[llvm] r177231 - Improve PPC VR (Altivec) register spilling
Hal Finkel
hfinkel at anl.gov
Sat Mar 16 21:43:45 PDT 2013
Author: hfinkel
Date: Sat Mar 16 23:43:44 2013
New Revision: 177231
URL: http://llvm.org/viewvc/llvm-project?rev=177231&view=rev
Log:
Improve PPC VR (Altivec) register spilling
This change cleans up two issues with Altivec register spilling:
1. The spilling code was inefficient (using two instructions, and add and a
load, when just one would do)
2. The code assumed that r0 would always be available (true for now, but this
will change)
The new code handles VR spilling just like GPR spills but forced into r+r mode.
As a result, when any VR spills are present, we must now always allocate the
register-scavenger spill slot.
Modified:
llvm/trunk/lib/Target/PowerPC/PPCFrameLowering.cpp
llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp
llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.h
llvm/trunk/lib/Target/PowerPC/PPCMachineFunctionInfo.h
llvm/trunk/lib/Target/PowerPC/PPCRegisterInfo.cpp
llvm/trunk/test/CodeGen/PowerPC/vrspill.ll
Modified: llvm/trunk/lib/Target/PowerPC/PPCFrameLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCFrameLowering.cpp?rev=177231&r1=177230&r2=177231&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCFrameLowering.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCFrameLowering.cpp Sat Mar 16 23:43:44 2013
@@ -193,6 +193,11 @@ static bool hasSpills(const MachineFunct
return FuncInfo->hasSpills();
}
+static bool hasNonRISpills(const MachineFunction &MF) {
+ const PPCFunctionInfo *FuncInfo = MF.getInfo<PPCFunctionInfo>();
+ return FuncInfo->hasNonRISpills();
+}
+
/// determineFrameLayout - Determine the size of the frame and maximum call
/// frame size.
unsigned PPCFrameLowering::determineFrameLayout(MachineFunction &MF,
@@ -1048,7 +1053,7 @@ PPCFrameLowering::addScavengingSpillSlot
// needed alignment padding.
unsigned StackSize = determineFrameLayout(MF, false, true);
MachineFrameInfo *MFI = MF.getFrameInfo();
- if (MFI->hasVarSizedObjects() || spillsCR(MF) ||
+ if (MFI->hasVarSizedObjects() || spillsCR(MF) || hasNonRISpills(MF) ||
(hasSpills(MF) && !isInt<16>(StackSize))) {
const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
Modified: llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp?rev=177231&r1=177230&r2=177231&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp Sat Mar 16 23:43:44 2013
@@ -439,7 +439,8 @@ PPCInstrInfo::StoreRegToStackSlot(Machin
unsigned SrcReg, bool isKill,
int FrameIdx,
const TargetRegisterClass *RC,
- SmallVectorImpl<MachineInstr*> &NewMIs) const{
+ SmallVectorImpl<MachineInstr*> &NewMIs,
+ bool &NonRI) const{
DebugLoc DL;
if (PPC::GPRCRegClass.hasSubClassEq(RC)) {
if (SrcReg != PPC::LR) {
@@ -521,23 +522,14 @@ PPCInstrInfo::StoreRegToStackSlot(Machin
Reg = PPC::CR7;
return StoreRegToStackSlot(MF, Reg, isKill, FrameIdx,
- &PPC::CRRCRegClass, NewMIs);
+ &PPC::CRRCRegClass, NewMIs, NonRI);
} else if (PPC::VRRCRegClass.hasSubClassEq(RC)) {
- // We don't have indexed addressing for vector loads. Emit:
- // R0 = ADDI FI#
- // STVX VAL, 0, R0
- //
- // FIXME: We use R0 here, because it isn't available for RA.
