mirror of
https://github.com/golang/go
synced 2024-11-24 18:40:14 -07:00
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
|
|
|
|
// Copyright 2021 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package codegen
|
|
|
|
func andn64(x, y int64) int64 {
|
|
// amd64/v3:"ANDNQ"
|
|
return x &^ y
|
|
}
|
|
|
|
func andn32(x, y int32) int32 {
|
|
// amd64/v3:"ANDNL"
|
|
return x &^ y
|
|
}
|
|
|
|
func blsi64(x int64) int64 {
|
|
// amd64/v3:"BLSIQ"
|
|
return x & -x
|
|
}
|
|
|
|
func blsi32(x int32) int32 {
|
|
// amd64/v3:"BLSIL"
|
|
return x & -x
|
|
}
|
|
|
|
func blsmsk64(x int64) int64 {
|
|
// amd64/v3:"BLSMSKQ"
|
|
return x ^ (x - 1)
|
|
}
|
|
|
|
func blsmsk32(x int32) int32 {
|
|
// amd64/v3:"BLSMSKL"
|
|
return x ^ (x - 1)
|
|
}
|
|
|
|
func blsr64(x int64) int64 {
|
|
// amd64/v3:"BLSRQ"
|
|
return x & (x - 1)
|
|
}
|
|
|
|
func blsr32(x int32) int32 {
|
|
// amd64/v3:"BLSRL"
|
|
return x & (x - 1)
|
|
}
|
|
|
|
func isPowerOfTwo64(x int64) bool {
|
|
// amd64/v3:"BLSRQ",-"TESTQ",-"CALL"
|
|
return blsr64(x) == 0
|
|
}
|
|
|
|
func isPowerOfTwo32(x int32) bool {
|
|
// amd64/v3:"BLSRL",-"TESTL",-"CALL"
|
|
return blsr32(x) == 0
|
|
}
|
|
|
|
func isPowerOfTwoSelect64(x, a, b int64) int64 {
|
|
var r int64
|
|
// amd64/v3:"BLSRQ",-"TESTQ",-"CALL"
|
|
if isPowerOfTwo64(x) {
|
|
r = a
|
|
} else {
|
|
r = b
|
|
}
|
|
// amd64/v3:"CMOVQEQ",-"TESTQ",-"CALL"
|
|
return r * 2 // force return blocks joining
|
|
}
|
|
|
|
func isPowerOfTwoSelect32(x, a, b int32) int32 {
|
|
var r int32
|
|
// amd64/v3:"BLSRL",-"TESTL",-"CALL"
|
|
if isPowerOfTwo32(x) {
|
|
r = a
|
|
} else {
|
|
r = b
|
|
}
|
|
// amd64/v3:"CMOVLEQ",-"TESTL",-"CALL"
|
|
return r * 2 // force return blocks joining
|
|
}
|
|
|
|
func isPowerOfTwoBranch64(x int64, a func(bool), b func(string)) {
|
|
// amd64/v3:"BLSRQ",-"TESTQ",-"CALL"
|
|
if isPowerOfTwo64(x) {
|
|
a(true)
|
|
} else {
|
|
b("false")
|
|
}
|
|
}
|
|
|
|
func isPowerOfTwoBranch32(x int32, a func(bool), b func(string)) {
|
|
// amd64/v3:"BLSRL",-"TESTL",-"CALL"
|
|
if isPowerOfTwo32(x) {
|
|
a(true)
|
|
} else {
|
|
b("false")
|
|
}
|
|
}
|
|
|
|
func isNotPowerOfTwo64(x int64) bool {
|
|
// amd64/v3:"BLSRQ",-"TESTQ",-"CALL"
|
|
return blsr64(x) != 0
|
|
}
|
|
|
|
func isNotPowerOfTwo32(x int32) bool {
|
|
// amd64/v3:"BLSRL",-"TESTL",-"CALL"
|
|
return blsr32(x) != 0
|
|
}
|
|
|
|
func isNotPowerOfTwoSelect64(x, a, b int64) int64 {
|
|
var r int64
|
|
// amd64/v3:"BLSRQ",-"TESTQ",-"CALL"
|
|
if isNotPowerOfTwo64(x) {
