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lib/Target/ARM/ARMFrameLowering.cpp
| Show First 20 Lines • Show All 1,654 Lines • ▼ Show 20 Lines | void ARMFrameLowering::determineCalleeSaves(MachineFunction &MF, | ||||
| if (RegInfo->hasBasePointer(MF)) | if (RegInfo->hasBasePointer(MF)) | ||||
| SavedRegs.set(RegInfo->getBaseRegister()); | SavedRegs.set(RegInfo->getBaseRegister()); | ||||
| // Don't spill FP if the frame can be eliminated. This is determined | // Don't spill FP if the frame can be eliminated. This is determined | ||||
| // by scanning the callee-save registers to see if any is modified. | // by scanning the callee-save registers to see if any is modified. | ||||
| const MCPhysReg *CSRegs = RegInfo->getCalleeSavedRegs(&MF); | const MCPhysReg *CSRegs = RegInfo->getCalleeSavedRegs(&MF); | ||||
| for (unsigned i = 0; CSRegs[i]; ++i) { | for (unsigned i = 0; CSRegs[i]; ++i) { | ||||
| unsigned Reg = CSRegs[i]; | unsigned Reg = CSRegs[i]; | ||||
| if (STI.isRWPI() && Reg == ARM::R9) { | |||||
| // Paranoid check for use of R9 with RWPI. Clobbering R9 with -frwpi will | |||||
| // emit warnings about undefined behaviour but maybe theres's a valid use | |||||
| // case so on that basis allow it to be pushed/popped in the | |||||
| // prologue/epilogue. | |||||
| } else if (Reg > ARM::R0 && ARM::GPRRegClass.contains(Reg) && | |||||
| STI.isRRegisterReserved(Reg - ARM::R0)) { | |||||
| LLVM_DEBUG(dbgs() | |||||
| << printReg(Reg, TRI) | |||||
| << " has been reserved and" | |||||
| << " should not be allocatable" | |||||
| << " or spillable.\n"); | |||||
| SavedRegs.reset(Reg); | |||||
| continue; | |||||
| } | |||||
| bool Spilled = false; | bool Spilled = false; | ||||
| if (SavedRegs.test(Reg)) { | if (SavedRegs.test(Reg)) { | ||||
| Spilled = true; | Spilled = true; | ||||
| CanEliminateFrame = false; | CanEliminateFrame = false; | ||||
| } | } | ||||
| if (!ARM::GPRRegClass.contains(Reg)) { | if (!ARM::GPRRegClass.contains(Reg)) { | ||||
| if (Spilled) { | if (Spilled) { | ||||
| ▲ Show 20 Lines • Show All 172 Lines • ▼ Show 20 Lines | if (AFI->isThumb1OnlyFunction()) { | ||||
| // r4-r6 can be used in the prologue if they are pushed by the first push | // r4-r6 can be used in the prologue if they are pushed by the first push | ||||
| // instruction. | // instruction. | ||||
| for (unsigned Reg : {ARM::R4, ARM::R5, ARM::R6}) { | for (unsigned Reg : {ARM::R4, ARM::R5, ARM::R6}) { | ||||
| if (SavedRegs.test(Reg)) { | if (SavedRegs.test(Reg)) { | ||||
| --RegDeficit; | --RegDeficit; | ||||
| LLVM_DEBUG(dbgs() << printReg(Reg, TRI) | LLVM_DEBUG(dbgs() << printReg(Reg, TRI) | ||||
| << " is saved low register, RegDeficit = " | << " is saved low register, RegDeficit = " | ||||
| << RegDeficit << "\n"); | << RegDeficit << "\n"); | ||||
| } else { | } else if (!STI.isRRegisterReserved(Reg - ARM::R0)) { | ||||
| AvailableRegs.push_back(Reg); | AvailableRegs.push_back(Reg); | ||||
| LLVM_DEBUG( | LLVM_DEBUG( | ||||
| dbgs() | dbgs() | ||||
| << printReg(Reg, TRI) | << printReg(Reg, TRI) | ||||
| << " is non-saved low register, adding to AvailableRegs\n"); | << " is non-saved low register, adding to AvailableRegs\n"); | ||||
| } | } | ||||
| } | } | ||||
| // r7 can be used if it is not being used as the frame pointer. | // r7 can be used if it is not being used as the frame pointer. | ||||
| if (!HasFP) { | if (!HasFP) { | ||||
| if (SavedRegs.test(ARM::R7)) { | if (SavedRegs.test(ARM::R7)) { | ||||
| --RegDeficit; | --RegDeficit; | ||||
| LLVM_DEBUG(dbgs() << "%r7 is saved low register, RegDeficit = " | LLVM_DEBUG(dbgs() << "%r7 is saved low register, RegDeficit = " | ||||
| << RegDeficit << "\n"); | << RegDeficit << "\n"); | ||||
| } else { | } else if (!STI.isRRegisterReserved(7)) { | ||||
| AvailableRegs.push_back(ARM::R7); | AvailableRegs.push_back(ARM::R7); | ||||
| LLVM_DEBUG( | LLVM_DEBUG( | ||||
| dbgs() | dbgs() | ||||
| << "%r7 is non-saved low register, adding to AvailableRegs\n"); | << "%r7 is non-saved low register, adding to AvailableRegs\n"); | ||||
| } | } | ||||
| } | } | ||||
| // Each of r8-r11 needs to be copied to a low register, then pushed. | // Each of r8-r11 needs to be copied to a low register, then pushed. | ||||
| ▲ Show 20 Lines • Show All 638 Lines • Show Last 20 Lines | |||||