Displaying 4 results from an estimated 4 matches for "issignbit".
2016 Apr 07
7
Implementing a proposed InstCombine optimization
...ts.llvm.org>> wrote:
> Hi,
>
> I'm interested in implementing an InstCombine optimization that I discovered and verified with Alive-NJ (with the help of the authors of Alive-NJ). The optimization is described in Alive-NJ format as follows:
>
> Name: xor->fsub
> Pre: isSignBit(C)
> %x = bitcast %A
> %y = xor %x, C
> %z = bitcast %y
> =>
> %z = fsub -0.0, %A
>
> Effectively the optimization targets code that casts a float to an int with the same width, XORs the sign bit, and casts back to float, and replaces it with a subtraction from -0.0.
>...
2016 Apr 07
2
Implementing a proposed InstCombine optimization
Hi,
I'm interested in implementing an InstCombine optimization that I discovered and verified with Alive-NJ (with the help of the authors of Alive-NJ). The optimization is described in Alive-NJ format as follows:
Name: xor->fsub
Pre: isSignBit(C)
%x = bitcast %A
%y = xor %x, C
%z = bitcast %y
=>
%z = fsub -0.0, %A
Effectively the optimization targets code that casts a float to an int with the same width, XORs the sign bit, and casts back to float, and replaces it with a subtraction from -0.0.
I am not very familiar with C++ or the L...
2016 Apr 09
2
Implementing a proposed InstCombine optimization
...>>
>>> I'm interested in implementing an InstCombine optimization that I discovered and verified with Alive-NJ (with the help of the authors of Alive-NJ). The optimization is described in Alive-NJ format as follows:
>>>
>>> Name: xor->fsub
>>> Pre: isSignBit(C)
>>> %x = bitcast %A
>>> %y = xor %x, C
>>> %z = bitcast %y
>>> =>
>>> %z = fsub -0.0, %A
>>>
>>> Effectively the optimization targets code that casts a float to an int with the same width, XORs the sign bit, and casts back to flo...
2016 Apr 11
4
Implementing a proposed InstCombine optimization
....org<mailto:llvm-dev at lists.llvm.org>> wrote:
Hi,
I'm interested in implementing an InstCombine optimization that I discovered and verified with Alive-NJ (with the help of the authors of Alive-NJ). The optimization is described in Alive-NJ format as follows:
Name: xor->fsub
Pre: isSignBit(C)
%x = bitcast %A
%y = xor %x, C
%z = bitcast %y
=>
%z = fsub -0.0, %A
Effectively the optimization targets code that casts a float to an int with the same width, XORs the sign bit, and casts back to float, and replaces it with a subtraction from -0.0.
I am not very familiar with C++ or the L...