go/test/codegen/comparisons.go
Alexander Musman dda7c8253d cmd/compile,internal/bytealg: add MemEq intrinsic for runtime.memequal
Introduce a new MemEq SSA operation for runtime.memequal. The operation
is initially implemented for arm64. The change adds opt rules (following
existing rules for call to runtime.memequal), working with MemEq, and a
later op version LoweredMemEq which may be lowered differently for more
constant size cases in future (for other targets as well as for arm64).
The new MemEq SSA operation does not have memory result, allowing cse of
loads operations around it.

Code size difference (for arm64 linux):

Executable            Old .text  New .text     Change
-------------------------------------------------------
asm                     1970420    1969668     -0.04%
cgo                     1741220    1740212     -0.06%
compile                 8956756    8959428     +0.03%
cover                   1879332    1878772     -0.03%
link                    2574116    2572660     -0.06%
preprofile               867124     866820     -0.04%
vet                     2890404    2888596     -0.06%

Change-Id: I6ab507929b861884d17d5818cfbd152cf7879751
Reviewed-on: https://go-review.googlesource.com/c/go/+/686655
Reviewed-by: Keith Randall <khr@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2025-11-26 09:58:51 -08:00

886 lines
16 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 (
"cmp"
"unsafe"
)
// This file contains code generation tests related to the comparison
// operators.
// -------------- //
// Equality //
// -------------- //
// Check that compare to constant string use 2/4/8 byte compares
func CompareString1(s string) bool {
// amd64:`CMPW \(.*\), [$]`
// arm64:`MOVHU \(.*\), [R]`,`MOVD [$]`,`CMPW R`
// ppc64le:`MOVHZ \(.*\), [R]`,`CMPW .*, [$]`
// s390x:`MOVHBR \(.*\), [R]`,`CMPW .*, [$]`
return s == "xx"
}
func CompareString2(s string) bool {
// amd64:`CMPL \(.*\), [$]`
// arm64:`MOVWU \(.*\), [R]`,`CMPW .*, [R]`
// ppc64le:`MOVWZ \(.*\), [R]`,`CMPW .*, [R]`
// s390x:`MOVWBR \(.*\), [R]`,`CMPW .*, [$]`
return s == "xxxx"
}
func CompareString3(s string) bool {
// amd64:`CMPQ \(.*\), [A-Z]`
// arm64:-`CMPW `
// ppc64x:-`CMPW `
// s390x:-`CMPW `
return s == "xxxxxxxx"
}
// Check that arrays compare use 2/4/8 byte compares
func CompareArray1(a, b [2]byte) bool {
// amd64:`CMPW command-line-arguments[.+_a-z0-9]+\(SP\), [A-Z]`
// arm64:-`MOVBU `
// ppc64le:-`MOVBZ `
// s390x:-`MOVBZ `
return a == b
}
func CompareArray2(a, b [3]uint16) bool {
// amd64:`CMPL command-line-arguments[.+_a-z0-9]+\(SP\), [A-Z]`
// amd64:`CMPW command-line-arguments[.+_a-z0-9]+\(SP\), [A-Z]`
return a == b
}
func CompareArray3(a, b [3]int16) bool {
// amd64:`CMPL command-line-arguments[.+_a-z0-9]+\(SP\), [A-Z]`
// amd64:`CMPW command-line-arguments[.+_a-z0-9]+\(SP\), [A-Z]`
return a == b
}
func CompareArray4(a, b [12]int8) bool {
// amd64:`CMPQ command-line-arguments[.+_a-z0-9]+\(SP\), [A-Z]`
// amd64:`CMPL command-line-arguments[.+_a-z0-9]+\(SP\), [A-Z]`
return a == b
}
func CompareArray5(a, b [15]byte) bool {
// amd64:`CMPQ command-line-arguments[.+_a-z0-9]+\(SP\), [A-Z]`
return a == b
}
// This was a TODO in mapaccess1_faststr
func CompareArray6(a, b unsafe.Pointer) bool {
// amd64:`CMPL \(.*\), [A-Z]`
// arm64:`MOVWU \(.*\), [R]`,`CMPW .*, [R]`
// ppc64le:`MOVWZ \(.*\), [R]`,`CMPW .*, [R]`
// s390x:`MOVWBR \(.*\), [R]`,`CMPW .*, [R]`
return *((*[4]byte)(a)) != *((*[4]byte)(b))
}
// Check that some structs generate 2/4/8 byte compares.
