go/test/codegen/mathbits.go
Michael Munday 854e892ce1 cmd/compile: optimize shift pairs and masks on s390x
Optimize combinations of left and right shifts by a constant value
into a 'rotate then insert selected bits [into zero]' instruction.
Use the same instruction for contiguous masks since it has some
benefits over 'and immediate' (not restricted to 32-bits, does not
overwrite source register).

To keep the complexity of this change under control I've only
implemented 64 bit operations for now.

There are a lot more optimizations that can be done with this
instruction family. However, since their function overlaps with other
instructions we need to be somewhat careful not to break existing
optimization rules by creating optimization dead ends. This is
particularly true of the load/store merging rules which contain lots
of zero extensions and shifts.

This CL does interfere with the store merging rules when an operand
is shifted left before it is stored:

  binary.BigEndian.PutUint64(b, x << 1)

This is unfortunate but it's not critical and somewhat complex so
I plan to fix that in a follow up CL.

file      before    after     Δ       %
addr2line 4117446   4117282   -164    -0.004%
api       4945184   4942752   -2432   -0.049%
asm       4998079   4991891   -6188   -0.124%
buildid   2685158   2684074   -1084   -0.040%
cgo       4553732   4553394   -338    -0.007%
compile   19294446  19245070  -49376  -0.256%
cover     4897105   4891319   -5786   -0.118%
dist      3544389   3542785   -1604   -0.045%
doc       3926795   3927617   +822    +0.021%
fix       3302958   3293868   -9090   -0.275%
link      6546274   6543456   -2818   -0.043%
nm        4102021   4100825   -1196   -0.029%
objdump   4542431   4548483   +6052   +0.133%
pack      2482465   2416389   -66076  -2.662%
pprof     13366541  13363915  -2626   -0.020%
test2json 2829007   2761515   -67492  -2.386%
trace     10216164  10219684  +3520   +0.034%
vet       6773956   6773572   -384    -0.006%
total     107124151 106917891 -206260 -0.193%

Change-Id: I7591cce41e06867ba10a745daae9333513062746
Reviewed-on: https://go-review.googlesource.com/c/go/+/233317
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Trust: Michael Munday <mike.munday@ibm.com>
2020-11-06 10:45:31 +00:00

742 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 "math/bits"
// ----------------------- //
// bits.LeadingZeros //
// ----------------------- //
func LeadingZeros(n uint) int {
// amd64:"BSRQ"
