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Diffstat (limited to 'llvm/lib/Target/RISCV/RISCVFrameLowering.cpp')
-rw-r--r--llvm/lib/Target/RISCV/RISCVFrameLowering.cpp122
1 files changed, 76 insertions, 46 deletions
diff --git a/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp b/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
index 6c8e3da..23b4554 100644
--- a/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
@@ -95,6 +95,11 @@ static const std::pair<MCPhysReg, int8_t> FixedCSRFIQCIInterruptMap[] = {
/* -21, -22, -23, -24 are reserved */
};
+/// Returns true if DWARF CFI instructions ("frame moves") should be emitted.
+static bool needsDwarfCFI(const MachineFunction &MF) {
+ return MF.needsFrameMoves();
+}
+
// For now we use x3, a.k.a gp, as pointer to shadow call stack.
// User should not use x3 in their asm.
static void emitSCSPrologue(MachineFunction &MF, MachineBasicBlock &MBB,
@@ -141,6 +146,9 @@ static void emitSCSPrologue(MachineFunction &MF, MachineBasicBlock &MBB,
.addImm(-SlotSize)
.setMIFlag(MachineInstr::FrameSetup);
+ if (!needsDwarfCFI(MF))
+ return;
+
// Emit a CFI instruction that causes SlotSize to be subtracted from the value
// of the shadow stack pointer when unwinding past this frame.
char DwarfSCSReg = TRI->getDwarfRegNum(SCSPReg, /*IsEH*/ true);
@@ -199,8 +207,10 @@ static void emitSCSEpilogue(MachineFunction &MF, MachineBasicBlock &MBB,
.addReg(SCSPReg)
.addImm(-SlotSize)
.setMIFlag(MachineInstr::FrameDestroy);
- // Restore the SCS pointer
- CFIInstBuilder(MBB, MI, MachineInstr::FrameDestroy).buildRestore(SCSPReg);
+ if (needsDwarfCFI(MF)) {
+ // Restore the SCS pointer
+ CFIInstBuilder(MBB, MI, MachineInstr::FrameDestroy).buildRestore(SCSPReg);
+ }
}
// Insert instruction to swap mscratchsw with sp
@@ -935,6 +945,7 @@ void RISCVFrameLowering::emitPrologue(MachineFunction &MF,
MBBI = std::prev(MBBI, getRVVCalleeSavedInfo(MF, CSI).size() +
getUnmanagedCSI(MF, CSI).size());
CFIInstBuilder CFIBuilder(MBB, MBBI, MachineInstr::FrameSetup);
+ bool NeedsDwarfCFI = needsDwarfCFI(MF);
// If libcalls are used to spill and restore callee-saved registers, the frame
// has two sections; the opaque section managed by the libcalls, and the
@@ -962,10 +973,12 @@ void RISCVFrameLowering::emitPrologue(MachineFunction &MF,
alignTo((STI.getXLen() / 8) * LibCallRegs, getStackAlign());
RVFI->setLibCallStackSize(LibCallFrameSize);
- CFIBuilder.buildDefCFAOffset(LibCallFrameSize);
- for (const CalleeSavedInfo &CS : getPushOrLibCallsSavedInfo(MF, CSI))
- CFIBuilder.buildOffset(CS.getReg(),
- MFI.getObjectOffset(CS.getFrameIdx()));
+ if (NeedsDwarfCFI) {
+ CFIBuilder.buildDefCFAOffset(LibCallFrameSize);
+ for (const CalleeSavedInfo &CS : getPushOrLibCallsSavedInfo(MF, CSI))
+ CFIBuilder.buildOffset(CS.getReg(),
+ MFI.getObjectOffset(CS.getFrameIdx()));
+ }
}
// FIXME (note copied from Lanai): This appears to be overallocating. Needs
@@ -996,14 +1009,17 @@ void RISCVFrameLowering::emitPrologue(MachineFunction &MF,
// could only be the next instruction.
