diff options
Diffstat (limited to 'lib/Target/PowerPC/PPCInstrInfo.td')
| -rw-r--r-- | lib/Target/PowerPC/PPCInstrInfo.td | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/lib/Target/PowerPC/PPCInstrInfo.td b/lib/Target/PowerPC/PPCInstrInfo.td index 4d153c4..63b4581 100644 --- a/lib/Target/PowerPC/PPCInstrInfo.td +++ b/lib/Target/PowerPC/PPCInstrInfo.td @@ -1117,14 +1117,17 @@ def MFVRSAVE : XFXForm_1_ext<31, 339, 256, (outs GPRC:$rT), (ins), def MTCRF : XFXForm_5<31, 144, (outs), (ins crbitm:$FXM, GPRC:$rS), "mtcrf $FXM, $rS", BrMCRX>, PPC970_MicroCode, PPC970_Unit_CRU; -// FIXME: this Uses all the CR registers. Marking it as such is -// necessary for DeadMachineInstructionElim to do the right thing. -// However, marking it also exposes PR 2964, and causes crashes in -// the Local RA because it doesn't like this sequence: + +// This is a pseudo for MFCR, which implicitly uses all 8 of its subregisters; +// declaring that here gives the local register allocator problems with this: // vreg = MCRF CR0 // MFCR <kill of whatever preg got assigned to vreg> -// For now DeadMachineInstructionElim is turned off, so don't do the marking. -def MFCR : XFXForm_3<31, 19, (outs GPRC:$rT), (ins), "mfcr $rT", SprMFCR>, +// while not declaring it breaks DeadMachineInstructionElimination. +// As it turns out, in all cases where we currently use this, +// we're only interested in one subregister of it. Represent this in the +// instruction to keep the register allocator from becoming confused. +def MFCRpseud: XFXForm_3<31, 19, (outs GPRC:$rT), (ins crbitm:$FXM), + "mfcr $rT ${:comment} $FXM", SprMFCR>, PPC970_MicroCode, PPC970_Unit_CRU; def MFOCRF: XFXForm_5a<31, 19, (outs GPRC:$rT), (ins crbitm:$FXM), "mfcr $rT, $FXM", SprMFCR>, |