// s390x:"FLOGR"
// arm:"CLZ" arm64:"CLZ"
// mips:"CLZ"
// wasm:"I64Clz"
return bits.LeadingZeros(n)
}
func LeadingZeros64(n uint64) int {
// amd64:"BSRQ"
// s390x:"FLOGR"
// arm:"CLZ" arm64:"CLZ"
// mips:"CLZ"
// wasm:"I64Clz"
return bits.LeadingZeros64(n)
}
func LeadingZeros32(n uint32) int {
// amd64:"BSRQ","LEAQ",-"CMOVQEQ"
// s390x:"FLOGR"
// arm:"CLZ" arm64:"CLZW"
// mips:"CLZ"
// wasm:"I64Clz"
return bits.LeadingZeros32(n)
}
func LeadingZeros16(n uint16) int {
// amd64:"BSRL","LEAL",-"CMOVQEQ"
// s390x:"FLOGR"
// arm:"CLZ" arm64:"CLZ"
// mips:"CLZ"
// wasm:"I64Clz"
return bits.LeadingZeros16(n)
}
func LeadingZeros8(n uint8) int {
// amd64:"BSRL","LEAL",-"CMOVQEQ"
// s390x:"FLOGR"
// arm:"CLZ" arm64:"CLZ"
// mips:"CLZ"
// wasm:"I64Clz"
return bits.LeadingZeros8(n)
}
// --------------- //
// bits.Len* //
// --------------- //
func Len(n uint) int {
// amd64:"BSRQ"
// s390x:"FLOGR"
// arm:"CLZ" arm64:"CLZ"
// mips:"CLZ"
// wasm:"I64Clz"
return bits.Len(n)
}
func Len64(n uint64) int {
// amd64:"BSRQ"
// s390x:"FLOGR"
// arm:"CLZ" arm64:"CLZ"
// mips:"CLZ"
// wasm:"I64Clz"
// ppc64le:"SUBC","CNTLZD"
// ppc64:"SUBC","CNTLZD"
return bits.Len64(n)
}
func SubFromLen64(n uint64) int {
// ppc64le:"CNTLZD",-"SUBC"
// ppc64:"CNTLZD",-"SUBC"
return 64 - bits.Len64(n)
}
func Len32(n uint32) int {
// amd64:"BSRQ","LEAQ",-"CMOVQEQ"
// s390x:"FLOGR"
// arm:"CLZ" arm64:"CLZ"
// mips:"CLZ"
// wasm:"I64Clz"
return bits.Len32(n)
}
func Len16(n uint16) int {
// amd64:"BSRL","LEAL",-"CMOVQEQ"
// s390x:"FLOGR"
// arm:"CLZ" arm64:"CLZ"
// mips:"CLZ"
// wasm:"I64Clz"
return bits.Len16(n)
}
func Len8(n uint8) int {
// amd64:"BSRL","LEAL",-"CMOVQEQ"
// s390x:"FLOGR"
// arm:"CLZ" arm64:"CLZ"
// mips:"CLZ"
// wasm:"I64Clz"
return bits.Len8(n)
}
// -------------------- //
// bits.OnesCount //
// -------------------- //
// amd64:".*x86HasPOPCNT"
func OnesCount(n uint) int {
// amd64:"POPCNTQ"
// arm64:"VCNT","VUADDLV"
// s390x:"POPCNT"
// ppc64:"POPCNTD"
// ppc64le:"POPCNTD"
// wasm:"I64Popcnt"
return bits.OnesCount(n)
}
// amd64:".*x86HasPOPCNT"
func OnesCount64(n uint64) int {
// amd64:"POPCNTQ"
// arm64:"VCNT","VUADDLV"
// s390x:"POPCNT"
// ppc64:"POPCNTD"
// ppc64le:"POPCNTD"
// wasm:"I64Popcnt"
return bits.OnesCount64(n)
}
// amd64:".*x86HasPOPCNT"
func OnesCount32(n uint32) int {
// amd64:"POPCNTL"
// arm64:"VCNT","VUADDLV"
// s390x:"POPCNT"
// ppc64:"POPCNTW"
// ppc64le:"POPCNTW"
// wasm:"I64Popcnt"
return bits.OnesCount32(n)
}
// amd64:".*x86HasPOPCNT"
