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-rw-r--r--test/codegen/arithmetic.go613
1 files changed, 613 insertions, 0 deletions
diff --git a/test/codegen/arithmetic.go b/test/codegen/arithmetic.go
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+++ b/test/codegen/arithmetic.go
@@ -0,0 +1,613 @@
+// 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
+
+// This file contains codegen tests related to arithmetic
+// simplifications and optimizations on integer types.
+// For codegen tests on float types, see floats.go.
+
+// ----------------- //
+// Subtraction //
+// ----------------- //
+
+var ef int
+
+func SubMem(arr []int, b, c, d int) int {
+ // 386:`SUBL\s[A-Z]+,\s8\([A-Z]+\)`
+ // amd64:`SUBQ\s[A-Z]+,\s16\([A-Z]+\)`
+ arr[2] -= b
+ // 386:`SUBL\s[A-Z]+,\s12\([A-Z]+\)`
+ // amd64:`SUBQ\s[A-Z]+,\s24\([A-Z]+\)`
+ arr[3] -= b
+ // 386:`DECL\s16\([A-Z]+\)`
+ arr[4]--
+ // 386:`ADDL\s[$]-20,\s20\([A-Z]+\)`
+ arr[5] -= 20
+ // 386:`SUBL\s\([A-Z]+\)\([A-Z]+\*4\),\s[A-Z]+`
+ ef -= arr[b]
+ // 386:`SUBL\s[A-Z]+,\s\([A-Z]+\)\([A-Z]+\*4\)`
+ arr[c] -= b
+ // 386:`ADDL\s[$]-15,\s\([A-Z]+\)\([A-Z]+\*4\)`
+ arr[d] -= 15
+ // 386:`DECL\s\([A-Z]+\)\([A-Z]+\*4\)`
+ arr[b]--
+ // amd64:`DECQ\s64\([A-Z]+\)`
+ arr[8]--
+ // 386:"SUBL\t4"
+ // amd64:"SUBQ\t8"
+ return arr[0] - arr[1]
+}
+
+func SubFromConst(a int) int {
+ // ppc64le: `SUBC\tR[0-9]+,\s[$]40,\sR`
+ // ppc64: `SUBC\tR[0-9]+,\s[$]40,\sR`
+ b := 40 - a
+ return b
+}
+
+func SubFromConstNeg(a int) int {
+ // ppc64le: `ADD\t[$]40,\sR[0-9]+,\sR`
+ // ppc64: `ADD\t[$]40,\sR[0-9]+,\sR`
+ c := 40 - (-a)
+ return c
+}
+
+func SubSubFromConst(a int) int {
+ // ppc64le: `ADD\t[$]20,\sR[0-9]+,\sR`
+ // ppc64: `ADD\t[$]20,\sR[0-9]+,\sR`
+ c := 40 - (20 - a)
+ return c
+}
+
+func AddSubFromConst(a int) int {
+ // ppc64le: `SUBC\tR[0-9]+,\s[$]60,\sR`
+ // ppc64: `SUBC\tR[0-9]+,\s[$]60,\sR`
+ c := 40 + (20 - a)
+ return c
+}
+
+func NegSubFromConst(a int) int {
+ // ppc64le: `ADD\t[$]-20,\sR[0-9]+,\sR`
+ // ppc64: `ADD\t[$]-20,\sR[0-9]+,\sR`
+ c := -(20 - a)
+ return c
+}
+
+func NegAddFromConstNeg(a int) int {
+ // ppc64le: `SUBC\tR[0-9]+,\s[$]40,\sR`
+ // ppc64: `SUBC\tR[0-9]+,\s[$]40,\sR`
+ c := -(-40 + a)
+ return c
+}
+
+func SubSubNegSimplify(a, b int) int {
+ // amd64:"NEGQ"
+ // ppc64:"NEG"
+ // ppc64le:"NEG"
+ r := (a - b) - a
+ return r
+}
+
