Changes in directory llvm/lib/Target/PowerPC:
PPCRegisterInfo.cpp updated: 1.55 -> 1.56 --- Log message: Fix PR727: http://llvm.cs.uiuc.edu/PR727 , correctly handling large stack aligments on ppc --- Diffs of the changes: (+28 -32) PPCRegisterInfo.cpp | 60 ++++++++++++++++++++++++---------------------------- 1 files changed, 28 insertions(+), 32 deletions(-) Index: llvm/lib/Target/PowerPC/PPCRegisterInfo.cpp diff -u llvm/lib/Target/PowerPC/PPCRegisterInfo.cpp:1.55 llvm/lib/Target/PowerPC/PPCRegisterInfo.cpp:1.56 --- llvm/lib/Target/PowerPC/PPCRegisterInfo.cpp:1.55 Tue Apr 11 03:11:53 2006 +++ llvm/lib/Target/PowerPC/PPCRegisterInfo.cpp Tue Apr 11 14:29:21 2006 @@ -202,12 +202,10 @@ const MachineFrameInfo *MFI = MF.getFrameInfo(); unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment(); - // If frame pointers are forced, if there are variable sized stack objects, - // or if there is an object on the stack that requires more alignment than is - // normally provided, use a frame pointer. + // If frame pointers are forced, or if there are variable sized stack objects, + // use a frame pointer. // - return NoFramePointerElim || MFI->hasVarSizedObjects() || - MFI->getMaxAlignment() > TargetAlign; + return NoFramePointerElim || MFI->hasVarSizedObjects(); } void PPCRegisterInfo:: @@ -396,15 +394,26 @@ int NegNumbytes = -NumBytes; // Adjust stack pointer: r1 -= numbytes. - if (NumBytes <= 32768) { - BuildMI(MBB, MBBI, PPC::STWU, 3) - .addReg(PPC::R1).addSImm(-NumBytes).addReg(PPC::R1); + // If there is a preferred stack alignment, align R1 now + if (MaxAlign > TargetAlign) { + assert(isPowerOf2_32(MaxAlign) && MaxAlign < 32767 && "Invalid alignment!"); + assert(NumBytes <= 32768 && "Unhandled stack size and alignment combo!"); + BuildMI(MBB, MBBI, PPC::RLWINM, 4, PPC::R0) + .addReg(PPC::R1).addImm(0).addImm(32-Log2_32(MaxAlign)).addImm(31); + BuildMI(MBB, MBBI, PPC::SUBFIC,2,PPC::R0).addReg(PPC::R0).addSImm(MaxAlign); + BuildMI(MBB, MBBI, PPC::ADDI, 2, PPC::R0).addReg(PPC::R0) + .addSImm(NegNumbytes); + BuildMI(MBB, MBBI, PPC::STWUX, 3) + .addReg(PPC::R1).addReg(PPC::R1).addReg(PPC::R0); + } else if (NumBytes <= 32768) { + BuildMI(MBB, MBBI, PPC::STWU, 3).addReg(PPC::R1).addSImm(NegNumbytes) + .addReg(PPC::R1); } else { BuildMI(MBB, MBBI, PPC::LIS, 1, PPC::R0).addSImm(NegNumbytes >> 16); - BuildMI(MBB, MBBI, PPC::ORI, 2, PPC::R0) - .addReg(PPC::R0).addImm(NegNumbytes & 0xFFFF); - BuildMI(MBB, MBBI, PPC::STWUX, 3) - .addReg(PPC::R1).addReg(PPC::R1).addReg(PPC::R0); + BuildMI(MBB, MBBI, PPC::ORI, 2, PPC::R0).addReg(PPC::R0) + .addImm(NegNumbytes & 0xFFFF); + BuildMI(MBB, MBBI, PPC::STWUX, 3).addReg(PPC::R1).addReg(PPC::R1) + .addReg(PPC::R0); } if (DebugInfo && DebugInfo->hasInfo()) { @@ -419,19 +428,6 @@ BuildMI(MBB, MBBI, PPC::DWARF_LABEL, 1).addSImm(LabelID); } - // If there is a preferred stack alignment, align R1 now - // FIXME: If this ever matters, this could be made more efficient by folding - // this into the code above, so that we don't issue two store+update - // instructions. - if (MaxAlign > TargetAlign) { - assert(isPowerOf2_32(MaxAlign) && MaxAlign < 32767 && "Invalid alignment!"); - BuildMI(MBB, MBBI, PPC::RLWINM, 4, PPC::R0) - .addReg(PPC::R1).addImm(0).addImm(32-Log2_32(MaxAlign)).addImm(31); - BuildMI(MBB, MBBI, PPC::SUBFIC, 2,PPC::R0).addReg(PPC::R0).addImm(MaxAlign); - BuildMI(MBB, MBBI, PPC::STWUX, 3) - .addReg(PPC::R1).addReg(PPC::R1).addReg(PPC::R0); - } - // If there is a frame pointer, copy R1 (SP) into R31 (FP) if (HasFP) { BuildMI(MBB, MBBI, PPC::STW, 3) @@ -446,8 +442,12 @@ assert(MBBI->getOpcode() == PPC::BLR && "Can only insert epilog into returning blocks"); + // Get alignment info so we know how to restore r1 + const MachineFrameInfo *MFI = MF.getFrameInfo(); + unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment(); + // Get the number of bytes allocated from the FrameInfo. - unsigned NumBytes = MF.getFrameInfo()->getStackSize(); + unsigned NumBytes = MFI->getStackSize(); unsigned GPRSize = 4; if (NumBytes != 0) { @@ -460,15 +460,11 @@ // The loaded (or persistent) stack pointer value is offseted by the 'stwu' // on entry to the function. Add this offset back now. - if (NumBytes < 32768) { + if (NumBytes < 32768 && TargetAlign >= MFI->getMaxAlignment()) { BuildMI(MBB, MBBI, PPC::ADDI, 2, PPC::R1) .addReg(PPC::R1).addSImm(NumBytes); } else { - BuildMI(MBB, MBBI, PPC::LIS, 1, PPC::R0).addSImm(NumBytes >> 16); - BuildMI(MBB, MBBI, PPC::ORI, 2, PPC::R0) - .addReg(PPC::R0).addImm(NumBytes & 0xFFFF); - BuildMI(MBB, MBBI, PPC::ADD4, 2, PPC::R1) - .addReg(PPC::R0).addReg(PPC::R1); + BuildMI(MBB, MBBI, PPC::LWZ, 2, PPC::R1).addSImm(0).addReg(PPC::R1); } } } _______________________________________________ llvm-commits mailing list llvm-commits@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