func OnesCount16(n uint16) int {
// amd64:"POPCNTL"
// arm64:"VCNT","VUADDLV"
// s390x:"POPCNT"
// ppc64:"POPCNTW"
// ppc64le:"POPCNTW"
// wasm:"I64Popcnt"
return bits.OnesCount16(n)
}
func OnesCount8(n uint8) int {
// s390x:"POPCNT"
// ppc64:"POPCNTB"
// ppc64le:"POPCNTB"
// wasm:"I64Popcnt"
return bits.OnesCount8(n)
}
// ----------------------- //
// bits.ReverseBytes //
// ----------------------- //
func ReverseBytes(n uint) uint {
// amd64:"BSWAPQ"
// s390x:"MOVDBR"
// arm64:"REV"
return bits.ReverseBytes(n)
}
func ReverseBytes64(n uint64) uint64 {
// amd64:"BSWAPQ"
// s390x:"MOVDBR"
// arm64:"REV"
return bits.ReverseBytes64(n)
}
func ReverseBytes32(n uint32) uint32 {
// amd64:"BSWAPL"
// s390x:"MOVWBR"
// arm64:"REVW"
return bits.ReverseBytes32(n)
}
func ReverseBytes16(n uint16) uint16 {
// amd64:"ROLW"
// arm64:"REV16W",-"UBFX",-"ORR"
// arm/5:"SLL","SRL","ORR"
// arm/6:"REV16"
// arm/7:"REV16"
return bits.ReverseBytes16(n)
}
// --------------------- //
// bits.RotateLeft //
// --------------------- //
func RotateLeft64(n uint64) uint64 {
// amd64:"ROLQ"
// arm64:"ROR"
// ppc64:"ROTL"
// ppc64le:"ROTL"
// s390x:"RISBGZ\t[$]0, [$]63, [$]37, "
// wasm:"I64Rotl"
return bits.RotateLeft64(n, 37)
}
func RotateLeft32(n uint32) uint32 {
// amd64:"ROLL" 386:"ROLL"
// arm:`MOVW\tR[0-9]+@>23`
// arm64:"RORW"
// ppc64:"ROTLW"
// ppc64le:"ROTLW"
// s390x:"RLL"
// wasm:"I32Rotl"
return bits.RotateLeft32(n, 9)
}
func RotateLeft16(n uint16) uint16 {
// amd64:"ROLW" 386:"ROLW"
return bits.RotateLeft16(n, 5)
}
func RotateLeft8(n uint8) uint8 {
// amd64:"ROLB" 386:"ROLB"
return bits.RotateLeft8(n, 5)
}
func RotateLeftVariable(n uint, m int) uint {
// amd64:"ROLQ"
// arm64:"ROR"
// ppc64:"ROTL"
// ppc64le:"ROTL"
// s390x:"RLLG"
// wasm:"I64Rotl"
return bits.RotateLeft(n, m)
}
func RotateLeftVariable64(n uint64, m int) uint64 {
// amd64:"ROLQ"
// arm64:"ROR"
// ppc64:"ROTL"
// ppc64le:"ROTL"
// s390x:"RLLG"
// wasm:"I64Rotl"
return bits.RotateLeft64(n, m)
}
func RotateLeftVariable32(n uint32, m int) uint32 {
// arm:`MOVW\tR[0-9]+@>R[0-9]+`
// amd64:"ROLL"
// arm64:"RORW"
// ppc64:"ROTLW"
// ppc64le:"ROTLW"
// s390x:"RLL"
// wasm:"I32Rotl"
return bits.RotateLeft32(n, m)
}
// ------------------------ //
// bits.TrailingZeros //
// ------------------------ //
func TrailingZeros(n uint) int {
// amd64:"BSFQ","MOVL\t\\$64","CMOVQEQ"
// arm:"CLZ"
// arm64:"RBIT","CLZ"
// s390x:"FLOGR"
// ppc64/power8:"ANDN","POPCNTD"
// ppc64le/power8:"ANDN","POPCNTD"