+func SubAddSimplify(a, b int) int {
+ // amd64:-"SUBQ",-"ADDQ"
+ // ppc64:-"SUB",-"ADD"
+ // ppc64le:-"SUB",-"ADD"
+ r := a + (b - a)
+ return r
+}
+
+func SubAddNegSimplify(a, b int) int {
+ // amd64:"NEGQ",-"ADDQ",-"SUBQ"
+ // ppc64:"NEG",-"ADD",-"SUB"
+ // ppc64le:"NEG",-"ADD",-"SUB"
+ r := a - (b + a)
+ return r
+}
+
+func AddAddSubSimplify(a, b, c int) int {
+ // amd64:-"SUBQ"
+ // ppc64:-"SUB"
+ // ppc64le:-"SUB"
+ r := a + (b + (c - a))
+ return r
+}
+
+// -------------------- //
+// Multiplication //
+// -------------------- //
+
+func Pow2Muls(n1, n2 int) (int, int) {
+ // amd64:"SHLQ\t[$]5",-"IMULQ"
+ // 386:"SHLL\t[$]5",-"IMULL"
+ // arm:"SLL\t[$]5",-"MUL"
+ // arm64:"LSL\t[$]5",-"MUL"
+ // ppc64:"SLD\t[$]5",-"MUL"
+ // ppc64le:"SLD\t[$]5",-"MUL"
+ a := n1 * 32
+
+ // amd64:"SHLQ\t[$]6",-"IMULQ"
+ // 386:"SHLL\t[$]6",-"IMULL"
+ // arm:"SLL\t[$]6",-"MUL"
+ // arm64:`NEG\sR[0-9]+<<6,\sR[0-9]+`,-`LSL`,-`MUL`
+ // ppc64:"SLD\t[$]6","NEG\\sR[0-9]+,\\sR[0-9]+",-"MUL"
+ // ppc64le:"SLD\t[$]6","NEG\\sR[0-9]+,\\sR[0-9]+",-"MUL"
+ b := -64 * n2
+
+ return a, b
+}
+
+func Mul_96(n int) int {
+ // amd64:`SHLQ\t[$]5`,`LEAQ\t\(.*\)\(.*\*2\),`,-`IMULQ`
+ // 386:`SHLL\t[$]5`,`LEAL\t\(.*\)\(.*\*2\),`,-`IMULL`
+ // arm64:`LSL\t[$]5`,`ADD\sR[0-9]+<<1,\sR[0-9]+`,-`MUL`
+ // arm:`SLL\t[$]5`,`ADD\sR[0-9]+<<1,\sR[0-9]+`,-`MUL`
+ // s390x:`SLD\t[$]5`,`SLD\t[$]6`,-`MULLD`
+ return n * 96
+}
+
+func Mul_n120(n int) int {
+ // s390x:`SLD\t[$]3`,`SLD\t[$]7`,-`MULLD`
+ return n * -120
+}
+
+func MulMemSrc(a []uint32, b []float32) {
+ // 386:`IMULL\s4\([A-Z]+\),\s[A-Z]+`
+ a[0] *= a[1]
+ // 386/sse2:`MULSS\s4\([A-Z]+\),\sX[0-9]+`
+ // amd64:`MULSS\s4\([A-Z]+\),\sX[0-9]+`
+ b[0] *= b[1]
+}
+
+// Multiplications merging tests
+
+func MergeMuls1(n int) int {
+ // amd64:"IMUL3Q\t[$]46"
+ // 386:"IMUL3L\t[$]46"
+ // ppc64le:"MULLD\t[$]46"
+ // ppc64:"MULLD\t[$]46"
+ return 15*n + 31*n // 46n
+}
+
+func MergeMuls2(n int) int {
+ // amd64:"IMUL3Q\t[$]23","(ADDQ\t[$]29)|(LEAQ\t29)"
+ // 386:"IMUL3L\t[$]23","ADDL\t[$]29"
+ // ppc64le/power9:"MADDLD",-"MULLD\t[$]23",-"ADD\t[$]29"
+ // ppc64le/power8:"MULLD\t[$]23","ADD\t[$]29"
+ return 5*n + 7*(n+1) + 11*(n+2) // 23n + 29
+}
+
+func MergeMuls3(a, n int) int {
+ // amd64:"ADDQ\t[$]19",-"IMULQ\t[$]19"
+ // 386:"ADDL\t[$]19",-"IMULL\t[$]19"
+ // ppc64:"ADD\t[$]19",-"MULLD\t[$]19"
