Imported Upstream version 5.18.0.161

Former-commit-id: 4db48158d3a35497b8f118ab21b5f08ac3d86d98

external/llvm/test/Analysis/MemorySSA/lifetime-simple.ll

@@ -0,0 +1,30 @@
+; 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
+; This test checks a number of things:
+; First, the lifetime markers should not clobber any uses of Q or P.
+; Second, the loads of P are MemoryUse(LiveOnEntry) due to the placement of the markers vs the loads.
+
+define i8 @test(i8* %P, i8* %Q) {
+entry:
+; CHECK:  1 = MemoryDef(liveOnEntry)
+; CHECK-NEXT:   call void @llvm.lifetime.start.p0i8(i64 32, i8* %P)
+  call void @llvm.lifetime.start.p0i8(i64 32, i8* %P)
+; CHECK:  MemoryUse(1)
+; CHECK-NEXT:   %0 = load i8, i8* %P
+  %0 = load i8, i8* %P
+; CHECK:  2 = MemoryDef(1)
+; CHECK-NEXT:   store i8 1, i8* %P
+  store i8 1, i8* %P
+; CHECK:  3 = MemoryDef(2)
+; CHECK-NEXT:   call void @llvm.lifetime.end.p0i8(i64 32, i8* %P)
+  call void @llvm.lifetime.end.p0i8(i64 32, i8* %P)
+; CHECK:  MemoryUse(liveOnEntry)
+; CHECK-NEXT:   %1 = load i8, i8* %P
+  %1 = load i8, i8* %P
+; CHECK:  MemoryUse(2)
+; CHECK-NEXT:   %2 = load i8, i8* %Q
+  %2 = load i8, i8* %Q
+  ret i8 %1
+}
+declare void @llvm.lifetime.start.p0i8(i64 %S, i8* nocapture %P) readonly
+declare void @llvm.lifetime.end.p0i8(i64 %S, i8* nocapture %P)