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Diffstat (limited to 'lib/Target/X86/X86FrameLowering.cpp')
-rw-r--r--lib/Target/X86/X86FrameLowering.cpp91
1 files changed, 51 insertions, 40 deletions
diff --git a/lib/Target/X86/X86FrameLowering.cpp b/lib/Target/X86/X86FrameLowering.cpp
index f0ad4d1..4c1374f 100644
--- a/lib/Target/X86/X86FrameLowering.cpp
+++ b/lib/Target/X86/X86FrameLowering.cpp
@@ -182,7 +182,7 @@ void emitSPUpdate(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
}
}
- MachineInstr *MI = NULL;
+ MachineInstr *MI = nullptr;
if (UseLEA) {
MI = addRegOffset(BuildMI(MBB, MBBI, DL, TII.get(Opc), StackPtr),
@@ -204,7 +204,7 @@ void emitSPUpdate(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
/// mergeSPUpdatesUp - Merge two stack-manipulating instructions upper iterator.
static
void mergeSPUpdatesUp(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
- unsigned StackPtr, uint64_t *NumBytes = NULL) {
+ unsigned StackPtr, uint64_t *NumBytes = nullptr) {
if (MBBI == MBB.begin()) return;
MachineBasicBlock::iterator PI = std::prev(MBBI);
@@ -225,11 +225,12 @@ void mergeSPUpdatesUp(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
}
}
-/// mergeSPUpdatesDown - Merge two stack-manipulating instructions lower iterator.
+/// mergeSPUpdatesDown - Merge two stack-manipulating instructions lower
+/// iterator.
static
void mergeSPUpdatesDown(MachineBasicBlock &MBB,
MachineBasicBlock::iterator &MBBI,
- unsigned StackPtr, uint64_t *NumBytes = NULL) {
+ unsigned StackPtr, uint64_t *NumBytes = nullptr) {
// FIXME: THIS ISN'T RUN!!!
return;
@@ -257,19 +258,19 @@ void mergeSPUpdatesDown(MachineBasicBlock &MBB,
}
/// mergeSPUpdates - Checks the instruction before/after the passed
-/// instruction. If it is an ADD/SUB/LEA instruction it is deleted argument and the
-/// stack adjustment is returned as a positive value for ADD/LEA and a negative for
-/// SUB.
+/// instruction. If it is an ADD/SUB/LEA instruction it is deleted argument and
+/// the stack adjustment is returned as a positive value for ADD/LEA and a
+/// negative for SUB.
static int mergeSPUpdates(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MBBI,
- unsigned StackPtr,
- bool doMergeWithPrevious) {
+ MachineBasicBlock::iterator &MBBI, unsigned StackPtr,
+ bool doMergeWithPrevious) {
if ((doMergeWithPrevious && MBBI == MBB.begin()) ||
(!doMergeWithPrevious && MBBI == MBB.end()))
return 0;
MachineBasicBlock::iterator PI = doMergeWithPrevious ? std::prev(MBBI) : MBBI;
- MachineBasicBlock::iterator NI = doMergeWithPrevious ? 0 : std::next(MBBI);
+ MachineBasicBlock::iterator NI = doMergeWithPrevious ? nullptr
+ : std::next(MBBI);
unsigned Opc = PI->getOpcode();
int Offset = 0;
@@ -366,8 +367,10 @@ void X86FrameLowering::emitCalleeSavedFrameMoves(
unsigned DwarfReg = MRI->getDwarfRegNum(Reg, true);
unsigned CFIIndex =
- MMI.addFrameInst(MCCFIInstruction::createOffset(0, DwarfReg, Offset));
- BuildMI(MBB, MBBI, DL, TII.get(X86::CFI_INSTRUCTION)).addCFIIndex(CFIIndex);
+ MMI.addFrameInst(MCCFIInstruction::createOffset(nullptr, DwarfReg,
+ Offset));
+ BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
+ .addCFIIndex(CFIIndex);
}
}
@@ -446,7 +449,7 @@ void X86FrameLowering::emitPrologue(MachineFunction &MF) const {
!MFI->adjustsStack() && // No calls.
