Index: lib/Transforms/Utils/InlineFunction.cpp =================================================================== --- lib/Transforms/Utils/InlineFunction.cpp +++ lib/Transforms/Utils/InlineFunction.cpp @@ -755,8 +755,13 @@ } builder.CreateLifetimeStart(AI, AllocaSize); - for (ReturnInst *RI : Returns) + for (ReturnInst *RI : Returns) { + // Don't insert llvm.lifetime.end calls between a musttail call and a + // return. The return kills all local allocas. + if (InlinedMustTailCalls && getPrecedingMustTailCall(RI)) + continue; IRBuilder<>(RI).CreateLifetimeEnd(AI, AllocaSize); + } } } @@ -774,8 +779,13 @@ // Insert a call to llvm.stackrestore before any return instructions in the // inlined function. - for (ReturnInst *RI : Returns) + for (ReturnInst *RI : Returns) { + // Don't insert llvm.stackrestore calls between a musttail call and a + // return. The return will restore the stack pointer. + if (InlinedMustTailCalls && getPrecedingMustTailCall(RI)) + continue; IRBuilder<>(RI).CreateCall(StackRestore, SavedPtr); + } } // If we are inlining for an invoke instruction, we must make sure to rewrite Index: test/Transforms/Inline/inline-tail.ll =================================================================== --- test/Transforms/Inline/inline-tail.ll +++ test/Transforms/Inline/inline-tail.ll @@ -49,6 +49,42 @@ ret void } +; Don't insert lifetime end markers here, the lifetime is trivially over due +; the return. +; CHECK: define void @test_byval_a( +; CHECK: musttail call void @test_byval_c( +; CHECK-NEXT: ret void + +declare void @test_byval_c(i32* byval %p) +define internal void @test_byval_b(i32* byval %p) { + musttail call void @test_byval_c(i32* byval %p) + ret void +} +define void @test_byval_a(i32* byval %p) { + musttail call void @test_byval_b(i32* byval %p) + ret void +} + +; Don't insert a stack restore, we're about to return. +; CHECK: define void @test_dynalloca_a( +; CHECK: call i8* @llvm.stacksave( +; CHECK: alloca i8, i32 %n +; CHECK: musttail call void @test_dynalloca_c( +; CHECK-NEXT: ret void + +declare void @escape(i8* %buf) +declare void @test_dynalloca_c(i32* byval %p, i32 %n) +define internal void @test_dynalloca_b(i32* byval %p, i32 %n) alwaysinline { + %buf = alloca i8, i32 %n ; dynamic alloca + call void @escape(i8* %buf) ; escape it + musttail call void @test_dynalloca_c(i32* byval %p, i32 %n) + ret void +} +define void @test_dynalloca_a(i32* byval %p, i32 %n) { + musttail call void @test_dynalloca_b(i32* byval %p, i32 %n) + ret void +} + ; We can't merge the returns. ; CHECK: define void @test_multiret_a( ; CHECK: musttail call void @test_multiret_c(