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-rw-r--r--lib/Target/PowerPC/PPCFrameLowering.cpp88
-rw-r--r--lib/Target/PowerPC/PPCFrameLowering.h5
-rw-r--r--lib/Target/PowerPC/PPCInstrInfo.cpp7
-rw-r--r--lib/Target/PowerPC/PPCMachineFunctionInfo.h7
4 files changed, 72 insertions, 35 deletions
diff --git a/lib/Target/PowerPC/PPCFrameLowering.cpp b/lib/Target/PowerPC/PPCFrameLowering.cpp
index 6feec9f216..0f8da5f046 100644
--- a/lib/Target/PowerPC/PPCFrameLowering.cpp
+++ b/lib/Target/PowerPC/PPCFrameLowering.cpp
@@ -188,13 +188,21 @@ static bool spillsCR(const MachineFunction &MF) {
return FuncInfo->isCRSpilled();
}
+static bool hasSpills(const MachineFunction &MF) {
+ const PPCFunctionInfo *FuncInfo = MF.getInfo<PPCFunctionInfo>();
+ return FuncInfo->hasSpills();
+}
+
/// determineFrameLayout - Determine the size of the frame and maximum call
/// frame size.
-void PPCFrameLowering::determineFrameLayout(MachineFunction &MF) const {
+unsigned PPCFrameLowering::determineFrameLayout(MachineFunction &MF,
+ bool UpdateMF,
+ bool UseEstimate) const {
MachineFrameInfo *MFI = MF.getFrameInfo();
// Get the number of bytes to allocate from the FrameInfo
- unsigned FrameSize = MFI->getStackSize();
+ unsigned FrameSize =
+ UseEstimate ? MFI->estimateStackSize(MF) : MFI->getStackSize();
// Get the alignments provided by the target, and the maximum alignment
// (if any) of the fixed frame objects.
@@ -223,8 +231,9 @@ void PPCFrameLowering::determineFrameLayout(MachineFunction &MF) const {
&& spillsCR(MF)) &&
(!ALIGN_STACK || MaxAlign <= TargetAlign)) { // No special alignment.
// No need for frame
- MFI->setStackSize(0);
- return;
+ if (UpdateMF)
+ MFI->setStackSize(0);
+ return 0;
}
// Get the maximum call frame size of all the calls.
@@ -241,7 +250,8 @@ void PPCFrameLowering::determineFrameLayout(MachineFunction &MF) const {
maxCallFrameSize = (maxCallFrameSize + AlignMask) & ~AlignMask;
// Update maximum call frame size.
- MFI->setMaxCallFrameSize(maxCallFrameSize);
+ if (UpdateMF)
+ MFI->setMaxCallFrameSize(maxCallFrameSize);
// Include call frame size in total.
FrameSize += maxCallFrameSize;
@@ -250,7 +260,10 @@ void PPCFrameLowering::determineFrameLayout(MachineFunction &MF) const {
FrameSize = (FrameSize + AlignMask) & ~AlignMask;
// Update frame info.
- MFI->setStackSize(FrameSize);
+ if (UpdateMF)
+ MFI->setStackSize(FrameSize);
+
+ return FrameSize;
}
// hasFP - Return true if the specified function actually has a dedicated frame
@@ -311,11 +324,7 @@ void PPCFrameLowering::emitPrologue(MachineFunction &MF) const {
MBBI = MBB.begin();
// Work out frame sizes.
- // FIXME: determineFrameLayout() may change the frame size. This should be
- // moved upper, to some hook.
- determineFrameLayout(MF);
- unsigned FrameSize = MFI->getStackSize();
-
+ unsigned FrameSize = determineFrameLayout(MF);
int NegFrameSize = -FrameSize;
// Get processor type.
@@ -780,7 +789,7 @@ static bool MustSaveLR(const MachineFunction &MF, unsigned LR) {
void
PPCFrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
- RegScavenger *RS) const {
+ RegScavenger *) const {
const TargetRegisterInfo *RegInfo = MF.getTarget().getRegisterInfo();
// Save and clear the LR state.
@@ -822,30 +831,15 @@ PPCFrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
int FrameIdx = MFI->CreateFixedObject((uint64_t)4, (int64_t)-4, true);
FI->setCRSpillFrameIndex(FrameIdx);
}
-
- // Reserve a slot closest to SP or frame pointer if we have a dynalloc or
- // a large stack, which will require scavenging a register to materialize a
- // large offset.
- // FIXME: this doesn't actually check stack size, so is a bit pessimistic
- // FIXME: doesn't detect whether or not we need to spill vXX, which requires
- // r0 for now.
-
- if (RegInfo->requiresRegisterScavenging(MF))
- if (MFI->hasVarSizedObjects() || spillsCR(MF)) {
- const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
- const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
- const TargetRegisterClass *RC = isPPC64 ? G8RC : GPRC;
- RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
- RC->getAlignment(),
- false));
- }
}
void PPCFrameLowering::processFunctionBeforeFrameFinalized(MachineFunction &MF,
- RegScavenger *) const {
+ RegScavenger *RS) const {
// Early exit if not using the SVR4 ABI.
- if (!Subtarget.isSVR4ABI())
+ if (!Subtarget.isSVR4ABI()) {
+ addScavengingSpillSlot(MF, RS);
return;
+ }
// Get callee saved register information.
