Another attempt at getting the clang self-host to like my instcombine patch.

llvm-svn: 108614

1 files changed, 32 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index 3f4a857c41a..35b55428f0c 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -472,6 +472,22 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
       Value *NewOr = Builder->CreateOr(Val, Val2);
       return Builder->CreateICmp(LHSCC, NewOr, LHSCst);
     }
+    
+    // (icmp ne (A & C1), 0) & (icmp ne (A & C2), 0) -->
+    // (icmp eq (A & (C1|C2)), (C1|C2)) where C1 and C2 are non-zero POT
+    if (LHSCC == ICmpInst::ICMP_NE && LHSCst->isZero()) {
+      Value *Op1 = 0, *Op2 = 0;
+      ConstantInt *CI1 = 0, *CI2 = 0;
+      if (match(LHS->getOperand(0), m_And(m_Value(Op1), m_ConstantInt(CI1))) &&
+          match(RHS->getOperand(0), m_And(m_Value(Op2), m_ConstantInt(CI2)))) {
+        if (Op1 == Op2 && !CI1->isZero() && !CI2->isZero() &&
+            CI1->getValue().isPowerOf2() && CI2->getValue().isPowerOf2()) {
+          Constant *ConstOr = ConstantExpr::getOr(CI1, CI2);
+          Value *NewAnd = Builder->CreateAnd(Op1, ConstOr);
+          return Builder->CreateICmp(ICmpInst::ICMP_EQ, NewAnd, ConstOr);
+        }
+      }
+    }
   }
   
   // From here on, we only handle:
@@ -1158,6 +1174,22 @@ Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
     return Builder->CreateICmp(LHSCC, NewOr, LHSCst);
   }
   
+  // (icmp eq (A & C1), 0) | (icmp eq (A & C2), 0) -->
+  // (icmp ne (A & (C1|C2)), (C1|C2)) where C1 and C2 are non-zero POT
+  if (LHSCC == ICmpInst::ICMP_EQ && LHSCst->isZero()) {
+    Value *Op1 = 0, *Op2 = 0;
+    ConstantInt *CI1 = 0, *CI2 = 0;
+    if (match(LHS->getOperand(0), m_And(m_Value(Op1), m_ConstantInt(CI1))) &&
+        match(RHS->getOperand(0), m_And(m_Value(Op2), m_ConstantInt(CI2)))) {
+      if (Op1 == Op2 && !CI1->isZero() && !CI2->isZero() &&
+          CI1->getValue().isPowerOf2() && CI2->getValue().isPowerOf2()) {
+        Constant *ConstOr = ConstantExpr::getOr(CI1, CI2);
+        Value *NewAnd = Builder->CreateAnd(Op1, ConstOr);
+        return Builder->CreateICmp(ICmpInst::ICMP_NE, NewAnd, ConstOr);
+      }
+    }
+  }
+  
   // From here on, we only handle:
   //    (icmp1 A, C1) | (icmp2 A, C2) --> something simpler.
   if (Val != Val2) return 0;