From 5d2f8072d41bcde63c9f4267efe2d50bacc1e5f3 Mon Sep 17 00:00:00 2001 From: Owen Anderson Date: Tue, 5 Aug 2008 21:40:45 +0000 Subject: [PATCH] Correctly handle replacement and removal of PHIs with one incoming register. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54374 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/UnreachableBlockElim.cpp | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/lib/CodeGen/UnreachableBlockElim.cpp b/lib/CodeGen/UnreachableBlockElim.cpp index 19341ee7215..ca682fd65a0 100644 --- a/lib/CodeGen/UnreachableBlockElim.cpp +++ b/lib/CodeGen/UnreachableBlockElim.cpp @@ -27,6 +27,7 @@ #include "llvm/Pass.h" #include "llvm/Type.h" #include "llvm/CodeGen/MachineFunctionPass.h" +#include "llvm/CodeGen/MachineRegisterInfo.h" #include "llvm/Support/CFG.h" #include "llvm/Support/Compiler.h" #include "llvm/Target/TargetInstrInfo.h" @@ -128,10 +129,15 @@ bool UnreachableMachineBlockElim::runOnMachineFunction(MachineFunction &F) { start->RemoveOperand(i-1); } - if (start->getNumOperands() == 1) { + if (start->getNumOperands() == 3) { MachineInstr* phi = start; + unsigned Input = phi->getOperand(1).getReg(); + unsigned Output = phi->getOperand(0).getReg(); + start++; phi->eraseFromParent(); + + F.getRegInfo().replaceRegWith(Output, Input); } else start++; }