diff options
| -rw-r--r-- | llvm/lib/CodeGen/Analysis.cpp | 4 | ||||
| -rw-r--r-- | llvm/test/CodeGen/X86/tailcall-lifetime-end.ll | 27 |
2 files changed, 31 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/Analysis.cpp b/llvm/lib/CodeGen/Analysis.cpp index aae04a573af..27dce7fd7b7 100644 --- a/llvm/lib/CodeGen/Analysis.cpp +++ b/llvm/lib/CodeGen/Analysis.cpp @@ -496,6 +496,10 @@ bool llvm::isInTailCallPosition(ImmutableCallSite CS, const TargetMachine &TM) { // Debug info intrinsics do not get in the way of tail call optimization. if (isa<DbgInfoIntrinsic>(BBI)) continue; + // A lifetime end intrinsic should not stop tail call optimization. + if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(BBI)) + if (II->getIntrinsicID() == Intrinsic::lifetime_end) + continue; if (BBI->mayHaveSideEffects() || BBI->mayReadFromMemory() || !isSafeToSpeculativelyExecute(&*BBI)) return false; diff --git a/llvm/test/CodeGen/X86/tailcall-lifetime-end.ll b/llvm/test/CodeGen/X86/tailcall-lifetime-end.ll new file mode 100644 index 00000000000..3aedd007d44 --- /dev/null +++ b/llvm/test/CodeGen/X86/tailcall-lifetime-end.ll @@ -0,0 +1,27 @@ +; RUN: llc -mtriple=x86_64-unknown-linux-gnu -o - %s | FileCheck %s + +; A lifetime end intrinsic should not prevent a call from being tail call +; optimized. + +define void @foobar() { +; CHECK-LABEL: foobar +; CHECK: pushq %rax +; CHECK: leaq 4(%rsp), %rdi +; CHECK: callq foo +; CHECK: popq %rax +; CHECK: jmp bar +entry: + %i = alloca i32 + %0 = bitcast i32* %i to i8* + call void @llvm.lifetime.start.p0i8(i64 4, i8* nonnull %0) + call void @foo(i32* nonnull %i) + tail call void @bar() + call void @llvm.lifetime.end.p0i8(i64 4, i8* nonnull %0) + ret void +} + +declare void @foo(i32* nocapture %p) +declare void @bar() + +declare void @llvm.lifetime.start.p0i8(i64, i8* nocapture) +declare void @llvm.lifetime.end.p0i8(i64, i8* nocapture) |
