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shift.go
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shift.go
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// 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 lshGuarded64(v int64, s uint) int64 {
if s < 64 {
// s390x:-".*AND",-".*MOVDGE"
return v >> s
}
panic("shift too large")
}
func rshGuarded64U(v uint64, s uint) uint64 {
if s < 64 {
// s390x:-".*AND",-".*MOVDGE"
return v >> s
}
panic("shift too large")
}
func rshGuarded64(v int64, s uint) int64 {
if s < 64 {
// s390x:-".*AND",-".*MOVDGE"
return v << s
}
panic("shift too large")
}