type T1 struct {
a [8]byte
}
func CompareStruct1(s1, s2 T1) bool {
// amd64:`CMPQ command-line-arguments[.+_a-z0-9]+\(SP\), [A-Z]`
// amd64:-`CALL`
return s1 == s2
}
type T2 struct {
a [16]byte
}
func CompareStruct2(s1, s2 T2) bool {
// amd64:`CMPQ command-line-arguments[.+_a-z0-9]+\(SP\), [A-Z]`
// amd64:-`CALL`
return s1 == s2
}
// Assert that a memequal call is still generated when
// inlining would increase binary size too much.
type T3 struct {
a [24]byte
}
func CompareStruct3(s1, s2 T3) bool {
// amd64:-`CMPQ command-line-arguments[.+_a-z0-9]+\(SP\), [A-Z]`
// amd64:`CALL`
return s1 == s2
}
type T4 struct {
a [32]byte
}
func CompareStruct4(s1, s2 T4) bool {
// amd64:-`CMPQ command-line-arguments[.+_a-z0-9]+\(SP\), [A-Z]`
// amd64:`CALL`
return s1 == s2
}
// -------------- //
// Ordering //
// -------------- //
// Test that LEAQ/ADDQconst are folded into SETx ops
var r bool
func CmpFold(x uint32) {
// amd64:`SETHI .*\(SB\)`
r = x > 4
}
// Test that direct comparisons with memory are generated when
// possible
func CmpMem1(p int, q *int) bool {
// amd64:`CMPQ \(.*\), [A-Z]`
return p < *q
}
func CmpMem2(p *int, q int) bool {
// amd64:`CMPQ \(.*\), [A-Z]`
return *p < q
}
func CmpMem3(p *int) bool {
// amd64:`CMPQ \(.*\), [$]7`
return *p < 7
}
func CmpMem4(p *int) bool {
// amd64:`CMPQ \(.*\), [$]7`
return 7 < *p
}
func CmpMem5(p **int) {
// amd64:`CMPL runtime.writeBarrier\(SB\), [$]0`
*p = nil
}
func CmpMem6(a []int) int {
// 386:`CMPL\s8\([A-Z]+\),`
// amd64:`CMPQ\s16\([A-Z]+\),`
if a[1] > a[2] {
return 1
} else {
return 2
}
}
// Check tbz/tbnz are generated when comparing against zero on arm64
func CmpZero1(a int32, ptr *int) {
if a < 0 { // arm64:"TBZ"
*ptr = 0
}
}
func CmpZero2(a int64, ptr *int) {
if a < 0 { // arm64:"TBZ"
*ptr = 0
}
}
func CmpZero3(a int32, ptr *int) {
if a >= 0 { // arm64:"TBNZ"
*ptr = 0
}
}
func CmpZero4(a int64, ptr *int) {
if a >= 0 { // arm64:"TBNZ"
*ptr = 0
}
}
func CmpToZero(a, b, d int32, e, f int64, deOptC0, deOptC1 bool) int32 {
// arm:`TST`,-`AND`
// arm64:`TSTW`,-`AND`
// 386:`TESTL`,-`ANDL`
// amd64:`TESTL`,-`ANDL`
c0 := a&b < 0
// arm:`CMN`,-`ADD`
// arm64:`CMNW`,-`ADD`
c1 := a+b < 0
// arm:`TEQ`,-`XOR`
c2 := a^b < 0
// arm64:`TST`,-`AND`
// amd64:`TESTQ`,-`ANDQ`
c3 := e&f < 0
// arm64:`CMN`,-`ADD`
c4 := e+f < 0
// not optimized to single CMNW/CMN due to further use of b+d
// arm64:`ADD`,-`CMNW`
// arm:`ADD`,-`CMN`
c5 := b+d == 0
// not optimized to single TSTW/TST due to further use of a&d
// arm64:`AND`,-`TSTW`
// arm:`AND`,-`TST`
// 386:`ANDL`
c6 := a&d >= 0
// For arm64, could be TST+BGE or AND+TBZ
c7 := e&(f<<3) < 0
// For arm64, could be CMN+BPL or ADD+TBZ
c8 := e+(f<<3) < 0
// arm64:`TST\sR[0-9],\sR[0-9]+`
