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![Keith Randall](/assets/img/avatar_default.png)
If we're not using the upper bits, don't bother issuing a sign/zero extension operation. For arm64, after CL 520916 which fixed a correctness bug with extensions but as a side effect leaves many unnecessary ones still in place. Change-Id: I5f4fe4efbf2e9f80969ab5b9a6122fb812dc2ec0 Reviewed-on: https://go-review.googlesource.com/c/go/+/521496 Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: Keith Randall <khr@google.com> Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gopher Robot <gobot@golang.org>
287 lines
5.4 KiB
Go
287 lines
5.4 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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import "math/bits"
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var sval64 [8]int64
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var sval32 [8]int32
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var sval16 [8]int16
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var sval8 [8]int8
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var val64 [8]uint64
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var val32 [8]uint32
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var val16 [8]uint16
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var val8 [8]uint8
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// Avoid zero/sign extensions following a load
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// which has extended the value correctly.
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// Note: No tests are done for int8 since
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// an extra extension is usually needed due to
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// no signed byte load.
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func set16(x8 int8, u8 *uint8, y8 int8, z8 uint8) {
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// Truncate not needed, load does sign/zero extend
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// ppc64x:-"MOVBZ\tR\\d+,\\sR\\d+"
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val16[0] = uint16(*u8)
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// AND not needed due to size
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// ppc64x:-"ANDCC"
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sval16[1] = 255 & int16(x8+y8)
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// ppc64x:-"ANDCC"
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val16[1] = 255 & uint16(*u8+z8)
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}
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func shiftidx(u8 *uint8, x16 *int16, u16 *uint16) {
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// ppc64x:-"MOVBZ\tR\\d+,\\sR\\d+"
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val16[0] = uint16(sval16[*u8>>2])
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// ppc64x:-"MOVH\tR\\d+,\\sR\\d+"
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sval16[1] = int16(val16[*x16>>1])
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// ppc64x:-"MOVHZ\tR\\d+,\\sR\\d+"
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val16[1] = uint16(sval16[*u16>>2])
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}
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func setnox(x8 int8, u8 *uint8, y8 *int8, z8 *uint8, x16 *int16, u16 *uint16, x32 *int32, u32 *uint32) {
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// ppc64x:-"MOVBZ\tR\\d+,\\sR\\d+"
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val16[0] = uint16(*u8)
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// AND not needed due to size
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// ppc64x:-"ANDCC"
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sval16[1] = 255 & int16(x8+*y8)
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// ppc64x:-"ANDCC"
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val16[1] = 255 & uint16(*u8+*z8)
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// ppc64x:-"MOVH\tR\\d+,\\sR\\d+"
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sval32[1] = int32(*x16)
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// ppc64x:-"MOVBZ\tR\\d+,\\sR\\d+"
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val32[0] = uint32(*u8)
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// ppc64x:-"MOVHZ\tR\\d+,\\sR\\d+"
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val32[1] = uint32(*u16)
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// ppc64x:-"MOVH\tR\\d+,\\sR\\d+"
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sval64[1] = int64(*x16)
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// ppc64x:-"MOVW\tR\\d+,\\sR\\d+"
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sval64[2] = int64(*x32)
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// ppc64x:-"MOVBZ\tR\\d+,\\sR\\d+"
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val64[0] = uint64(*u8)
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// ppc64x:-"MOVHZ\tR\\d+,\\sR\\d+"
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val64[1] = uint64(*u16)
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// ppc64x:-"MOVWZ\tR\\d+,\\sR\\d+"
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val64[2] = uint64(*u32)
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}
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func cmp16(u8 *uint8, x32 *int32, u32 *uint32, x64 *int64, u64 *uint64) bool {
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// ppc64x:-"MOVBZ\tR\\d+,\\sR\\d+"
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if uint16(*u8) == val16[0] {
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return true
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}
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// ppc64x:-"MOVHZ\tR\\d+,\\sR\\d+"
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if uint16(*u32>>16) == val16[0] {
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return true
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}
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// ppc64x:-"MOVHZ\tR\\d+,\\sR\\d+"
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if uint16(*u64>>48) == val16[0] {
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return true
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}
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// Verify the truncates are using the correct sign.
