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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@9903 91177308-0d34-0410-b5e6-96231b3b80d8
35 lines
1.3 KiB
C++
35 lines
1.3 KiB
C++
//===- DemoteRegToStack.h - Move a virtual reg. to stack --------*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file was developed by the LLVM research group and is distributed under
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// the University of Illinois Open Source License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file provides the function:
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// AllocaInst* DemoteRegToStack(Instruction& X):
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//
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// This function takes a virtual register computed by an
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// Instruction& X and replaces it with a slot in the stack frame,
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// allocated via alloca. It has to:
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// (1) Identify all Phi operations that have X as an operand and
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// transitively other Phis that use such Phis;
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// (2) Store all values merged with X via Phi operations to the stack slot;
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// (3) Load the value from the stack slot just before any use of X or any
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// of the Phis that were eliminated; and
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// (4) Delete X and all the Phis, which should all now be dead.
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//
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// Returns the pointer to the alloca inserted to create a stack slot for X.
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//
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//===----------------------------------------------------------------------===//
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namespace llvm {
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class Instruction;
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class AllocaInst;
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AllocaInst *DemoteRegToStack(Instruction &X);
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} // End llvm namespace
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