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go/test/codegen/shift.go
Joel Sing 70c7fb75e9 cmd/compile: correct code generation for right shifts on riscv64
The code generation on riscv64 will currently result in incorrect
assembly when a 32 bit integer is right shifted by an amount that
exceeds the size of the type. In particular, this occurs when an
int32 or uint32 is cast to a 64 bit type and right shifted by a
value larger than 31.

Fix this by moving the SRAW/SRLW conversion into the right shift
rules and removing the SignExt32to64/ZeroExt32to64. Add additional
rules that rewrite to SRAIW/SRLIW when the shift is less than the
size of the type, or replace/eliminate the shift when it exceeds
the size of the type.

Add SSA tests that would have caught this issue. Also add additional
codegen tests to ensure that the resulting assembly is what we
expect in these overflow cases.

Fixes #64285

Change-Id: Ie97b05668597cfcb91413afefaab18ee1aa145ec
Reviewed-on: https://go-review.googlesource.com/c/go/+/545035
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: M Zhuo <mzh@golangcn.org>
Reviewed-by: Mark Ryan <markdryan@rivosinc.com>
Run-TryBot: Joel Sing <joel@sing.id.au>
TryBot-Result: Gopher Robot <gobot@golang.org>
2023-12-01 19:30:59 +00:00

477 lines
11 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
// ------------------ //
// constant shifts //
// ------------------ //
func lshConst64x64(v int64) int64 {
// ppc64x:"SLD"
// riscv64:"SLLI",-"AND",-"SLTIU"
return v << uint64(33)
}
func rshConst64Ux64(v uint64) uint64 {
// ppc64x:"SRD"
// riscv64:"SRLI\t",-"AND",-"SLTIU"
return v >> uint64(33)
}
func rshConst64Ux64Overflow32(v uint32) uint64 {
// riscv64:"MOV\t\\$0,",-"SRL"
return uint64(v) >> 32
}
func rshConst64Ux64Overflow16(v uint16) uint64 {
// riscv64:"MOV\t\\$0,",-"SRL"
return uint64(v) >> 16
}
func rshConst64Ux64Overflow8(v uint8) uint64 {
// riscv64:"MOV\t\\$0,",-"SRL"
return uint64(v) >> 8
}
func rshConst64x64(v int64) int64 {
// ppc64x:"SRAD"
// riscv64:"SRAI\t",-"OR",-"SLTIU"
return v >> uint64(33)
}
func rshConst64x64Overflow32(v int32) int64 {
// riscv64:"SRAIW",-"SLLI",-"SRAI\t"
return int64(v) >> 32
}
func rshConst64x64Overflow16(v int16) int64 {
// riscv64:"SLLI","SRAI",-"SRAIW"
return int64(v) >> 16
}
func rshConst64x64Overflow8(v int8) int64 {
// riscv64:"SLLI","SRAI",-"SRAIW"
return int64(v) >> 8
}
func lshConst32x64(v int32) int32 {
// ppc64x:"SLW"
// riscv64:"SLLI",-"AND",-"SLTIU", -"MOVW"
return v << uint64(29)
}
func rshConst32Ux64(v uint32) uint32 {
// ppc64x:"SRW"
// riscv64:"SRLIW",-"AND",-"SLTIU", -"MOVW"
return v >> uint64(29)
}
func rshConst32x64(v int32) int32 {
// ppc64x:"SRAW"
// riscv64:"SRAIW",-"OR",-"SLTIU", -"MOVW"
return v >> uint64(29)
}
func lshConst64x32(v int64) int64 {
// ppc64x:"SLD"
// riscv64:"SLLI",-"AND",-"SLTIU"
return v << uint32(33)
}
func rshConst64Ux32(v uint64) uint64 {
// ppc64x:"SRD"
// riscv64:"SRLI\t",-"AND",-"SLTIU"
return v >> uint32(33)
}
func rshConst64x32(v int64) int64 {
// ppc64x:"SRAD"
