R600/SI: Fix crash in SIInstrInfo::areLoadsFromSameBasePtr()

This function assumed that SMRD instructions always have immediate
offsets, which is not always the case.

llvm-svn: 232957

1 files changed, 10 insertions, 2 deletions

diff --git a/llvm/lib/Target/R600/SIInstrInfo.cpp b/llvm/lib/Target/R600/SIInstrInfo.cpp
index 95334c30d17..c8468f98524 100644
--- a/llvm/lib/Target/R600/SIInstrInfo.cpp
+++ b/llvm/lib/Target/R600/SIInstrInfo.cpp
@@ -120,12 +120,20 @@ bool SIInstrInfo::areLoadsFromSameBasePtr(SDNode *Load0, SDNode *Load1,
     if (Load0->getOperand(0) != Load1->getOperand(0))
       return false;
 
+    const ConstantSDNode *Load0Offset =
+        dyn_cast<ConstantSDNode>(Load0->getOperand(1));
+    const ConstantSDNode *Load1Offset =
+        dyn_cast<ConstantSDNode>(Load1->getOperand(1));
+
+    if (!Load0Offset || !Load1Offset)
+      return false;
+
     // Check chain.
     if (findChainOperand(Load0) != findChainOperand(Load1))
       return false;
 
-    Offset0 = cast<ConstantSDNode>(Load0->getOperand(1))->getZExtValue();
-    Offset1 = cast<ConstantSDNode>(Load1->getOperand(1))->getZExtValue();
+    Offset0 = Load0Offset->getZExtValue();
+    Offset1 = Load1Offset->getZExtValue();
     return true;
   }