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go/test/codegen/mathbits.go
erifan01 4e2b0dda8c cmd/compile: eliminate unnecessary type conversions in TrailingZeros(16|8) for arm64
This CL eliminates unnecessary type conversion operations: OpZeroExt16to64 and OpZeroExt8to64.
If the input argrument is a nonzero value, then ORconst operation can also be eliminated.

Benchmarks:

name               old time/op  new time/op  delta
TrailingZeros-8    2.75ns ± 0%  2.75ns ± 0%     ~     (all equal)
TrailingZeros8-8   3.49ns ± 1%  2.93ns ± 0%  -16.00%  (p=0.000 n=10+10)
TrailingZeros16-8  3.49ns ± 1%  2.93ns ± 0%  -16.05%  (p=0.000 n=9+10)
TrailingZeros32-8  2.67ns ± 1%  2.68ns ± 1%     ~     (p=0.468 n=10+10)
TrailingZeros64-8  2.67ns ± 1%  2.65ns ± 0%   -0.62%  (p=0.022 n=10+9)

code:

func f16(x uint) { z = bits.TrailingZeros16(uint16(x)) }

Before:

"".f16 STEXT size=48 args=0x8 locals=0x0 leaf
        0x0000 00000 (test.go:7)        TEXT    "".f16(SB), LEAF|NOFRAME|ABIInternal, $0-8
        0x0000 00000 (test.go:7)        FUNCDATA        ZR, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
        0x0000 00000 (test.go:7)        FUNCDATA        $1, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
        0x0000 00000 (test.go:7)        FUNCDATA        $3, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
        0x0000 00000 (test.go:7)        PCDATA  $2, ZR
        0x0000 00000 (test.go:7)        PCDATA  ZR, ZR
        0x0000 00000 (test.go:7)        MOVD    "".x(FP), R0
        0x0004 00004 (test.go:7)        MOVHU   R0, R0
        0x0008 00008 (test.go:7)        ORR     $65536, R0, R0
        0x000c 00012 (test.go:7)        RBIT    R0, R0
        0x0010 00016 (test.go:7)        CLZ     R0, R0
        0x0014 00020 (test.go:7)        MOVD    R0, "".z(SB)
        0x0020 00032 (test.go:7)        RET     (R30)

This line of code is unnecessary:
        0x0004 00004 (test.go:7)        MOVHU   R0, R0

After:

"".f16 STEXT size=32 args=0x8 locals=0x0 leaf
        0x0000 00000 (test.go:7)        TEXT    "".f16(SB), LEAF|NOFRAME|ABIInternal, $0-8
        0x0000 00000 (test.go:7)        FUNCDATA        ZR, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
        0x0000 00000 (test.go:7)        FUNCDATA        $1, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
        0x0000 00000 (test.go:7)        FUNCDATA        $3, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
        0x0000 00000 (test.go:7)        PCDATA  $2, ZR
        0x0000 00000 (test.go:7)        PCDATA  ZR, ZR
        0x0000 00000 (test.go:7)        MOVD    "".x(FP), R0
        0x0004 00004 (test.go:7)        ORR     $65536, R0, R0
        0x0008 00008 (test.go:7)        RBITW   R0, R0
        0x000c 00012 (test.go:7)        CLZW    R0, R0
        0x0010 00016 (test.go:7)        MOVD    R0, "".z(SB)
        0x001c 00028 (test.go:7)        RET     (R30)

The situation of TrailingZeros8 is similar to TrailingZeros16.

Change-Id: I473bdca06be8460a0be87abbae6fe640017e4c9d
Reviewed-on: https://go-review.googlesource.com/c/go/+/156999
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-03-07 14:24:56 +00:00