// riscv64:"SRAI\t",-"OR",-"SLTIU"
return v >> uint32(33)
}
// ------------------ //
// masked shifts //
// ------------------ //
func lshMask64x64(v int64, s uint64) int64 {
// arm64:"LSL",-"AND"
// ppc64x:"RLDICL",-"ORN",-"ISEL"
// riscv64:"SLL",-"AND\t",-"SLTIU"
// s390x:-"RISBGZ",-"AND",-"LOCGR"
return v << (s & 63)
}
func rshMask64Ux64(v uint64, s uint64) uint64 {
// arm64:"LSR",-"AND",-"CSEL"
// ppc64x:"RLDICL",-"ORN",-"ISEL"
// riscv64:"SRL\t",-"AND\t",-"SLTIU"
// s390x:-"RISBGZ",-"AND",-"LOCGR"
return v >> (s & 63)
}
func rshMask64x64(v int64, s uint64) int64 {
// arm64:"ASR",-"AND",-"CSEL"
// ppc64x:"RLDICL",-"ORN",-"ISEL"
// riscv64:"SRA\t",-"OR",-"SLTIU"
// s390x:-"RISBGZ",-"AND",-"LOCGR"
return v >> (s & 63)
}
func lshMask32x64(v int32, s uint64) int32 {
// arm64:"LSL",-"AND"
// ppc64x:"ISEL",-"ORN"
// riscv64:"SLL",-"AND\t",-"SLTIU"
// s390x:-"RISBGZ",-"AND",-"LOCGR"
return v << (s & 63)
}
func rshMask32Ux64(v uint32, s uint64) uint32 {
// arm64:"LSR",-"AND"
// ppc64x:"ISEL",-"ORN"
// riscv64:"SRLW","SLTIU","NEG","AND\t",-"SRL\t"
// s390x:-"RISBGZ",-"AND",-"LOCGR"
return v >> (s & 63)
}
func rsh5Mask32Ux64(v uint32, s uint64) uint32 {
// riscv64:"SRLW",-"AND\t",-"SLTIU",-"SRL\t"
return v >> (s & 31)
}
func rshMask32x64(v int32, s uint64) int32 {
// arm64:"ASR",-"AND"
// ppc64x:"ISEL",-"ORN"
// riscv64:"SRAW","OR","SLTIU"
// s390x:-"RISBGZ",-"AND",-"LOCGR"
return v >> (s & 63)
}
func rsh5Mask32x64(v int32, s uint64) int32 {
// riscv64:"SRAW",-"OR",-"SLTIU"
return v >> (s & 31)
}
func lshMask64x32(v int64, s uint32) int64 {
// arm64:"LSL",-"AND"
// ppc64x:"RLDICL",-"ORN"
// riscv64:"SLL",-"AND\t",-"SLTIU"
// s390x:-"RISBGZ",-"AND",-"LOCGR"
return v << (s & 63)
}
func rshMask64Ux32(v uint64, s uint32) uint64 {
// arm64:"LSR",-"AND",-"CSEL"
// ppc64x:"RLDICL",-"ORN"
// riscv64:"SRL\t",-"AND\t",-"SLTIU"
// s390x:-"RISBGZ",-"AND",-"LOCGR"
return v >> (s & 63)
}
func rshMask64x32(v int64, s uint32) int64 {
// arm64:"ASR",-"AND",-"CSEL"
// ppc64x:"RLDICL",-"ORN",-"ISEL"
// riscv64:"SRA\t",-"OR",-"SLTIU"
// s390x:-"RISBGZ",-"AND",-"LOCGR"
return v >> (s & 63)
}
func lshMask64x32Ext(v int64, s int32) int64 {
// ppc64x:"RLDICL",-"ORN",-"ISEL"
// riscv64:"SLL",-"AND\t",-"SLTIU"
// s390x:-"RISBGZ",-"AND",-"LOCGR"
return v << uint(s&63)
}
func rshMask64Ux32Ext(v uint64, s int32) uint64 {
// ppc64x:"RLDICL",-"ORN",-"ISEL"
// riscv64:"SRL\t",-"AND\t",-"SLTIU"
// s390x:-"RISBGZ",-"AND",-"LOCGR"
return v >> uint(s&63)
}
func rshMask64x32Ext(v int64, s int32) int64 {
// ppc64x:"RLDICL",-"ORN",-"ISEL"
// riscv64:"SRA\t",-"OR",-"SLTIU"
// s390x:-"RISBGZ",-"AND",-"LOCGR"
return v >> uint(s&63)
}
// --------------- //
// signed shifts //
// --------------- //
// We do want to generate a test + panicshift for these cases.
func lshSigned(v8 int8, v16 int16, v32 int32, v64 int64, x int) {
// amd64:"TESTB"
_ = x << v8
// amd64:"TESTW"
_ = x << v16
// amd64:"TESTL"
_ = x << v32
// amd64:"TESTQ"
_ = x << v64
}
// We want to avoid generating a test + panicshift for these cases.
