search for: issignbit

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...