|
|
r = a
|
|
} else {
|
|
r = b
|
|
}
|
|
// amd64/v3:"CMOVQNE",-"TESTQ",-"CALL"
|
|
return r * 2 // force return blocks joining
|
|
}
|
|
|
|
func isNotPowerOfTwoSelect32(x, a, b int32) int32 {
|
|
var r int32
|
|
// amd64/v3:"BLSRL",-"TESTL",-"CALL"
|
|
if isNotPowerOfTwo32(x) {
|
|
r = a
|
|
} else {
|
|
r = b
|
|
}
|
|
// amd64/v3:"CMOVLNE",-"TESTL",-"CALL"
|
|
return r * 2 // force return blocks joining
|
|
}
|
|
|
|
func isNotPowerOfTwoBranch64(x int64, a func(bool), b func(string)) {
|
|
// amd64/v3:"BLSRQ",-"TESTQ",-"CALL"
|
|
if isNotPowerOfTwo64(x) {
|
|
a(true)
|
|
} else {
|
|
b("false")
|
|
}
|
|
}
|
|
|
|
func isNotPowerOfTwoBranch32(x int32, a func(bool), b func(string)) {
|
|
// amd64/v3:"BLSRL",-"TESTL",-"CALL"
|
|
if isNotPowerOfTwo32(x) {
|
|
a(true)
|
|
} else {
|
|
b("false")
|
|
}
|
|
}
|
|
|
|
func sarx64(x, y int64) int64 {
|
|
// amd64/v3:"SARXQ"
|
|
return x >> y
|
|
}
|
|
|
|
func sarx32(x, y int32) int32 {
|
|
// amd64/v3:"SARXL"
|
|
return x >> y
|
|
}
|
|
|
|
func sarx64_load(x []int64, i int) int64 {
|
|
// amd64/v3: `SARXQ\t[A-Z]+[0-9]*, \([A-Z]+[0-9]*\)\([A-Z]+[0-9]*\*8\), [A-Z]+[0-9]*`
|
|
s := x[i] >> (i & 63)
|
|
// amd64/v3: `SARXQ\t[A-Z]+[0-9]*, 8\([A-Z]+[0-9]*\)\([A-Z]+[0-9]*\*8\), [A-Z]+[0-9]*`
|
|
s = x[i+1] >> (s & 63)
|
|
return s
|
|
}
|
|
|
|
func sarx32_load(x []int32, i int) int32 {
|
|
// amd64/v3: `SARXL\t[A-Z]+[0-9]*, \([A-Z]+[0-9]*\)\([A-Z]+[0-9]*\*4\), [A-Z]+[0-9]*`
|
|
s := x[i] >> (i & 63)
|
|
// amd64/v3: `SARXL\t[A-Z]+[0-9]*, 4\([A-Z]+[0-9]*\)\([A-Z]+[0-9]*\*4\), [A-Z]+[0-9]*`
|
|
s = x[i+1] >> (s & 63)
|
|
return s
|
|
}
|
|
|
|
func shlrx64(x, y uint64) uint64 {
|
|
// amd64/v3:"SHRXQ"
|
|
s := x >> y
|
|
// amd64/v3:"SHLXQ"
|
|
s = s << y
|
|
return s
|
|
}
|
|
|
|
func shlrx32(x, y uint32) uint32 {
|
|
// amd64/v3:"SHRXL"
|
|
s := x >> y
|
|
// amd64/v3:"SHLXL"
|
|
s = s << y
|
|
return s
|
|
}
|
|
|
|
func shlrx64_load(x []uint64, i int, s uint64) uint64 {
|
|
// amd64/v3: `SHRXQ\t[A-Z]+[0-9]*, \([A-Z]+[0-9]*\)\([A-Z]+[0-9]*\*8\), [A-Z]+[0-9]*`
|
|
s = x[i] >> i
|
|
// amd64/v3: `SHLXQ\t[A-Z]+[0-9]*, 8\([A-Z]+[0-9]*\)\([A-Z]+[0-9]*\*8\), [A-Z]+[0-9]*`
|
|
s = x[i+1] << s
|
|
return s
|
|
}
|
|
|
|
func shlrx32_load(x []uint32, i int, s uint32) uint32 {
|
|
// amd64/v3: `SHRXL\t[A-Z]+[0-9]*, \([A-Z]+[0-9]*\)\([A-Z]+[0-9]*\*4\), [A-Z]+[0-9]*`
|
|
s = x[i] >> i
|
|
// amd64/v3: `SHLXL\t[A-Z]+[0-9]*, 4\([A-Z]+[0-9]*\)\([A-Z]+[0-9]*\*4\), [A-Z]+[0-9]*`
|
|
s = x[i+1] << s
|
|
return s
|
|
}
|