func lshSignedMasked(v8 int8, v16 int16, v32 int32, v64 int64, x int) {
// amd64:-"TESTB"
_ = x << (v8 & 7)
// amd64:-"TESTW"
_ = x << (v16 & 15)
// amd64:-"TESTL"
_ = x << (v32 & 31)
// amd64:-"TESTQ"
_ = x << (v64 & 63)
}
// ------------------ //
// bounded shifts //
// ------------------ //
func lshGuarded64(v int64, s uint) int64 {
if s < 64 {
// riscv64:"SLL",-"AND",-"SLTIU"
// s390x:-"RISBGZ",-"AND",-"LOCGR"
// wasm:-"Select",-".*LtU"
// arm64:"LSL",-"CSEL"
return v << s
}
panic("shift too large")
}
func rshGuarded64U(v uint64, s uint) uint64 {
if s < 64 {
// riscv64:"SRL\t",-"AND",-"SLTIU"
// s390x:-"RISBGZ",-"AND",-"LOCGR"
// wasm:-"Select",-".*LtU"
// arm64:"LSR",-"CSEL"
return v >> s
}
panic("shift too large")
}
func rshGuarded64(v int64, s uint) int64 {
if s < 64 {
// riscv64:"SRA\t",-"OR",-"SLTIU"
// s390x:-"RISBGZ",-"AND",-"LOCGR"
// wasm:-"Select",-".*LtU"
// arm64:"ASR",-"CSEL"
return v >> s
}
panic("shift too large")
}
func provedUnsignedShiftLeft(val64 uint64, val32 uint32, val16 uint16, val8 uint8, shift int) (r1 uint64, r2 uint32, r3 uint16, r4 uint8) {
if shift >= 0 && shift < 64 {
// arm64:"LSL",-"CSEL"
r1 = val64 << shift
}
if shift >= 0 && shift < 32 {
// arm64:"LSL",-"CSEL"
r2 = val32 << shift
}
if shift >= 0 && shift < 16 {
// arm64:"LSL",-"CSEL"
r3 = val16 << shift
}
if shift >= 0 && shift < 8 {
// arm64:"LSL",-"CSEL"
r4 = val8 << shift
}
return r1, r2, r3, r4
}
func provedSignedShiftLeft(val64 int64, val32 int32, val16 int16, val8 int8, shift int) (r1 int64, r2 int32, r3 int16, r4 int8) {
if shift >= 0 && shift < 64 {
// arm64:"LSL",-"CSEL"
r1 = val64 << shift
}
if shift >= 0 && shift < 32 {
// arm64:"LSL",-"CSEL"
r2 = val32 << shift
}
if shift >= 0 && shift < 16 {
// arm64:"LSL",-"CSEL"
r3 = val16 << shift
}
if shift >= 0 && shift < 8 {
// arm64:"LSL",-"CSEL"
r4 = val8 << shift
}
return r1, r2, r3, r4
}
func provedUnsignedShiftRight(val64 uint64, val32 uint32, val16 uint16, val8 uint8, shift int) (r1 uint64, r2 uint32, r3 uint16, r4 uint8) {
if shift >= 0 && shift < 64 {
// arm64:"LSR",-"CSEL"
r1 = val64 >> shift
}
if shift >= 0 && shift < 32 {
// arm64:"LSR",-"CSEL"
r2 = val32 >> shift
}
if shift >= 0 && shift < 16 {
// arm64:"LSR",-"CSEL"
r3 = val16 >> shift
}
if shift >= 0 && shift < 8 {
// arm64:"LSR",-"CSEL"
r4 = val8 >> shift
}
return r1, r2, r3, r4
}
func provedSignedShiftRight(val64 int64, val32 int32, val16 int16, val8 int8, shift int) (r1 int64, r2 int32, r3 int16, r4 int8) {
if shift >= 0 && shift < 64 {
// arm64:"ASR",-"CSEL"
r1 = val64 >> shift
}
if shift >= 0 && shift < 32 {
// arm64:"ASR",-"CSEL"
r2 = val32 >> shift
}
if shift >= 0 && shift < 16 {
// arm64:"ASR",-"CSEL"
r3 = val16 >> shift
}
if shift >= 0 && shift < 8 {
// arm64:"ASR",-"CSEL"
r4 = val8 >> shift
}
return r1, r2, r3, r4
}
func checkUnneededTrunc(tab *[100000]uint32, d uint64, v uint32, h uint16, b byte) (uint32, uint64) {
// ppc64x:-".*RLWINM",-".*RLDICR",".*CLRLSLDI"
f := tab[byte(v)^b]
// ppc64x:-".*RLWINM",-".*RLDICR",".*CLRLSLDI"
f += tab[byte(v)&b]