+ // ppc64le:"ADD\t[$]19",-"MULLD\t[$]19"
+ return a*n + 19*n // (a+19)n
+}
+
+func MergeMuls4(n int) int {
+ // amd64:"IMUL3Q\t[$]14"
+ // 386:"IMUL3L\t[$]14"
+ // ppc64:"MULLD\t[$]14"
+ // ppc64le:"MULLD\t[$]14"
+ return 23*n - 9*n // 14n
+}
+
+func MergeMuls5(a, n int) int {
+ // amd64:"ADDQ\t[$]-19",-"IMULQ\t[$]19"
+ // 386:"ADDL\t[$]-19",-"IMULL\t[$]19"
+ // ppc64:"ADD\t[$]-19",-"MULLD\t[$]19"
+ // ppc64le:"ADD\t[$]-19",-"MULLD\t[$]19"
+ return a*n - 19*n // (a-19)n
+}
+
+// -------------- //
+// Division //
+// -------------- //
+
+func DivMemSrc(a []float64) {
+ // 386/sse2:`DIVSD\s8\([A-Z]+\),\sX[0-9]+`
+ // amd64:`DIVSD\s8\([A-Z]+\),\sX[0-9]+`
+ a[0] /= a[1]
+}
+
+func Pow2Divs(n1 uint, n2 int) (uint, int) {
+ // 386:"SHRL\t[$]5",-"DIVL"
+ // amd64:"SHRQ\t[$]5",-"DIVQ"
+ // arm:"SRL\t[$]5",-".*udiv"
+ // arm64:"LSR\t[$]5",-"UDIV"
+ // ppc64:"SRD"
+ // ppc64le:"SRD"
+ a := n1 / 32 // unsigned
+
+ // amd64:"SARQ\t[$]6",-"IDIVQ"
+ // 386:"SARL\t[$]6",-"IDIVL"
+ // arm:"SRA\t[$]6",-".*udiv"
+ // arm64:"ASR\t[$]6",-"SDIV"
+ // ppc64:"SRAD"
+ // ppc64le:"SRAD"
+ b := n2 / 64 // signed
+
+ return a, b
+}
+
+// Check that constant divisions get turned into MULs
+func ConstDivs(n1 uint, n2 int) (uint, int) {
+ // amd64:"MOVQ\t[$]-1085102592571150095","MULQ",-"DIVQ"
+ // 386:"MOVL\t[$]-252645135","MULL",-"DIVL"
+ // arm64:`MOVD`,`UMULH`,-`DIV`
+ // arm:`MOVW`,`MUL`,-`.*udiv`
+ a := n1 / 17 // unsigned
+
+ // amd64:"MOVQ\t[$]-1085102592571150095","IMULQ",-"IDIVQ"
+ // 386:"MOVL\t[$]-252645135","IMULL",-"IDIVL"
+ // arm64:`SMULH`,-`DIV`
+ // arm:`MOVW`,`MUL`,-`.*udiv`
+ b := n2 / 17 // signed
+
+ return a, b
+}
+
+func FloatDivs(a []float32) float32 {
+ // amd64:`DIVSS\s8\([A-Z]+\),\sX[0-9]+`
+ // 386/sse2:`DIVSS\s8\([A-Z]+\),\sX[0-9]+`
+ return a[1] / a[2]
+}
+
+func Pow2Mods(n1 uint, n2 int) (uint, int) {
+ // 386:"ANDL\t[$]31",-"DIVL"
+ // amd64:"ANDL\t[$]31",-"DIVQ"
+ // arm:"AND\t[$]31",-".*udiv"
+ // arm64:"AND\t[$]31",-"UDIV"
+ // ppc64:"ANDCC\t[$]31"
+ // ppc64le:"ANDCC\t[$]31"
+ a := n1 % 32 // unsigned
+
+ // 386:"SHRL",-"IDIVL"
+ // amd64:"SHRQ",-"IDIVQ"
+ // arm:"SRA",-".*udiv"
+ // arm64:"ASR",-"REM"
+ // ppc64:"SRAD"
+ // ppc64le:"SRAD"
+ b := n2 % 64 // signed
+
+ return a, b
+}
+
+// Check that signed divisibility checks get converted to AND on low bits
+func Pow2DivisibleSigned(n1, n2 int) (bool, bool) {
