From 7971de4178d3be9b31ac03c20e2b50c3e7f4641c Mon Sep 17 00:00:00 2001
From: Pete Cooper <peter_cooper@apple.com>
Date: Thu, 26 Jul 2012 23:10:24 +0000
Subject: Simplify demanded bits of select sources where the condition is a
 constant vector

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160835 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/InstCombine/InstCombineSelect.cpp | 11 +++++++++++
 1 file changed, 11 insertions(+)

(limited to 'lib/Transforms/InstCombine/InstCombineSelect.cpp')

diff --git a/lib/Transforms/InstCombine/InstCombineSelect.cpp b/lib/Transforms/InstCombine/InstCombineSelect.cpp
index eb9945b..bdd97a8 100644
--- a/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -899,5 +899,16 @@ Instruction *InstCombiner::visitSelectInst(SelectInst &SI) {
     return &SI;
   }
 
+  if (VectorType* VecTy = dyn_cast<VectorType>(SI.getType())) {
+    unsigned VWidth = VecTy->getNumElements();
+    APInt UndefElts(VWidth, 0);
+    APInt AllOnesEltMask(APInt::getAllOnesValue(VWidth));
+    if (Value *V = SimplifyDemandedVectorElts(&SI, AllOnesEltMask, UndefElts)) {
+      if (V != &SI)
+        return ReplaceInstUsesWith(SI, V);
+      return &SI;
+    }
+  }
+
   return 0;
 }
-- 
cgit v1.1


From 75564e35147dd6e36b864946298b6a35417bb9e6 Mon Sep 17 00:00:00 2001
From: Nuno Lopes <nunoplopes@sapo.pt>
Date: Fri, 27 Jul 2012 18:03:57 +0000
Subject: fix infinite loop in instcombine in the presence of a (malformed)
 self-referencing select inst. This can happen as long as the instruction is
 not reachable. Instcombine does generate these unreachable malformed selects
 when doing RAUW

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160874 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/InstCombine/InstCombineSelect.cpp | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'lib/Transforms/InstCombine/InstCombineSelect.cpp')

diff --git a/lib/Transforms/InstCombine/InstCombineSelect.cpp b/lib/Transforms/InstCombine/InstCombineSelect.cpp
index bdd97a8..291e800 100644
--- a/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -881,12 +881,16 @@ Instruction *InstCombiner::visitSelectInst(SelectInst &SI) {
 
   if (SelectInst *TrueSI = dyn_cast<SelectInst>(TrueVal)) {
     if (TrueSI->getCondition() == CondVal) {
+      if (SI.getTrueValue() == TrueSI->getTrueValue())
+        return 0;
       SI.setOperand(1, TrueSI->getTrueValue());
       return &SI;
     }
   }
   if (SelectInst *FalseSI = dyn_cast<SelectInst>(FalseVal)) {
     if (FalseSI->getCondition() == CondVal) {
+      if (SI.getFalseValue() == FalseSI->getFalseValue())
+        return 0;
       SI.setOperand(2, FalseSI->getFalseValue());
       return &SI;
     }
-- 
cgit v1.1