diff options
Diffstat (limited to 'llvm/lib/Target/AArch64/AArch64PrologueEpilogue.cpp')
| -rw-r--r-- | llvm/lib/Target/AArch64/AArch64PrologueEpilogue.cpp | 213 |
1 files changed, 114 insertions, 99 deletions
diff --git a/llvm/lib/Target/AArch64/AArch64PrologueEpilogue.cpp b/llvm/lib/Target/AArch64/AArch64PrologueEpilogue.cpp index 7e03b97..965585f 100644 --- a/llvm/lib/Target/AArch64/AArch64PrologueEpilogue.cpp +++ b/llvm/lib/Target/AArch64/AArch64PrologueEpilogue.cpp @@ -253,6 +253,8 @@ static void fixupSEHOpcode(MachineBasicBlock::iterator MBBI, case AArch64::SEH_SaveReg: case AArch64::SEH_SaveFRegP: case AArch64::SEH_SaveFReg: + case AArch64::SEH_SaveAnyRegI: + case AArch64::SEH_SaveAnyRegIP: case AArch64::SEH_SaveAnyRegQP: case AArch64::SEH_SaveAnyRegQPX: ImmOpnd = &MBBI->getOperand(ImmIdx); @@ -370,6 +372,22 @@ SVEFrameSizes AArch64PrologueEpilogueCommon::getSVEStackFrameSizes() const { {ZPRCalleeSavesSize, PPRLocalsSize + ZPRLocalsSize}}; } +SVEStackAllocations AArch64PrologueEpilogueCommon::getSVEStackAllocations( + SVEFrameSizes const &SVE) { + StackOffset AfterZPRs = SVE.ZPR.LocalsSize; + StackOffset BeforePPRs = SVE.ZPR.CalleeSavesSize + SVE.PPR.CalleeSavesSize; + StackOffset AfterPPRs = {}; + if (SVELayout == SVEStackLayout::Split) { + BeforePPRs = SVE.PPR.CalleeSavesSize; + // If there are no ZPR CSRs, place all local allocations after the ZPRs. + if (SVE.ZPR.CalleeSavesSize) + AfterPPRs += SVE.PPR.LocalsSize + SVE.ZPR.CalleeSavesSize; + else + AfterZPRs += SVE.PPR.LocalsSize; // Group allocation of locals. + } + return {BeforePPRs, AfterPPRs, AfterZPRs}; +} + struct SVEPartitions { struct { MachineBasicBlock::iterator Begin, End; @@ -687,16 +705,19 @@ void AArch64PrologueEmitter::emitPrologue() { // All of the remaining stack allocations are for locals. determineLocalsStackSize(NumBytes, PrologueSaveSize); + auto [PPR, ZPR] = getSVEStackFrameSizes(); + SVEStackAllocations SVEAllocs = getSVEStackAllocations({PPR, ZPR}); + MachineBasicBlock::iterator FirstGPRSaveI = PrologueBeginI; if (SVELayout == SVEStackLayout::CalleeSavesAboveFrameRecord) { + assert(!SVEAllocs.AfterPPRs && + "unexpected SVE allocs after PPRs with CalleeSavesAboveFrameRecord"); // If we're doing SVE saves first, we need to immediately allocate space // for fixed objects, then space for the SVE callee saves. // // Windows unwind requires that the scalable size is a multiple of 16; // that's handled when the callee-saved size is computed. - auto SaveSize = - StackOffset::getScalable(AFI->getSVECalleeSavedStackSize()) + - StackOffset::getFixed(FixedObject); + auto SaveSize = SVEAllocs.BeforePPRs + StackOffset::getFixed(FixedObject); allocateStackSpace(PrologueBeginI, 0, SaveSize, false, StackOffset{}, /*FollowupAllocs=*/true); NumBytes -= FixedObject; @@ -764,12 +785,11 @@ void AArch64PrologueEmitter::emitPrologue() { if (AFL.windowsRequiresStackProbe(MF, NumBytes + RealignmentPadding)) emitWindowsStackProbe(AfterGPRSavesI, DL, NumBytes, RealignmentPadding); - auto [PPR, ZPR] = getSVEStackFrameSizes(); - StackOffset SVECalleeSavesSize = ZPR.CalleeSavesSize + PPR.CalleeSavesSize; StackOffset NonSVELocalsSize = StackOffset::getFixed(NumBytes); + SVEAllocs.AfterZPRs += NonSVELocalsSize; + StackOffset CFAOffset = StackOffset::getFixed(MFI.getStackSize()) - NonSVELocalsSize; - MachineBasicBlock::iterator AfterSVESavesI = AfterGPRSavesI; // Allocate space for the callee saves and PPR locals (if any). if (SVELayout != SVEStackLayout::CalleeSavesAboveFrameRecord) { @@ -780,31 +800,23 @@ void AArch64PrologueEmitter::emitPrologue() { if (EmitAsyncCFI) emitCalleeSavedSVELocations(AfterSVESavesI); - StackOffset