[MIPS] Implement support for -mstack-alignment.
Summary:
This is modeled on the implementation for x86 which stores the command line
option in a 'StackAlignOverride' field in MipsSubtarget and then uses this
to compute a 'stackAlignment' value in
MipsSubtarget::initializeSubtargetDependencies.
The stackAlignment() method in MipsSubTarget is renamed to getStackAlignment()
and returns the computed 'stackAlignment'.
Reviewers: sdardis
Reviewed By: sdardis
Subscribers: llvm-commits, arichardson
Differential Revision: https://reviews.llvm.org/D35874
llvm-svn: 310891
diff --git a/llvm/lib/Target/Mips/Mips16FrameLowering.cpp b/llvm/lib/Target/Mips/Mips16FrameLowering.cpp
index 17dc90a..00f8901 100644
--- a/llvm/lib/Target/Mips/Mips16FrameLowering.cpp
+++ b/llvm/lib/Target/Mips/Mips16FrameLowering.cpp
@@ -38,7 +38,7 @@
using namespace llvm;
Mips16FrameLowering::Mips16FrameLowering(const MipsSubtarget &STI)
- : MipsFrameLowering(STI, STI.stackAlignment()) {}
+ : MipsFrameLowering(STI, STI.getStackAlignment()) {}
void Mips16FrameLowering::emitPrologue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
diff --git a/llvm/lib/Target/Mips/MipsAsmPrinter.cpp b/llvm/lib/Target/Mips/MipsAsmPrinter.cpp
index 20e6c69..75adabd 100644
--- a/llvm/lib/Target/Mips/MipsAsmPrinter.cpp
+++ b/llvm/lib/Target/Mips/MipsAsmPrinter.cpp
@@ -718,7 +718,7 @@
StringRef CPU = MIPS_MC::selectMipsCPU(TT, TM.getTargetCPU());
StringRef FS = TM.getTargetFeatureString();
const MipsTargetMachine &MTM = static_cast<const MipsTargetMachine &>(TM);
- const MipsSubtarget STI(TT, CPU, FS, MTM.isLittleEndian(), MTM);
+ const MipsSubtarget STI(TT, CPU, FS, MTM.isLittleEndian(), MTM, 0);
bool IsABICalls = STI.isABICalls();
const MipsABIInfo &ABI = MTM.getABI();
diff --git a/llvm/lib/Target/Mips/MipsSEFrameLowering.cpp b/llvm/lib/Target/Mips/MipsSEFrameLowering.cpp
index 66afe99..4c7e25b 100644
--- a/llvm/lib/Target/Mips/MipsSEFrameLowering.cpp
+++ b/llvm/lib/Target/Mips/MipsSEFrameLowering.cpp
@@ -390,7 +390,7 @@
}
MipsSEFrameLowering::MipsSEFrameLowering(const MipsSubtarget &STI)
- : MipsFrameLowering(STI, STI.stackAlignment()) {}
+ : MipsFrameLowering(STI, STI.getStackAlignment()) {}
void MipsSEFrameLowering::emitPrologue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
diff --git a/llvm/lib/Target/Mips/MipsSubtarget.cpp b/llvm/lib/Target/Mips/MipsSubtarget.cpp
index e160eac..cd462c7 100644
--- a/llvm/lib/Target/Mips/MipsSubtarget.cpp
+++ b/llvm/lib/Target/Mips/MipsSubtarget.cpp
@@ -60,7 +60,8 @@
void MipsSubtarget::anchor() {}
MipsSubtarget::MipsSubtarget(const Triple &TT, StringRef CPU, StringRef FS,
- bool little, const MipsTargetMachine &TM)
+ bool little, const MipsTargetMachine &TM,
+ unsigned StackAlignOverride)
: MipsGenSubtargetInfo(TT, CPU, FS), MipsArchVersion(MipsDefault),
IsLittle(little), IsSoftFloat(false), IsSingleFloat(false), IsFPXX(false),
NoABICalls(false), IsFP64bit(false), UseOddSPReg(true),
@@ -70,10 +71,10 @@
InMips16HardFloat(Mips16HardFloat), InMicroMipsMode(false), HasDSP(false),
HasDSPR2(false), HasDSPR3(false), AllowMixed16_32(Mixed16_32 | Mips_Os16),
Os16(Mips_Os16), HasMSA(false), UseTCCInDIV(false), HasSym32(false),
- HasEVA(false), DisableMadd4(false), HasMT(false), TM(TM),
- TargetTriple(TT), TSInfo(),
