[llvm-commits] [llvm] r108429 - in /llvm/trunk/lib/Transforms/InstCombine: InstCombineAndOrXor.cpp InstCombineSelect.cpp

[Owen Anderson]

Author: resistor
Date: Thu Jul 15 12:24:23 2010
New Revision: 108429

URL: http://llvm.org/viewvc/llvm-project?rev=108429&view=rev
Log:
Per Chris' suggestion, get rid of the select canonicalization and just add
the corresponding or-icmp-and pattern.  This has the added benefit of doing
the matching earlier, and thus being less susceptible to being confused by
earlier transforms.

Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
    llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp?rev=108429&r1=108428&r2=108429&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp Thu Jul 15 12:24:23 2010
@@ -1177,6 +1177,25 @@
     return Builder->CreateICmp(LHSCC, NewOr, LHSCst);
   }
   
+  // (icmp eq (A & C1), 0) | (icmp eq (A & C2), 0) -->
+  // (icmp ne (A & (C1|C2)), (C1|C2))
+  if (LHSCC == ICmpInst::ICMP_EQ && LHSCst->isZero()) {
+    Instruction *I1 = dyn_cast<Instruction>(Val);
+    Instruction *I2 = dyn_cast<Instruction>(Val2);
+    if (I1 && I1->getOpcode() == Instruction::And &&
+        I2 && I2->getOpcode() == Instruction::And &&
+        I1->getOperand(0) == I1->getOperand(0)) {
+      ConstantInt *CI1 = dyn_cast<ConstantInt>(I1->getOperand(1));
+      ConstantInt *CI2 = dyn_cast<ConstantInt>(I2->getOperand(1));
+      if (CI1 && !CI1->isZero() && CI2 && !CI2->isZero() &&
+          CI1->getValue().operator&(CI2->getValue()) == 0) {
+        Constant *ConstOr = ConstantExpr::getOr(CI1, CI2);
+        Value *NewAnd = Builder->CreateAnd(I1->getOperand(0), 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;

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp?rev=108429&r1=108428&r2=108429&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp Thu Jul 15 12:24:23 2010
@@ -699,34 +699,6 @@
     SI.setOperand(2, TrueVal);
     return &SI;
   }
-  
-  // select (A == 0 | B == 0), T, F--> select (A != 0 & B != 0), F, T
-  // Note: This is a canonicalization rather than an optimization, and is used
-  // to expose opportunities to other instcombine transforms.
-  Instruction* CondInst = dyn_cast<Instruction>(CondVal);
-  if (CondInst && CondInst->hasOneUse() && 
-      CondInst->getOpcode() == Instruction::Or) {
-    ICmpInst *LHSCmp = dyn_cast<ICmpInst>(CondInst->getOperand(0));
-    ICmpInst *RHSCmp = dyn_cast<ICmpInst>(CondInst->getOperand(1));
-    if (LHSCmp && LHSCmp->hasOneUse() &&
-                  LHSCmp->getPredicate() == ICmpInst::ICMP_EQ &&
-        RHSCmp && RHSCmp->hasOneUse() &&
-                  RHSCmp->getPredicate() == ICmpInst::ICMP_EQ) {
-      ConstantInt* C1 = dyn_cast<ConstantInt>(LHSCmp->getOperand(1));
-      ConstantInt* C2 = dyn_cast<ConstantInt>(RHSCmp->getOperand(1));
-      if (C1 && C1->isZero() && C2 && C2->isZero()) {
-        LHSCmp->setPredicate(ICmpInst::ICMP_NE);
-        RHSCmp->setPredicate(ICmpInst::ICMP_NE);
-        Value *And =
-          InsertNewInstBefore(BinaryOperator::CreateAnd(LHSCmp, RHSCmp,
-                                             "and."+CondVal->getName()), SI);
-        SI.setOperand(0, And);
-        SI.setOperand(1, FalseVal);
-        SI.setOperand(2, TrueVal);
-        return &SI;
-      }
-    }
-  }
 
   return 0;
 }