+ // 386:"TESTL\t[$]63",-"DIVL",-"SHRL"
+ // amd64:"TESTQ\t[$]63",-"DIVQ",-"SHRQ"
+ // arm:"AND\t[$]63",-".*udiv",-"SRA"
+ // arm64:"AND\t[$]63",-"UDIV",-"ASR"
+ // ppc64:"ANDCC\t[$]63",-"SRAD"
+ // ppc64le:"ANDCC\t[$]63",-"SRAD"
+ a := n1%64 == 0 // signed divisible
+
+ // 386:"TESTL\t[$]63",-"DIVL",-"SHRL"
+ // amd64:"TESTQ\t[$]63",-"DIVQ",-"SHRQ"
+ // arm:"AND\t[$]63",-".*udiv",-"SRA"
+ // arm64:"AND\t[$]63",-"UDIV",-"ASR"
+ // ppc64:"ANDCC\t[$]63",-"SRAD"
+ // ppc64le:"ANDCC\t[$]63",-"SRAD"
+ b := n2%64 != 0 // signed indivisible
+
+ return a, b
+}
+
+// Check that constant modulo divs get turned into MULs
+func ConstMods(n1 uint, n2 int) (uint, int) {
+ // amd64:"MOVQ\t[$]-1085102592571150095","MULQ",-"DIVQ"
+ // 386:"MOVL\t[$]-252645135","MULL",-"DIVL"
+ // arm64:`MOVD`,`UMULH`,-`DIV`
+ // arm:`MOVW`,`MUL`,-`.*udiv`
+ a := n1 % 17 // unsigned
+
+ // amd64:"MOVQ\t[$]-1085102592571150095","IMULQ",-"IDIVQ"
+ // 386:"MOVL\t[$]-252645135","IMULL",-"IDIVL"
+ // arm64:`SMULH`,-`DIV`
+ // arm:`MOVW`,`MUL`,-`.*udiv`
+ b := n2 % 17 // signed
+
+ return a, b
+}
+
+// Check that divisibility checks x%c==0 are converted to MULs and rotates
+func Divisible(n1 uint, n2 int) (bool, bool, bool, bool) {
+ // amd64:"MOVQ\t[$]-6148914691236517205","IMULQ","ROLQ\t[$]63",-"DIVQ"
+ // 386:"IMUL3L\t[$]-1431655765","ROLL\t[$]31",-"DIVQ"
+ // arm64:"MOVD\t[$]-6148914691236517205","MUL","ROR",-"DIV"
+ // arm:"MUL","CMP\t[$]715827882",-".*udiv"
+ // ppc64:"MULLD","ROTL\t[$]63"
+ // ppc64le:"MULLD","ROTL\t[$]63"
+ evenU := n1%6 == 0
+
+ // amd64:"MOVQ\t[$]-8737931403336103397","IMULQ",-"ROLQ",-"DIVQ"
+ // 386:"IMUL3L\t[$]678152731",-"ROLL",-"DIVQ"
+ // arm64:"MOVD\t[$]-8737931403336103397","MUL",-"ROR",-"DIV"
+ // arm:"MUL","CMP\t[$]226050910",-".*udiv"
+ // ppc64:"MULLD",-"ROTL"
+ // ppc64le:"MULLD",-"ROTL"
+ oddU := n1%19 == 0
+
+ // amd64:"IMULQ","ADD","ROLQ\t[$]63",-"DIVQ"
+ // 386:"IMUL3L\t[$]-1431655765","ADDL\t[$]715827882","ROLL\t[$]31",-"DIVQ"
+ // arm64:"MUL","ADD\t[$]3074457345618258602","ROR",-"DIV"
+ // arm:"MUL","ADD\t[$]715827882",-".*udiv"
+ // ppc64/power8:"MULLD","ADD","ROTL\t[$]63"
+ // ppc64le/power8:"MULLD","ADD","ROTL\t[$]63"
+ // ppc64/power9:"MADDLD","ROTL\t[$]63"
+ // ppc64le/power9:"MADDLD","ROTL\t[$]63"
+ evenS := n2%6 == 0
+
+ // amd64:"IMULQ","ADD",-"ROLQ",-"DIVQ"