- InstrInfo(
- MipsInstrInfo::create(initializeSubtargetDependencies(CPU, FS, TM))),
+ HasEVA(false), DisableMadd4(false), HasMT(false),
+ StackAlignOverride(StackAlignOverride), TM(TM), TargetTriple(TT),
+ TSInfo(), InstrInfo(MipsInstrInfo::create(
+ initializeSubtargetDependencies(CPU, FS, TM))),
FrameLowering(MipsFrameLowering::create(*this)),
TLInfo(MipsTargetLowering::create(TM, *this)) {
@@ -157,6 +158,15 @@
if (InMips16Mode && !IsSoftFloat)
InMips16HardFloat = true;
+ if (StackAlignOverride)
+ stackAlignment = StackAlignOverride;
+ else if (isABI_N32() || isABI_N64())
+ stackAlignment = 16;
+ else {
+ assert(isABI_O32() && "Unknown ABI for stack alignment!");
+ stackAlignment = 8;
+ }
+
return *this;
}
diff --git a/llvm/lib/Target/Mips/MipsSubtarget.h b/llvm/lib/Target/Mips/MipsSubtarget.h
index ef04c93..0c96888 100644
--- a/llvm/lib/Target/Mips/MipsSubtarget.h
+++ b/llvm/lib/Target/Mips/MipsSubtarget.h
@@ -155,6 +155,13 @@
// Disable use of the `jal` instruction.
bool UseLongCalls = false;
+ /// The minimum alignment known to hold of the stack frame on
+ /// entry to the function and which must be maintained by every function.
+ unsigned stackAlignment;
+
+ /// The overridden stack alignment.
+ unsigned StackAlignOverride;
+
InstrItineraryData InstrItins;
// We can override the determination of whether we are in mips16 mode
@@ -186,7 +193,7 @@
/// This constructor initializes the data members to match that
/// of the specified triple.
MipsSubtarget(const Triple &TT, StringRef CPU, StringRef FS, bool little,
- const MipsTargetMachine &TM);
+ const MipsTargetMachine &TM, unsigned StackAlignOverride);
/// ParseSubtargetFeatures - Parses features string setting specified
/// subtarget options. Definition of function is auto generated by tblgen.
@@ -295,9 +302,7 @@
// really use them if in addition we are in mips16 mode
static bool useConstantIslands();
- unsigned stackAlignment() const {
- return isABI_N32() || isABI_N64() ? 16 : 8;
- }
+ unsigned getStackAlignment() const { return stackAlignment; }
// Grab relocation model
Reloc::Model getRelocationModel() const;
diff --git a/llvm/lib/Target/Mips/MipsTargetMachine.cpp b/llvm/lib/Target/Mips/MipsTargetMachine.cpp
index 4ed0647..2f01b24 100644
--- a/llvm/lib/Target/Mips/MipsTargetMachine.cpp
+++ b/llvm/lib/Target/Mips/MipsTargetMachine.cpp
@@ -114,11 +114,12 @@
getEffectiveCodeModel(CM), OL),
isLittle(isLittle), TLOF(llvm::make_unique<MipsTargetObjectFile>()),
ABI(MipsABIInfo::computeTargetABI(TT, CPU, Options.MCOptions)),
- Subtarget(nullptr), DefaultSubtarget(TT, CPU, FS, isLittle, *this),
+ Subtarget(nullptr), DefaultSubtarget(TT, CPU, FS, isLittle, *this,
+ Options.StackAlignmentOverride),
NoMips16Subtarget(TT, CPU, FS.empty() ? "-mips16" : FS.str() + ",-mips16",
- isLittle, *this),
+ isLittle, *this, Options.StackAlignmentOverride),
Mips16Subtarget(TT, CPU, FS.empty() ? "+mips16" : FS.str() + ",+mips16",
- isLittle, *this) {
+ isLittle, *this, Options.StackAlignmentOverride) {
Subtarget = &DefaultSubtarget;
initAsmInfo();
}
@@ -191,7 +192,7 @@
// function that reside in TargetOptions.
resetTargetOptions(F);
I = llvm::make_unique<MipsSubtarget>(TargetTriple, CPU, FS, isLittle,
- *this);
+ *this, Options.StackAlignmentOverride);
}
return I.get();
}