llvm-6502/lib/Target/NVPTX/NVPTXAllocaHoisting.h
Josh Magee 5b6af7163d [stackprotector] Use analysis from the StackProtector pass for stack layout in PEI a nd LocalStackSlot passes.
This changes the MachineFrameInfo API to use the new SSPLayoutKind information
produced by the StackProtector pass (instead of a boolean flag) and updates a
few pass dependencies (to preserve the SSP analysis).

The stack layout follows the same approach used prior to this change - i.e.,
only LargeArray stack objects will be placed near the canary and everything
else will be laid out normally.  After this change, structures containing large
arrays will also be placed near the canary - a case previously missed by the
old implementation.

Out of tree targets will need to update their usage of
MachineFrameInfo::CreateStackObject to remove the MayNeedSP argument. 

The next patch will implement the rules for sspstrong and sspreq.  The end goal
is to support ssp-strong stack layout rules.

WIP.

Differential Revision: http://llvm-reviews.chandlerc.com/D2158


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197653 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-19 03:17:11 +00:00

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1.4 KiB
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//===-- AllocaHoisting.h - Hosist allocas to the entry block ----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Hoist the alloca instructions in the non-entry blocks to the entry blocks.
//
//===----------------------------------------------------------------------===//
#ifndef NVPTX_ALLOCA_HOISTING_H_
#define NVPTX_ALLOCA_HOISTING_H_
#include "llvm/CodeGen/MachineFunctionAnalysis.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/Pass.h"
namespace llvm {
class FunctionPass;
class Function;
// Hoisting the alloca instructions in the non-entry blocks to the entry
// block.
class NVPTXAllocaHoisting : public FunctionPass {
public:
static char ID; // Pass ID
NVPTXAllocaHoisting() : FunctionPass(ID) {}
void getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<DataLayout>();
AU.addPreserved("stack-protector");
AU.addPreserved<MachineFunctionAnalysis>();
}
virtual const char *getPassName() const {
return "NVPTX specific alloca hoisting";
}
virtual bool runOnFunction(Function &function);
};
extern FunctionPass *createAllocaHoisting();
} // end namespace llvm
#endif // NVPTX_ALLOCA_HOISTING_H_