diff --git a/lib/CodeGen/TailDuplication.cpp b/lib/CodeGen/TailDuplication.cpp index d16369a4ca6..e5c23b36d29 100644 --- a/lib/CodeGen/TailDuplication.cpp +++ b/lib/CodeGen/TailDuplication.cpp @@ -207,7 +207,7 @@ bool TailDuplicatePass::TailDuplicateBlocks(MachineFunction &MF) { // TailBB's immediate successors are now successors of those predecessors // which duplicated TailBB. Add the predecessors as sources to the PHI // instructions. - bool isDead = MBB->pred_empty(); + bool isDead = MBB->pred_empty() && !MBB->hasAddressTaken(); if (PreRegAlloc) UpdateSuccessorsPHIs(MBB, isDead, TDBBs, Succs); @@ -568,9 +568,9 @@ bool TailDuplicatePass::isSimpleBB(MachineBasicBlock *TailBB) { if (TailBB->succ_size() != 1) return false; - MachineBasicBlock::iterator I = TailBB->getFirstNonPHI(); + MachineBasicBlock::iterator I = TailBB->begin(); MachineBasicBlock::iterator E = TailBB->end(); - while (I->isDebugValue() && I != E) + while (I != E && I->isDebugValue()) ++I; if (I == E) return true; @@ -712,7 +712,7 @@ TailDuplicatePass::TailDuplicate(MachineBasicBlock *TailBB, MachineFunction &MF, DenseSet UsedByPhi; getRegsUsedByPHIs(*TailBB, &UsedByPhi); - if (0 && isSimpleBB(TailBB)) + if (isSimpleBB(TailBB)) return duplicateSimpleBB(TailBB, TDBBs, UsedByPhi, Copies); // Iterate through all the unique predecessors and tail-duplicate this diff --git a/test/CodeGen/X86/tail-dup-addr.ll b/test/CodeGen/X86/tail-dup-addr.ll new file mode 100644 index 00000000000..c5a105cb587 --- /dev/null +++ b/test/CodeGen/X86/tail-dup-addr.ll @@ -0,0 +1,28 @@ +; RUN: llc < %s -mtriple=x86_64-apple-darwin | FileCheck %s + +; Test that we don't drop a block that has its address taken. + +; CHECK: Ltmp1: ## Block address taken +; CHECK: Ltmp2: ## Block address taken + +@a = common global i32 0, align 4 +@p = common global i8* null, align 8 + +define void @foo() noreturn nounwind uwtable ssp { +entry: + %tmp = load i32* @a, align 4 + %foo = icmp eq i32 0, %tmp + br i1 %foo, label %sw.bb, label %sw.default + +sw.bb: ; preds = %entry + store i8* blockaddress(@foo, %sw.bb1), i8** @p, align 8 + br label %sw.bb1 + +sw.bb1: ; preds = %sw.default, %sw.bb, %entry + store i8* blockaddress(@foo, %sw.default), i8** @p, align 8 + br label %sw.default + +sw.default: ; preds = %sw.bb1, %entry + store i8* blockaddress(@foo, %sw.bb1), i8** @p, align 8 + br label %sw.bb1 +}