++PossiblePush;
- // Insert the CFI metadata before where we think the `(QC.)CM.PUSH(FP)`
- // could be. The PUSH will also get its own CFI metadata for its own
- // modifications, which should come after the PUSH.
- CFIInstBuilder PushCFIBuilder(MBB, PossiblePush, MachineInstr::FrameSetup);
- PushCFIBuilder.buildDefCFAOffset(QCIInterruptPushAmount);
- for (const CalleeSavedInfo &CS : getQCISavedInfo(MF, CSI))
- PushCFIBuilder.buildOffset(CS.getReg(),
- MFI.getObjectOffset(CS.getFrameIdx()));
+ if (NeedsDwarfCFI) {
+ // Insert the CFI metadata before where we think the `(QC.)CM.PUSH(FP)`
+ // could be. The PUSH will also get its own CFI metadata for its own
+ // modifications, which should come after the PUSH.
+ CFIInstBuilder PushCFIBuilder(MBB, PossiblePush,
+ MachineInstr::FrameSetup);
+ PushCFIBuilder.buildDefCFAOffset(QCIInterruptPushAmount);
+ for (const CalleeSavedInfo &CS : getQCISavedInfo(MF, CSI))
+ PushCFIBuilder.buildOffset(CS.getReg(),
+ MFI.getObjectOffset(CS.getFrameIdx()));
+ }
}
if (RVFI->isPushable(MF) && PossiblePush != MBB.end() &&
@@ -1017,10 +1033,12 @@ void RISCVFrameLowering::emitPrologue(MachineFunction &MF,
PossiblePush->getOperand(1).setImm(StackAdj);
StackSize -= StackAdj;
- CFIBuilder.buildDefCFAOffset(RealStackSize - StackSize);
- for (const CalleeSavedInfo &CS : getPushOrLibCallsSavedInfo(MF, CSI))
- CFIBuilder.buildOffset(CS.getReg(),
- MFI.getObjectOffset(CS.getFrameIdx()));
+ if (NeedsDwarfCFI) {
+ CFIBuilder.buildDefCFAOffset(RealStackSize - StackSize);
+ for (const CalleeSavedInfo &CS : getPushOrLibCallsSavedInfo(MF, CSI))
+ CFIBuilder.buildOffset(CS.getReg(),
+ MFI.getObjectOffset(CS.getFrameIdx()));
+ }
}
// Allocate space on the stack if necessary.
@@ -1031,7 +1049,7 @@ void RISCVFrameLowering::emitPrologue(MachineFunction &MF,
bool DynAllocation =
MF.getInfo<RISCVMachineFunctionInfo>()->hasDynamicAllocation();
if (StackSize != 0)
- allocateStack(MBB, MBBI, MF, StackSize, RealStackSize, /*EmitCFI=*/true,
+ allocateStack(MBB, MBBI, MF, StackSize, RealStackSize, NeedsDwarfCFI,
NeedProbe, ProbeSize, DynAllocation,
MachineInstr::FrameSetup);
@@ -1049,8 +1067,10 @@ void RISCVFrameLowering::emitPrologue(MachineFunction &MF,
// Iterate over list of callee-saved registers and emit .cfi_offset
// directives.
- for (const CalleeSavedInfo &CS : getUnmanagedCSI(MF, CSI))
- CFIBuilder.buildOffset(CS.getReg(), MFI.getObjectOffset(CS.getFrameIdx()));
+ if (NeedsDwarfCFI)
+ for (const CalleeSavedInfo &CS : getUnmanagedCSI(MF, CSI))
+ CFIBuilder.buildOffset(CS.getReg(),
+ MFI.getObjectOffset(CS.getFrameIdx()));
// Generate new FP.