c9 := e&(-19) < 0
if c0 {
return 1
} else if c1 {
return 2
} else if c2 {
return 3
} else if c3 {
return 4
} else if c4 {
return 5
} else if c5 {
return 6
} else if c6 {
return 7
} else if c7 {
return 9
} else if c8 {
return 10
} else if c9 {
return 11
} else if deOptC0 {
return b + d
} else if deOptC1 {
return a & d
} else {
return 0
}
}
func CmpLogicalToZero(a, b, c uint32, d, e, f, g uint64) uint64 {
// ppc64x:"ANDCC" -"CMPW"
// wasm:"I64Eqz" -"I32Eqz" -"I64ExtendI32U" -"I32WrapI64"
if a&63 == 0 {
return 1
}
// ppc64x:"ANDCC" -"CMP"
// wasm:"I64Eqz" -"I32Eqz" -"I64ExtendI32U" -"I32WrapI64"
if d&255 == 0 {
return 1
}
// ppc64x:"ANDCC" -"CMP"
// wasm:"I64Eqz" -"I32Eqz" -"I64ExtendI32U" -"I32WrapI64"
if d&e == 0 {
return 1
}
// ppc64x:"ORCC" -"CMP"
// wasm:"I64Eqz" -"I32Eqz" -"I64ExtendI32U" -"I32WrapI64"
if f|g == 0 {
return 1
}
// ppc64x:"XORCC" -"CMP"
// wasm:"I64Eqz" "I32Eqz" -"I64ExtendI32U" -"I32WrapI64"
if e^d == 0 {
return 1
}
return 0
}
// The following CmpToZero_ex* check that cmp|cmn with bmi|bpl are generated for
// 'comparing to zero' expressions
// var + const
// 'x-const' might be canonicalized to 'x+(-const)', so we check both
// CMN and CMP for subtraction expressions to make the pattern robust.
func CmpToZero_ex1(a int64, e int32) int {
// arm64:`CMN`,-`ADD`,`(BMI|BPL)`
if a+3 < 0 {
return 1
}
// arm64:`CMN`,-`ADD`,`BEQ`,`(BMI|BPL)`
if a+5 <= 0 {
return 1
}
// arm64:`CMN`,-`ADD`,`(BMI|BPL)`
if a+13 >= 0 {
return 2
}
// arm64:`CMP|CMN`,-`(ADD|SUB)`,`(BMI|BPL)`
if a-7 < 0 {
return 3
}
// arm64:`SUB`,`TBZ`
if a-11 >= 0 {
return 4
}
// arm64:`SUB`,`CMP`,`BGT`
if a-19 > 0 {
return 4
}
// arm64:`CMNW`,-`ADDW`,`(BMI|BPL)`
// arm:`CMN`,-`ADD`,`(BMI|BPL)`
if e+3 < 0 {
return 5
}
// arm64:`CMNW`,-`ADDW`,`(BMI|BPL)`
// arm:`CMN`,-`ADD`,`(BMI|BPL)`
if e+13 >= 0 {
return 6
}
// arm64:`CMPW|CMNW`,`(BMI|BPL)`
// arm:`CMP|CMN`, -`(ADD|SUB)`, `(BMI|BPL)`
if e-7 < 0 {
return 7
}
// arm64:`SUB`,`TBNZ`
// arm:`CMP|CMN`, -`(ADD|SUB)`, `(BMI|BPL)`
if e-11 >= 0 {
return 8
}
return 0
}
// var + var
// TODO: optimize 'var - var'
func CmpToZero_ex2(a, b, c int64, e, f, g int32) int {
// arm64:`CMN`,-`ADD`,`(BMI|BPL)`
if a+b < 0 {
return 1
}
// arm64:`CMN`,-`ADD`,`BEQ`,`(BMI|BPL)`
if a+c <= 0 {
return 1
}
// arm64:`CMN`,-`ADD`,`(BMI|BPL)`
if b+c >= 0 {
return 2
}
// arm64:`CMNW`,-`ADDW`,`(BMI|BPL)`
// arm:`CMN`,-`ADD`,`(BMI|BPL)`
if e+f < 0 {
return 5
}
// arm64:`CMNW`,-`ADDW`,`(BMI|BPL)`
// arm:`CMN`,-`ADD`,`(BMI|BPL)`
if f+g >= 0 {
return 6
}
return 0
}
// var + var*var
func CmpToZero_ex3(a, b, c, d int64, e, f, g, h int32) int {
// arm64:`CMN`,-`MADD`,`MUL`,`(BMI|BPL)`
if a+b*c < 0 {
return 1
}
// arm64:`CMN`,-`MADD`,`MUL`,`(BMI|BPL)`
if b+c*d >= 0 {
return 2
}
