[llvm-commits] [SignlessTypes] CVS: llvm/lib/Transforms/Scalar/InstructionCombining.cpp

[Reid Spencer]

Changes in directory llvm/lib/Transforms/Scalar:

InstructionCombining.cpp updated: 1.520.2.3 -> 1.520.2.4
---
Log message:

Implement backwards compatibility in bytecode reader for signless types.
Bump bytecode writer version number (to 6).
Fix bugs in DIV -> SDIV/UDIV changes.


---
Diffs of the changes:  (+4 -4)

 InstructionCombining.cpp |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)


Index: llvm/lib/Transforms/Scalar/InstructionCombining.cpp
diff -u llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.520.2.3 llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.520.2.4
--- llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.520.2.3	Thu Oct 19 23:27:17 2006
+++ llvm/lib/Transforms/Scalar/InstructionCombining.cpp	Sat Oct 21 03:59:42 2006
@@ -1977,7 +1977,7 @@
       // 0 - (X sdiv C)  -> (X sdiv -C)
       if (Op1I->getOpcode() == Instruction::SDiv)
         if (ConstantInt *CSI = dyn_cast<ConstantInt>(Op0))
-          if (CSI->isNullValue())
+          if (CSI->isNullValue() && CSI->getType()->isSigned())
             if (Constant *DivRHS = dyn_cast<Constant>(Op1I->getOperand(1)))
               return BinaryOperator::createSDiv(Op1I->getOperand(0),
                                                ConstantExpr::getNeg(DivRHS));
@@ -2173,14 +2173,14 @@
     if (RHS->isAllOnesValue())
       return BinaryOperator::createNeg(Op0);
 
+    // (X / C1) / C2  -> X / (C1*C2)
     if (Instruction *LHS = dyn_cast<Instruction>(Op0))
       if (LHS->getOpcode() == Instruction::SDiv || 
           LHS->getOpcode()==Instruction::UDiv)
         if (ConstantInt *LHSRHS = dyn_cast<ConstantInt>(LHS->getOperand(1))) {
-          // (X / C1) / C2  -> X / (C1*C2)
           return BinaryOperator::create(
             Instruction::BinaryOps(LHS->getOpcode()), LHS->getOperand(0),
-                                           ConstantExpr::getMul(RHS, LHSRHS),"");
+                                          ConstantExpr::getMul(RHS, LHSRHS),"");
         }
 
     // Check to see if this is an unsigned division with an exact power of 2,
@@ -3724,7 +3724,7 @@
 static bool MulWithOverflow(ConstantInt *&Result, ConstantInt *In1,
                             ConstantInt *In2) {
   Result = cast<ConstantInt>(ConstantExpr::getMul(In1, In2));
-  return !In2->isNullValue() && ConstantExpr::getUDiv(Result, In2) != In1;
+  return !In2->isNullValue() && ConstantExpr::getSDiv(Result, In2) != In1;
 }
 
 static bool isPositive(ConstantInt *C) {