[llvm] r177011 - Teach X86 MC instruction lowering that VMOVAPSrr and other VEX-encoded register to register moves should be switched from using the MRMSrcReg form to the MRMDestReg form if the source register is a 64-bit extended register and the destination register is not. This allows the instruction to be encoded using the 2-byte VEX form instead of the 3-byte VEX form. The GNU assembler has similar behavior.
Craig Topper
craig.topper at gmail.com
Fri Mar 15 20:45:54 PDT 2013
Committed in r177221 with some comment additions and a better test name.
On Fri, Mar 15, 2013 at 8:08 PM, Michael Liao <michael.liao at intel.com>wrote:
> Here is the full patch including old JIT code emitter. In addition,
> logic in MC lowering is revised. VMOVSS/SD needs check operand 0 and 2
> and the use of _REV is only enabled it's profitable.
>
> Yours
> - Michael
>
> On Fri, 2013-03-15 at 19:18 -0700, Craig Topper wrote:
> > This doesn't look right. Shouldn't that be getOperand(CurOp)?
> >
> > if (X86II::isX86_64ExtendedReg(MI.getOperand(1).getReg()))
> > VEX_R = 0x0;
> > + CurOp++;
> >
> >
> > I'll go ahead and finish this up. I'll also fix the old JIT code
> > emitter.
> >
> > On Fri, Mar 15, 2013 at 6:43 PM, Michael Liao <michael.liao at intel.com>
> > wrote:
> > Here is the revised patch. VMOVSS/VMOVSD should check operand
> > 0 and 2
> > and operand 1 is encoded in VEX.vvvv.
> >
> > Yours
> > - Michael
> >
> > On Fri, 2013-03-15 at 18:32 -0700, Michael Liao wrote:
> > > Hi Craig
> > >
> > > It's turned out that VEX.vvvv is not supported in DstReg
> > form. I add
> > > quick fix to that. It won't crash during code emission on
> > VMOVSS. Test
> > > case is added as well. Please have a look.
> > >
> > > Yours
> > > - Michael
> > >
> > > On Fri, 2013-03-15 at 15:38 -0700, Craig Topper wrote:
> > > > What assertion is failing?
> > > >
> > > > On Fri, Mar 15, 2013 at 2:31 PM, Nadav Rotem
> > <nrotem at apple.com> wrote:
> > > > Hi Craig,
> > > >
> > > >
> > > > This commit causes an assertion failure in the X86
> > code
> > > > emitter and one of the build bots is failing. I
> > attached a
> > > > test case.
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > Thanks,
> > > > - Nadav
> > > >
> > > >
> > > >
> > > > On Mar 14, 2013, at 12:09 AM, Craig Topper
> > > > <craig.topper at gmail.com> wrote:
> > > >
> > > > > Author: ctopper
> > > > > Date: Thu Mar 14 02:09:57 2013
> > > > > New Revision: 177011
> > > > >
> > > > > URL:
> > http://llvm.org/viewvc/llvm-project?rev=177011&view=rev
> > > > > Log:
> > > > > Teach X86 MC instruction lowering that VMOVAPSrr
> > and other
> > > > > VEX-encoded register to register moves should be
> > switched
> > > > > from using the MRMSrcReg form to the MRMDestReg
> > form if the
> > > > > source register is a 64-bit extended register
> > and the
> > > > > destination register is not. This allows the
> > instruction to
> > > > > be encoded using the 2-byte VEX form instead of
> > the 3-byte
> > > > > VEX form. The GNU assembler has similar
> > behavior.
> > > > >
> > > > > Modified:
> > > > > llvm/trunk/lib/Target/X86/X86MCInstLower.cpp
> > > > >
> > > > > Modified:
> > llvm/trunk/lib/Target/X86/X86MCInstLower.cpp
> > > > > URL:
> >
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86MCInstLower.cpp?rev=177011&r1=177010&r2=177011&view=diff
> > > > >
> >
> ==============================================================================
> > > > > --- llvm/trunk/lib/Target/X86/X86MCInstLower.cpp
> > (original)
> > > > > +++ llvm/trunk/lib/Target/X86/X86MCInstLower.cpp
> > Thu Mar 14
> > > > > 02:09:57 2013
> > > > > @@ -407,6 +407,48 @@ ReSimplify:
> > > > > LowerUnaryToTwoAddr(OutMI, X86::XOR32rr); //
> > MOV32r0 ->
> > > > > XOR32rr
> > > > > break;
> > > > >
> > > > > + // Commute operands to get a smaller encoding
> > by using
> > > > > VEX.R instead of VEX.B
> > > > > + // if one of the registers is extended, but
> > other isn't.