!IsWin64 && // Win64 has no Red Zone
!usesTheStack(MF) && // Don't push and pop.
- !MF.getTarget().Options.EnableSegmentedStacks) { // Regular stack
+ !MF.shouldSplitStack()) { // Regular stack
uint64_t MinSize = X86FI->getCalleeSavedFrameSize();
if (HasFP) MinSize += SlotSize;
StackSize = std::max(MinSize, StackSize > 128 ? StackSize - 128 : 0);
@@ -511,15 +514,16 @@ void X86FrameLowering::emitPrologue(MachineFunction &MF) const {
// Define the current CFA rule to use the provided offset.
assert(StackSize);
unsigned CFIIndex = MMI.addFrameInst(
- MCCFIInstruction::createDefCfaOffset(0, 2 * stackGrowth));
- BuildMI(MBB, MBBI, DL, TII.get(X86::CFI_INSTRUCTION))
+ MCCFIInstruction::createDefCfaOffset(nullptr, 2 * stackGrowth));
+ BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
// Change the rule for the FramePtr to be an "offset" rule.
unsigned DwarfFramePtr = RegInfo->getDwarfRegNum(FramePtr, true);
CFIIndex = MMI.addFrameInst(
- MCCFIInstruction::createOffset(0, DwarfFramePtr, 2 * stackGrowth));
- BuildMI(MBB, MBBI, DL, TII.get(X86::CFI_INSTRUCTION))
+ MCCFIInstruction::createOffset(nullptr,
+ DwarfFramePtr, 2 * stackGrowth));
+ BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
}
@@ -534,8 +538,8 @@ void X86FrameLowering::emitPrologue(MachineFunction &MF) const {
// Define the current CFA to use the EBP/RBP register.
unsigned DwarfFramePtr = RegInfo->getDwarfRegNum(FramePtr, true);
unsigned CFIIndex = MMI.addFrameInst(
- MCCFIInstruction::createDefCfaRegister(0, DwarfFramePtr));
- BuildMI(MBB, MBBI, DL, TII.get(X86::CFI_INSTRUCTION))
+ MCCFIInstruction::createDefCfaRegister(nullptr, DwarfFramePtr));
+ BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
}
@@ -564,7 +568,7 @@ void X86FrameLowering::emitPrologue(MachineFunction &MF) const {
assert(StackSize);
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createDefCfaOffset(nullptr, StackOffset));
- BuildMI(MBB, MBBI, DL, TII.get(X86::CFI_INSTRUCTION))
+ BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
StackOffset += stackGrowth;
}
@@ -698,9 +702,10 @@ void X86FrameLowering::emitPrologue(MachineFunction &MF) const {
// Define the current CFA rule to use the provided offset.
assert(StackSize);
unsigned CFIIndex = MMI.addFrameInst(
- MCCFIInstruction::createDefCfaOffset(0, -StackSize + stackGrowth));
+ MCCFIInstruction::createDefCfaOffset(nullptr,
+ -StackSize + stackGrowth));
- BuildMI(MBB, MBBI, DL, TII.get(X86::CFI_INSTRUCTION))
+ BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
}
@@ -905,7 +910,8 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
}
}
-int X86FrameLowering::getFrameIndexOffset(const MachineFunction &MF, int FI) const {
+int X86FrameLowering::getFrameIndexOffset(const MachineFunction &MF,
+ int FI) const {
const X86RegisterInfo *RegInfo =
static_cast<const X86RegisterInfo*>(MF.getTarget().getRegisterInfo());
const MachineFrameInfo *MFI = MF.getFrameInfo();
@@ -1170,6 +1176,15 @@ X86FrameLowering::adjustForSegmentedStacks(MachineFunction &MF) const {
!STI.isTargetWin32() && !STI.isTargetWin64() && !STI.isTargetFreeBSD())
report_fatal_error("Segmented stacks not supported on this platform.");
+ // Eventually StackSize will be calculated by a link-time pass; which will
+ // also decide whether checking code needs to be injected into this particular
+ // prologue.