MachineFrameInfo *FFI = MF.getFrameInfo();
@@ -853,6 +847,7 @@ void PPCFrameLowering::processFunctionBeforeFrameFinalized(MachineFunction &MF,
// Early exit if no callee saved registers are modified!
if (CSI.empty() && !needsFP(MF)) {
+ addScavengingSpillSlot(MF, RS);
return;
}
@@ -1031,6 +1026,37 @@ void PPCFrameLowering::processFunctionBeforeFrameFinalized(MachineFunction &MF,
FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
}
}
+
+ addScavengingSpillSlot(MF, RS);
+}
+
+void
+PPCFrameLowering::addScavengingSpillSlot(MachineFunction &MF,
+ RegScavenger *RS) const {
+ // Reserve a slot closest to SP or frame pointer if we have a dynalloc or
+ // a large stack, which will require scavenging a register to materialize a
+ // large offset.
+
+ // We need to have a scavenger spill slot for spills if the frame size is
+ // large. In case there is no free register for large-offset addressing,
+ // this slot is used for the necessary emergency spill. Also, we need the
+ // slot for dynamic stack allocations.
+
+ // The scavenger might be invoked if the frame offset does not fit into
+ // the 16-bit immediate. We don't know the complete frame size here
+ // because we've not yet computed callee-saved register spills or the
+ // needed alignment padding.
+ unsigned StackSize = determineFrameLayout(MF, false, true);
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+ if (MFI->hasVarSizedObjects() || spillsCR(MF) ||
+ (hasSpills(MF) && !isInt<16>(StackSize))) {
+ const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
+ const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
+ const TargetRegisterClass *RC = Subtarget.isPPC64() ? G8RC : GPRC;
+ RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
+ RC->getAlignment(),
+ false));
+ }
}
bool
diff --git a/lib/Target/PowerPC/PPCFrameLowering.h b/lib/Target/PowerPC/PPCFrameLowering.h
index 8d9d395dc5..53ee32601f 100644
--- a/lib/Target/PowerPC/PPCFrameLowering.h
+++ b/lib/Target/PowerPC/PPCFrameLowering.h
@@ -32,7 +32,9 @@ public:
Subtarget(sti) {
}
- void determineFrameLayout(MachineFunction &MF) const;
+ unsigned determineFrameLayout(MachineFunction &MF,
+ bool UpdateMF = true,
+ bool UseEstimate = false) const;
/// emitProlog/emitEpilog - These methods insert prolog and epilog code into
/// the function.
@@ -46,6 +48,7 @@ public:
RegScavenger *RS = NULL) const;
void processFunctionBeforeFrameFinalized(MachineFunction &MF,
RegScavenger *RS = NULL) const;
+ void addScavengingSpillSlot(MachineFunction &MF, RegScavenger *RS) const;
bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
diff --git a/lib/Target/PowerPC/PPCInstrInfo.cpp b/lib/Target/PowerPC/PPCInstrInfo.cpp
index 1b4d3618a0..7ae3442330 100644
--- a/lib/Target/PowerPC/PPCInstrInfo.cpp
+++ b/lib/Target/PowerPC/PPCInstrInfo.cpp
@@ -554,10 +554,11 @@ PPCInstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
MachineFunction &MF = *MBB.getParent();
SmallVector<MachineInstr*, 4> NewMIs;
- if (StoreRegToStackSlot(MF, SrcReg, isKill, FrameIdx, RC, NewMIs)) {
- PPCFunctionInfo *FuncInfo = MF.getInfo<PPCFunctionInfo>();
+ PPCFunctionInfo *FuncInfo = MF.getInfo<PPCFunctionInfo>();
+ FuncInfo->setHasSpills();
+
+ if (StoreRegToStackSlot(MF, SrcReg, isKill, FrameIdx, RC, NewMIs))
FuncInfo->setSpillsCR();
- }
for (unsigned i = 0, e = NewMIs.size(); i != e; ++i)
MBB.insert(MI, NewMIs[i]);
diff --git a/lib/Target/PowerPC/PPCMachineFunctionInfo.h b/lib/Target/PowerPC/PPCMachineFunctionInfo.h
index 045b375dd8..10b2160b3d 100644
--- a/lib/Target/PowerPC/PPCMachineFunctionInfo.h
+++ b/lib/Target/PowerPC/PPCMachineFunctionInfo.h
@@ -37,6 +37,9 @@ class PPCFunctionInfo : public MachineFunctionInfo {
/// PEI.
bool MustSaveLR;
+ /// Does this function have any stack spills.
+ bool HasSpills;
+
/// SpillsCR - Indicates whether CR is spilled in the current function.
bool SpillsCR;
@@ -78,6 +81,7 @@ public:
explicit PPCFunctionInfo(MachineFunction &MF)
: FramePointerSaveIndex(0),
ReturnAddrSaveIndex(0),
+ HasSpills(false),
SpillsCR(false),
LRStoreRequired(false),
MinReservedArea(0),
@@ -109,6 +113,9 @@ public:
void setMustSaveLR(bool U) { MustSaveLR = U; }
bool mustSaveLR() const { return MustSaveLR; }
+ void setHasSpills() { HasSpills = true; }
+ bool hasSpills() const { return HasSpills; }
+
void setSpillsCR() { SpillsCR = true; }
bool isCRSpilled() const { return SpillsCR; }
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2025-04-27 04:01:24 +0000