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d93ff73ae2
For an extension operation like MOWWreg, if the operand is already extended, we optimize the second extension out. Usually a LoadReg of a proper type would come already extended, as a MOVW/MOVWU etc. instruction does. But for a LoadReg to a floating point register, the instruction does not do the extension. So we cannot elide the extension. Fixes #50671. Change-Id: Id8991df78d5acdecd3fd6138c558428cbd5f6ba3 Reviewed-on: https://go-review.googlesource.com/c/go/+/379236 Trust: Cherry Mui <cherryyz@google.com> Run-TryBot: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: David Chase <drchase@google.com>
36 lines
599 B
Go
36 lines
599 B
Go
// run
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// Copyright 2022 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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// Issue 50671: sign extension eliminated incorrectly on MIPS64.
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package main
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//go:noinline
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func F(x int32) (float64, int64) {
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a := float64(x)
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b := int64(x)
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return a, b
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}
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var a, b, c float64
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// Poison some floating point registers with non-zero high bits.
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//
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//go:noinline
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func poison(x float64) {
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a = x - 123.45
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b = a * 1.2
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c = b + 3.4
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}
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func main() {
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poison(333.3)
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_, b := F(123)
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if b != 123 {
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panic("FAIL")
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}
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}
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