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93b7eb973f
Load/store-merging and move optimizations can result in unaligned memory accesses. This is fine so long as the load/store instruction used does not take a relative offset. In the SSA rules this means we must not merge (MOVDaddr (SB)) ops into loads/stores unless we can guarantee the alignment of the target. Fixes #21048. Change-Id: I70f13a62a148d5f0a56e704e8f76e36b4a4226d9 Reviewed-on: https://go-review.googlesource.com/49250 Run-TryBot: Michael Munday <mike.munday@ibm.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
73 lines
1.1 KiB
Go
73 lines
1.1 KiB
Go
// run
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// Copyright 2017 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 21048: s390x merged address generation into stores
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// to unaligned global variables. This resulted in an illegal
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// instruction.
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package main
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type T struct {
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_ [1]byte
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a [2]byte // offset: 1
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_ [3]byte
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b [2]uint16 // offset: 6
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_ [2]byte
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c [2]uint32 // offset: 12
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_ [2]byte
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d [2]int16 // offset: 22
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_ [2]byte
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e [2]int32 // offset: 28
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}
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var Source, Sink T
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func newT() T {
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return T{
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a: [2]byte{1, 2},
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b: [2]uint16{1, 2},
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c: [2]uint32{1, 2},
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d: [2]int16{1, 2},
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e: [2]int32{1, 2},
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}
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}
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//go:noinline
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func moves() {
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Sink.a = Source.a
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Sink.b = Source.b
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Sink.c = Source.c
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Sink.d = Source.d
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Sink.e = Source.e
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}
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//go:noinline
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func loads() *T {
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t := newT()
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t.a = Source.a
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t.b = Source.b
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t.c = Source.c
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t.d = Source.d
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t.e = Source.e
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return &t
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}
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//go:noinline
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func stores() {
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t := newT()
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Sink.a = t.a
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Sink.b = t.b
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Sink.c = t.c
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Sink.d = t.d
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Sink.e = t.e
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}
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func main() {
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moves()
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loads()
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stores()
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}
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