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go/test/codegen/mathbits.go
erifan01 204cc14bdd cmd/compile: implement non-constant rotates using ROR on arm64
Add some rules to match the Go code like:
	y &= 63
	x << y | x >> (64-y)
or
	y &= 63
	x >> y | x << (64-y)
as a ROR instruction. Make math/bits.RotateLeft faster on arm64.

Extends CL 132435 to arm64.

Benchmarks of math/bits.RotateLeftxxN:
name            old time/op       new time/op       delta
RotateLeft-8    3.548750ns +- 1%  2.003750ns +- 0%  -43.54%  (p=0.000 n=8+8)
RotateLeft8-8   3.925000ns +- 0%  3.925000ns +- 0%     ~     (p=1.000 n=8+8)
RotateLeft16-8  3.925000ns +- 0%  3.927500ns +- 0%     ~     (p=0.608 n=8+8)
RotateLeft32-8  3.925000ns +- 0%  2.002500ns +- 0%  -48.98%  (p=0.000 n=8+8)
RotateLeft64-8  3.536250ns +- 0%  2.003750ns +- 0%  -43.34%  (p=0.000 n=8+8)

Change-Id: I77622cd7f39b917427e060647321f5513973232c
Reviewed-on: https://go-review.googlesource.com/122542
Run-TryBot: Ben Shi <powerman1st@163.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2018-09-07 14:52:02 +00:00