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// ppc64x:-"MOVHZ\tR\\d+,\\sR\\d+"
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if int16(*x32) == sval16[0] {
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return true
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}
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// ppc64x:-"MOVH\tR\\d+,\\sR\\d+"
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if uint16(*u32) == val16[0] {
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return true
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}
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// ppc64x:-"MOVHZ\tR\\d+,\\sR\\d+"
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if int16(*x64) == sval16[0] {
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return true
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}
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// ppc64x:-"MOVH\tR\\d+,\\sR\\d+"
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if uint16(*u64) == val16[0] {
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return true
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}
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return false
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}
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func cmp32(u8 *uint8, x16 *int16, u16 *uint16, x64 *int64, u64 *uint64) bool {
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// ppc64x:-"MOVBZ\tR\\d+,\\sR\\d+"
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if uint32(*u8) == val32[0] {
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return true
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}
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// ppc64x:-"MOVH\tR\\d+,\\sR\\d+"
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if int32(*x16) == sval32[0] {
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return true
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}
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// ppc64x:-"MOVHZ\tR\\d+,\\sR\\d+"
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if uint32(*u16) == val32[0] {
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return true
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}
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// Verify the truncates are using the correct sign.
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// ppc64x:-"MOVWZ\tR\\d+,\\sR\\d+"
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if int32(*x64) == sval32[0] {
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return true
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}
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// ppc64x:-"MOVW\tR\\d+,\\sR\\d+"
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if uint32(*u64) == val32[0] {
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return true
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}
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return false
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}
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func cmp64(u8 *uint8, x16 *int16, u16 *uint16, x32 *int32, u32 *uint32) bool {
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// ppc64x:-"MOVBZ\tR\\d+,\\sR\\d+"
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if uint64(*u8) == val64[0] {
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return true
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}
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// ppc64x:-"MOVH\tR\\d+,\\sR\\d+"
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if int64(*x16) == sval64[0] {
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return true
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}
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// ppc64x:-"MOVHZ\tR\\d+,\\sR\\d+"
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if uint64(*u16) == val64[0] {
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return true
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}
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// ppc64x:-"MOVW\tR\\d+,\\sR\\d+"
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if int64(*x32) == sval64[0] {
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return true
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}
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// ppc64x:-"MOVWZ\tR\\d+,\\sR\\d+"
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if uint64(*u32) == val64[0] {
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return true
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}
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return false
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}
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// no unsign extension following 32 bits ops
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func noUnsignEXT(t1, t2, t3, t4 uint32, k int64) uint64 {
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var ret uint64
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// arm64:"RORW",-"MOVWU"
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ret += uint64(bits.RotateLeft32(t1, 7))
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// arm64:"MULW",-"MOVWU"
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ret *= uint64(t1 * t2)
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// arm64:"MNEGW",-"MOVWU"
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ret += uint64(-t1 * t3)
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// arm64:"UDIVW",-"MOVWU"
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ret += uint64(t1 / t4)
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// arm64:-"MOVWU"
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ret += uint64(t2 % t3)
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// arm64:"MSUBW",-"MOVWU"
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ret += uint64(t1 - t2*t3)
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// arm64:"MADDW",-"MOVWU"
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ret += uint64(t3*t4 + t2)
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// arm64:"REVW",-"MOVWU"
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ret += uint64(bits.ReverseBytes32(t1))
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// arm64:"RBITW",-"MOVWU"
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ret += uint64(bits.Reverse32(t1))
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// arm64:"CLZW",-"MOVWU"
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ret += uint64(bits.LeadingZeros32(t1))
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// arm64:"REV16W",-"MOVWU"
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ret += uint64(((t1 & 0xff00ff00) >> 8) | ((t1 & 0x00ff00ff) << 8))
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// arm64:"EXTRW",-"MOVWU"
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ret += uint64((t1 << 25) | (t2 >> 7))
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return ret
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}
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// no sign extension when the upper bits of the result are zero
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func noSignEXT(x int) int64 {
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t1 := int32(x)
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var ret int64
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// arm64:-"MOVW"
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ret += int64(t1 & 1)
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// arm64:-"MOVW"
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ret += int64(int32(x & 0x7fffffff))
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// arm64:-"MOVH"
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ret += int64(int16(x & 0x7fff))
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// arm64:-"MOVB"
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ret += int64(int8(x & 0x7f))
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return ret
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}
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// corner cases that sign extension must not be omitted
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func shouldSignEXT(x int) int64 {
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t1 := int32(x)
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var ret int64
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// arm64:"MOVW"
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ret += int64(t1 & (-1))
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// arm64:"MOVW"
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ret += int64(int32(x & 0x80000000))
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// arm64:"MOVW"
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ret += int64(int32(x & 0x1100000011111111))
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// arm64:"MOVH"
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ret += int64(int16(x & 0x1100000000001111))
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// arm64:"MOVB"
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ret += int64(int8(x & 0x1100000000000011))
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return ret
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}
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func noIntermediateExtension(a, b, c uint32) uint32 {
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// arm64:-"MOVWU"
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return a*b*9 + c
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}
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