// ppc64/power9: "CNTTZD"
// ppc64le/power9: "CNTTZD"
// wasm:"I64Ctz"
return bits.TrailingZeros(n)
}
func TrailingZeros64(n uint64) int {
// amd64:"BSFQ","MOVL\t\\$64","CMOVQEQ"
// arm64:"RBIT","CLZ"
// s390x:"FLOGR"
// ppc64/power8:"ANDN","POPCNTD"
// ppc64le/power8:"ANDN","POPCNTD"
// ppc64/power9: "CNTTZD"
// ppc64le/power9: "CNTTZD"
// wasm:"I64Ctz"
return bits.TrailingZeros64(n)
}
func TrailingZeros64Subtract(n uint64) int {
// ppc64le/power8:"NEG","SUBC","ANDN","POPCNTD"
// ppc64le/power9:"SUBC","CNTTZD"
return bits.TrailingZeros64(1 - n)
}
func TrailingZeros32(n uint32) int {
// amd64:"BTSQ\\t\\$32","BSFQ"
// arm:"CLZ"
// arm64:"RBITW","CLZW"
// s390x:"FLOGR","MOVWZ"
// ppc64/power8:"ANDN","POPCNTW"
// ppc64le/power8:"ANDN","POPCNTW"
// ppc64/power9: "CNTTZW"
// ppc64le/power9: "CNTTZW"
// wasm:"I64Ctz"
return bits.TrailingZeros32(n)
}
func TrailingZeros16(n uint16) int {
// amd64:"BSFL","BTSL\\t\\$16"
// 386:"BSFL\t"
// arm:"ORR\t\\$65536","CLZ",-"MOVHU\tR"
// arm64:"ORR\t\\$65536","RBITW","CLZW",-"MOVHU\tR",-"RBIT\t",-"CLZ\t"
// s390x:"FLOGR","OR\t\\$65536"
// ppc64/power8:"POPCNTD","OR\\t\\$65536"
// ppc64le/power8:"POPCNTD","OR\\t\\$65536"
// ppc64/power9:"CNTTZD","OR\\t\\$65536"
// ppc64le/power9:"CNTTZD","OR\\t\\$65536"
// wasm:"I64Ctz"
return bits.TrailingZeros16(n)
}
func TrailingZeros8(n uint8) int {
// amd64:"BSFL","BTSL\\t\\$8"
// arm:"ORR\t\\$256","CLZ",-"MOVBU\tR"
// arm64:"ORR\t\\$256","RBITW","CLZW",-"MOVBU\tR",-"RBIT\t",-"CLZ\t"
// s390x:"FLOGR","OR\t\\$256"
// wasm:"I64Ctz"
return bits.TrailingZeros8(n)
}
// IterateBitsNN checks special handling of TrailingZerosNN when the input is known to be non-zero.
func IterateBits(n uint) int {
i := 0
for n != 0 {
// amd64:"BSFQ",-"CMOVEQ"
i += bits.TrailingZeros(n)
n &= n - 1
}
return i
}
func IterateBits64(n uint64) int {
i := 0
for n != 0 {
// amd64:"BSFQ",-"CMOVEQ"
i += bits.TrailingZeros64(n)
n &= n - 1
}
return i
}
func IterateBits32(n uint32) int {
i := 0
for n != 0 {
// amd64:"BSFL",-"BTSQ"
i += bits.TrailingZeros32(n)
n &= n - 1
}
return i
}
func IterateBits16(n uint16) int {
i := 0
for n != 0 {
// amd64:"BSFL",-"BTSL"
// arm64:"RBITW","CLZW",-"ORR"
i += bits.TrailingZeros16(n)
n &= n - 1
}
return i
}
func IterateBits8(n uint8) int {
i := 0
for n != 0 {
// amd64:"BSFL",-"BTSL"
// arm64:"RBITW","CLZW",-"ORR"
i += bits.TrailingZeros8(n)
n &= n - 1
}
return i
}
// --------------- //
// bits.Add* //
// --------------- //
func Add(x, y, ci uint) (r, co uint) {
