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go/test/codegen/noextend.go
ruinan 4d180f71dc cmd/compile: omit redundant sign/unsign extension on arm64
On Arm64, all 32-bit instructions will ignore the upper 32 bits and
clear them to zero for the result. No need to do an unsign extend before
a 32 bit op.

This CL removes the redundant unsign extension only for the existing
32-bit opcodes, and also omits the sign extension when the upper bit of
the result can be predicted.

Fixes #42162

Change-Id: I61e6670bfb8982572430e67a4fa61134a3ea240a
CustomizedGitHooks: yes
Reviewed-on: https://go-review.googlesource.com/c/go/+/427454
Reviewed-by: Keith Randall <khr@google.com>
Auto-Submit: Eric Fang <eric.fang@arm.com>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Eric Fang <eric.fang@arm.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2023-02-28 03:16:44 +00:00

282 lines
5.3 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"
var sval64 [8]int64
var sval32 [8]int32
var sval16 [8]int16
var sval8 [8]int8
var val64 [8]uint64
var val32 [8]uint32
var val16 [8]uint16
var val8 [8]uint8
// Avoid zero/sign extensions following a load
// which has extended the value correctly.
// Note: No tests are done for int8 since
// an extra extension is usually needed due to
// no signed byte load.
func set16(x8 int8, u8 *uint8, y8 int8, z8 uint8) {
// Truncate not needed, load does sign/zero extend
// ppc64x:-"MOVBZ\tR\\d+,\\sR\\d+"
val16[0] = uint16(*u8)
// AND not needed due to size
// ppc64x:-"ANDCC"
sval16[1] = 255 & int16(x8+y8)
// ppc64x:-"ANDCC"
val16[1] = 255 & uint16(*u8+z8)
}
func shiftidx(u8 *uint8, x16 *int16, u16 *uint16) {
// ppc64x:-"MOVBZ\tR\\d+,\\sR\\d+"
val16[0] = uint16(sval16[*u8>>2])
// ppc64x:-"MOVH\tR\\d+,\\sR\\d+"
sval16[1] = int16(val16[*x16>>1])
// ppc64x:-"MOVHZ\tR\\d+,\\sR\\d+"
val16[1] = uint16(sval16[*u16>>2])
}
func setnox(x8 int8, u8 *uint8, y8 *int8, z8 *uint8, x16 *int16, u16 *uint16, x32 *int32, u32 *uint32) {
// ppc64x:-"MOVBZ\tR\\d+,\\sR\\d+"
val16[0] = uint16(*u8)
// AND not needed due to size
// ppc64x:-"ANDCC"
sval16[1] = 255 & int16(x8+*y8)
// ppc64x:-"ANDCC"
val16[1] = 255 & uint16(*u8+*z8)
// ppc64x:-"MOVH\tR\\d+,\\sR\\d+"
sval32[1] = int32(*x16)
// ppc64x:-"MOVBZ\tR\\d+,\\sR\\d+"
val32[0] = uint32(*u8)
// ppc64x:-"MOVHZ\tR\\d+,\\sR\\d+"
val32[1] = uint32(*u16)
// ppc64x:-"MOVH\tR\\d+,\\sR\\d+"
sval64[1] = int64(*x16)
// ppc64x:-"MOVW\tR\\d+,\\sR\\d+"
sval64[2] = int64(*x32)
// ppc64x:-"MOVBZ\tR\\d+,\\sR\\d+"
val64[0] = uint64(*u8)
// ppc64x:-"MOVHZ\tR\\d+,\\sR\\d+"
val64[1] = uint64(*u16)
// ppc64x:-"MOVWZ\tR\\d+,\\sR\\d+"
val64[2] = uint64(*u32)
}
func cmp16(u8 *uint8, x32 *int32, u32 *uint32, x64 *int64, u64 *uint64) bool {
// ppc64x:-"MOVBZ\tR\\d+,\\sR\\d+"
if uint16(*u8) == val16[0] {
return true
}
// ppc64x:-"MOVHZ\tR\\d+,\\sR\\d+"
if uint16(*u32>>16) == val16[0] {
return true
}
// ppc64x:-"MOVHZ\tR\\d+,\\sR\\d+"
if uint16(*u64>>48) == val16[0] {
return true
}
