Revert r155682, "Use ConstantExpr::getExtractElement when constant-folding vectors"

It broke stage2 build. stage1/clang sometimes crashed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155699 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 14 deletions

diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
index 59248c9ca0..783c32e666 100644
--- a/lib/Analysis/ConstantFolding.cpp
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -788,10 +788,6 @@ Constant *llvm::ConstantFoldInstruction(Instruction *I,
       CommonValue = C;
     }
 
-    // Fold the PHI's operands.
-    if (ConstantExpr *NewCE = dyn_cast<ConstantExpr>(CommonValue))
-      CommonValue = ConstantFoldConstantExpression(NewCE, TD, TLI);
-
     // If we reach here, all incoming values are the same constant or undef.
     return CommonValue ? CommonValue : UndefValue::get(PN->getType());
   }
@@ -799,18 +795,12 @@ Constant *llvm::ConstantFoldInstruction(Instruction *I,
   // Scan the operand list, checking to see if they are all constants, if so,
   // hand off to ConstantFoldInstOperands.
   SmallVector<Constant*, 8> Ops;
-  for (User::op_iterator i = I->op_begin(), e = I->op_end(); i != e; ++i) {
-    Constant *Op = dyn_cast<Constant>(*i);
-    if (!Op)
+  for (User::op_iterator i = I->op_begin(), e = I->op_end(); i != e; ++i)
+    if (Constant *Op = dyn_cast<Constant>(*i))
+      Ops.push_back(Op);
+    else
       return 0;  // All operands not constant!
 
-    // Fold the Instruction's operands.
-    if (ConstantExpr *NewCE = dyn_cast<ConstantExpr>(Op))
-      Op = ConstantFoldConstantExpression(NewCE, TD, TLI);
-
-    Ops.push_back(Op);
-  }
-
   if (const CmpInst *CI = dyn_cast<CmpInst>(I))
     return ConstantFoldCompareInstOperands(CI->getPredicate(), Ops[0], Ops[1],
                                            TD, TLI);