+ // 386:"IMUL3L\t[$]678152731","ADDL\t[$]113025455",-"ROLL",-"DIVQ"
+ // arm64:"MUL","ADD\t[$]485440633518672410",-"ROR",-"DIV"
+ // arm:"MUL","ADD\t[$]113025455",-".*udiv"
+ // ppc64/power8:"MULLD","ADD",-"ROTL"
+ // ppc64/power9:"MADDLD",-"ROTL"
+ // ppc64le/power8:"MULLD","ADD",-"ROTL"
+ // ppc64le/power9:"MADDLD",-"ROTL"
+ oddS := n2%19 == 0
+
+ return evenU, oddU, evenS, oddS
+}
+
+// Check that fix-up code is not generated for divisions where it has been proven that
+// that the divisor is not -1 or that the dividend is > MinIntNN.
+func NoFix64A(divr int64) (int64, int64) {
+ var d int64 = 42
+ var e int64 = 84
+ if divr > 5 {
+ d /= divr // amd64:-"JMP"
+ e %= divr // amd64:-"JMP"
+ // The following statement is to avoid conflict between the above check
+ // and the normal JMP generated at the end of the block.
+ d += e
+ }
+ return d, e
+}
+
+func NoFix64B(divd int64) (int64, int64) {
+ var d int64
+ var e int64
+ var divr int64 = -1
+ if divd > -9223372036854775808 {
+ d = divd / divr // amd64:-"JMP"
+ e = divd % divr // amd64:-"JMP"
+ d += e
+ }
+ return d, e
+}
+
+func NoFix32A(divr int32) (int32, int32) {
+ var d int32 = 42
+ var e int32 = 84
+ if divr > 5 {
+ // amd64:-"JMP"
+ // 386:-"JMP"
+ d /= divr
+ // amd64:-"JMP"
+ // 386:-"JMP"
+ e %= divr
+ d += e
+ }
+ return d, e
+}
+
+func NoFix32B(divd int32) (int32, int32) {
+ var d int32
+ var e int32
+ var divr int32 = -1
+ if divd > -2147483648 {
+ // amd64:-"JMP"
+ // 386:-"JMP"
+ d = divd / divr
+ // amd64:-"JMP"
+ // 386:-"JMP"
+ e = divd % divr
+ d += e
+ }
+ return d, e
+}
+
+func NoFix16A(divr int16) (int16, int16) {
+ var d int16 = 42
+ var e int16 = 84
+ if divr > 5 {
+ // amd64:-"JMP"
+ // 386:-"JMP"
+ d /= divr
+ // amd64:-"JMP"
+ // 386:-"JMP"
+ e %= divr
+ d += e
+ }
+ return d, e
+}
+
+func NoFix16B(divd int16) (int16, int16) {
+ var d int16
+ var e int16
+ var divr int16 = -1
+ if divd > -32768 {
+ // amd64:-"JMP"
+ // 386:-"JMP"
+ d = divd / divr
+ // amd64:-"JMP"
+ // 386:-"JMP"
+ e = divd % divr
+ d += e
+ }
+ return d, e
+}
+
+// Check that len() and cap() calls divided by powers of two are
+// optimized into shifts and ands
+
+func LenDiv1(a []int) int {
+ // 386:"SHRL\t[$]10"
+ // amd64:"SHRQ\t[$]10"
+ // arm64:"LSR\t[$]10",-"SDIV"
+ // arm:"SRL\t[$]10",-".*udiv"
+ // ppc64:"SRD"\t[$]10"
+ // ppc64le:"SRD"\t[$]10"
+ return len(a) / 1024
+}
+