// arm64:"ADDS","ADCS","ADC",-"ADD\t",-"CMP"
// amd64:"NEGL","ADCQ","SBBQ","NEGQ"
// s390x:"ADDE","ADDC\t[$]-1,"
return bits.Add(x, y, ci)
}
func AddC(x, ci uint) (r, co uint) {
// arm64:"ADDS","ADCS","ADC",-"ADD\t",-"CMP"
// amd64:"NEGL","ADCQ","SBBQ","NEGQ"
// s390x:"ADDE","ADDC\t[$]-1,"
return bits.Add(x, 7, ci)
}
func AddZ(x, y uint) (r, co uint) {
// arm64:"ADDS","ADC",-"ADCS",-"ADD\t",-"CMP"
// amd64:"ADDQ","SBBQ","NEGQ",-"NEGL",-"ADCQ"
// s390x:"ADDC",-"ADDC\t[$]-1,"
return bits.Add(x, y, 0)
}
func AddR(x, y, ci uint) uint {
// arm64:"ADDS","ADCS",-"ADD\t",-"CMP"
// amd64:"NEGL","ADCQ",-"SBBQ",-"NEGQ"
// s390x:"ADDE","ADDC\t[$]-1,"
r, _ := bits.Add(x, y, ci)
return r
}
func AddM(p, q, r *[3]uint) {
var c uint
r[0], c = bits.Add(p[0], q[0], c)
// arm64:"ADCS",-"ADD\t",-"CMP"
// amd64:"ADCQ",-"NEGL",-"SBBQ",-"NEGQ"
// s390x:"ADDE",-"ADDC\t[$]-1,"
r[1], c = bits.Add(p[1], q[1], c)
r[2], c = bits.Add(p[2], q[2], c)
}
func Add64(x, y, ci uint64) (r, co uint64) {
// arm64:"ADDS","ADCS","ADC",-"ADD\t",-"CMP"
// amd64:"NEGL","ADCQ","SBBQ","NEGQ"
// ppc64: "ADDC", "ADDE", "ADDZE"
// ppc64le: "ADDC", "ADDE", "ADDZE"
// s390x:"ADDE","ADDC\t[$]-1,"
return bits.Add64(x, y, ci)
}
func Add64C(x, ci uint64) (r, co uint64) {
// arm64:"ADDS","ADCS","ADC",-"ADD\t",-"CMP"
// amd64:"NEGL","ADCQ","SBBQ","NEGQ"
// ppc64: "ADDC", "ADDE", "ADDZE"
// ppc64le: "ADDC", "ADDE", "ADDZE"
// s390x:"ADDE","ADDC\t[$]-1,"
return bits.Add64(x, 7, ci)
}
func Add64Z(x, y uint64) (r, co uint64) {
// arm64:"ADDS","ADC",-"ADCS",-"ADD\t",-"CMP"
// amd64:"ADDQ","SBBQ","NEGQ",-"NEGL",-"ADCQ"
// ppc64: "ADDC", "ADDE", "ADDZE"
// ppc64le: "ADDC", "ADDE", "ADDZE"
// s390x:"ADDC",-"ADDC\t[$]-1,"
return bits.Add64(x, y, 0)
}
func Add64R(x, y, ci uint64) uint64 {
// arm64:"ADDS","ADCS",-"ADD\t",-"CMP"
// amd64:"NEGL","ADCQ",-"SBBQ",-"NEGQ"
// ppc64: "ADDC", "ADDE", "ADDZE"
// ppc64le: "ADDC", "ADDE", "ADDZE"
// s390x:"ADDE","ADDC\t[$]-1,"
r, _ := bits.Add64(x, y, ci)
return r
}
func Add64M(p, q, r *[3]uint64) {
var c uint64
r[0], c = bits.Add64(p[0], q[0], c)
// arm64:"ADCS",-"ADD\t",-"CMP"
// amd64:"ADCQ",-"NEGL",-"SBBQ",-"NEGQ"
// ppc64: "ADDC", "ADDE", "ADDZE"
// ppc64le: "ADDC", "ADDE", "ADDZE"
// s390x:"ADDE",-"ADDC\t[$]-1,"
r[1], c = bits.Add64(p[1], q[1], c)
r[2], c = bits.Add64(p[2], q[2], c)
}
func Add64PanicOnOverflowEQ(a, b uint64) uint64 {
r, c := bits.Add64(a, b, 0)
// s390x:"BRC\t[$]3,",-"ADDE"
if c == 1 {
panic("overflow")
}
return r
}
func Add64PanicOnOverflowNE(a, b uint64) uint64 {