- bool Is64Bit = TM.getSubtargetImpl()->isPPC64();
- unsigned Instr = Is64Bit ? PPC::ADDI8 : PPC::ADDI;
- unsigned GPR0 = Is64Bit ? PPC::X0 : PPC::R0;
- NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(Instr), GPR0),
- FrameIdx, 0, 0));
- NewMIs.push_back(BuildMI(MF, DL, get(PPC::STVX))
- .addReg(SrcReg, getKillRegState(isKill))
- .addReg(GPR0)
- .addReg(GPR0));
+ NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::STVX))
+ .addReg(SrcReg,
+ getKillRegState(isKill)),
+ FrameIdx));
+ NonRI = true;
} else {
llvm_unreachable("Unknown regclass!");
}
@@ -557,9 +549,13 @@ PPCInstrInfo::storeRegToStackSlot(Machin
PPCFunctionInfo *FuncInfo = MF.getInfo<PPCFunctionInfo>();
FuncInfo->setHasSpills();
- if (StoreRegToStackSlot(MF, SrcReg, isKill, FrameIdx, RC, NewMIs))
+ bool NonRI = false;
+ if (StoreRegToStackSlot(MF, SrcReg, isKill, FrameIdx, RC, NewMIs, NonRI))
FuncInfo->setSpillsCR();
+ if (NonRI)
+ FuncInfo->setHasNonRISpills();
+
for (unsigned i = 0, e = NewMIs.size(); i != e; ++i)
MBB.insert(MI, NewMIs[i]);
@@ -576,7 +572,8 @@ bool
PPCInstrInfo::LoadRegFromStackSlot(MachineFunction &MF, DebugLoc DL,
unsigned DestReg, int FrameIdx,
const TargetRegisterClass *RC,
- SmallVectorImpl<MachineInstr*> &NewMIs)const{
+ SmallVectorImpl<MachineInstr*> &NewMIs,
+ bool &NonRI) const{
if (PPC::GPRCRegClass.hasSubClassEq(RC)) {
if (DestReg != PPC::LR) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::LWZ),
@@ -635,21 +632,12 @@ PPCInstrInfo::LoadRegFromStackSlot(Machi
Reg = PPC::CR7;
return LoadRegFromStackSlot(MF, DL, Reg, FrameIdx,
- &PPC::CRRCRegClass, NewMIs);
+ &PPC::CRRCRegClass, NewMIs, NonRI);
} else if (PPC::VRRCRegClass.hasSubClassEq(RC)) {
- // We don't have indexed addressing for vector loads. Emit:
- // R0 = ADDI FI#
- // Dest = LVX 0, R0
- //
- // FIXME: We use R0 here, because it isn't available for RA.
- bool Is64Bit = TM.getSubtargetImpl()->isPPC64();
- unsigned Instr = Is64Bit ? PPC::ADDI8 : PPC::ADDI;
- unsigned GPR0 = Is64Bit ? PPC::X0 : PPC::R0;
- NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(Instr), GPR0),
- FrameIdx, 0, 0));
- NewMIs.push_back(BuildMI(MF, DL, get(PPC::LVX),DestReg).addReg(GPR0)
- .addReg(GPR0));
+ NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::LVX), DestReg),
+ FrameIdx));
+ NonRI = true;
} else {
llvm_unreachable("Unknown regclass!");
}
@@ -667,10 +655,17 @@ PPCInstrInfo::loadRegFromStackSlot(Machi
SmallVector<MachineInstr*, 4> NewMIs;
DebugLoc DL;
if (MI != MBB.end()) DL = MI->getDebugLoc();
- if (LoadRegFromStackSlot(MF, DL, DestReg, FrameIdx, RC, NewMIs)) {
- PPCFunctionInfo *FuncInfo = MF.getInfo<PPCFunctionInfo>();
+
+ PPCFunctionInfo *FuncInfo = MF.getInfo<PPCFunctionInfo>();
+ FuncInfo->setHasSpills();
+
+ bool NonRI = false;
+ if (LoadRegFromStackSlot(MF, DL, DestReg, FrameIdx, RC, NewMIs, NonRI))
FuncInfo->setSpillsCR();
- }
+
+ if (NonRI)
+ FuncInfo->setHasNonRISpills();
+
for (unsigned i = 0, e = NewMIs.size(); i != e; ++i)
MBB.insert(MI, NewMIs[i]);
Modified: llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.h?rev=177231&r1=177230&r2=177231&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.h (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.h Sat Mar 16 23:43:44 2013
@@ -71,11 +71,13 @@ class PPCInstrInfo : public PPCGenInstrI
bool StoreRegToStackSlot(MachineFunction &MF,
unsigned SrcReg, bool isKill, int FrameIdx,
const TargetRegisterClass *RC,
- SmallVectorImpl<MachineInstr*> &NewMIs) const;
+ SmallVectorImpl<MachineInstr*> &NewMIs,
+ bool &NonRI) const;
bool LoadRegFromStackSlot(MachineFunction &MF, DebugLoc DL,
unsigned DestReg, int FrameIdx,
const TargetRegisterClass *RC,
- SmallVectorImpl<MachineInstr*> &NewMIs) const;
+ SmallVectorImpl<MachineInstr*> &NewMIs,
+ bool &NonRI) const;
public:
explicit PPCInstrInfo(PPCTargetMachine &TM);
Modified: llvm/trunk/lib/Target/PowerPC/PPCMachineFunctionInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCMachineFunctionInfo.h?rev=177231&r1=177230&r2=177231&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCMachineFunctionInfo.h (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCMachineFunctionInfo.h Sat Mar 16 23:43:44 2013
@@ -40,6 +40,10 @@ class PPCFunctionInfo : public MachineFu
/// Does this function have any stack spills.
