commit d615c8615ad5112f0e4359d08c51032cac7362b5
author Jim Stichnoth <stichnot@chromium.org> Mon Jun 27 16:11:03 2016 -0700
committer Jim Stichnoth <stichnot@chromium.org> Mon Jun 27 16:11:03 2016 -0700
tree cdcb3fe014e9ec39120a2f7f1adb526a862de208
parent fe2caab8cb0fecc764fdb710014b3a60b9d7b2d2

Subzero: Fix a potential null-pointer dereference.

BUG= none
R=jpp@chromium.org, manasijm@google.com

Review URL: https://codereview.chromium.org/2103613002 .

src/IceTargetLoweringX86BaseImpl.h

diff --git a/src/IceTargetLoweringX86BaseImpl.h b/src/IceTargetLoweringX86BaseImpl.h
index 1dcb9a3..0cd2789 100644
--- a/src/IceTargetLoweringX86BaseImpl.h
+++ b/src/IceTargetLoweringX86BaseImpl.h
@@ -5327,14 +5327,17 @@
         }
       } else if (VarDef->getOp() == InstArithmetic::Mul) {
         SizeT PowerOfTwo = 0;
-        ConstantInteger32 *MultConst =
-            llvm::dyn_cast<ConstantInteger32>(VarDef->getSrc(0));
-        if (llvm::isPowerOf2_32(MultConst->getValue())) {
-          PowerOfTwo += MultConst->getValue();
+        if (auto *MultConst =
+                llvm::dyn_cast<ConstantInteger32>(VarDef->getSrc(0))) {
+          if (llvm::isPowerOf2_32(MultConst->getValue())) {
+            PowerOfTwo += MultConst->getValue();
+          }
         }
-        MultConst = llvm::dyn_cast<ConstantInteger32>(VarDef->getSrc(1));
-        if (llvm::isPowerOf2_32(MultConst->getValue())) {
-          PowerOfTwo += MultConst->getValue();
+        if (auto *MultConst =
+                llvm::dyn_cast<ConstantInteger32>(VarDef->getSrc(1))) {
+          if (llvm::isPowerOf2_32(MultConst->getValue())) {
+            PowerOfTwo += MultConst->getValue();
+          }
         }
         ZeroesAvailable = llvm::Log2_32(PowerOfTwo) + 1;
       }