> > > > > + case X86::VMOVAPDrr:
> > > > > + case X86::VMOVAPDYrr:
> > > > > + case X86::VMOVAPSrr:
> > > > > + case X86::VMOVAPSYrr:
> > > > > + case X86::VMOVDQArr:
> > > > > + case X86::VMOVDQAYrr:
> > > > > + case X86::VMOVDQUrr:
> > > > > + case X86::VMOVDQUYrr:
> > > > > + case X86::VMOVSDrr:
> > > > > + case X86::VMOVSSrr:
> > > > > + case X86::VMOVUPDrr:
> > > > > + case X86::VMOVUPDYrr:
> > > > > + case X86::VMOVUPSrr:
> > > > > + case X86::VMOVUPSYrr: {
> > > > > + if
> > > > >
> > (X86II::isX86_64ExtendedReg(OutMI.getOperand(0).getReg()) &&
> > > > > + !
> > > > >
> > X86II::isX86_64ExtendedReg(OutMI.getOperand(1).getReg()))
> > > > > + break;
> > > > > +
> > > > > + unsigned NewOpc;
> > > > > + switch (OutMI.getOpcode()) {
> > > > > + default: llvm_unreachable("Invalid
> > opcode");
> > > > > + case X86::VMOVAPDrr: NewOpc =
> > X86::VMOVAPDrr_REV;
> > > > > break;
> > > > > + case X86::VMOVAPDYrr: NewOpc =
> > X86::VMOVAPDYrr_REV;
> > > > > break;
> > > > > + case X86::VMOVAPSrr: NewOpc =
> > X86::VMOVAPSrr_REV;
> > > > > break;
> > > > > + case X86::VMOVAPSYrr: NewOpc =
> > X86::VMOVAPSYrr_REV;
> > > > > break;
> > > > > + case X86::VMOVDQArr: NewOpc =
> > X86::VMOVDQArr_REV;
> > > > > break;
> > > > > + case X86::VMOVDQAYrr: NewOpc =
> > X86::VMOVDQAYrr_REV;
> > > > > break;
> > > > > + case X86::VMOVDQUrr: NewOpc =
> > X86::VMOVDQUrr_REV;
> > > > > break;
> > > > > + case X86::VMOVDQUYrr: NewOpc =
> > X86::VMOVDQUYrr_REV;
> > > > > break;
> > > > > + case X86::VMOVSDrr: NewOpc =
> > X86::VMOVSDrr_REV;
> > > > > break;
> > > > > + case X86::VMOVSSrr: NewOpc =
> > X86::VMOVSSrr_REV;
> > > > > break;
> > > > > + case X86::VMOVUPDrr: NewOpc =
> > X86::VMOVUPDrr_REV;
> > > > > break;
> > > > > + case X86::VMOVUPDYrr: NewOpc =
> > X86::VMOVUPDYrr_REV;
> > > > > break;
> > > > > + case X86::VMOVUPSrr: NewOpc =
> > X86::VMOVUPSrr_REV;
> > > > > break;
> > > > > + case X86::VMOVUPSYrr: NewOpc =
> > X86::VMOVUPSYrr_REV;
> > > > > break;
> > > > > + }
> > > > > + OutMI.setOpcode(NewOpc);
> > > > > + break;
> > > > > + }
> > > > > +
> > > > > // TAILJMPr64, CALL64r, CALL64pcrel32 - These
> > instructions
> > > > > have register
> > > > > // inputs modeled as normal uses instead of
> > implicit
> > > > > uses. As such, truncate
> > > > > // off all but the first operand (the
> > callee). FIXME:
> > > > > Change isel.
> > > > >
> > > > >
> > > > > _______________________________________________
> > > > > llvm-commits mailing list
> > > > > llvm-commits at cs.uiuc.edu
> > > > >
> > http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > --
> > > > ~Craig
> > > > _______________________________________________
> > > > llvm-commits mailing list
> > > > llvm-commits at cs.uiuc.edu
> > > > http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
> > >
> > > _______________________________________________
> > > llvm-commits mailing list
> > > llvm-commits at cs.uiuc.edu
> > > http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
> >
> >
> >
> >
> >
> > --
> > ~Craig
>
>
--
~Craig
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