/// setMaxAlignment - Set the preferred alignment.
///
void setMaxAlignment(unsigned Align) { MaxAlignment = Align; }
-
+
+ /// calculateMaxStackAlignment() - If there is a local object which requires
+ /// greater alignment than the current max alignment, adjust accordingly.
+ void calculateMaxStackAlignment() {
+ for (int i = getObjectIndexBegin(),
+ e = getObjectIndexEnd(); i != e; ++i) {
+ if (isDeadObjectIndex(i))
+ continue;
+
+ unsigned Align = getObjectAlignment(i);
+ MaxAlignment = std::max(MaxAlignment, Align);
+ }
+ }
+
/// hasCalls - Return true if the current function has no function calls.
/// This is only valid during or after prolog/epilog code emission.
///
/// the GCC-style builtin setjmp/longjmp (sjlj) to handling EH control flow.
FunctionPass *createSjLjEHPass(const TargetLowering *tli);
+ /// createMaxStackAlignmentCalculatorPass() - Determine the maximum required
+ /// alignment for a function.
+ FunctionPass* createMaxStackAlignmentCalculatorPass();
+
} // End llvm namespace
#endif
--- /dev/null
+//===-- MaxStackAlignment.cpp - Compute the required stack alignment -- ---===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass looks for vector register usage and aligned local objects to
+// calculate the maximum required alignment for a function. This is used by
+// targets which support it to determine if dynamic stack realignment is
+// necessary.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/Passes.h"
+
+using namespace llvm;
+
+namespace {
+ struct MaximalStackAlignmentCalculator : public MachineFunctionPass {
+ static char ID;
+ MaximalStackAlignmentCalculator() : MachineFunctionPass(&ID) {}
+
+ virtual bool runOnMachineFunction(MachineFunction &MF) {
+ MachineFrameInfo *FFI = MF.getFrameInfo();
+ MachineRegisterInfo &RI = MF.getRegInfo();
+
+ // Calculate max stack alignment of all already allocated stack objects.
+ FFI->calculateMaxStackAlignment();
+ unsigned MaxAlign = FFI->getMaxAlignment();
+
+ // Be over-conservative: scan over all vreg defs and find whether vector
+ // registers are used. If yes, there is probability that vector registers
+ // will be spilled and thus the stack needs to be aligned properly.
+ // FIXME: It would be better to only do this if a spill actually
+ // happens rather than conseratively aligning the stack regardless.
+ for (unsigned RegNum = TargetRegisterInfo::FirstVirtualRegister;
+ RegNum < RI.getLastVirtReg(); ++RegNum)
+ MaxAlign = std::max(MaxAlign, RI.getRegClass(RegNum)->getAlignment());
+
+ if (FFI->getMaxAlignment() == MaxAlign)
+ return false;
+
+ FFI->setMaxAlignment(MaxAlign);
+ return true;
+ }
+
+ virtual const char *getPassName() const {
+ return "Stack Alignment Requirements Auto-Detector";
+ }
+
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesCFG();
+ MachineFunctionPass::getAnalysisUsage(AU);
+ }
+ };
+
+ char MaximalStackAlignmentCalculator::ID = 0;
+}
+
+FunctionPass*
+llvm::createMaxStackAlignmentCalculatorPass() {
+ return new MaximalStackAlignmentCalculator();
+}
+
FunctionPass *createNEONMoveFixPass();
FunctionPass *createThumb2ITBlockPass();
FunctionPass *createThumb2SizeReductionPass();
-FunctionPass *createARMMaxStackAlignmentCalculatorPass();
extern Target TheARMTarget, TheThumbTarget;
}
}
-static unsigned calculateMaxStackAlignment(const MachineFrameInfo *FFI) {
- unsigned MaxAlign = 0;
-
- for (int i = FFI->getObjectIndexBegin(),
- e = FFI->getObjectIndexEnd(); i != e; ++i) {
- if (FFI->isDeadObjectIndex(i))
- continue;
-
- unsigned Align = FFI->getObjectAlignment(i);
- MaxAlign = std::max(MaxAlign, Align);
- }
-
- return MaxAlign;
-}
-
/// hasFP - Return true if the specified function should have a dedicated frame
/// pointer register. This is true if the function has variable sized allocas
/// or if frame pointer elimination is disabled.
SmallVector<unsigned, 4> UnspilledCS2GPRs;
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- MachineFrameInfo *MFI = MF.getFrameInfo();
// Calculate and set max stack object alignment early, so we can decide
// whether we will need stack realignment (and thus FP).
if (RealignStack) {
- unsigned MaxAlign = std::max(MFI->getMaxAlignment(),
- calculateMaxStackAlignment(MFI));
- MFI->setMaxAlignment(MaxAlign);
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+ MFI->calculateMaxStackAlignment();
}
// Don't spill FP if the frame can be eliminated. This is determined
emitSPUpdate(isARM, MBB, MBBI, dl, TII, VARegSaveSize);
}
-namespace {
- struct MaximalStackAlignmentCalculator : public MachineFunctionPass {
- static char ID;
- MaximalStackAlignmentCalculator() : MachineFunctionPass(&ID) {}
-
- virtual bool runOnMachineFunction(MachineFunction &MF) {
- MachineFrameInfo *FFI = MF.getFrameInfo();
- MachineRegisterInfo &RI = MF.getRegInfo();
-
- // Calculate max stack alignment of all already allocated stack objects.