498 lines
9.8 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:"CLZW"
// 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",".*x86HasPOPCNT"
// arm64:"VCNT","VUADDLV"
// s390x:"POPCNT"
// ppc64:"POPCNTD"
// ppc64le:"POPCNTD"
return bits.OnesCount(n)
}
func OnesCount64(n uint64) int {
// amd64:"POPCNTQ",".*x86HasPOPCNT"
// arm64:"VCNT","VUADDLV"
// s390x:"POPCNT"
// ppc64:"POPCNTD"
// ppc64le:"POPCNTD"
return bits.OnesCount64(n)
}
func OnesCount32(n uint32) int {
// amd64:"POPCNTL",".*x86HasPOPCNT"
// arm64:"VCNT","VUADDLV"
// s390x:"POPCNT"
// ppc64:"POPCNTW"
// ppc64le:"POPCNTW"
return bits.OnesCount32(n)
}
func OnesCount16(n uint16) int {
// amd64:"POPCNTL",".*x86HasPOPCNT"
// arm64:"VCNT","VUADDLV"
// s390x:"POPCNT"
// ppc64:"POPCNTW"
// ppc64le:"POPCNTW"
return bits.OnesCount16(n)
}
func OnesCount8(n uint8) int {
// s390x:"POPCNT"
// ppc64:"POPCNTB"
// ppc64le:"POPCNTB"
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"
// arm64:"REV16W",-"UBFX",-"ORR"
// arm/5:"SLL","SRL","ORR"
// arm/6:"REV16"
// arm/7:"REV16"
return bits.ReverseBytes16(n)
}
// --------------------- //
// bits.RotateLeft //
// --------------------- //
func RotateLeft64(n uint64) uint64 {
// amd64:"ROLQ"
// arm64:"ROR"
// ppc64:"ROTL"
// ppc64le:"ROTL"
// s390x:"RLLG"
return bits.RotateLeft64(n, 37)
}
func RotateLeft32(n uint32) uint32 {
// amd64:"ROLL" 386:"ROLL"
// arm64:"RORW"
// ppc64:"ROTLW"
// ppc64le:"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"
// ppc64le:"ROTL"
// s390x:"RLLG"
return bits.RotateLeft(n, m)
}
func RotateLeftVariable64(n uint64, m int) uint64 {
// amd64:"ROLQ"
// arm64:"ROR"
// ppc64:"ROTL"
// ppc64le:"ROTL"
// s390x:"RLLG"
return bits.RotateLeft64(n, m)
}
func RotateLeftVariable32(n uint32, m int) uint32 {
// amd64:"ROLL"
// arm64:"RORW"
// ppc64:"ROTLW"
// ppc64le:"ROTLW"
// s390x:"RLL"
return bits.RotateLeft32(n, m)
}
// ------------------------ //
// bits.TrailingZeros //
// ------------------------ //
func TrailingZeros(n uint) int {
// amd64:"BSFQ","MOVL\t\\$64","CMOVQEQ"
// arm64:"RBIT","CLZ"
// s390x:"FLOGR"
// ppc64:"ANDN","POPCNTD"
// ppc64le:"ANDN","POPCNTD"
return bits.TrailingZeros(n)
}
func TrailingZeros64(n uint64) int {
// amd64:"BSFQ","MOVL\t\\$64","CMOVQEQ"
// arm64:"RBIT","CLZ"
// s390x:"FLOGR"
// ppc64:"ANDN","POPCNTD"
// ppc64le:"ANDN","POPCNTD"
return bits.TrailingZeros64(n)
}
func TrailingZeros32(n uint32) int {
// amd64:"BTSQ\\t\\$32","BSFQ"
// arm64:"RBITW","CLZW"
// s390x:"FLOGR","MOVWZ"
// ppc64:"ANDN","POPCNTW"
// ppc64le:"ANDN","POPCNTW"
return bits.TrailingZeros32(n)
}
func TrailingZeros16(n uint16) int {
// amd64:"BSFL","BTSL\\t\\$16"
// arm64:"ORR\t\\$65536","RBITW","CLZW",-"MOVHU\tR",-"RBIT\t",-"CLZ\t"
// s390x:"FLOGR","OR\t\\$65536"
// ppc64:"POPCNTD","OR\\t\\$65536"
// ppc64le:"POPCNTD","OR\\t\\$65536"
return bits.TrailingZeros16(n)
}
func TrailingZeros8(n uint8) int {
// amd64:"BSFL","BTSL\\t\\$8"
// arm64:"ORR\t\\$256","RBITW","CLZW",-"MOVBU\tR",-"RBIT\t",-"CLZ\t"
// 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"
// arm64:"RBITW","CLZW",-"ORR"
i += bits.TrailingZeros16(n)
n &= n - 1
}
return i
}
func IterateBits8(n uint8) int {
i := 0
for n != 0 {
// amd64:"BSFL",-"BTSL"
// arm64:"RBITW","CLZW",-"ORR"
i += bits.TrailingZeros8(n)
n &= n - 1
}
return i
}