// arm64:`CMNW`,-`MADDW`,`MULW`,`BEQ`,`(BMI|BPL)`
// arm:`CMN`,-`MULA`,`MUL`,`BEQ`,`(BMI|BPL)`
if e+f*g > 0 {
return 5
}
// arm64:`CMNW`,-`MADDW`,`MULW`,`BEQ`,`(BMI|BPL)`
// arm:`CMN`,-`MULA`,`MUL`,`BEQ`,`(BMI|BPL)`
if f+g*h <= 0 {
return 6
}
return 0
}
// var - var*var
func CmpToZero_ex4(a, b, c, d int64, e, f, g, h int32) int {
// arm64:`CMP`,-`MSUB`,`MUL`,`BEQ`,`(BMI|BPL)`
if a-b*c > 0 {
return 1
}
// arm64:`CMP`,-`MSUB`,`MUL`,`(BMI|BPL)`
if b-c*d >= 0 {
return 2
}
// arm64:`CMPW`,-`MSUBW`,`MULW`,`(BMI|BPL)`
if e-f*g < 0 {
return 5
}
// arm64:`CMPW`,-`MSUBW`,`MULW`,`(BMI|BPL)`
if f-g*h >= 0 {
return 6
}
return 0
}
func CmpToZero_ex5(e, f int32, u uint32) int {
// arm:`CMN`,-`ADD`,`BEQ`,`(BMI|BPL)`
if e+f<<1 > 0 {
return 1
}
// arm:`CMP`,-`SUB`,`(BMI|BPL)`
if f-int32(u>>2) >= 0 {
return 2
}
return 0
}
func UintLtZero(a uint8, b uint16, c uint32, d uint64) int {
// amd64: -`(TESTB|TESTW|TESTL|TESTQ|JCC|JCS)`
// arm64: -`(CMPW|CMP|BHS|BLO)`
if a < 0 || b < 0 || c < 0 || d < 0 {
return 1
}
return 0
}
func UintGeqZero(a uint8, b uint16, c uint32, d uint64) int {
// amd64: -`(TESTB|TESTW|TESTL|TESTQ|JCS|JCC)`
// arm64: -`(CMPW|CMP|BLO|BHS)`
if a >= 0 || b >= 0 || c >= 0 || d >= 0 {
return 1
}
return 0
}
func UintGtZero(a uint8, b uint16, c uint32, d uint64) int {
// arm64: `(CBN?ZW)`, `(CBN?Z[^W])`, -`(CMPW|CMP|BLS|BHI)`
if a > 0 || b > 0 || c > 0 || d > 0 {
return 1
}
return 0
}
func UintLeqZero(a uint8, b uint16, c uint32, d uint64) int {
// arm64: `(CBN?ZW)`, `(CBN?Z[^W])`, -`(CMPW|CMP|BHI|BLS)`
if a <= 0 || b <= 0 || c <= 0 || d <= 0 {
return 1
}
return 0
}
func UintLtOne(a uint8, b uint16, c uint32, d uint64) int {
// arm64: `(CBN?ZW)`, `(CBN?Z[^W])`, -`(CMPW|CMP|BHS|BLO)`
if a < 1 || b < 1 || c < 1 || d < 1 {
return 1
}
return 0
}
func UintGeqOne(a uint8, b uint16, c uint32, d uint64) int {
// arm64: `(CBN?ZW)`, `(CBN?Z[^W])`, -`(CMPW|CMP|BLO|BHS)`
if a >= 1 || b >= 1 || c >= 1 || d >= 1 {
return 1
}
return 0
}
func CmpToZeroU_ex1(a uint8, b uint16, c uint32, d uint64) int {
// wasm:"I64Eqz"-"I64LtU"
if 0 < a {
return 1
}
// wasm:"I64Eqz"-"I64LtU"
if 0 < b {
return 1
}
// wasm:"I64Eqz"-"I64LtU"
if 0 < c {
return 1
}
// wasm:"I64Eqz"-"I64LtU"
if 0 < d {
return 1
}
return 0
}
func CmpToZeroU_ex2(a uint8, b uint16, c uint32, d uint64) int {
// wasm:"I64Eqz"-"I64LeU"
if a <= 0 {
return 1
}
// wasm:"I64Eqz"-"I64LeU"
if b <= 0 {
return 1
}
// wasm:"I64Eqz"-"I64LeU"
if c <= 0 {
return 1
}
// wasm:"I64Eqz"-"I64LeU"
if d <= 0 {
return 1
}
return 0
}
func CmpToOneU_ex1(a uint8, b uint16, c uint32, d uint64) int {
// wasm:"I64Eqz"-"I64LtU"
if a < 1 {
return 1
}
// wasm:"I64Eqz"-"I64LtU"
if b < 1 {
return 1
}
// wasm:"I64Eqz"-"I64LtU"
if c < 1 {
return 1
}
