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

[Reid Spencer]

Changes in directory llvm/lib/Transforms/Scalar:

InstructionCombining.cpp updated: 1.520.2.7 -> 1.520.2.8
---
Log message:

Don't try to replicate integer transforms/folding for floating point values.
Its not valid!


---
Diffs of the changes:  (+4 -36)

 InstructionCombining.cpp |   40 ++++------------------------------------
 1 files changed, 4 insertions(+), 36 deletions(-)


Index: llvm/lib/Transforms/Scalar/InstructionCombining.cpp
diff -u llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.520.2.7 llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.520.2.8
--- llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.520.2.7	Sun Oct 22 03:59:00 2006
+++ llvm/lib/Transforms/Scalar/InstructionCombining.cpp	Sun Oct 22 18:27:20 2006
@@ -1983,7 +1983,7 @@
       // 0 - (X sdiv C)  -> (X sdiv -C)
       if (Op1I->getOpcode() == Instruction::SDiv)
         if (ConstantInt *CSI = dyn_cast<ConstantInt>(Op0))
-          if (CSI->isNullValue() && CSI->getType()->isSigned())
+          if (CSI->getType()->isSigned() && CSI->isNullValue())
             if (Constant *DivRHS = dyn_cast<Constant>(Op1I->getOperand(1)))
               return BinaryOperator::createSDiv(Op1I->getOperand(0),
                                                ConstantExpr::getNeg(DivRHS));
@@ -2356,39 +2356,6 @@
   if (common)
     return common;
 
-  // If right hand side is a constant floating point ...
-  if (ConstantFP *RHS = dyn_cast<ConstantFP>(Op1)) {
-    // div X, 1 == X
-    if (RHS->isExactlyValue(1.0))
-      return ReplaceInstUsesWith(I, Op0);
-
-    // div X, -1 == -X
-    if (RHS->isExactlyValue(-1.0))
-      return BinaryOperator::createNeg(Op0);
-
-    // (X / C1) / C2  -> X / (C1*C2)
-    if (Instruction *LHS = dyn_cast<Instruction>(Op0))
-      if (LHS->getOpcode()==Instruction::FDiv)
-        if (ConstantFP *LHSRHS = dyn_cast<ConstantFP>(LHS->getOperand(1))) {
-          return BinaryOperator::create(Instruction::FDiv, LHS->getOperand(0),
-                                          ConstantExpr::getMul(RHS, LHSRHS));
-        }
-
-    if (!RHS->isNullValue()) { // avoid X fdiv 0
-      if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
-        if (Instruction *R = FoldOpIntoSelect(I, SI, this))
-          return R;
-      if (isa<PHINode>(Op0))
-        if (Instruction *NV = FoldOpIntoPhi(I))
-          return NV;
-    }
-  }
-
-  // 0 / X == 0
-  if (ConstantFP *LHS = dyn_cast<ConstantFP>(Op0))
-    if (LHS->isExactlyValue(0))
-      return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
-
   // Handle div X, Cond?Y:Z
   if (SelectInst *SI = dyn_cast<SelectInst>(Op1)) {
     // div X, (Cond ? 0 : Y) -> div X, Y.  If the div and the select are in the
@@ -3838,7 +3805,9 @@
 static bool MulWithOverflow(ConstantInt *&Result, ConstantInt *In1,
                             ConstantInt *In2) {
   Result = cast<ConstantInt>(ConstantExpr::getMul(In1, In2));
-  return !In2->isNullValue() && ConstantExpr::getSDiv(Result, In2) != In1;
+  return !In2->isNullValue() && (In2->getType()->isSigned() ? 
+     ConstantExpr::getSDiv(Result, In2) :
+     ConstantExpr::getUDiv(Result, In2)) != In1;
 }
 
 static bool isPositive(ConstantInt *C) {
@@ -4497,7 +4466,6 @@
 
       case Instruction::SDiv:
       case Instruction::UDiv:
-      case Instruction::FDiv:
         // Fold: (div X, C1) op C2 -> range check
         if (ConstantInt *DivRHS = dyn_cast<ConstantInt>(LHSI->getOperand(1))) {
           // Fold this div into the comparison, producing a range check.