Displaying 4 results from an estimated 4 matches for "optimizeexpression".
2010 Mar 03
2
[LLVMdev] folding x * 0 = 0
> You should check out the -enable-finite-only-fp-math and -enable-unsafe-fp-math options.
Good hint, but
llvm::UnsafeFPMath = true;
llvm::FiniteOnlyFPMathOption = true;
at the beginning of my code does not help.
I found llvm::Reassociate::OptimizeExpression in
llvm\lib\Transforms\Scalar\Reassociate.cpp
which looks like it does X * 0 = 0 for int, but it does not get called
for int,
but it works for int.
-Jochen
2010 Mar 03
2
[LLVMdev] folding x * 0 = 0
> Is x*0 => 0 true if isnan(x)?
>
then where do I have to add it if I want to make it a non-standard
modification
of my local llvm version?
would it make sense to add a subset of float to llvm or a kind of modifier
(e.g. valid float to indicate that it is always valid and not nan) to
allow more aggressive optimization?
just like e.g. inbounds for load
-Jochen
2010 Mar 03
0
[LLVMdev] folding x * 0 = 0
On Mar 3, 2010, at 9:32 AM, Jochen Wilhelmy wrote:
>
>> Is x*0 => 0 true if isnan(x)?
>>
> then where do I have to add it if I want to make it a non-standard
> modification
> of my local llvm version?
> would it make sense to add a subset of float to llvm or a kind of modifier
> (e.g. valid float to indicate that it is always valid and not nan) to
> allow
2010 Mar 03
0
[LLVMdev] folding x * 0 = 0
...>> You should check out the -enable-finite-only-fp-math and -enable-unsafe-fp-math options.
>
> Good hint, but
>
> llvm::UnsafeFPMath = true;
> llvm::FiniteOnlyFPMathOption = true;
>
> at the beginning of my code does not help.
> I found llvm::Reassociate::OptimizeExpression in
> llvm\lib\Transforms\Scalar\Reassociate.cpp
> which looks like it does X * 0 = 0 for int, but it does not get called
> for int,
> but it works for int.
These flags only affect the code generator. If you want to add this optimization to your copy of llvm, you can do so by adding i...