commit 2cac58f6045ef3d5e8407d10dc2ccb30bc470caf
author Hal Finkel <hfinkel@anl.gov> Mon Jul 11 03:37:59 2016 +0000
committer Hal Finkel <hfinkel@anl.gov> Mon Jul 11 03:37:59 2016 +0000
tree 5e14afe26cdb3a8fa03a35688a640a05d8c9b141
parent bf3957a553810f8cab2050b6d81707e43583d007

Pointer-comparison folding should look through returned-argument functions

For functions which are known to return a specific argument, pointer-comparison
folding can look through the function calls as part of its analysis.

Differential Revision: http://reviews.llvm.org/D9387

llvm-svn: 275039

llvm/lib/Analysis/InstructionSimplify.cpp

diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index a41be07..27c10ee 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -621,6 +621,11 @@
         break;
       V = GA->getAliasee();
     } else {
+      if (auto CS = CallSite(V))
+        if (Value *RV = CS.getReturnedArgOperand()) {
+          V = RV;
+          continue;
+        }
       break;
     }
     assert(V->getType()->getScalarType()->isPointerTy() &&