AllocateBeforePPRs = SVECalleeSavesSize; - StackOffset AllocateAfterPPRs = PPR.LocalsSize; - if (SVELayout == SVEStackLayout::Split) { - AllocateBeforePPRs = PPR.CalleeSavesSize; - AllocateAfterPPRs = PPR.LocalsSize + ZPR.CalleeSavesSize; - } - allocateStackSpace(PPRRange.Begin, 0, AllocateBeforePPRs, + allocateStackSpace(PPRRange.Begin, 0, SVEAllocs.BeforePPRs, EmitAsyncCFI && !HasFP, CFAOffset, - MFI.hasVarSizedObjects() || AllocateAfterPPRs || - ZPR.LocalsSize || NonSVELocalsSize); - CFAOffset += AllocateBeforePPRs; + MFI.hasVarSizedObjects() || SVEAllocs.AfterPPRs || + SVEAllocs.AfterZPRs); + CFAOffset += SVEAllocs.BeforePPRs; assert(PPRRange.End == ZPRRange.Begin && "Expected ZPR callee saves after PPR locals"); - allocateStackSpace(PPRRange.End, RealignmentPadding, AllocateAfterPPRs, + allocateStackSpace(PPRRange.End, 0, SVEAllocs.AfterPPRs, EmitAsyncCFI && !HasFP, CFAOffset, - MFI.hasVarSizedObjects() || ZPR.LocalsSize || - NonSVELocalsSize); - CFAOffset += AllocateAfterPPRs; + MFI.hasVarSizedObjects() || SVEAllocs.AfterZPRs); + CFAOffset += SVEAllocs.AfterPPRs; } else { assert(SVELayout == SVEStackLayout::CalleeSavesAboveFrameRecord); - // Note: With CalleeSavesAboveFrameRecord, the SVE CS have already been - // allocated (and separate PPR locals are not supported, all SVE locals, - // both PPR and ZPR, are within the ZPR locals area). - assert(!PPR.LocalsSize && "Unexpected PPR locals!"); - CFAOffset += SVECalleeSavesSize; + // Note: With CalleeSavesAboveFrameRecord, the SVE CS (BeforePPRs) have + // already been allocated. PPR locals (included in AfterPPRs) are not + // supported (note: this is asserted above). + CFAOffset += SVEAllocs.BeforePPRs; } // Allocate space for the rest of the frame including ZPR locals. Align the @@ -815,9 +827,9 @@ void AArch64PrologueEmitter::emitPrologue() { // FIXME: in the case of dynamic re-alignment, NumBytes doesn't have the // correct value here, as NumBytes also includes padding bytes, which // shouldn't be counted here. - allocateStackSpace( - AfterSVESavesI, RealignmentPadding, ZPR.LocalsSize + NonSVELocalsSize, - EmitAsyncCFI && !HasFP, CFAOffset, MFI.hasVarSizedObjects()); + allocateStackSpace(AfterSVESavesI, RealignmentPadding, SVEAllocs.AfterZPRs, + EmitAsyncCFI && !HasFP, CFAOffset, + MFI.hasVarSizedObjects()); } // If we need a base pointer, set it up here. It's whatever the value of the @@ -1308,6 +1320,26 @@ AArch64EpilogueEmitter::AArch64EpilogueEmitter(MachineFunction &MF, SEHEpilogueStartI = MBB.end(); } +void AArch64EpilogueEmitter::moveSPBelowFP(MachineBasicBlock::iterator MBBI, + StackOffset Offset) { + // Other combinations could be supported, but are not currently needed. + assert(Offset.getScalable() < 0 && Offset.getFixed() <= 0 && + "expected negative offset (with optional fixed portion)"); + Register Base = AArch64::FP; + if (int64_t FixedOffset = Offset.getFixed()) { + // If we have a negative fixed offset, we need to first subtract it in a + // temporary register first (to avoid briefly deallocating the scalable + // portion of the offset). + Base = MF.getRegInfo().createVirtualRegister(&AArch64::GPR64RegClass); + emitFrameOffset(MBB, MBBI, DL, Base, AArch64::FP, + StackOffset::getFixed(FixedOffset), TII, + MachineInstr::FrameDestroy); + } + emitFrameOffset(MBB, MBBI, DL, AArch64::SP, Base, + StackOffset::getScalable(Offset.getScalable()), TII, + MachineInstr::FrameDestroy); +} + void AArch64EpilogueEmitter::emitEpilogue() { MachineBasicBlock::iterator EpilogueEndI = MBB.getLastNonDebugInstr(); if (MBB.end() != EpilogueEndI) { @@ -1408,6 +1440,7 @@ void AArch64EpilogueEmitter::emitEpilogue() { AfterCSRPopSize += ProloguePopSize; } } + // Move past the restores of the callee-saved registers. // If we plan on combining the sp bump of the local stack size and the callee // save stack size, we might need to adjust the CSR save and restore offsets. @@ -1472,27 +1505,25 @@ void AArch64EpilogueEmitter::emitEpilogue() { assert(NumBytes >= 0 && "Negative stack allocation size!?"); StackOffset SVECalleeSavesSize = ZPR.CalleeSavesSize + PPR.CalleeSavesSize; - StackOffset SVEStackSize = - SVECalleeSavesSize + PPR.LocalsSize + ZPR.LocalsSize; - MachineBasicBlock::iterator RestoreBegin = ZPRRange.Begin; - MachineBasicBlock::iterator RestoreEnd = PPRRange.End; + SVEStackAllocations SVEAllocs = getSVEStackAllocations({PPR, ZPR}); // Deallocate the SVE area. if (SVELayout == SVEStackLayout::CalleeSavesAboveFrameRecord) { - StackOffset SVELocalsSize = ZPR.LocalsSize + PPR.LocalsSize; + assert(!SVEAllocs.AfterPPRs && + "unexpected SVE allocs after PPRs with CalleeSavesAboveFrameRecord"); // If the callee-save area is before FP, restoring the FP implicitly - // deallocates non-callee-save SVE allocations. Otherwise, deallocate them + // deallocates non-callee-save SVE allocations. Otherwise, deallocate them // explicitly. if (!AFI->isStackRealigned() && !MFI.hasVarSizedObjects()) { emitFrameOffset(MBB, FirstGPRRestoreI, DL, AArch64::SP, AArch64::SP, - SVELocalsSize, TII, MachineInstr::FrameDestroy, false, - NeedsWinCFI, &HasWinCFI); + SVEAllocs.AfterZPRs, TII, MachineInstr::FrameDestroy, + false, NeedsWinCFI, &HasWinCFI); } // Deallocate callee-save SVE registers. - emitFrameOffset(MBB, RestoreEnd, DL, AArch64::SP, AArch64::SP, - SVECalleeSavesSize, TII, MachineInstr::FrameDestroy, false, - NeedsWinCFI, &HasWinCFI); + emitFrameOffset(MBB, PPRRange.End, DL, AArch64::SP, AArch64::SP, + SVEAllocs.BeforePPRs, TII, MachineInstr::FrameDestroy, + false, NeedsWinCFI, &HasWinCFI); } else if (AFI->hasSVEStackSize()) { // If we have stack realignment or variable-sized objects we must use the FP // to restore SVE callee saves (as there is an unknown amount of @@ -1501,69 +1532,53 @@ void AArch64EpilogueEmitter::emitEpilogue() { (AFI->isStackRealigned() || MFI.hasVarSizedObjects()) ? AArch64::FP : AArch64::SP; if (SVECalleeSavesSize && BaseForSVEDealloc == AArch64::FP) { - // TODO: Support stack realigment and variable-sized objects. - assert( - SVELayout != SVEStackLayout::Split && - "unexpected stack realignment or variable sized objects with split " - "SVE stack objects"); - - Register CalleeSaveBase = AArch64::FP; - if (int64_t CalleeSaveBaseOffset = - AFI->getCalleeSaveBaseToFrameRecordOffset()) { - // If we have have an non-zero offset to the non-SVE CS base we need to - // compute the base address by subtracting the offest in a temporary - // register first (to avoid briefly deallocating the SVE CS). - CalleeSaveBase = MBB.getParent()->getRegInfo().createVirtualRegister( - &AArch64::GPR64RegClass); - emitFrameOffset(MBB, RestoreBegin, DL, CalleeSaveBase, AArch64::FP, - StackOffset::getFixed(-CalleeSaveBaseOffset), TII, - MachineInstr::FrameDestroy); + if (ZPR.CalleeSavesSize || SVELayout != SVEStackLayout::Split) { + // The offset from the frame-pointer to the start of the ZPR saves. + StackOffset FPOffsetZPR = + -SVECalleeSavesSize - PPR.LocalsSize - + StackOffset::getFixed(AFI->getCalleeSaveBaseToFrameRecordOffset()); + // Deallocate the stack space space by moving the SP to the start of the + // ZPR/PPR callee-save area. + moveSPBelowFP(ZPRRange.Begin, FPOffsetZPR); } - // The code below will deallocate the stack space space by moving the SP - // to the start of the SVE callee-save