search for: fsfld0ss

Hi all, I think I found a bug in LLVM 3.0: When compiling for a target without SSE2 support, there were some 128-bit PXOR instructions in the generated code. I traced it down to the following definition in X86InstrSSE.td: def FsFLD0SS : I<0xEF, MRMInitReg, (outs FR32:$dst), (ins), "", [(set FR32:$dst, fp32imm0)]>, Requires<[HasSSE1]>, TB, OpSize; I tried replacing the HasSSE1 with a HasSSE2 but that didn't do the trick. I noticed that TOT has a different definit...

Hi, I noticed a bunch of psuedo instructions used for creation of constants without generating loads. e.g. pxor xmm0, xmm0 Here is an example of what i am referring to snipped from X86InstrSSE.td: def FsFLD0SS : I<0xEF, MRMInitReg, (outs FR32:$dst), (ins), "", [(set FR32:$dst, fp32imm0)]>, Requires<[HasSSE1]>, TB, OpSize; My question is why was there a need to define such a pseudo instruction? Wouldn't it be cleaner to use a def: Pat<> wh...

...ns at gmail.com> wrote: > Hi all, > > I think I found a bug in LLVM 3.0: When compiling for a target without > SSE2 support, there were some 128-bit PXOR instructions in the generated > code. > > I traced it down to the following definition in X86InstrSSE.td: > >   def FsFLD0SS : I<0xEF, MRMInitReg, (outs FR32:$dst), (ins), "", >                    [(set FR32:$dst, fp32imm0)]>, >                    Requires<[HasSSE1]>, TB, OpSize; > > I tried replacing the HasSSE1 with a HasSSE2 but that didn't do the > trick. I noticed that TOT ha...