[llvm] r259177 - Since LI/LIS sign extend the constant passed into the instruction we should

[Hal Finkel via llvm-commits]

----- Original Message -----
> From: "Hans Wennborg" <hans at chromium.org>
> To: "Eric Christopher" <echristo at gmail.com>, "Hal Finkel" <hfinkel at anl.gov>
> Cc: "llvm-commits" <llvm-commits at lists.llvm.org>
> Sent: Wednesday, February 3, 2016 3:42:58 PM
> Subject: Re: [llvm] r259177 - Since LI/LIS sign extend the constant passed into the instruction we should
> 
> Hal: OK for 3.8?

Yes, thanks!

 -Hal

> 
> On Wed, Feb 3, 2016 at 10:02 AM, Eric Christopher
> <echristo at gmail.com> wrote:
> > Hi Hans,
> >
> > Would you please pull this into the 3.8 release as well?
> >
> > Thanks!
> >
> > -eric
> >
> >
> > On Thu, Jan 28, 2016 at 11:24 PM Eric Christopher via llvm-commits
> > <llvm-commits at lists.llvm.org> wrote:
> >>
> >> Author: echristo
> >> Date: Fri Jan 29 01:20:01 2016
> >> New Revision: 259177
> >>
> >> URL: http://llvm.org/viewvc/llvm-project?rev=259177&view=rev
> >> Log:
> >> Since LI/LIS sign extend the constant passed into the instruction
> >> we
> >> should
> >> check that the sign extended constant fits into 16-bits if we want
> >> a
> >> zero extended value, otherwise go ahead and put it together
> >> piecemeal.
> >>
> >> Fixes PR26356.
> >>
> >> Modified:
> >>     llvm/trunk/lib/Target/PowerPC/PPCFastISel.cpp
> >>     llvm/trunk/test/CodeGen/PowerPC/fast-isel-ret.ll
> >>
> >> Modified: llvm/trunk/lib/Target/PowerPC/PPCFastISel.cpp
> >> URL:
> >> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCFastISel.cpp?rev=259177&r1=259176&r2=259177&view=diff
> >>
> >> ==============================================================================
> >> --- llvm/trunk/lib/Target/PowerPC/PPCFastISel.cpp (original)
> >> +++ llvm/trunk/lib/Target/PowerPC/PPCFastISel.cpp Fri Jan 29
> >> 01:20:01 2016
> >> @@ -2098,7 +2098,9 @@ unsigned PPCFastISel::PPCMaterializeInt(
> >>      BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
> >>      TII.get(Opc),
> >> ImmReg)
> >>          .addImm(CI->getSExtValue());
> >>      return ImmReg;
> >> -  } else if (!UseSExt && isUInt<16>(CI->getZExtValue())) {
> >> +  } else if (!UseSExt && isUInt<16>(CI->getSExtValue())) {
> >> +    // Since LI will sign extend the constant we need to make
> >> sure that
> >> for
> >> +    // our zeroext constants that the sign extended constant fits
> >> into
> >> 16-bits.
> >>      unsigned Opc = (VT == MVT::i64) ? PPC::LI8 : PPC::LI;
> >>      unsigned ImmReg = createResultReg(RC);
> >>      BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
> >>      TII.get(Opc),
> >> ImmReg)
> >> @@ -2108,7 +2110,6 @@ unsigned PPCFastISel::PPCMaterializeInt(
> >>
> >>    // Construct the constant piecewise.
> >>    int64_t Imm = CI->getZExtValue();
> >> -
> >>    if (VT == MVT::i64)
> >>      return PPCMaterialize64BitInt(Imm, RC);
> >>    else if (VT == MVT::i32)
> >>
> >> Modified: llvm/trunk/test/CodeGen/PowerPC/fast-isel-ret.ll
> >> URL:
> >> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/fast-isel-ret.ll?rev=259177&r1=259176&r2=259177&view=diff
> >>
> >> ==============================================================================
> >> --- llvm/trunk/test/CodeGen/PowerPC/fast-isel-ret.ll (original)
> >> +++ llvm/trunk/test/CodeGen/PowerPC/fast-isel-ret.ll Fri Jan 29
> >> 01:20:01
> >> 2016
> >> @@ -186,3 +186,12 @@ entry:
> >>  ; ELF64: blr
> >>    ret i32 -1
> >>  }
> >> +
> >> +define zeroext i16 @ret20() nounwind {
> >> +entry:
> >> +; ELF64-LABEL: ret20
> >> +; ELF64: lis{{.*}}0
> >> +; ELF64: ori{{.*}}32768
> >> +; ELF64: blr
> >> +  ret i16 32768
> >> +}
> >>
> >>
> >> _______________________________________________
> >> llvm-commits mailing list
> >> llvm-commits at lists.llvm.org
> >> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
> 

-- 
Hal Finkel
Assistant Computational Scientist
Leadership Computing Facility
Argonne National Laboratory