Fix for PR34888.

The issue is that we assume operand zero of the input to the add instruction
is a register. In this case, the input comes from inline assembly and
operand zero is not a register thereby causing a crash.
The code will bail anyway if the input instruction doesn't have the right
opcode. So do that check first and let short-circuiting prevent the crash.

llvm-svn: 315285

1 files changed, 4 insertions, 3 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCMIPeephole.cpp b/llvm/lib/Target/PowerPC/PPCMIPeephole.cpp
index 66c1bb1c05c..8e7e067a21e 100644
--- a/llvm/lib/Target/PowerPC/PPCMIPeephole.cpp
+++ b/llvm/lib/Target/PowerPC/PPCMIPeephole.cpp
@@ -394,9 +394,10 @@ bool PPCMIPeephole::simplifyCode(void) {
           for (unsigned i = 1; i < DefPhiMI->getNumOperands(); i += 2) {
             MachineInstr *LiMI =
                 getVRegDefOrNull(&DefPhiMI->getOperand(i), MRI);
-            if (!LiMI || !MRI->hasOneNonDBGUse(LiMI->getOperand(0).getReg()) ||
-                !MDT->dominates(DefDomMI, LiMI) ||
-                (LiMI->getOpcode() != PPC::LI && LiMI->getOpcode() != PPC::LI8))
+            if (!LiMI ||
+                (LiMI->getOpcode() != PPC::LI && LiMI->getOpcode() != PPC::LI8)
+                || !MRI->hasOneNonDBGUse(LiMI->getOperand(0).getReg()) ||
+                !MDT->dominates(DefDomMI, LiMI))
               return false;
           }