mirror of
https://github.com/golang/go
synced 2024-11-18 08:44:43 -07:00
8fedb2d338
Use the shiftIsBounded function to generate more efficient Shift instructions. Updates #25167 Change-Id: Id350f8462dc3a7ed3bfed0bcbea2860b8f40048a Reviewed-on: https://go-review.googlesource.com/c/go/+/182558 Run-TryBot: Agniva De Sarker <agniva.quicksilver@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com> Reviewed-by: Richard Musiol <neelance@gmail.com>
128 lines
2.6 KiB
Go
128 lines
2.6 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
|
|
|
|
// ------------------ //
|
|
// masked shifts //
|
|
// ------------------ //
|
|
|
|
func lshMask64x64(v int64, s uint64) int64 {
|
|
// s390x:-".*AND",-".*MOVDGE"
|
|
return v << (s & 63)
|
|
}
|
|
|
|
func rshMask64Ux64(v uint64, s uint64) uint64 {
|
|
// s390x:-".*AND",-".*MOVDGE"
|
|
return v >> (s & 63)
|
|
}
|
|
|
|
func rshMask64x64(v int64, s uint64) int64 {
|
|
// s390x:-".*AND",-".*MOVDGE"
|
|
return v >> (s & 63)
|
|
}
|
|
|
|
func lshMask32x64(v int32, s uint64) int32 {
|
|
// s390x:-".*AND",-".*MOVDGE"
|
|
return v << (s & 63)
|
|
}
|
|
|
|
func rshMask32Ux64(v uint32, s uint64) uint32 {
|
|
// s390x:-".*AND",-".*MOVDGE"
|
|
return v >> (s & 63)
|
|
}
|
|
|
|
func rshMask32x64(v int32, s uint64) int32 {
|
|
// s390x:-".*AND",-".*MOVDGE"
|
|
return v >> (s & 63)
|
|
}
|
|
|
|
func lshMask64x32(v int64, s uint32) int64 {
|
|
// s390x:-".*AND",-".*MOVDGE"
|
|
return v << (s & 63)
|
|
}
|
|
|
|
func rshMask64Ux32(v uint64, s uint32) uint64 {
|
|
// s390x:-".*AND",-".*MOVDGE"
|
|
return v >> (s & 63)
|
|
}
|
|
|
|
func rshMask64x32(v int64, s uint32) int64 {
|
|
// s390x:-".*AND",-".*MOVDGE"
|
|
return v >> (s & 63)
|
|
}
|
|
|
|
func lshMask64x32Ext(v int64, s int32) int64 {
|
|
// s390x:-".*AND",-".*MOVDGE"
|
|
return v << uint(s&63)
|
|
}
|
|
|
|
func rshMask64Ux32Ext(v uint64, s int32) uint64 {
|
|
// s390x:-".*AND",-".*MOVDGE"
|
|
return v >> uint(s&63)
|
|
}
|
|
|
|
func rshMask64x32Ext(v int64, s int32) int64 {
|
|
// s390x:-".*AND",-".*MOVDGE"
|
|
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 rshGuarded64(v int64, s uint) int64 {
|
|
if s < 64 {
|
|
// s390x:-".*AND",-".*MOVDGE" wasm:-"Select",-".*LtU"
|
|
return v >> s
|
|
}
|
|
panic("shift too large")
|
|
}
|
|
|
|
func rshGuarded64U(v uint64, s uint) uint64 {
|
|
if s < 64 {
|
|
// s390x:-".*AND",-".*MOVDGE" wasm:-"Select",-".*LtU"
|
|
return v >> s
|
|
}
|
|
panic("shift too large")
|
|
}
|
|
|
|
func lshGuarded64(v int64, s uint) int64 {
|
|
if s < 64 {
|
|
// s390x:-".*AND",-".*MOVDGE" wasm:-"Select",-".*LtU"
|
|
return v << s
|
|
}
|
|
panic("shift too large")
|
|
}
|