+func LenDiv2(s string) int {
+ // 386:"SHRL\t[$]11"
+ // amd64:"SHRQ\t[$]11"
+ // arm64:"LSR\t[$]11",-"SDIV"
+ // arm:"SRL\t[$]11",-".*udiv"
+ // ppc64:"SRD\t[$]11"
+ // ppc64le:"SRD\t[$]11"
+ return len(s) / (4097 >> 1)
+}
+
+func LenMod1(a []int) int {
+ // 386:"ANDL\t[$]1023"
+ // amd64:"ANDL\t[$]1023"
+ // arm64:"AND\t[$]1023",-"SDIV"
+ // arm/6:"AND",-".*udiv"
+ // arm/7:"BFC",-".*udiv",-"AND"
+ // ppc64:"ANDCC\t[$]1023"
+ // ppc64le:"ANDCC\t[$]1023"
+ return len(a) % 1024
+}
+
+func LenMod2(s string) int {
+ // 386:"ANDL\t[$]2047"
+ // amd64:"ANDL\t[$]2047"
+ // arm64:"AND\t[$]2047",-"SDIV"
+ // arm/6:"AND",-".*udiv"
+ // arm/7:"BFC",-".*udiv",-"AND"
+ // ppc64:"ANDCC\t[$]2047"
+ // ppc64le:"ANDCC\t[$]2047"
+ return len(s) % (4097 >> 1)
+}
+
+func CapDiv(a []int) int {
+ // 386:"SHRL\t[$]12"
+ // amd64:"SHRQ\t[$]12"
+ // arm64:"LSR\t[$]12",-"SDIV"
+ // arm:"SRL\t[$]12",-".*udiv"
+ // ppc64:"SRD\t[$]12"
+ // ppc64le:"SRD\t[$]12"
+ return cap(a) / ((1 << 11) + 2048)
+}
+
+func CapMod(a []int) int {
+ // 386:"ANDL\t[$]4095"
+ // amd64:"ANDL\t[$]4095"
+ // arm64:"AND\t[$]4095",-"SDIV"
+ // arm/6:"AND",-".*udiv"
+ // arm/7:"BFC",-".*udiv",-"AND"
+ // ppc64:"ANDCC\t[$]4095"
+ // ppc64le:"ANDCC\t[$]4095"
+ return cap(a) % ((1 << 11) + 2048)
+}
+
+func AddMul(x int) int {
+ // amd64:"LEAQ\t1"
+ return 2*x + 1
+}
+
+func MULA(a, b, c uint32) (uint32, uint32, uint32) {
+ // arm:`MULA`,-`MUL\s`
+ // arm64:`MADDW`,-`MULW`
+ r0 := a*b + c
+ // arm:`MULA`,-`MUL\s`
+ // arm64:`MADDW`,-`MULW`
+ r1 := c*79 + a
+ // arm:`ADD`,-`MULA`,-`MUL\s`
+ // arm64:`ADD`,-`MADD`,-`MULW`
+ // ppc64:`ADD`,-`MULLD`
+ // ppc64le:`ADD`,-`MULLD`
+ r2 := b*64 + c
+ return r0, r1, r2
+}
+
+func MULS(a, b, c uint32) (uint32, uint32, uint32) {
+ // arm/7:`MULS`,-`MUL\s`
+ // arm/6:`SUB`,`MUL\s`,-`MULS`
+ // arm64:`MSUBW`,-`MULW`
+ r0 := c - a*b
+ // arm/7:`MULS`,-`MUL\s`
+ // arm/6:`SUB`,`MUL\s`,-`MULS`
+ // arm64:`MSUBW`,-`MULW`
+ r1 := a - c*79
+ // arm/7:`SUB`,-`MULS`,-`MUL\s`
+ // arm64:`SUB`,-`MSUBW`,-`MULW`
+ // ppc64:`SUB`,-`MULLD`
+ // ppc64le:`SUB`,-`MULLD`
+ r2 := c - b*64
+ return r0, r1, r2
+}
+
+func addSpecial(a, b, c uint32) (uint32, uint32, uint32) {
+ // amd64:`INCL`
+ a++
+ // amd64:`DECL`
+ b--
+ // amd64:`SUBL.*-128`
+ c += 128
+ return a, b, c
+}
+
+// Divide -> shift rules usually require fixup for negative inputs.