- unsigned MaxAlign = calculateMaxStackAlignment(FFI);
-
- // Be over-conservative: scan over all vreg defs and find, whether vector
- // registers are used. If yes - there is probability, that vector register
- // will be spilled and thus stack needs to be aligned properly.
- for (unsigned RegNum = TargetRegisterInfo::FirstVirtualRegister;
- RegNum < RI.getLastVirtReg(); ++RegNum)
- MaxAlign = std::max(MaxAlign, RI.getRegClass(RegNum)->getAlignment());
-
- if (FFI->getMaxAlignment() == MaxAlign)
- return false;
-
- FFI->setMaxAlignment(MaxAlign);
- return true;
- }
-
- virtual const char *getPassName() const {
- return "ARM Stack Required Alignment Auto-Detector";
- }
-
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.setPreservesCFG();
- MachineFunctionPass::getAnalysisUsage(AU);
- }
- };
-
- char MaximalStackAlignmentCalculator::ID = 0;
-}
-
-FunctionPass*
-llvm::createARMMaxStackAlignmentCalculatorPass() {
- return new MaximalStackAlignmentCalculator();
-}
-
#include "ARMGenRegisterInfo.inc"
// Calculate and set max stack object alignment early, so we can decide
// whether we will need stack realignment (and thus FP).
- PM.add(createARMMaxStackAlignmentCalculatorPass());
+ PM.add(createMaxStackAlignmentCalculatorPass());
// FIXME: temporarily disabling load / store optimization pass for Thumb1.
if (OptLevel != CodeGenOpt::None && !Subtarget.isThumb1Only())
///
FunctionPass *createEmitX86CodeToMemory();
-/// createX86MaxStackAlignmentCalculatorPass - This function returns a pass
-/// which calculates maximal stack alignment required for function
-///
-FunctionPass *createX86MaxStackAlignmentCalculatorPass();
-
extern Target TheX86_32Target, TheX86_64Target;
} // End llvm namespace
// Stack Frame Processing methods
//===----------------------------------------------------------------------===//
-static unsigned calculateMaxStackAlignment(const MachineFrameInfo *FFI) {
- unsigned MaxAlign = 0;
-
- for (int i = FFI->getObjectIndexBegin(),
- e = FFI->getObjectIndexEnd(); i != e; ++i) {
- if (FFI->isDeadObjectIndex(i))
- continue;
-
- unsigned Align = FFI->getObjectAlignment(i);
- MaxAlign = std::max(MaxAlign, Align);
- }
-
- return MaxAlign;
-}
-
/// hasFP - Return true if the specified function should have a dedicated frame
/// pointer register. This is true if the function has variable sized allocas
/// or if frame pointer elimination is disabled.
// Calculate and set max stack object alignment early, so we can decide
// whether we will need stack realignment (and thus FP).
- unsigned MaxAlign = std::max(MFI->getMaxAlignment(),
- calculateMaxStackAlignment(MFI));
-
- MFI->setMaxAlignment(MaxAlign);
+ MFI->calculateMaxStackAlignment();
X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
int32_t TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta();
}
#include "X86GenRegisterInfo.inc"
-
-namespace {
- struct MSAC : public MachineFunctionPass {
- static char ID;
- MSAC() : MachineFunctionPass(&ID) {}
-
- virtual bool runOnMachineFunction(MachineFunction &MF) {
- MachineFrameInfo *FFI = MF.getFrameInfo();
- MachineRegisterInfo &RI = MF.getRegInfo();
-
- // Calculate max stack alignment of all already allocated stack objects.
- unsigned MaxAlign = calculateMaxStackAlignment(FFI);
-
- // Be over-conservative: scan over all vreg defs and find, whether vector
- // registers are used. If yes - there is probability, that vector register
- // will be spilled and thus stack needs to be aligned properly.
- for (unsigned RegNum = TargetRegisterInfo::FirstVirtualRegister;
- RegNum < RI.getLastVirtReg(); ++RegNum)
- MaxAlign = std::max(MaxAlign, RI.getRegClass(RegNum)->getAlignment());
-
- if (FFI->getMaxAlignment() == MaxAlign)
- return false;
-
- FFI->setMaxAlignment(MaxAlign);
- return true;
- }
-
- virtual const char *getPassName() const {
- return "X86 Maximal Stack Alignment Calculator";
- }
-
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.setPreservesCFG();
- MachineFunctionPass::getAnalysisUsage(AU);
- }
- };
-
- char MSAC::ID = 0;
-}
-
-FunctionPass*
-llvm::createX86MaxStackAlignmentCalculatorPass() { return new MSAC(); }
CodeGenOpt::Level OptLevel) {
// Calculate and set max stack object alignment early, so we can decide
// whether we will need stack realignment (and thus FP).
- PM.add(createX86MaxStackAlignmentCalculatorPass());
+ PM.add(createMaxStackAlignmentCalculatorPass());
return false; // -print-machineinstr shouldn't print after this.
}
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