+ StackSize = MFI->getStackSize();
+
+ // Do not generate a prologue for functions with a stack of size zero
+ if (StackSize == 0)
+ return;
+
MachineBasicBlock *allocMBB = MF.CreateMachineBasicBlock();
MachineBasicBlock *checkMBB = MF.CreateMachineBasicBlock();
X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
@@ -1194,11 +1209,6 @@ X86FrameLowering::adjustForSegmentedStacks(MachineFunction &MF) const {
MF.push_front(allocMBB);
MF.push_front(checkMBB);
- // Eventually StackSize will be calculated by a link-time pass; which will
- // also decide whether checking code needs to be injected into this particular
- // prologue.
- StackSize = MFI->getStackSize();
-
// When the frame size is less than 256 we just compare the stack
// boundary directly to the value of the stack pointer, per gcc.
bool CompareStackPointer = StackSize < kSplitStackAvailable;
@@ -1256,22 +1266,23 @@ X86FrameLowering::adjustForSegmentedStacks(MachineFunction &MF) const {
.addReg(0).addImm(0).addReg(0).addImm(TlsOffset).addReg(TlsReg);
} else if (STI.isTargetDarwin()) {
- // TlsOffset doesn't fit into a mod r/m byte so we need an extra register
+ // TlsOffset doesn't fit into a mod r/m byte so we need an extra register.
unsigned ScratchReg2;
bool SaveScratch2;
if (CompareStackPointer) {
- // The primary scratch register is available for holding the TLS offset
+ // The primary scratch register is available for holding the TLS offset.
ScratchReg2 = GetScratchRegister(Is64Bit, MF, true);
SaveScratch2 = false;
} else {
// Need to use a second register to hold the TLS offset
ScratchReg2 = GetScratchRegister(Is64Bit, MF, false);
- // Unfortunately, with fastcc the second scratch register may hold an arg
+ // Unfortunately, with fastcc the second scratch register may hold an
+ // argument.
SaveScratch2 = MF.getRegInfo().isLiveIn(ScratchReg2);
}
- // If Scratch2 is live-in then it needs to be saved
+ // If Scratch2 is live-in then it needs to be saved.
assert((!MF.getRegInfo().isLiveIn(ScratchReg2) || SaveScratch2) &&
"Scratch register is live-in and not saved");
@@ -1348,14 +1359,14 @@ X86FrameLowering::adjustForSegmentedStacks(MachineFunction &MF) const {
/// http://publications.uu.se/uu/fulltext/nbn_se_uu_diva-2688.pdf)
///
/// CheckStack:
-/// temp0 = sp - MaxStack
-/// if( temp0 < SP_LIMIT(P) ) goto IncStack else goto OldStart
+/// temp0 = sp - MaxStack
+/// if( temp0 < SP_LIMIT(P) ) goto IncStack else goto OldStart
/// OldStart:
-/// ...
+/// ...
/// IncStack:
-/// call inc_stack # doubles the stack space
-/// temp0 = sp - MaxStack
-/// if( temp0 < SP_LIMIT(P) ) goto IncStack else goto OldStart
+/// call inc_stack # doubles the stack space
+/// temp0 = sp - MaxStack
+/// if( temp0 < SP_LIMIT(P) ) goto IncStack else goto OldStart
void X86FrameLowering::adjustForHiPEPrologue(MachineFunction &MF) const {
const X86InstrInfo &TII = *TM.getInstrInfo();
MachineFrameInfo *MFI = MF.getFrameInfo();
@@ -1514,7 +1525,7 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
unsigned StackAlign = TM.getFrameLowering()->getStackAlignment();
Amount = (Amount + StackAlign - 1) / StackAlign * StackAlign;
- MachineInstr *New = 0;
+ MachineInstr *New = nullptr;
if (Opcode == TII.getCallFrameSetupOpcode()) {
New = BuildMI(MF, DL, TII.get(getSUBriOpcode(IsLP64, Amount)),
StackPtr)
generated by cgit v1.1 at 2025-05-15 00:05:00 +0000