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This CL adds rewrite rules for CSETM, CSINC, CSINV, and CSNEG. By adding these rules, we can save one instruction. For example, func test(cond bool, a int) int { if cond { a++ } return a } Before: MOVD "".a+8(RSP), R0 ADD $1, R0, R1 MOVBU "".cond(RSP), R2 CMPW $0, R2 CSEL NE, R1, R0, R0 After: MOVBU "".cond(RSP), R0 CMPW $0, R0 MOVD "".a+8(RSP), R0 CSINC EQ, R0, R0, R0 This patch is a copy of CL 285694. Co-authored-by: JunchenLi <junchen.li@arm.com> Change-Id: Ic1a79e8b8ece409b533becfcb7950f11e7b76f24 Reviewed-on: https://go-review.googlesource.com/c/go/+/302231 Trust: fannie zhang <Fannie.Zhang@arm.com> Run-TryBot: fannie zhang <Fannie.Zhang@arm.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
403 lines
5.3 KiB
Go
403 lines
5.3 KiB
Go
// asmcheck
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// Copyright 2018 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package codegen
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func cmovint(c int) int {
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x := c + 4
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if x < 0 {
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x = 182
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}
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// amd64:"CMOVQLT"
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// arm64:"CSEL\tLT"
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// wasm:"Select"
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return x
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}
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func cmovchan(x, y chan int) chan int {
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if x != y {
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x = y
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}
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// amd64:"CMOVQNE"
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// arm64:"CSEL\tNE"
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// wasm:"Select"
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return x
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}
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func cmovuintptr(x, y uintptr) uintptr {
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if x < y {
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x = -y
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}
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// amd64:"CMOVQ(HI|CS)"
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// arm64:"CSNEG\tLS"
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// wasm:"Select"
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return x
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}
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func cmov32bit(x, y uint32) uint32 {
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if x < y {
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x = -y
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}
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// amd64:"CMOVL(HI|CS)"
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// arm64:"CSNEG\t(LS|HS)"
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// wasm:"Select"
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return x
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}
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func cmov16bit(x, y uint16) uint16 {
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if x < y {
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x = -y
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}
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// amd64:"CMOVW(HI|CS)"
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// arm64:"CSNEG\t(LS|HS)"
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// wasm:"Select"
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return x
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}
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// Floating point comparison. For EQ/NE, we must
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// generate special code to handle NaNs.
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func cmovfloateq(x, y float64) int {
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a := 128
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if x == y {
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a = 256
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}
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// amd64:"CMOVQNE","CMOVQPC"
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// arm64:"CSEL\tEQ"
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// wasm:"Select"
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return a
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}
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func cmovfloatne(x, y float64) int {
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a := 128
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if x != y {
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a = 256
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}
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// amd64:"CMOVQNE","CMOVQPS"
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// arm64:"CSEL\tNE"
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// wasm:"Select"
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return a
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}
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//go:noinline
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func frexp(f float64) (frac float64, exp int) {
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return 1.0, 4
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}
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//go:noinline
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func ldexp(frac float64, exp int) float64 {
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return 1.0
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}
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// Generate a CMOV with a floating comparison and integer move.
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func cmovfloatint2(x, y float64) float64 {
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yfr, yexp := 4.0, 5
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r := x
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for r >= y {
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rfr, rexp := frexp(r)
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if rfr < yfr {
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rexp = rexp - 1
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}
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// amd64:"CMOVQHI"
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// arm64:"CSEL\tMI"
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// wasm:"Select"
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r = r - ldexp(y, rexp-yexp)
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}
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return r
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}
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func cmovloaded(x [4]int, y int) int {
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if x[2] != 0 {
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y = x[2]
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} else {
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y = y >> 2
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}
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// amd64:"CMOVQNE"
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// arm64:"CSEL\tNE"
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// wasm:"Select"
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return y
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}
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func cmovuintptr2(x, y uintptr) uintptr {
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a := x * 2
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if a == 0 {
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a = 256
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}
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// amd64:"CMOVQEQ"
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// arm64:"CSEL\tEQ"
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// wasm:"Select"
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return a
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}
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// Floating point CMOVs are not supported by amd64/arm64
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func cmovfloatmove(x, y int) float64 {
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a := 1.0
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if x <= y {
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a = 2.0
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}
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// amd64:-"CMOV"
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// arm64:-"CSEL"
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// wasm:-"Select"
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return a
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}
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// On amd64, the following patterns trigger comparison inversion.
