Displaying 3 results from an estimated 3 matches for "getoverflow".
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2009 Feb 08
0
[LLVMdev] overflow + saturation stuff
Hi Chris,
Would it be better to split add into multiple opcodes instead of using
SubclassData bits? Compare this:
switch (I->getOpcode()) {
case Instruction::Add: {
switch (cast<Add>(I)->getOverflowBehavior()) {
case AddInstruction::Wrapping:
// ...
case AddInstruction::UndefinedSigned:
// ...
case AddInstruction::UndefinedUnsigned:
// ...
}
}
}
with this:
switch (I->getOpcode()) {
case Instruction::Add:
// .....
2009 Feb 08
2
[LLVMdev] overflow + saturation stuff
...nice to not have it be in the opcode field.
This also interacts with FP rounding mode stuff, which I expect to
handle the same way with FP operations some day.
> Compare this:
>
> switch (I->getOpcode()) {
> case Instruction::Add: {
> switch (cast<Add>(I)->getOverflowBehavior()) {
> case AddInstruction::Wrapping:
> // ...
> case AddInstruction::UndefinedSigned:
> // ...
> case AddInstruction::UndefinedUnsigned:
Sure, that is ugly. However, I think it would be much more common to
look at these in "isa&qu...
2009 Feb 07
6
[LLVMdev] overflow + saturation stuff
Edwin was asking about how we should handle PR3328, how we should make
GEP respect -fwrapv etc. I wrote up some thoughts here if anyone is
interested:
http://nondot.org/sabre/LLVMNotes/IntegerOverflow.txt
-Chris