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Diffstat (limited to 'llvm/test/Analysis/MemorySSA/load-invariant.ll')
| -rw-r--r-- | llvm/test/Analysis/MemorySSA/load-invariant.ll | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/llvm/test/Analysis/MemorySSA/load-invariant.ll b/llvm/test/Analysis/MemorySSA/load-invariant.ll new file mode 100644 index 00000000000..defb74641ea --- /dev/null +++ b/llvm/test/Analysis/MemorySSA/load-invariant.ll @@ -0,0 +1,38 @@ +; RUN: opt -basicaa -print-memoryssa -verify-memoryssa -analyze < %s 2>&1 | FileCheck %s +; RUN: opt -aa-pipeline=basic-aa -passes='print<memoryssa>' -verify-memoryssa -disable-output < %s 2>&1 | FileCheck %s +; +; Invariant loads should be considered live on entry, because, once the +; location is known to be dereferenceable, the value can never change. + +@g = external global i32 + +declare void @clobberAllTheThings() + +; CHECK-LABEL: define i32 @foo +define i32 @foo() { +; CHECK: 1 = MemoryDef(liveOnEntry) +; CHECK-NEXT: call void @clobberAllTheThings() + call void @clobberAllTheThings() +; CHECK: MemoryUse(liveOnEntry) +; CHECK-NEXT: %1 = load i32 + %1 = load i32, i32* @g, align 4, !invariant.load !0 + ret i32 %1 +} + +; CHECK-LABEL: define i32 @bar +define i32 @bar(i32* %a) { +; CHECK: 1 = MemoryDef(liveOnEntry) +; CHECK-NEXT: call void @clobberAllTheThings() + call void @clobberAllTheThings() + +; CHECK: 2 = MemoryDef(1) +; CHECK-NEXT: %1 = load atomic i32 + %1 = load atomic i32, i32* %a acquire, align 4, !invariant.load !0 + +; CHECK: MemoryUse(2) +; CHECK-NEXT: %2 = load i32 + %2 = load i32, i32* %a, align 4 + ret i32 %2 +} + +!0 = !{} |