// wasm:"I64Eqz"-"I64LtU"
if d < 1 {
return 1
}
return 0
}
func CmpToOneU_ex2(a uint8, b uint16, c uint32, d uint64) int {
// wasm:"I64Eqz"-"I64LeU"
if 1 <= a {
return 1
}
// wasm:"I64Eqz"-"I64LeU"
if 1 <= b {
return 1
}
// wasm:"I64Eqz"-"I64LeU"
if 1 <= c {
return 1
}
// wasm:"I64Eqz"-"I64LeU"
if 1 <= d {
return 1
}
return 0
}
// Check that small memequals are replaced with eq instructions
func equalConstString1() bool {
a := string("A")
b := string("Z")
// amd64:-".*memequal"
// arm64:-".*memequal"
// ppc64x:-".*memequal"
return a == b
}
func equalVarString1(a string) bool {
b := string("Z")
// amd64:-".*memequal"
// arm64:-".*memequal"
// ppc64x:-".*memequal"
return a[:1] == b
}
func equalConstString2() bool {
a := string("AA")
b := string("ZZ")
// amd64:-".*memequal"
// arm64:-".*memequal"
// ppc64x:-".*memequal"
return a == b
}
func equalVarString2(a string) bool {
b := string("ZZ")
// amd64:-".*memequal"
// arm64:-".*memequal"
// ppc64x:-".*memequal"
return a[:2] == b
}
func equalConstString4() bool {
a := string("AAAA")
b := string("ZZZZ")
// amd64:-".*memequal"
// arm64:-".*memequal"
// ppc64x:-".*memequal"
return a == b
}
func equalVarString4(a string) bool {
b := string("ZZZZ")
// amd64:-".*memequal"
// arm64:-".*memequal"
// ppc64x:-".*memequal"
return a[:4] == b
}
func equalConstString8() bool {
a := string("AAAAAAAA")
b := string("ZZZZZZZZ")
// amd64:-".*memequal"
// arm64:-".*memequal"
// ppc64x:-".*memequal"
return a == b
}
func equalVarString8(a string) bool {
b := string("ZZZZZZZZ")
// amd64:-".*memequal"
// arm64:-".*memequal"
// ppc64x:-".*memequal"
return a[:8] == b
}
func equalVarStringNoSpill(a,b string) bool {
s := string("ZZZZZZZZZ")
// arm64:".*memequal"
memeq1 := a[:9] == s
// arm64:-".*"
memeq2 := s == a[:9]
// arm64:-"MOVB\tR0,.*SP",".*memequal"
memeq3 := s == b[:9]
return memeq1 && memeq2 && memeq3
}
func cmpToCmn(a, b, c, d int) int {
var c1, c2, c3, c4, c5, c6, c7, c8, c9, c10, c11 int
// arm64:`CMN`,-`CMP`
if a < -8 {
c1 = 1
}
// arm64:`CMN`,-`CMP`
if a+1 == 0 {
c2 = 1
}
// arm64:`CMN`,-`CMP`
if a+3 != 0 {
c3 = 1
}
// arm64:`CMN`,-`CMP`
if a+b == 0 {
c4 = 1
}
// arm64:`CMN`,-`CMP`
if b+c != 0 {
c5 = 1
}
// arm64:`CMN`,-`CMP`
if a == -c {
c6 = 1
}
// arm64:`CMN`,-`CMP`
if b != -d {
c7 = 1
}
// arm64:`CMN`,-`CMP`
if a*b+c == 0 {
c8 = 1
}
// arm64:`CMN`,-`CMP`
if a*c+b != 0 {
c9 = 1
}
// arm64:`CMP`,-`CMN`
if b*c-a == 0 {
c10 = 1
}
// arm64:`CMP`,-`CMN`
if a*d-b != 0 {
c11 = 1
}
return c1 + c2 + c3 + c4 + c5 + c6 + c7 + c8 + c9 + c10 + c11
}
func cmpToCmnLessThan(a, b, c, d int) int {
var c1, c2, c3, c4 int
// arm64:`CMN`,`CSET MI`,-`CMP`
if a+1 < 0 {
c1 = 1
}
// arm64:`CMN`,`CSET MI`,-`CMP`
if a+b < 0 {
c2 = 1
}
// arm64:`CMN`,`CSET MI`,-`CMP`
