06c192d454
Upgrade of the IR text tests should be the only thing blocking making typed byval mandatory. Partially done through regex and partially manual.
97 lines
2.6 KiB
LLVM
97 lines
2.6 KiB
LLVM
; RUN: opt -S -basic-aa -dse -enable-dse-memoryssa=false < %s | FileCheck %s
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; We conservative choose to prevent dead store elimination
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; across release or stronger fences. It's not required
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; (since the must still be a race on %addd.i), but
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; it is conservatively correct. A legal optimization
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; could hoist the second store above the fence, and then
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; DSE one of them.
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define void @test1(i32* %addr.i) {
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; CHECK-LABEL: @test1
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; CHECK: store i32 5
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; CHECK: fence
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; CHECK: store i32 5
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; CHECK: ret
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store i32 5, i32* %addr.i, align 4
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fence release
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store i32 5, i32* %addr.i, align 4
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ret void
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}
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; Same as previous, but with different values. If we ever optimize
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; this more aggressively, this allows us to check that the correct
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; store is retained (the 'i32 1' store in this case)
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define void @test1b(i32* %addr.i) {
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; CHECK-LABEL: @test1b
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; CHECK: store i32 42
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; CHECK: fence release
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; CHECK: store i32 1
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; CHECK: ret
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store i32 42, i32* %addr.i, align 4
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fence release
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store i32 1, i32* %addr.i, align 4
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ret void
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}
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; We *could* DSE across this fence, but don't. No other thread can
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; observe the order of the acquire fence and the store.
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define void @test2(i32* %addr.i) {
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; CHECK-LABEL: @test2
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; CHECK: store
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; CHECK: fence
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; CHECK: store
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; CHECK: ret
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store i32 5, i32* %addr.i, align 4
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fence acquire
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store i32 5, i32* %addr.i, align 4
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ret void
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}
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; We DSE stack alloc'ed and byval locations, in the presence of fences.
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; Fence does not make an otherwise thread local store visible.
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; Right now the DSE in presence of fence is only done in end blocks (with no successors),
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; but the same logic applies to other basic blocks as well.
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; The store to %addr.i can be removed since it is a byval attribute
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define void @test3(i32* byval(i32) %addr.i) {
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; CHECK-LABEL: @test3
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; CHECK-NOT: store
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; CHECK: fence
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; CHECK: ret
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store i32 5, i32* %addr.i, align 4
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fence release
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ret void
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}
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declare void @foo(i8* nocapture %p)
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declare noalias i8* @malloc(i32)
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; DSE of stores in locations allocated through library calls.
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define void @test_nocapture() {
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; CHECK-LABEL: @test_nocapture
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; CHECK: malloc
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; CHECK: foo
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; CHECK-NOT: store
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; CHECK: fence
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%m = call i8* @malloc(i32 24)
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call void @foo(i8* %m)
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store i8 4, i8* %m
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fence release
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ret void
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}
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; This is a full fence, but it does not make a thread local store visible.
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; We can DSE the store in presence of the fence.
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define void @fence_seq_cst() {
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; CHECK-LABEL: @fence_seq_cst
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; CHECK-NEXT: fence seq_cst
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; CHECK-NEXT: ret void
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%P1 = alloca i32
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store i32 0, i32* %P1, align 4
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fence seq_cst
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store i32 4, i32* %P1, align 4
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ret void
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}
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