// Verify the truncates are using the correct sign.
// ppc64x:-"MOVHZ\tR\\d+,\\sR\\d+"
if int16(*x32) == sval16[0] {
return true
}
// ppc64x:-"MOVH\tR\\d+,\\sR\\d+"
if uint16(*u32) == val16[0] {
return true
}
// ppc64x:-"MOVHZ\tR\\d+,\\sR\\d+"
if int16(*x64) == sval16[0] {
return true
}
// ppc64x:-"MOVH\tR\\d+,\\sR\\d+"
if uint16(*u64) == val16[0] {
return true
}
return false
}
func cmp32(u8 *uint8, x16 *int16, u16 *uint16, x64 *int64, u64 *uint64) bool {
// ppc64x:-"MOVBZ\tR\\d+,\\sR\\d+"
if uint32(*u8) == val32[0] {
return true
}
// ppc64x:-"MOVH\tR\\d+,\\sR\\d+"
if int32(*x16) == sval32[0] {
return true
}
// ppc64x:-"MOVHZ\tR\\d+,\\sR\\d+"
if uint32(*u16) == val32[0] {
return true
}
// Verify the truncates are using the correct sign.
// ppc64x:-"MOVWZ\tR\\d+,\\sR\\d+"
if int32(*x64) == sval32[0] {
return true
}
// ppc64x:-"MOVW\tR\\d+,\\sR\\d+"
if uint32(*u64) == val32[0] {
return true
}
return false
}
func cmp64(u8 *uint8, x16 *int16, u16 *uint16, x32 *int32, u32 *uint32) bool {
// ppc64x:-"MOVBZ\tR\\d+,\\sR\\d+"
if uint64(*u8) == val64[0] {
return true
}
// ppc64x:-"MOVH\tR\\d+,\\sR\\d+"
if int64(*x16) == sval64[0] {
return true
}
// ppc64x:-"MOVHZ\tR\\d+,\\sR\\d+"
if uint64(*u16) == val64[0] {
return true
}
// ppc64x:-"MOVW\tR\\d+,\\sR\\d+"
if int64(*x32) == sval64[0] {
return true
}
// ppc64x:-"MOVWZ\tR\\d+,\\sR\\d+"
if uint64(*u32) == val64[0] {
return true
}
return false
}
// no unsign extension following 32 bits ops
func noUnsignEXT(t1, t2, t3, t4 uint32, k int64) uint64 {
var ret uint64
// arm64:"RORW",-"MOVWU"
ret += uint64(bits.RotateLeft32(t1, 7))
// arm64:"MULW",-"MOVWU"
ret *= uint64(t1 * t2)
// arm64:"MNEGW",-"MOVWU"
ret += uint64(-t1 * t3)
// arm64:"UDIVW",-"MOVWU"
ret += uint64(t1 / t4)
// arm64:-"MOVWU"
ret += uint64(t2 % t3)
// arm64:"MSUBW",-"MOVWU"
ret += uint64(t1 - t2*t3)
// arm64:"MADDW",-"MOVWU"
ret += uint64(t3*t4 + t2)
// arm64:"REVW",-"MOVWU"
ret += uint64(bits.ReverseBytes32(t1))
// arm64:"RBITW",-"MOVWU"
ret += uint64(bits.Reverse32(t1))
// arm64:"CLZW",-"MOVWU"
ret += uint64(bits.LeadingZeros32(t1))
// arm64:"REV16W",-"MOVWU"
ret += uint64(((t1 & 0xff00ff00) >> 8) | ((t1 & 0x00ff00ff) << 8))
// arm64:"EXTRW",-"MOVWU"
ret += uint64((t1 << 25) | (t2 >> 7))
return ret
}
// no sign extension when the upper bits of the result are zero
func noSignEXT(x int) int64 {
t1 := int32(x)
var ret int64
// arm64:-"MOVW"
ret += int64(t1 & 1)
// arm64:-"MOVW"
ret += int64(int32(x & 0x7fffffff))
// arm64:-"MOVH"
ret += int64(int16(x & 0x7fff))
// arm64:-"MOVB"
ret += int64(int8(x & 0x7f))
return ret
}
// corner cases that sign extension must not be omitted
func shouldSignEXT(x int) int64 {
t1 := int32(x)
var ret int64
// arm64:"MOVW"
ret += int64(t1 & (-1))
// arm64:"MOVW"
ret += int64(int32(x & 0x80000000))
// arm64:"MOVW"
ret += int64(int32(x & 0x1100000011111111))
// arm64:"MOVH"
ret += int64(int16(x & 0x1100000000001111))
// arm64:"MOVB"
ret += int64(int8(x & 0x1100000000000011))
return ret
}