From: Chris Lattner <sabre@nondot.org>
Date: Mon, 3 Jan 2011 18:43:03 +0000 (+0000)
Subject: stength reduce my previous patch a bit.  The only instructions
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=10b883b13ff3ad44892758c7a57a435cdb379b45;p=oota-llvm.git

stength reduce my previous patch a bit.  The only instructions
that are allowed to have metadata operands are intrinsic calls,
and the only ones that take metadata currently return void.
Just reject all void instructions, which should not be value
numbered anyway.  To future proof things, add an assert to the
getHashValue impl for calls to check that metadata operands
aren't present.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122759 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Scalar/EarlyCSE.cpp b/lib/Transforms/Scalar/EarlyCSE.cpp
index 61830e02d6c..6c2ea39896a 100644
--- a/lib/Transforms/Scalar/EarlyCSE.cpp
+++ b/lib/Transforms/Scalar/EarlyCSE.cpp
@@ -145,14 +145,13 @@ namespace {
     }
     
     static bool canHandle(Instruction *Inst) {
+      // Don't value number anything that returns void.
+      if (Inst->getType()->isVoidTy())
+        return false;
+      
       CallInst *CI = dyn_cast<CallInst>(Inst);
       if (CI == 0 || !CI->onlyReadsMemory())
         return false;
-      
-      // Check that there are no metadata operands.
-      for (unsigned i = 0, e = CI->getNumOperands(); i != e; ++i)
-        if (CI->getOperand(i)->getType()->isMetadataTy())
-          return false;
       return true;
     }
   };
@@ -179,8 +178,12 @@ unsigned DenseMapInfo<CallValue>::getHashValue(CallValue Val) {
   Instruction *Inst = Val.Inst;
   // Hash in all of the operands as pointers.
   unsigned Res = 0;
-  for (unsigned i = 0, e = Inst->getNumOperands(); i != e; ++i)
+  for (unsigned i = 0, e = Inst->getNumOperands(); i != e; ++i) {
+    assert(!Inst->getOperand(i)->getType()->isMetadataTy() &&
+           "Cannot value number calls with metadata operands");
     Res ^= getHash(Inst->getOperand(i)) << i;
+  }
+  
   // Mix in the opcode.
   return (Res << 1) ^ Inst->getOpcode();
 }