From 2bfaf521aed6d486b2d80dbf12b84b456100cb47 Mon Sep 17 00:00:00 2001 From: Chad Rosier Date: Sat, 1 Oct 2011 19:30:36 +0000 Subject: [PATCH] Revert r140924 "Attempt to fix dynamic stack realignment for thumb1 functions." to appease nightly testers. Not quite there yet. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140953 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/ARM/ARMBaseRegisterInfo.cpp | 7 +++++-- lib/Target/ARM/ARMFrameLowering.cpp | 6 ++---- lib/Target/ARM/Thumb1FrameLowering.cpp | 21 --------------------- 3 files changed, 7 insertions(+), 27 deletions(-) diff --git a/lib/Target/ARM/ARMBaseRegisterInfo.cpp b/lib/Target/ARM/ARMBaseRegisterInfo.cpp index 48e3c524606..7c42342229a 100644 --- a/lib/Target/ARM/ARMBaseRegisterInfo.cpp +++ b/lib/Target/ARM/ARMBaseRegisterInfo.cpp @@ -626,10 +626,13 @@ bool ARMBaseRegisterInfo::hasBasePointer(const MachineFunction &MF) const { bool ARMBaseRegisterInfo::canRealignStack(const MachineFunction &MF) const { const MachineFrameInfo *MFI = MF.getFrameInfo(); + const ARMFunctionInfo *AFI = MF.getInfo(); // We can't realign the stack if: // 1. Dynamic stack realignment is explicitly disabled, - // 2. There are VLAs in the function and the base pointer is disabled. - return (RealignStack && (!MFI->hasVarSizedObjects() || EnableBasePointer)); + // 2. This is a Thumb1 function (it's not useful, so we don't bother), or + // 3. There are VLAs in the function and the base pointer is disabled. + return (RealignStack && !AFI->isThumb1OnlyFunction() && + (!MFI->hasVarSizedObjects() || EnableBasePointer)); } bool ARMBaseRegisterInfo:: diff --git a/lib/Target/ARM/ARMFrameLowering.cpp b/lib/Target/ARM/ARMFrameLowering.cpp index 4bac6c5fa95..2d1de6fe8e9 100644 --- a/lib/Target/ARM/ARMFrameLowering.cpp +++ b/lib/Target/ARM/ARMFrameLowering.cpp @@ -881,12 +881,10 @@ ARMFrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF, // for sure what the stack size will be, but for this, an estimate is good // enough. If there anything changes it, it'll be a spill, which implies // we've used all the registers and so R4 is already used, so not marking - // it here will be OK. Also spill R4 if Thumb1 function requires stack - // realignment. + // it here will be OK. // FIXME: It will be better just to find spare register here. unsigned StackSize = estimateStackSize(MF); - if (MFI->hasVarSizedObjects() || RegInfo->needsStackRealignment(MF) || - StackSize > 508) + if (MFI->hasVarSizedObjects() || StackSize > 508) MF.getRegInfo().setPhysRegUsed(ARM::R4); } diff --git a/lib/Target/ARM/Thumb1FrameLowering.cpp b/lib/Target/ARM/Thumb1FrameLowering.cpp index 9ff3ffcfa2b..d4d59ea59da 100644 --- a/lib/Target/ARM/Thumb1FrameLowering.cpp +++ b/lib/Target/ARM/Thumb1FrameLowering.cpp @@ -155,27 +155,6 @@ void Thumb1FrameLowering::emitPrologue(MachineFunction &MF) const { AFI->setGPRCalleeSavedArea2Size(GPRCS2Size); AFI->setDPRCalleeSavedAreaSize(DPRCSSize); - if (RegInfo->needsStackRealignment(MF)) { - // We cannot use sp as source/dest register here, thus we're emitting the - // following sequence: - // mov r4, sp - // lsrs r4, r4, Log2MaxAlign - // lsls r4, r4, Log2MaxAlign - // mov sp, r4 - unsigned MaxAlign = MFI->getMaxAlignment(); - unsigned Log2MaxAlign = Log2_32(MaxAlign); - AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr), ARM::R4) - .addReg(ARM::SP, RegState::Kill)); - AddDefaultPred(AddDefaultT1CC(BuildMI(MBB, MBBI, dl, TII.get(ARM::tLSRri), ARM::R4)) - .addReg(ARM::R4, RegState::Kill) - .addImm(Log2MaxAlign)); - AddDefaultPred(AddDefaultT1CC(BuildMI(MBB, MBBI, dl, TII.get(ARM::tLSLri), ARM::R4)) - .addReg(ARM::R4, RegState::Kill) - .addImm(Log2MaxAlign)); - AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr), ARM::SP) - .addReg(ARM::R4, RegState::Kill)); - } - // If we need a base pointer, set it up here. It's whatever the value // of the stack pointer is at this point. Any variable size objects // will be allocated after this, so we can still use the base pointer -- 2.34.1