r, c := bits.Add64(a, b, 0)
// s390x:"BRC\t[$]3,",-"ADDE"
if c != 0 {
panic("overflow")
}
return r
}
func Add64PanicOnOverflowGT(a, b uint64) uint64 {
r, c := bits.Add64(a, b, 0)
// s390x:"BRC\t[$]3,",-"ADDE"
if c > 0 {
panic("overflow")
}
return r
}
func Add64MPanicOnOverflowEQ(a, b [2]uint64) [2]uint64 {
var r [2]uint64
var c uint64
r[0], c = bits.Add64(a[0], b[0], c)
r[1], c = bits.Add64(a[1], b[1], c)
// s390x:"BRC\t[$]3,"
if c == 1 {
panic("overflow")
}
return r
}
func Add64MPanicOnOverflowNE(a, b [2]uint64) [2]uint64 {
var r [2]uint64
var c uint64
r[0], c = bits.Add64(a[0], b[0], c)
r[1], c = bits.Add64(a[1], b[1], c)
// s390x:"BRC\t[$]3,"
if c != 0 {
panic("overflow")
}
return r
}
func Add64MPanicOnOverflowGT(a, b [2]uint64) [2]uint64 {
var r [2]uint64
var c uint64
r[0], c = bits.Add64(a[0], b[0], c)
r[1], c = bits.Add64(a[1], b[1], c)
// s390x:"BRC\t[$]3,"
if c > 0 {
panic("overflow")
}
return r
}
// --------------- //
// bits.Sub* //
// --------------- //
func Sub(x, y, ci uint) (r, co uint) {
// amd64:"NEGL","SBBQ","NEGQ"
// arm64:"NEGS","SBCS","NGC","NEG",-"ADD",-"SUB",-"CMP"
// s390x:"SUBE"
return bits.Sub(x, y, ci)
}
func SubC(x, ci uint) (r, co uint) {
// amd64:"NEGL","SBBQ","NEGQ"
// arm64:"NEGS","SBCS","NGC","NEG",-"ADD",-"SUB",-"CMP"
// s390x:"SUBE"
return bits.Sub(x, 7, ci)
}
func SubZ(x, y uint) (r, co uint) {
// amd64:"SUBQ","SBBQ","NEGQ",-"NEGL"
// arm64:"SUBS","NGC","NEG",-"SBCS",-"ADD",-"SUB\t",-"CMP"
// s390x:"SUBC"
return bits.Sub(x, y, 0)
}
func SubR(x, y, ci uint) uint {
// amd64:"NEGL","SBBQ",-"NEGQ"
// arm64:"NEGS","SBCS",-"NGC",-"NEG\t",-"ADD",-"SUB",-"CMP"
// s390x:"SUBE"
r, _ := bits.Sub(x, y, ci)
return r
}
func SubM(p, q, r *[3]uint) {
var c uint
r[0], c = bits.Sub(p[0], q[0], c)
// amd64:"SBBQ",-"NEGL",-"NEGQ"
// arm64:"SBCS",-"NEGS",-"NGC",-"NEG",-"ADD",-"SUB",-"CMP"
// s390x:"SUBE"
r[1], c = bits.Sub(p[1], q[1], c)
r[2], c = bits.Sub(p[2], q[2], c)
}
func Sub64(x, y, ci uint64) (r, co uint64) {
// amd64:"NEGL","SBBQ","NEGQ"
// arm64:"NEGS","SBCS","NGC","NEG",-"ADD",-"SUB",-"CMP"
// s390x:"SUBE"
return bits.Sub64(x, y, ci)
}
func Sub64C(x, ci uint64) (r, co uint64) {
// amd64:"NEGL","SBBQ","NEGQ"
// arm64:"NEGS","SBCS","NGC","NEG",-"ADD",-"SUB",-"CMP"
// s390x:"SUBE"
return bits.Sub64(x, 7, ci)
}
func Sub64Z(x, y uint64) (r, co uint64) {
// amd64:"SUBQ","SBBQ","NEGQ",-"NEGL"
// arm64:"SUBS","NGC","NEG",-"SBCS",-"ADD",-"SUB\t",-"CMP"
// s390x:"SUBC"
return bits.Sub64(x, y, 0)
}
