From: Nick Lewycky <nicholas@mxc.ca>
Date: Sat, 20 Dec 2008 16:48:00 +0000 (+0000)
Subject: Remove redundant test for vector-nature. Scan the vector first to see whether
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=9dce873c1af959d635f1a8dd4ae2ccb5ac62584d;p=oota-llvm.git

Remove redundant test for vector-nature. Scan the vector first to see whether
our optz'n will apply to it, then build the replacement vector only if needed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61279 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 41ed449958a..5f22fd7ae23 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -3090,11 +3090,17 @@ Instruction *InstCombiner::visitSRem(BinaryOperator &I) {
   }
 
   // If it's a constant vector, flip any negative values positive.
-  if (isa<VectorType>(I.getType())) {
-    if (ConstantVector *RHSV = dyn_cast<ConstantVector>(Op1)) {
-      unsigned VWidth = RHSV->getNumOperands();
-      std::vector<Constant *> Elts(VWidth);
+  if (ConstantVector *RHSV = dyn_cast<ConstantVector>(Op1)) {
+    unsigned VWidth = RHSV->getNumOperands();
+
+    bool hasNegative = false;
+    for (unsigned i = 0; !hasNegative && i != VWidth; ++i)
+      if (ConstantInt *RHS = dyn_cast<ConstantInt>(RHSV->getOperand(i)))
+        if (RHS->getValue().isNegative())
+          hasNegative = true;
 
+    if (hasNegative) {
+      std::vector<Constant *> Elts(VWidth);
       for (unsigned i = 0; i != VWidth; ++i) {
         if (ConstantInt *RHS = dyn_cast<ConstantInt>(RHSV->getOperand(i))) {
           if (RHS->getValue().isNegative())