if (hasFP(MF)) {
@@ -1069,7 +1089,8 @@ void RISCVFrameLowering::emitPrologue(MachineFunction &MF,
MachineInstr::FrameSetup, getStackAlign());
}
- CFIBuilder.buildDefCFA(FPReg, RVFI->getVarArgsSaveSize());
+ if (NeedsDwarfCFI)
+ CFIBuilder.buildDefCFA(FPReg, RVFI->getVarArgsSaveSize());
}
uint64_t SecondSPAdjustAmount = 0;
@@ -1080,15 +1101,16 @@ void RISCVFrameLowering::emitPrologue(MachineFunction &MF,
"SecondSPAdjustAmount should be greater than zero");
allocateStack(MBB, MBBI, MF, SecondSPAdjustAmount,
- getStackSizeWithRVVPadding(MF), !hasFP(MF), NeedProbe,
- ProbeSize, DynAllocation, MachineInstr::FrameSetup);
+ getStackSizeWithRVVPadding(MF), NeedsDwarfCFI && !hasFP(MF),
+ NeedProbe, ProbeSize, DynAllocation,
+ MachineInstr::FrameSetup);
}
if (RVVStackSize) {
if (NeedProbe) {
allocateAndProbeStackForRVV(MF, MBB, MBBI, DL, RVVStackSize,
- MachineInstr::FrameSetup, !hasFP(MF),
- DynAllocation);
+ MachineInstr::FrameSetup,
+ NeedsDwarfCFI && !hasFP(MF), DynAllocation);
} else {
// We must keep the stack pointer aligned through any intermediate
// updates.
@@ -1097,14 +1119,15 @@ void RISCVFrameLowering::emitPrologue(MachineFunction &MF,
MachineInstr::FrameSetup, getStackAlign());
}
- if (!hasFP(MF)) {
+ if (NeedsDwarfCFI && !hasFP(MF)) {
// Emit .cfi_def_cfa_expression "sp + StackSize + RVVStackSize * vlenb".
CFIBuilder.insertCFIInst(createDefCFAExpression(
*RI, SPReg, getStackSizeWithRVVPadding(MF), RVVStackSize / 8));
}
std::advance(MBBI, getRVVCalleeSavedInfo(MF, CSI).size());
- emitCalleeSavedRVVPrologCFI(MBB, MBBI, hasFP(MF));
+ if (NeedsDwarfCFI)
+ emitCalleeSavedRVVPrologCFI(MBB, MBBI, hasFP(MF));
}
if (hasFP(MF)) {
@@ -1171,8 +1194,9 @@ void RISCVFrameLowering::deallocateStack(MachineFunction &MF,
MachineInstr::FrameDestroy, getStackAlign());
StackSize = 0;
- CFIInstBuilder(MBB, MBBI, MachineInstr::FrameDestroy)
- .buildDefCFAOffset(CFAOffset);
+ if (needsDwarfCFI(MF))
+ CFIInstBuilder(MBB, MBBI, MachineInstr::FrameDestroy)
+ .buildDefCFAOffset(CFAOffset);
}
void RISCVFrameLowering::emitEpilogue(MachineFunction &MF,
@@ -1212,6 +1236,7 @@ void RISCVFrameLowering::emitEpilogue(MachineFunction &MF,
std::next(MBBI, getRVVCalleeSavedInfo(MF, CSI).size());
CFIInstBuilder CFIBuilder(MBB, FirstScalarCSRRestoreInsn,
MachineInstr::FrameDestroy);
+ bool NeedsDwarfCFI = needsDwarfCFI(MF);
uint64_t FirstSPAdjustAmount = getFirstSPAdjustAmount(MF);
uint64_t RealStackSize = FirstSPAdjustAmount ? FirstSPAdjustAmount
@@ -1232,10 +1257,11 @@ void RISCVFrameLowering::emitEpilogue(MachineFunction &MF,
StackOffset::getScalable(RVVStackSize),
MachineInstr::FrameDestroy, getStackAlign());
- if (!hasFP(MF))
- CFIBuilder.buildDefCFA(SPReg, RealStackSize);
-
- emitCalleeSavedRVVEpilogCFI(MBB, FirstScalarCSRRestoreInsn);