305 lines
5.6 KiB
Go

// asmcheck
// Copyright 2018 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
import "math/bits"
// ----------------------- //
// bits.LeadingZeros //
// ----------------------- //
func LeadingZeros(n uint) int {
// amd64:"BSRQ"
// s390x:"FLOGR"
// arm:"CLZ" arm64:"CLZ"
// mips:"CLZ"
return bits.LeadingZeros(n)
}
func LeadingZeros64(n uint64) int {
// amd64:"BSRQ"
// s390x:"FLOGR"
// arm:"CLZ" arm64:"CLZ"
// mips:"CLZ"
return bits.LeadingZeros64(n)
}
func LeadingZeros32(n uint32) int {
// amd64:"BSRQ","LEAQ",-"CMOVQEQ"
// s390x:"FLOGR"
// arm:"CLZ" arm64:"CLZ"
// mips:"CLZ"
return bits.LeadingZeros32(n)
}
func LeadingZeros16(n uint16) int {
// amd64:"BSRL","LEAL",-"CMOVQEQ"
// s390x:"FLOGR"
// arm:"CLZ" arm64:"CLZ"
// mips:"CLZ"
return bits.LeadingZeros16(n)
}
func LeadingZeros8(n uint8) int {
// amd64:"BSRL","LEAL",-"CMOVQEQ"
// s390x:"FLOGR"
// arm:"CLZ" arm64:"CLZ"
// mips:"CLZ"
return bits.LeadingZeros8(n)
}
// --------------- //
// bits.Len* //
// --------------- //
func Len(n uint) int {
// amd64:"BSRQ"
// s390x:"FLOGR"
// arm:"CLZ" arm64:"CLZ"
// mips:"CLZ"
return bits.Len(n)
}
func Len64(n uint64) int {
// amd64:"BSRQ"
// s390x:"FLOGR"
// arm:"CLZ" arm64:"CLZ"
// mips:"CLZ"
return bits.Len64(n)
}
func Len32(n uint32) int {
// amd64:"BSRQ","LEAQ",-"CMOVQEQ"
// s390x:"FLOGR"
// arm:"CLZ" arm64:"CLZ"
// mips:"CLZ"
return bits.Len32(n)
}
func Len16(n uint16) int {
// amd64:"BSRL","LEAL",-"CMOVQEQ"
// s390x:"FLOGR"
// arm:"CLZ" arm64:"CLZ"
// mips:"CLZ"
return bits.Len16(n)
}
func Len8(n uint8) int {
// amd64:"BSRL","LEAL",-"CMOVQEQ"
// s390x:"FLOGR"
// arm:"CLZ" arm64:"CLZ"
// mips:"CLZ"
return bits.Len8(n)
}
// -------------------- //
// bits.OnesCount //
// -------------------- //
func OnesCount(n uint) int {
// amd64:"POPCNTQ",".*support_popcnt"
// arm64:"VCNT","VUADDLV"
// s390x:"POPCNT"
return bits.OnesCount(n)
}
func OnesCount64(n uint64) int {
// amd64:"POPCNTQ",".*support_popcnt"
// arm64:"VCNT","VUADDLV"
// s390x:"POPCNT"
return bits.OnesCount64(n)
}
func OnesCount32(n uint32) int {
// amd64:"POPCNTL",".*support_popcnt"
// arm64:"VCNT","VUADDLV"
// s390x:"POPCNT"
return bits.OnesCount32(n)
}
func OnesCount16(n uint16) int {
// amd64:"POPCNTL",".*support_popcnt"
// arm64:"VCNT","VUADDLV"
// s390x:"POPCNT"
return bits.OnesCount16(n)
}
func OnesCount8(n uint8) int {
// s390x:"POPCNT"
return bits.OnesCount8(n)
}
// ----------------------- //
// bits.ReverseBytes //
// ----------------------- //
func ReverseBytes(n uint) uint {
// amd64:"BSWAPQ"
// s390x:"MOVDBR"
// arm64:"REV"
return bits.ReverseBytes(n)
}
func ReverseBytes64(n uint64) uint64 {
// amd64:"BSWAPQ"
// s390x:"MOVDBR"
// arm64:"REV"
return bits.ReverseBytes64(n)
}
func ReverseBytes32(n uint32) uint32 {
// amd64:"BSWAPL"
// s390x:"MOVWBR"
// arm64:"REVW"
return bits.ReverseBytes32(n)
}
func ReverseBytes16(n uint16) uint16 {
// amd64:"ROLW"
return bits.ReverseBytes16(n)
}
// --------------------- //
// bits.RotateLeft //
// --------------------- //
func RotateLeft64(n uint64) uint64 {
// amd64:"ROLQ"
// arm64:"ROR"
// ppc64:"ROTL"
// s390x:"RLLG"
return bits.RotateLeft64(n, 37)
}
func RotateLeft32(n uint32) uint32 {
// amd64:"ROLL" 386:"ROLL"
// arm64:"RORW"
// ppc64:"ROTLW"
// s390x:"RLL"
return bits.RotateLeft32(n, 9)
}
func RotateLeft16(n uint16) uint16 {
// amd64:"ROLW" 386:"ROLW"
return bits.RotateLeft16(n, 5)
}
func RotateLeft8(n uint8) uint8 {
// amd64:"ROLB" 386:"ROLB"
return bits.RotateLeft8(n, 5)
}
func RotateLeftVariable(n uint, m int) uint {
// amd64:"ROLQ"
// arm64:"ROR"
// ppc64:"ROTL"
// s390x:"RLLG"
return bits.RotateLeft(n, m)
}
func RotateLeftVariable64(n uint64, m int) uint64 {
// amd64:"ROLQ"
// arm64:"ROR"
// ppc64:"ROTL"
// s390x:"RLLG"
return bits.RotateLeft64(n, m)
}
func RotateLeftVariable32(n uint32, m int) uint32 {
// amd64:"ROLL"
// arm64:"RORW"
// ppc64:"ROTLW"
// s390x:"RLL"
return bits.RotateLeft32(n, m)
}
// ------------------------ //
// bits.TrailingZeros //
// ------------------------ //
func TrailingZeros(n uint) int {
// amd64:"BSFQ","MOVL\t\\$64","CMOVQEQ"
// s390x:"FLOGR"
return bits.TrailingZeros(n)
}
func TrailingZeros64(n uint64) int {
// amd64:"BSFQ","MOVL\t\\$64","CMOVQEQ"
// s390x:"FLOGR"
return bits.TrailingZeros64(n)
}
func TrailingZeros32(n uint32) int {
// amd64:"BTSQ\\t\\$32","BSFQ"
// s390x:"FLOGR","MOVWZ"
return bits.TrailingZeros32(n)
}
func TrailingZeros16(n uint16) int {
// amd64:"BSFL","BTSL\\t\\$16"
// s390x:"FLOGR","OR\t\\$65536"
return bits.TrailingZeros16(n)
}
func TrailingZeros8(n uint8) int {
// amd64:"BSFL","BTSL\\t\\$8"
// s390x:"FLOGR","OR\t\\$256"
return bits.TrailingZeros8(n)
}
// IterateBitsNN checks special handling of TrailingZerosNN when the input is known to be non-zero.
func IterateBits(n uint) int {
i := 0
for n != 0 {
// amd64:"BSFQ",-"CMOVEQ"
i += bits.TrailingZeros(n)
n &= n - 1
}
return i
}
func IterateBits64(n uint64) int {
i := 0
for n != 0 {
// amd64:"BSFQ",-"CMOVEQ"
i += bits.TrailingZeros64(n)
n &= n - 1
}
return i
}
func IterateBits32(n uint32) int {
i := 0
for n != 0 {
// amd64:"BSFL",-"BTSQ"
i += bits.TrailingZeros32(n)
n &= n - 1
}
return i
}
func IterateBits16(n uint16) int {
i := 0
for n != 0 {
// amd64:"BSFL",-"BTSL"
i += bits.TrailingZeros16(n)
n &= n - 1
}
return i
}
func IterateBits8(n uint8) int {
i := 0
for n != 0 {
// amd64:"BSFL",-"BTSL"
i += bits.TrailingZeros8(n)
n &= n - 1
}
return i
}