return new CastInst(NotCond, SI.getType());
}
}
+
+ // See if we are selecting two values based on a comparison of the two values.
+ if (SetCondInst *SCI = dyn_cast<SetCondInst>(CondVal)) {
+ if (SCI->getOperand(0) == TrueVal && SCI->getOperand(1) == FalseVal) {
+ // Transform (X == Y) ? X : Y -> Y
+ if (SCI->getOpcode() == Instruction::SetEQ)
+ return ReplaceInstUsesWith(SI, FalseVal);
+ // Transform (X != Y) ? X : Y -> X
+ if (SCI->getOpcode() == Instruction::SetNE)
+ return ReplaceInstUsesWith(SI, TrueVal);
+ // NOTE: if we wanted to, this is where to detect MIN/MAX/ABS/etc.
+
+ } else if (SCI->getOperand(0) == FalseVal && SCI->getOperand(1) == TrueVal){
+ // Transform (X == Y) ? Y : X -> X
+ if (SCI->getOpcode() == Instruction::SetEQ)
+ return ReplaceInstUsesWith(SI, TrueVal);
+ // Transform (X != Y) ? Y : X -> Y
+ if (SCI->getOpcode() == Instruction::SetNE)
+ return ReplaceInstUsesWith(SI, FalseVal);
+ // NOTE: if we wanted to, this is where to detect MIN/MAX/ABS/etc.
+ }
+ }
// See if we can fold the select into one of our operands.
if (SI.getType()->isInteger()) {