+ if (NeedsDwarfCFI) {
+ if (!hasFP(MF))
+ CFIBuilder.buildDefCFA(SPReg, RealStackSize);
+ emitCalleeSavedRVVEpilogCFI(MBB, FirstScalarCSRRestoreInsn);
+ }
}
if (FirstSPAdjustAmount) {
@@ -1251,7 +1277,7 @@ void RISCVFrameLowering::emitEpilogue(MachineFunction &MF,
StackOffset::getFixed(SecondSPAdjustAmount),
MachineInstr::FrameDestroy, getStackAlign());
- if (!hasFP(MF))
+ if (NeedsDwarfCFI && !hasFP(MF))
CFIBuilder.buildDefCFAOffset(FirstSPAdjustAmount);
}
@@ -1272,7 +1298,7 @@ void RISCVFrameLowering::emitEpilogue(MachineFunction &MF,
getStackAlign());
}
- if (hasFP(MF))
+ if (NeedsDwarfCFI && hasFP(MF))
CFIBuilder.buildDefCFA(SPReg, RealStackSize);
// Skip to after the restores of scalar callee-saved registers
@@ -1295,8 +1321,9 @@ void RISCVFrameLowering::emitEpilogue(MachineFunction &MF,
}
// Recover callee-saved registers.
- for (const CalleeSavedInfo &CS : getUnmanagedCSI(MF, CSI))
- CFIBuilder.buildRestore(CS.getReg());
+ if (NeedsDwarfCFI)
+ for (const CalleeSavedInfo &CS : getUnmanagedCSI(MF, CSI))
+ CFIBuilder.buildRestore(CS.getReg());
if (RVFI->isPushable(MF) && MBBI != MBB.end() && isPop(MBBI->getOpcode())) {
// Use available stack adjustment in pop instruction to deallocate stack
@@ -1315,15 +1342,17 @@ void RISCVFrameLowering::emitEpilogue(MachineFunction &MF,
auto NextI = next_nodbg(MBBI, MBB.end());
if (NextI == MBB.end() || NextI->getOpcode() != RISCV::PseudoRET) {
++MBBI;
- CFIBuilder.setInsertPoint(MBBI);
+ if (NeedsDwarfCFI) {
+ CFIBuilder.setInsertPoint(MBBI);
- for (const CalleeSavedInfo &CS : getPushOrLibCallsSavedInfo(MF, CSI))
- CFIBuilder.buildRestore(CS.getReg());
+ for (const CalleeSavedInfo &CS : getPushOrLibCallsSavedInfo(MF, CSI))
+ CFIBuilder.buildRestore(CS.getReg());
- // Update CFA Offset. If this is a QCI interrupt function, there will be a
- // leftover offset which is deallocated by `QC.C.MILEAVERET`, otherwise
- // getQCIInterruptStackSize() will be 0.
- CFIBuilder.buildDefCFAOffset(RVFI->getQCIInterruptStackSize());
+ // Update CFA Offset. If this is a QCI interrupt function, there will
+ // be a leftover offset which is deallocated by `QC.C.MILEAVERET`,
+ // otherwise getQCIInterruptStackSize() will be 0.
+ CFIBuilder.buildDefCFAOffset(RVFI->getQCIInterruptStackSize());
+ }
}
}
@@ -1812,7 +1841,8 @@ MachineBasicBlock::iterator RISCVFrameLowering::eliminateCallFramePseudoInstr(
// allocateStack.
bool DynAllocation =
MF.getInfo<RISCVMachineFunctionInfo>()->hasDynamicAllocation();
- allocateStack(MBB, MI, MF, -Amount, -Amount, !hasFP(MF),
+ allocateStack(MBB, MI, MF, -Amount, -Amount,
+ needsDwarfCFI(MF) && !hasFP(MF),
/*NeedProbe=*/true, ProbeSize, DynAllocation,
MachineInstr::NoFlags);
} else {
generated by cgit v1.1 at 2025-07-19 05:08:07 +0000