if a*b+c < 0 {
c3 = 1
}
// arm64:`CMP`,`CSET MI`,-`CMN`
if a-b*c < 0 {
c4 = 1
}
return c1 + c2 + c3 + c4
}
func less128Signed32(x int32) bool {
// amd64:`CMPL.*127`
// amd64:`SETLE`
return x < 128
}
func less128Signed64(x int64) bool {
// amd64:`CMPQ.*127`
// amd64:`SETLE`
return x < 128
}
func less128Unsigned32(x uint32) bool {
// amd64:`CMPL.*127`
// amd64:`SETLS`
return x < 128
}
func less128Unsigned64(x uint64) bool {
// amd64:`CMPQ.*127`
// amd64:`SETLS`
return x < 128
}
func ge128Unsigned32(x uint32) bool {
// amd64:`CMPL.*127`
// amd64:`SETHI`
return x >= 128
}
func ge128Unsigned64(x uint64) bool {
// amd64:`CMPQ.*127`
// amd64:`SETHI`
return x >= 128
}
func ge128Signed32(x int32) bool {
// amd64:`CMPL.*127`
// amd64:`SETGT`
return x >= 128
}
func ge128Signed64(x int64) bool {
// amd64:`CMPQ.*127`
// amd64:`SETGT`
return x >= 128
}
func cmpToCmnGreaterThanEqual(a, b, c, d int) int {
var c1, c2, c3, c4 int
// arm64:`CMN`,`CSET PL`,-`CMP`
if a+1 >= 0 {
c1 = 1
}
// arm64:`CMN`,`CSET PL`,-`CMP`
if a+b >= 0 {
c2 = 1
}
// arm64:`CMN`,`CSET PL`,-`CMP`
if a*b+c >= 0 {
c3 = 1
}
// arm64:`CMP`,`CSET PL`,-`CMN`
if a-b*c >= 0 {
c4 = 1
}
return c1 + c2 + c3 + c4
}
func cmp1(val string) bool {
var z string
// amd64:-".*memequal"
return z == val
}
func cmp2(val string) bool {
var z string
// amd64:-".*memequal"
return val == z
}
func cmp3(val string) bool {
z := "food"
// amd64:-".*memequal"
return z == val
}
func cmp4(val string) bool {
z := "food"
// amd64:-".*memequal"
return val == z
}
func cmp5[T comparable](val T) bool {
var z T
// amd64:-".*memequal"
return z == val
}
func cmp6[T comparable](val T) bool {
var z T
// amd64:-".*memequal"
return val == z
}
func cmp7() {
cmp5[string]("") // force instantiation
cmp6[string]("") // force instantiation
}
type Point struct {
X, Y int
}
// invertLessThanNoov checks (LessThanNoov (InvertFlags x)) is lowered as
// CMP, CSET, CSEL instruction sequence. InvertFlags are only generated under
// certain conditions, see canonLessThan, so if the code below does not
// generate an InvertFlags OP, this check may fail.
func invertLessThanNoov(p1, p2, p3 Point) bool {
// arm64:`CMP`,`CSET`,`CSEL`
return (p1.X-p3.X)*(p2.Y-p3.Y)-(p2.X-p3.X)*(p1.Y-p3.Y) < 0
}
func cmpstring1(x, y string) int {
// amd64:".*cmpstring"
if x < y {
return -1
}
// amd64:-".*cmpstring"
if x > y {
return +1
}
return 0
}
func cmpstring2(x, y string) int {
// We want to fail if there are two calls to cmpstring.
// They will both have the same line number, so a test
// like in cmpstring1 will not work. Instead, we
// look for spill/restore instructions, which only
// need to exist if there are 2 calls.
//amd64:-`MOVQ .*\(SP\)`
return cmp.Compare(x, y)
}