// ppc64x:-".*RLWINM",-".*RLDICR",".*CLRLSLDI"
f += tab[byte(v)|b]
// ppc64x:-".*RLWINM",-".*RLDICR",".*CLRLSLDI"
f += tab[uint16(v)&h]
// ppc64x:-".*RLWINM",-".*RLDICR",".*CLRLSLDI"
f += tab[uint16(v)^h]
// ppc64x:-".*RLWINM",-".*RLDICR",".*CLRLSLDI"
f += tab[uint16(v)|h]
// ppc64x:-".*AND",-"RLDICR",".*CLRLSLDI"
f += tab[v&0xff]
// ppc64x:-".*AND",".*CLRLSLWI"
f += 2 * uint32(uint16(d))
// ppc64x:-".*AND",-"RLDICR",".*CLRLSLDI"
g := 2 * uint64(uint32(d))
return f, g
}
func checkCombinedShifts(v8 uint8, v16 uint16, v32 uint32, x32 int32, v64 uint64) (uint8, uint16, uint32, uint64, int64) {
// ppc64x:-"AND","CLRLSLWI"
f := (v8 & 0xF) << 2
// ppc64x:"CLRLSLWI"
f += byte(v16) << 3
// ppc64x:-"AND","CLRLSLWI"
g := (v16 & 0xFF) << 3
// ppc64x:-"AND","CLRLSLWI"
h := (v32 & 0xFFFFF) << 2
// ppc64x:"CLRLSLDI"
i := (v64 & 0xFFFFFFFF) << 5
// ppc64x:-"CLRLSLDI"
i += (v64 & 0xFFFFFFF) << 38
// ppc64x/power9:-"CLRLSLDI"
i += (v64 & 0xFFFF00) << 10
// ppc64x/power9:-"SLD","EXTSWSLI"
j := int64(x32+32) * 8
return f, g, h, i, j
}
func checkWidenAfterShift(v int64, u uint64) (int64, uint64) {
// ppc64x:-".*MOVW"
f := int32(v >> 32)
// ppc64x:".*MOVW"
f += int32(v >> 31)
// ppc64x:-".*MOVH"
g := int16(v >> 48)
// ppc64x:".*MOVH"
g += int16(v >> 30)
// ppc64x:-".*MOVH"
g += int16(f >> 16)
// ppc64x:-".*MOVB"
h := int8(v >> 56)
// ppc64x:".*MOVB"
h += int8(v >> 28)
// ppc64x:-".*MOVB"
h += int8(f >> 24)
// ppc64x:".*MOVB"
h += int8(f >> 16)
return int64(h), uint64(g)
}
func checkShiftAndMask32(v []uint32) {
i := 0
// ppc64x: "RLWNM\t[$]24, R[0-9]+, [$]12, [$]19, R[0-9]+"
v[i] = (v[i] & 0xFF00000) >> 8
i++
// ppc64x: "RLWNM\t[$]26, R[0-9]+, [$]22, [$]29, R[0-9]+"
v[i] = (v[i] & 0xFF00) >> 6
i++
// ppc64x: "MOVW\tR0"
v[i] = (v[i] & 0xFF) >> 8
i++
// ppc64x: "MOVW\tR0"
v[i] = (v[i] & 0xF000000) >> 28
i++
// ppc64x: "RLWNM\t[$]26, R[0-9]+, [$]24, [$]31, R[0-9]+"
v[i] = (v[i] >> 6) & 0xFF
i++
// ppc64x: "RLWNM\t[$]26, R[0-9]+, [$]12, [$]19, R[0-9]+"
v[i] = (v[i] >> 6) & 0xFF000
i++
// ppc64x: "MOVW\tR0"
v[i] = (v[i] >> 20) & 0xFF000
i++
// ppc64x: "MOVW\tR0"
v[i] = (v[i] >> 24) & 0xFF00
i++
}
func checkMergedShifts32(a [256]uint32, b [256]uint64, u uint32, v uint32) {
// ppc64x: -"CLRLSLDI", "RLWNM\t[$]10, R[0-9]+, [$]22, [$]29, R[0-9]+"
a[0] = a[uint8(v>>24)]
// ppc64x: -"CLRLSLDI", "RLWNM\t[$]11, R[0-9]+, [$]21, [$]28, R[0-9]+"
b[0] = b[uint8(v>>24)]
// ppc64x: -"CLRLSLDI", "RLWNM\t[$]15, R[0-9]+, [$]21, [$]28, R[0-9]+"
b[1] = b[(v>>20)&0xFF]
// ppc64x: -"SLD", "RLWNM\t[$]10, R[0-9]+, [$]22, [$]28, R[0-9]+"
b[2] = b[v>>25]
}
// 128 bit shifts
func check128bitShifts(x, y uint64, bits uint) (uint64, uint64) {
s := bits & 63
ŝ := (64 - bits) & 63
// check that the shift operation has two commas (three operands)
// amd64:"SHRQ.*,.*,"
shr := x>>s | y<<ŝ
// amd64:"SHLQ.*,.*,"
shl := x<<s | y>>ŝ
return shr, shl
}
func checkShiftToMask(u []uint64, s []int64) {
// amd64:-"SHR",-"SHL","ANDQ"
u[0] = u[0] >> 5 << 5
// amd64:-"SAR",-"SHL","ANDQ"
s[0] = s[0] >> 5 << 5
// amd64:-"SHR",-"SHL","ANDQ"
u[1] = u[1] << 5 >> 5
}