func Sub64R(x, y, ci uint64) uint64 {
// amd64:"NEGL","SBBQ",-"NEGQ"
// arm64:"NEGS","SBCS",-"NGC",-"NEG\t",-"ADD",-"SUB",-"CMP"
// s390x:"SUBE"
r, _ := bits.Sub64(x, y, ci)
return r
}
func Sub64M(p, q, r *[3]uint64) {
var c uint64
r[0], c = bits.Sub64(p[0], q[0], c)
// amd64:"SBBQ",-"NEGL",-"NEGQ"
// arm64:"SBCS",-"NEGS",-"NGC",-"NEG",-"ADD",-"SUB",-"CMP"
// s390x:"SUBE"
r[1], c = bits.Sub64(p[1], q[1], c)
r[2], c = bits.Sub64(p[2], q[2], c)
}
func Sub64PanicOnOverflowEQ(a, b uint64) uint64 {
r, b := bits.Sub64(a, b, 0)
// s390x:"BRC\t[$]12,",-"ADDE",-"SUBE"
if b == 1 {
panic("overflow")
}
return r
}
func Sub64PanicOnOverflowNE(a, b uint64) uint64 {
r, b := bits.Sub64(a, b, 0)
// s390x:"BRC\t[$]12,",-"ADDE",-"SUBE"
if b != 0 {
panic("overflow")
}
return r
}
func Sub64PanicOnOverflowGT(a, b uint64) uint64 {
r, b := bits.Sub64(a, b, 0)
// s390x:"BRC\t[$]12,",-"ADDE",-"SUBE"
if b > 0 {
panic("overflow")
}
return r
}
func Sub64MPanicOnOverflowEQ(a, b [2]uint64) [2]uint64 {
var r [2]uint64
var c uint64
r[0], c = bits.Sub64(a[0], b[0], c)
r[1], c = bits.Sub64(a[1], b[1], c)
// s390x:"BRC\t[$]12,"
if c == 1 {
panic("overflow")
}
return r
}
func Sub64MPanicOnOverflowNE(a, b [2]uint64) [2]uint64 {
var r [2]uint64
var c uint64
r[0], c = bits.Sub64(a[0], b[0], c)
r[1], c = bits.Sub64(a[1], b[1], c)
// s390x:"BRC\t[$]12,"
if c != 0 {
panic("overflow")
}
return r
}
func Sub64MPanicOnOverflowGT(a, b [2]uint64) [2]uint64 {
var r [2]uint64
var c uint64
r[0], c = bits.Sub64(a[0], b[0], c)
r[1], c = bits.Sub64(a[1], b[1], c)
// s390x:"BRC\t[$]12,"
if c > 0 {
panic("overflow")
}
return r
}
// --------------- //
// bits.Mul* //
// --------------- //
func Mul(x, y uint) (hi, lo uint) {
// amd64:"MULQ"
// arm64:"UMULH","MUL"
// ppc64:"MULHDU","MULLD"
// ppc64le:"MULHDU","MULLD"
// s390x:"MLGR"
// mips64: "MULVU"
return bits.Mul(x, y)
}
func Mul64(x, y uint64) (hi, lo uint64) {
// amd64:"MULQ"
// arm64:"UMULH","MUL"
// ppc64:"MULHDU","MULLD"
// ppc64le:"MULHDU","MULLD"
// s390x:"MLGR"
// mips64: "MULVU"
return bits.Mul64(x, y)
}
// --------------- //
// bits.Div* //
// --------------- //
func Div(hi, lo, x uint) (q, r uint) {
// amd64:"DIVQ"
return bits.Div(hi, lo, x)
}
func Div32(hi, lo, x uint32) (q, r uint32) {
// arm64:"ORR","UDIV","MSUB",-"UREM"
return bits.Div32(hi, lo, x)
}
func Div64(hi, lo, x uint64) (q, r uint64) {
// amd64:"DIVQ"
return bits.Div64(hi, lo, x)
}
func Div64degenerate(x uint64) (q, r uint64) {
// amd64:-"DIVQ"
return bits.Div64(0, x, 5)
}