bool HasSpills;
+ /// Does this function spill using instructions with only r+r (not r+i)
+ /// forms.
+ bool HasNonRISpills;
+
/// SpillsCR - Indicates whether CR is spilled in the current function.
bool SpillsCR;
@@ -82,6 +86,7 @@ public:
: FramePointerSaveIndex(0),
ReturnAddrSaveIndex(0),
HasSpills(false),
+ HasNonRISpills(false),
SpillsCR(false),
LRStoreRequired(false),
MinReservedArea(0),
@@ -116,6 +121,9 @@ public:
void setHasSpills() { HasSpills = true; }
bool hasSpills() const { return HasSpills; }
+ void setHasNonRISpills() { HasNonRISpills = true; }
+ bool hasNonRISpills() const { return HasNonRISpills; }
+
void setSpillsCR() { SpillsCR = true; }
bool isCRSpilled() const { return SpillsCR; }
Modified: llvm/trunk/lib/Target/PowerPC/PPCRegisterInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCRegisterInfo.cpp?rev=177231&r1=177230&r2=177231&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCRegisterInfo.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCRegisterInfo.cpp Sat Mar 16 23:43:44 2013
@@ -442,7 +442,25 @@ PPCRegisterInfo::eliminateFrameIndex(Mac
isIXAddr = true;
break;
}
-
+
+ bool noImmForm = false;
+ switch (OpC) {
+ case PPC::LVEBX:
+ case PPC::LVEHX:
+ case PPC::LVEWX:
+ case PPC::LVX:
+ case PPC::LVXL:
+ case PPC::LVSL:
+ case PPC::LVSR:
+ case PPC::STVEBX:
+ case PPC::STVEHX:
+ case PPC::STVEWX:
+ case PPC::STVX:
+ case PPC::STVXL:
+ noImmForm = true;
+ break;
+ }
+
// Now add the frame object offset to the offset from r1.
int Offset = MFI->getObjectOffset(FrameIndex);
if (!isIXAddr)
@@ -466,7 +484,8 @@ PPCRegisterInfo::eliminateFrameIndex(Mac
// only "std" to a stack slot that is at least 4-byte aligned, but it can
// happen in invalid code.
if (OpC == PPC::DBG_VALUE || // DBG_VALUE is always Reg+Imm
- (isInt<16>(Offset) && (!isIXAddr || (Offset & 3) == 0))) {
+ (!noImmForm &&
+ isInt<16>(Offset) && (!isIXAddr || (Offset & 3) == 0))) {
if (isIXAddr)
Offset >>= 2; // The actual encoded value has the low two bits zero.
MI.getOperand(OffsetOperandNo).ChangeToImmediate(Offset);
@@ -493,7 +512,9 @@ PPCRegisterInfo::eliminateFrameIndex(Mac
// addi 0:rA 1:rB, 2, imm ==> add 0:rA, 1:rB, 2:r0
unsigned OperandBase;
- if (OpC != TargetOpcode::INLINEASM) {
+ if (noImmForm)
+ OperandBase = 1;
+ else if (OpC != TargetOpcode::INLINEASM) {
assert(ImmToIdxMap.count(OpC) &&
"No indexed form of load or store available!");
unsigned NewOpcode = ImmToIdxMap.find(OpC)->second;
Modified: llvm/trunk/test/CodeGen/PowerPC/vrspill.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/vrspill.ll?rev=177231&r1=177230&r2=177231&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/PowerPC/vrspill.ll (original)
+++ llvm/trunk/test/CodeGen/PowerPC/vrspill.ll Sat Mar 16 23:43:44 2013
@@ -13,7 +13,7 @@ entry:
ret void
}
-; CHECK: stvx 2, 0, 0
-; CHECK: lvx 2, 0, 0
+; CHECK: stvx 2, 1,
+; CHECK: lvx 2, 1,
declare void @foo(i32*)
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