diff options
| -rw-r--r-- | llvm/lib/Target/X86/X86FastISel.cpp | 6 | ||||
| -rw-r--r-- | llvm/test/CodeGen/X86/fast-isel-cmp-branch.ll | 29 |
2 files changed, 33 insertions, 2 deletions
diff --git a/llvm/lib/Target/X86/X86FastISel.cpp b/llvm/lib/Target/X86/X86FastISel.cpp index b7341f93eed..0c70eec4827 100644 --- a/llvm/lib/Target/X86/X86FastISel.cpp +++ b/llvm/lib/Target/X86/X86FastISel.cpp @@ -960,9 +960,11 @@ bool X86FastISel::X86SelectBranch(const Instruction *I) { MachineBasicBlock *TrueMBB = FuncInfo.MBBMap[BI->getSuccessor(0)]; MachineBasicBlock *FalseMBB = FuncInfo.MBBMap[BI->getSuccessor(1)]; - // Fold the common case of a conditional branch with a comparison. + // Fold the common case of a conditional branch with a comparison + // in the same block (values defined on other blocks may not have + // initialized registers). if (const CmpInst *CI = dyn_cast<CmpInst>(BI->getCondition())) { - if (CI->hasOneUse()) { + if (CI->hasOneUse() && CI->getParent() == I->getParent()) { EVT VT = TLI.getValueType(CI->getOperand(0)->getType()); // Try to take advantage of fallthrough opportunities. diff --git a/llvm/test/CodeGen/X86/fast-isel-cmp-branch.ll b/llvm/test/CodeGen/X86/fast-isel-cmp-branch.ll new file mode 100644 index 00000000000..4ab1bc61c7e --- /dev/null +++ b/llvm/test/CodeGen/X86/fast-isel-cmp-branch.ll @@ -0,0 +1,29 @@ +; RUN: llc -O0 -march=x86-64 -asm-verbose=false < %s | FileCheck %s +; rdar://8337108 + +; Fast-isel shouldn't try to look through the compare because it's in a +; different basic block, so its operands aren't necessarily exported +; for cross-block usage. + +; CHECK: movb %al, 7(%rsp) +; CHECK: callq {{_?}}bar +; CHECK: movb 7(%rsp), %al + +declare void @bar() + +define void @foo(i32 %a, i32 %b) nounwind { +entry: + %q = add i32 %a, 7 + %r = add i32 %b, 9 + %t = icmp ult i32 %q, %r + invoke void @bar() to label %next unwind label %unw +next: + br i1 %t, label %true, label %return +true: + call void @bar() + br label %return +return: + ret void +unw: + unreachable +} |
