diff options
Diffstat (limited to 'contrib/llvm/lib/Target/R600/MCTargetDesc/SIMCCodeEmitter.cpp')
-rw-r--r-- | contrib/llvm/lib/Target/R600/MCTargetDesc/SIMCCodeEmitter.cpp | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/R600/MCTargetDesc/SIMCCodeEmitter.cpp b/contrib/llvm/lib/Target/R600/MCTargetDesc/SIMCCodeEmitter.cpp new file mode 100644 index 000000000000..5af83209a0d5 --- /dev/null +++ b/contrib/llvm/lib/Target/R600/MCTargetDesc/SIMCCodeEmitter.cpp @@ -0,0 +1,201 @@ +//===-- SIMCCodeEmitter.cpp - SI Code Emitter -------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +/// \file +/// \brief The SI code emitter produces machine code that can be executed +/// directly on the GPU device. +// +//===----------------------------------------------------------------------===// + +#include "MCTargetDesc/AMDGPUMCTargetDesc.h" +#include "MCTargetDesc/AMDGPUMCCodeEmitter.h" +#include "llvm/MC/MCCodeEmitter.h" +#include "llvm/MC/MCContext.h" +#include "llvm/MC/MCFixup.h" +#include "llvm/MC/MCInst.h" +#include "llvm/MC/MCInstrInfo.h" +#include "llvm/MC/MCRegisterInfo.h" +#include "llvm/MC/MCSubtargetInfo.h" +#include "llvm/Support/raw_ostream.h" + +using namespace llvm; + +namespace { + +/// \brief Helper type used in encoding +typedef union { + int32_t I; + float F; +} IntFloatUnion; + +class SIMCCodeEmitter : public AMDGPUMCCodeEmitter { + SIMCCodeEmitter(const SIMCCodeEmitter &) LLVM_DELETED_FUNCTION; + void operator=(const SIMCCodeEmitter &) LLVM_DELETED_FUNCTION; + const MCInstrInfo &MCII; + const MCRegisterInfo &MRI; + + /// \brief Can this operand also contain immediate values? + bool isSrcOperand(const MCInstrDesc &Desc, unsigned OpNo) const; + + /// \brief Encode an fp or int literal + uint32_t getLitEncoding(const MCOperand &MO) const; + +public: + SIMCCodeEmitter(const MCInstrInfo &mcii, const MCRegisterInfo &mri, + const MCSubtargetInfo &sti, MCContext &ctx) + : MCII(mcii), MRI(mri) { } + + ~SIMCCodeEmitter() { } + + /// \breif Encode the instruction and write it to the OS. + virtual void EncodeInstruction(const MCInst &MI, raw_ostream &OS, + SmallVectorImpl<MCFixup> &Fixups) const; + + /// \returns the encoding for an MCOperand. + virtual uint64_t getMachineOpValue(const MCInst &MI, const MCOperand &MO, + SmallVectorImpl<MCFixup> &Fixups) const; +}; + +} // End anonymous namespace + +MCCodeEmitter *llvm::createSIMCCodeEmitter(const MCInstrInfo &MCII, + const MCRegisterInfo &MRI, + const MCSubtargetInfo &STI, + MCContext &Ctx) { + return new SIMCCodeEmitter(MCII, MRI, STI, Ctx); +} + +bool SIMCCodeEmitter::isSrcOperand(const MCInstrDesc &Desc, + unsigned OpNo) const { + + unsigned RegClass = Desc.OpInfo[OpNo].RegClass; + return (AMDGPU::SSrc_32RegClassID == RegClass) || + (AMDGPU::SSrc_64RegClassID == RegClass) || + (AMDGPU::VSrc_32RegClassID == RegClass) || + (AMDGPU::VSrc_64RegClassID == RegClass); +} + +uint32_t SIMCCodeEmitter::getLitEncoding(const MCOperand &MO) const { + + IntFloatUnion Imm; + if (MO.isImm()) + Imm.I = MO.getImm(); + else if (MO.isFPImm()) + Imm.F = MO.getFPImm(); + else + return ~0; + + if (Imm.I >= 0 && Imm.I <= 64) + return 128 + Imm.I; + + if (Imm.I >= -16 && Imm.I <= -1) + return 192 + abs(Imm.I); + + if (Imm.F == 0.5f) + return 240; + + if (Imm.F == -0.5f) + return 241; + + if (Imm.F == 1.0f) + return 242; + + if (Imm.F == -1.0f) + return 243; + + if (Imm.F == 2.0f) + return 244; + + if (Imm.F == -2.0f) + return 245; + + if (Imm.F == 4.0f) + return 246; + + if (Imm.F == -4.0f) + return 247; + + return 255; +} + +void SIMCCodeEmitter::EncodeInstruction(const MCInst &MI, raw_ostream &OS, + SmallVectorImpl<MCFixup> &Fixups) const { + + uint64_t Encoding = getBinaryCodeForInstr(MI, Fixups); + const MCInstrDesc &Desc = MCII.get(MI.getOpcode()); + unsigned bytes = Desc.getSize(); + + for (unsigned i = 0; i < bytes; i++) { + OS.write((uint8_t) ((Encoding >> (8 * i)) & 0xff)); + } + + if (bytes > 4) + return; + + // Check for additional literals in SRC0/1/2 (Op 1/2/3) + for (unsigned i = 0, e = MI.getNumOperands(); i < e; ++i) { + + // Check if this operand should be encoded as [SV]Src + if (!isSrcOperand(Desc, i)) + continue; + + // Is this operand a literal immediate? + const MCOperand &Op = MI.getOperand(i); + if (getLitEncoding(Op) != 255) + continue; + + // Yes! Encode it + IntFloatUnion Imm; + if (Op.isImm()) + Imm.I = Op.getImm(); + else + Imm.F = Op.getFPImm(); + + for (unsigned j = 0; j < 4; j++) { + OS.write((uint8_t) ((Imm.I >> (8 * j)) & 0xff)); + } + + // Only one literal value allowed + break; + } +} + +uint64_t SIMCCodeEmitter::getMachineOpValue(const MCInst &MI, + const MCOperand &MO, + SmallVectorImpl<MCFixup> &Fixups) const { + if (MO.isReg()) + return MRI.getEncodingValue(MO.getReg()); + + if (MO.isExpr()) { + const MCExpr *Expr = MO.getExpr(); + MCFixupKind Kind = MCFixupKind(FK_PCRel_4); + Fixups.push_back(MCFixup::Create(0, Expr, Kind, MI.getLoc())); + return 0; + } + + // Figure out the operand number, needed for isSrcOperand check + unsigned OpNo = 0; + for (unsigned e = MI.getNumOperands(); OpNo < e; ++OpNo) { + if (&MO == &MI.getOperand(OpNo)) + break; + } + + const MCInstrDesc &Desc = MCII.get(MI.getOpcode()); + if (isSrcOperand(Desc, OpNo)) { + uint32_t Enc = getLitEncoding(MO); + if (Enc != ~0U && (Enc != 255 || Desc.getSize() == 4)) + return Enc; + + } else if (MO.isImm()) + return MO.getImm(); + + llvm_unreachable("Encoding of this operand type is not supported yet."); + return 0; +} + |