mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-11-01 15:11:24 +00:00
aaecc0fc08
This optional register liveness analysis pass can be enabled with either -enable-stackmap-liveness, -enable-patchpoint-liveness, or both. The pass traverses each basic block in a machine function. For each basic block the instructions are processed in reversed order and if a patchpoint or stackmap instruction is encountered the current live-out register set is encoded as a register mask and attached to the instruction. Later on during stackmap generation the live-out register mask is processed and also emitted as part of the stackmap. This information is optional and intended for optimization purposes only. This will enable a client of the stackmap to reason about the registers it can use and which registers need to be preserved. Reviewed by Andy git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197317 91177308-0d34-0410-b5e6-96231b3b80d8
66 lines
2.3 KiB
C++
66 lines
2.3 KiB
C++
//===--- StackMapLivenessAnalysis - StackMap Liveness Analysis --*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This pass calculates the liveness for each basic block in a function and
|
|
// attaches the register live-out information to a stackmap or patchpoint
|
|
// intrinsic if present.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_CODEGEN_STACKMAP_LIVENESS_ANALYSIS_H
|
|
#define LLVM_CODEGEN_STACKMAP_LIVENESS_ANALYSIS_H
|
|
|
|
#include "llvm/CodeGen/LivePhysRegs.h"
|
|
#include "llvm/CodeGen/MachineFunctionPass.h"
|
|
|
|
|
|
namespace llvm {
|
|
|
|
/// \brief This pass calculates the liveness information for each basic block in
|
|
/// a function and attaches the register live-out information to a stackmap or
|
|
/// patchpoint intrinsic if present.
|
|
///
|
|
/// This is an optional pass that has to be explicitly enabled via the
|
|
/// -enable-stackmap-liveness and/or -enable-patchpoint-liveness flag. The pass
|
|
/// skips functions that don't have any stackmap or patchpoint intrinsics. The
|
|
/// information provided by this pass is optional and not required by the
|
|
/// aformentioned intrinsics to function.
|
|
class StackMapLiveness : public MachineFunctionPass {
|
|
MachineFunction *MF;
|
|
const TargetRegisterInfo *TRI;
|
|
LivePhysRegs LiveRegs;
|
|
public:
|
|
static char ID;
|
|
|
|
/// \brief Default construct and initialize the pass.
|
|
StackMapLiveness();
|
|
|
|
/// \brief Tell the pass manager which passes we depend on and what
|
|
/// information we preserve.
|
|
virtual void getAnalysisUsage(AnalysisUsage &AU) const;
|
|
|
|
/// \brief Calculate the liveness information for the given machine function.
|
|
virtual bool runOnMachineFunction(MachineFunction &MF);
|
|
|
|
private:
|
|
/// \brief Performs the actual liveness calculation for the function.
|
|
bool calculateLiveness();
|
|
|
|
/// \brief Add the current register live set to the instruction.
|
|
void addLiveOutSetToMI(MachineInstr &MI);
|
|
|
|
/// \brief Create a register mask and initialize it with the registers from
|
|
/// the register live set.
|
|
uint32_t *createRegisterMask() const;
|
|
};
|
|
|
|
} // llvm namespace
|
|
|
|
#endif // LLVM_CODEGEN_STACKMAP_LIVENESS_ANALYSIS_H
|