+// If the input is non-negative, make sure the fixup is eliminated.
+func divInt(v int64) int64 {
+ if v < 0 {
+ return 0
+ }
+ // amd64:-`.*SARQ.*63,`, -".*SHRQ", ".*SARQ.*[$]9,"
+ return v / 512
+}
+
+// The reassociate rules "x - (z + C) -> (x - z) - C" and
+// "(z + C) -x -> C + (z - x)" can optimize the following cases.
+func constantFold1(i0, j0, i1, j1, i2, j2, i3, j3 int) (int, int, int, int) {
+ // arm64:"SUB","ADD\t[$]2"
+ // ppc64:"SUB","ADD\t[$]2"
+ // ppc64le:"SUB","ADD\t[$]2"
+ r0 := (i0 + 3) - (j0 + 1)
+ // arm64:"SUB","SUB\t[$]4"
+ // ppc64:"SUB","ADD\t[$]-4"
+ // ppc64le:"SUB","ADD\t[$]-4"
+ r1 := (i1 - 3) - (j1 + 1)
+ // arm64:"SUB","ADD\t[$]4"
+ // ppc64:"SUB","ADD\t[$]4"
+ // ppc64le:"SUB","ADD\t[$]4"
+ r2 := (i2 + 3) - (j2 - 1)
+ // arm64:"SUB","SUB\t[$]2"
+ // ppc64:"SUB","ADD\t[$]-2"
+ // ppc64le:"SUB","ADD\t[$]-2"
+ r3 := (i3 - 3) - (j3 - 1)
+ return r0, r1, r2, r3
+}
+
+// The reassociate rules "x - (z + C) -> (x - z) - C" and
+// "(C - z) - x -> C - (z + x)" can optimize the following cases.
+func constantFold2(i0, j0, i1, j1 int) (int, int) {
+ // arm64:"ADD","MOVD\t[$]2","SUB"
+ // ppc64le: `SUBC\tR[0-9]+,\s[$]2,\sR`
+ // ppc64: `SUBC\tR[0-9]+,\s[$]2,\sR`
+ r0 := (3 - i0) - (j0 + 1)
+ // arm64:"ADD","MOVD\t[$]4","SUB"
+ // ppc64le: `SUBC\tR[0-9]+,\s[$]4,\sR`
+ // ppc64: `SUBC\tR[0-9]+,\s[$]4,\sR`
+ r1 := (3 - i1) - (j1 - 1)
+ return r0, r1
+}
+
+func constantFold3(i, j int) int {
+ // arm64: "MOVD\t[$]30","MUL",-"ADD",-"LSL"
+ // ppc64:"MULLD\t[$]30","MULLD"
+ // ppc64le:"MULLD\t[$]30","MULLD"
+ r := (5 * i) * (6 * j)
+ return r
+}