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// Test that we correctly invert the CMOV condition
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var gsink int64
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var gusink uint64
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func cmovinvert1(x, y int64) int64 {
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if x < gsink {
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y = -y
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}
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// amd64:"CMOVQGT"
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return y
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}
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func cmovinvert2(x, y int64) int64 {
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if x <= gsink {
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y = -y
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}
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// amd64:"CMOVQGE"
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return y
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}
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func cmovinvert3(x, y int64) int64 {
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if x == gsink {
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y = -y
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}
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// amd64:"CMOVQEQ"
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return y
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}
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func cmovinvert4(x, y int64) int64 {
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if x != gsink {
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y = -y
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}
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// amd64:"CMOVQNE"
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return y
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}
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func cmovinvert5(x, y uint64) uint64 {
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if x > gusink {
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y = -y
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}
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// amd64:"CMOVQCS"
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return y
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}
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func cmovinvert6(x, y uint64) uint64 {
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if x >= gusink {
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y = -y
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}
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// amd64:"CMOVQLS"
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return y
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}
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func cmovload(a []int, i int, b bool) int {
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if b {
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i++
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}
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// See issue 26306
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// amd64:-"CMOVQNE"
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return a[i]
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}
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func cmovstore(a []int, i int, b bool) {
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if b {
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i++
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}
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// amd64:"CMOVQNE"
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a[i] = 7
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}
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var r0, r1, r2, r3, r4, r5 int
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func cmovinc(cond bool, a, b, c int) {
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var x0, x1 int
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if cond {
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x0 = a
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} else {
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x0 = b + 1
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}
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// arm64:"CSINC\tNE", -"CSEL"
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r0 = x0
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if cond {
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x1 = b + 1
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} else {
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x1 = a
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}
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// arm64:"CSINC\tEQ", -"CSEL"
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r1 = x1
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if cond {
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c++
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}
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// arm64:"CSINC\tEQ", -"CSEL"
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r2 = c
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}
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func cmovinv(cond bool, a, b int) {
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var x0, x1 int
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if cond {
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x0 = a
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} else {
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x0 = ^b
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}
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// arm64:"CSINV\tNE", -"CSEL"
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r0 = x0
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if cond {
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x1 = ^b
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} else {
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x1 = a
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}
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// arm64:"CSINV\tEQ", -"CSEL"
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r1 = x1
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}
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func cmovneg(cond bool, a, b, c int) {
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var x0, x1 int
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if cond {
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x0 = a
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} else {
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x0 = -b
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}
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// arm64:"CSNEG\tNE", -"CSEL"
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r0 = x0
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if cond {
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x1 = -b
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} else {
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x1 = a
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}
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// arm64:"CSNEG\tEQ", -"CSEL"
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r1 = x1
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}
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func cmovsetm(cond bool, x int) {
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var x0, x1 int
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if cond {
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x0 = -1
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} else {
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x0 = 0
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}
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// arm64:"CSETM\tNE", -"CSEL"
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r0 = x0
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if cond {
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x1 = 0
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} else {
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x1 = -1
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}
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// arm64:"CSETM\tEQ", -"CSEL"
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r1 = x1
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}
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func cmovFcmp0(s, t float64, a, b int) {
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var x0, x1, x2, x3, x4, x5 int
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if s < t {
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x0 = a
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} else {
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x0 = b + 1
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}
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// arm64:"CSINC\tMI", -"CSEL"
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r0 = x0
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if s <= t {
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x1 = a
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} else {
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x1 = ^b
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}
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// arm64:"CSINV\tLS", -"CSEL"
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r1 = x1
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if s > t {
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x2 = a
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} else {
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x2 = -b
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}
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// arm64:"CSNEG\tMI", -"CSEL"
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r2 = x2
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if s >= t {
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x3 = -1
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} else {
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x3 = 0
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}
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// arm64:"CSETM\tLS", -"CSEL"
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r3 = x3
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if s == t {
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x4 = a
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} else {
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x4 = b + 1
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}
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// arm64:"CSINC\tEQ", -"CSEL"
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r4 = x4
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if s != t {
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x5 = a
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} else {
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x5 = b + 1
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}
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// arm64:"CSINC\tNE", -"CSEL"
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r5 = x5
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}
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func cmovFcmp1(s, t float64, a, b int) {
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var x0, x1, x2, x3, x4, x5 int
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if s < t {
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x0 = b + 1
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} else {
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x0 = a
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}
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// arm64:"CSINC\tPL", -"CSEL"
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r0 = x0
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if s <= t {
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x1 = ^b
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} else {
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x1 = a
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}
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// arm64:"CSINV\tHI", -"CSEL"
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r1 = x1
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if s > t {
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x2 = -b
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} else {
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x2 = a
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}
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// arm64:"CSNEG\tPL", -"CSEL"
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r2 = x2
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if s >= t {
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x3 = 0
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} else {
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x3 = -1
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}
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// arm64:"CSETM\tHI", -"CSEL"
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r3 = x3
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if s == t {
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x4 = b + 1
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} else {
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x4 = a
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}
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// arm64:"CSINC\tNE", -"CSEL"
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r4 = x4
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if s != t {
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x5 = b + 1
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} else {
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x5 = a
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}
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// arm64:"CSINC\tEQ", -"CSEL"
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r5 = x5
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}
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