area. - emitFrameOffset(MBB, RestoreBegin, DL, AArch64::SP, CalleeSaveBase, - -SVECalleeSavesSize, TII, MachineInstr::FrameDestroy); - } else if (BaseForSVEDealloc == AArch64::SP) { - auto CFAOffset = - SVEStackSize + StackOffset::getFixed(NumBytes + PrologueSaveSize); - - if (SVECalleeSavesSize) { - // Deallocate the non-SVE locals first before we can deallocate (and - // restore callee saves) from the SVE area. - auto NonSVELocals = StackOffset::getFixed(NumBytes); - emitFrameOffset(MBB, ZPRRange.Begin, DL, AArch64::SP, AArch64::SP, - NonSVELocals, TII, MachineInstr::FrameDestroy, false, - NeedsWinCFI, &HasWinCFI, EmitCFI && !HasFP, CFAOffset); - CFAOffset -= NonSVELocals; - NumBytes = 0; + // With split SVE, the predicates are stored in a separate area above the + // ZPR saves, so we must adjust the stack to the start of the PPRs. + if (PPR.CalleeSavesSize && SVELayout == SVEStackLayout::Split) { + // The offset from the frame-pointer to the start of the PPR saves. + StackOffset FPOffsetPPR = -PPR.CalleeSavesSize; + // Move to the start of the PPR area. + assert(!FPOffsetPPR.getFixed() && "expected only scalable offset"); + emitFrameOffset(MBB, ZPRRange.End, DL, AArch64::SP, AArch64::FP, + FPOffsetPPR, TII, MachineInstr::FrameDestroy); } - - if (ZPR.LocalsSize) { - emitFrameOffset(MBB, ZPRRange.Begin, DL, AArch64::SP, AArch64::SP, - ZPR.LocalsSize, TII, MachineInstr::FrameDestroy, false, - NeedsWinCFI, &HasWinCFI, EmitCFI && !HasFP, CFAOffset); - CFAOffset -= ZPR.LocalsSize; - } - - StackOffset SVECalleeSavesToDealloc = SVECalleeSavesSize; - if (SVELayout == SVEStackLayout::Split && - (PPR.LocalsSize || ZPR.CalleeSavesSize)) { - assert(PPRRange.Begin == ZPRRange.End && - "Expected PPR restores after ZPR"); - emitFrameOffset(MBB, PPRRange.Begin, DL, AArch64::SP, AArch64::SP, - PPR.LocalsSize + ZPR.CalleeSavesSize, TII, - MachineInstr::FrameDestroy, false, NeedsWinCFI, - &HasWinCFI, EmitCFI && !HasFP, CFAOffset); - CFAOffset -= PPR.LocalsSize + ZPR.CalleeSavesSize; - SVECalleeSavesToDealloc -= ZPR.CalleeSavesSize; + } else if (BaseForSVEDealloc == AArch64::SP) { + auto NonSVELocals = StackOffset::getFixed(NumBytes); + auto CFAOffset = NonSVELocals + StackOffset::getFixed(PrologueSaveSize) + + SVEAllocs.totalSize(); + + if (SVECalleeSavesSize || SVELayout == SVEStackLayout::Split) { + // Deallocate non-SVE locals now. This is needed to reach the SVE callee + // saves, but may also allow combining stack hazard bumps for split SVE. + SVEAllocs.AfterZPRs += NonSVELocals; + NumBytes -= NonSVELocals.getFixed(); } - - // If split SVE is on, this dealloc PPRs, otherwise, deallocs ZPRs + PPRs: - if (SVECalleeSavesToDealloc) - emitFrameOffset(MBB, PPRRange.End, DL, AArch64::SP, AArch64::SP, - SVECalleeSavesToDealloc, TII, - MachineInstr::FrameDestroy, false, NeedsWinCFI, - &HasWinCFI, EmitCFI && !HasFP, CFAOffset); + // To deallocate the SVE stack adjust by the allocations in reverse. + emitFrameOffset(MBB, ZPRRange.Begin, DL, AArch64::SP, AArch64::SP, + SVEAllocs.AfterZPRs, TII, MachineInstr::FrameDestroy, + false, NeedsWinCFI, &HasWinCFI, EmitCFI && !HasFP, + CFAOffset); + CFAOffset -= SVEAllocs.AfterZPRs; + assert(PPRRange.Begin == ZPRRange.End && + "Expected PPR restores after ZPR"); + emitFrameOffset(MBB, PPRRange.Begin, DL, AArch64::SP, AArch64::SP, + SVEAllocs.AfterPPRs, TII, MachineInstr::FrameDestroy, + false, NeedsWinCFI, &HasWinCFI, EmitCFI && !HasFP, + CFAOffset); + CFAOffset -= SVEAllocs.AfterPPRs; + emitFrameOffset(MBB, PPRRange.End, DL, AArch64::SP, AArch64::SP, + SVEAllocs.BeforePPRs, TII, MachineInstr::FrameDestroy, + false, NeedsWinCFI, &HasWinCFI, EmitCFI && !HasFP, + CFAOffset); } if (EmitCFI) |