z]+[0-9]*\*8\), [A-Z]+[0-9]*`
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s = x[i+1] >> (s & 63)
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return s
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}
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func sarx32_load(x []int32, i int) int32 {
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// amd64/v3: `SARXL\t[A-Z]+[0-9]*, \([A-Z]+[0-9]*\)\([A-Z]+[0-9]*\*4\), [A-Z]+[0-9]*`
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s := x[i] >> (i & 63)
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// amd64/v3: `SARXL\t[A-Z]+[0-9]*, 4\([A-Z]+[0-9]*\)\([A-Z]+[0-9]*\*4\), [A-Z]+[0-9]*`
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s = x[i+1] >> (s & 63)
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return s
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}
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func shlrx64(x, y uint64) uint64 {
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// amd64/v3:"SHRXQ"
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s := x >> y
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// amd64/v3:"SHLXQ"
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s = s << y
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return s
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}
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func shlrx32(x, y uint32) uint32 {
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// amd64/v3:"SHRXL"
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s := x >> y
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// amd64/v3:"SHLXL"
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s = s << y
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return s
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}
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func shlrx64_load(x []uint64, i int, s uint64) uint64 {
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// amd64/v3: `SHRXQ\t[A-Z]+[0-9]*, \([A-Z]+[0-9]*\)\([A-Z]+[0-9]*\*8\), [A-Z]+[0-9]*`
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s = x[i] >> i
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// amd64/v3: `SHLXQ\t[A-Z]+[0-9]*, 8\([A-Z]+[0-9]*\)\([A-Z]+[0-9]*\*8\), [A-Z]+[0-9]*`
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s = x[i+1] << s
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return s
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}
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func shlrx32_load(x []uint32, i int, s uint32) uint32 {
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// amd64/v3: `SHRXL\t[A-Z]+[0-9]*, \([A-Z]+[0-9]*\)\([A-Z]+[0-9]*\*4\), [A-Z]+[0-9]*`
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s = x[i] >> i
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// amd64/v3: `SHLXL\t[A-Z]+[0-9]*, 4\([A-Z]+[0-9]*\)\([A-Z]+[0-9]*\*4\), [A-Z]+[0-9]*`
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s = x[i+1] << s
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return s
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}
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