// --------------- //
// bits.Add* //
// --------------- //
func Add(x, y, ci uint) (r, co uint) {
// amd64:"NEGL","ADCQ","SBBQ","NEGQ"
return bits.Add(x, y, ci)
}
func AddC(x, ci uint) (r, co uint) {
// amd64:"NEGL","ADCQ","SBBQ","NEGQ"
return bits.Add(x, 7, ci)
}
func AddZ(x, y uint) (r, co uint) {
// amd64:"ADDQ","SBBQ","NEGQ",-"NEGL",-"ADCQ"
return bits.Add(x, y, 0)
}
func AddR(x, y, ci uint) uint {
// amd64:"NEGL","ADCQ",-"SBBQ",-"NEGQ"
r, _ := bits.Add(x, y, ci)
return r
}
func AddM(p, q, r *[3]uint) {
var c uint
r[0], c = bits.Add(p[0], q[0], c)
// amd64:"ADCQ",-"NEGL",-"SBBQ",-"NEGQ"
r[1], c = bits.Add(p[1], q[1], c)
r[2], c = bits.Add(p[2], q[2], c)
}
func Add64(x, y, ci uint64) (r, co uint64) {
// amd64:"NEGL","ADCQ","SBBQ","NEGQ"
return bits.Add64(x, y, ci)
}
func Add64C(x, ci uint64) (r, co uint64) {
// amd64:"NEGL","ADCQ","SBBQ","NEGQ"
return bits.Add64(x, 7, ci)
}
func Add64Z(x, y uint64) (r, co uint64) {
// amd64:"ADDQ","SBBQ","NEGQ",-"NEGL",-"ADCQ"
return bits.Add64(x, y, 0)
}
func Add64R(x, y, ci uint64) uint64 {
// amd64:"NEGL","ADCQ",-"SBBQ",-"NEGQ"
r, _ := bits.Add64(x, y, ci)
return r
}
func Add64M(p, q, r *[3]uint64) {
var c uint64
r[0], c = bits.Add64(p[0], q[0], c)
// amd64:"ADCQ",-"NEGL",-"SBBQ",-"NEGQ"
r[1], c = bits.Add64(p[1], q[1], c)
r[2], c = bits.Add64(p[2], q[2], c)
}
// --------------- //
// bits.Sub* //
// --------------- //
func Sub(x, y, ci uint) (r, co uint) {
// amd64:"NEGL","SBBQ","NEGQ"
return bits.Sub(x, y, ci)
}
func SubC(x, ci uint) (r, co uint) {
// amd64:"NEGL","SBBQ","NEGQ"
return bits.Sub(x, 7, ci)
}
func SubZ(x, y uint) (r, co uint) {
// amd64:"SUBQ","SBBQ","NEGQ",-"NEGL"
return bits.Sub(x, y, 0)
}
func SubR(x, y, ci uint) uint {
// amd64:"NEGL","SBBQ",-"NEGQ"
r, _ := bits.Sub(x, y, ci)
return r
}
func SubM(p, q, r *[3]uint) {
var c uint
r[0], c = bits.Sub(p[0], q[0], c)
// amd64:"SBBQ",-"NEGL",-"NEGQ"
r[1], c = bits.Sub(p[1], q[1], c)
r[2], c = bits.Sub(p[2], q[2], c)
}
func Sub64(x, y, ci uint64) (r, co uint64) {
// amd64:"NEGL","SBBQ","NEGQ"
return bits.Sub64(x, y, ci)
}
func Sub64C(x, ci uint64) (r, co uint64) {
// amd64:"NEGL","SBBQ","NEGQ"
return bits.Sub64(x, 7, ci)
}
func Sub64Z(x, y uint64) (r, co uint64) {
// amd64:"SUBQ","SBBQ","NEGQ",-"NEGL"
return bits.Sub64(x, y, 0)
}
func Sub64R(x, y, ci uint64) uint64 {
// amd64:"NEGL","SBBQ",-"NEGQ"
r, _ := bits.Sub64(x, y, ci)
return r
}
func Sub64M(p, q, r *[3]uint64) {
var c uint64
r[0], c = bits.Sub64(p[0], q[0], c)
// amd64:"SBBQ",-"NEGL",-"NEGQ"
r[1], c = bits.Sub64(p[1], q[1], c)
r[2], c = bits.Sub64(p[2], q[2], c)
}
// --------------- //
// bits.Mul* //
// --------------- //
func Mul(x, y uint) (hi, lo uint) {
// amd64:"MULQ"
// arm64:"UMULH","MUL"
// ppc64:"MULHDU","MULLD"
// ppc64le:"MULHDU","MULLD"
return bits.Mul(x, y)
}
func Mul64(x, y uint64) (hi, lo uint64) {
// amd64:"MULQ"
// arm64:"UMULH","MUL"
// ppc64:"MULHDU","MULLD"
// ppc64le:"MULHDU","MULLD"
return bits.Mul64(x, y)
}
// --------------- //
// bits.Div* //
// --------------- //
func Div(hi, lo, x uint) (q, r uint) {
// amd64:"DIVQ"
return bits.Div(hi, lo, x)
}
func Div32(hi, lo, x uint32) (q, r uint32) {
// arm64:"ORR","UDIV","MSUB",-"UREM"
return bits.Div32(hi, lo, x)
}
func Div64(hi, lo, x uint64) (q, r uint64) {
// amd64:"DIVQ"
return bits.Div64(hi, lo, x)
}