llvm-6502/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp

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//===-- PPCInstPrinter.cpp - Convert PPC MCInst to assembly syntax --------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This class prints an PPC MCInst to a .s file.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "asm-printer"
#include "PPCInstPrinter.h"
#include "MCTargetDesc/PPCBaseInfo.h"
#include "MCTargetDesc/PPCPredicates.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstrInfo.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
#include "PPCGenAsmWriter.inc"
void PPCInstPrinter::printRegName(raw_ostream &OS, unsigned RegNo) const {
OS << getRegisterName(RegNo);
}
void PPCInstPrinter::printInst(const MCInst *MI, raw_ostream &O,
StringRef Annot) {
// Check for slwi/srwi mnemonics.
if (MI->getOpcode() == PPC::RLWINM) {
unsigned char SH = MI->getOperand(2).getImm();
unsigned char MB = MI->getOperand(3).getImm();
unsigned char ME = MI->getOperand(4).getImm();
bool useSubstituteMnemonic = false;
if (SH <= 31 && MB == 0 && ME == (31-SH)) {
O << "\tslwi "; useSubstituteMnemonic = true;
}
if (SH <= 31 && MB == (32-SH) && ME == 31) {
O << "\tsrwi "; useSubstituteMnemonic = true;
SH = 32-SH;
}
if (useSubstituteMnemonic) {
printOperand(MI, 0, O);
O << ", ";
printOperand(MI, 1, O);
O << ", " << (unsigned int)SH;
printAnnotation(O, Annot);
return;
}
}
if ((MI->getOpcode() == PPC::OR || MI->getOpcode() == PPC::OR8) &&
MI->getOperand(1).getReg() == MI->getOperand(2).getReg()) {
O << "\tmr ";
printOperand(MI, 0, O);
O << ", ";
printOperand(MI, 1, O);
printAnnotation(O, Annot);
return;
}
if (MI->getOpcode() == PPC::RLDICR) {
unsigned char SH = MI->getOperand(2).getImm();
unsigned char ME = MI->getOperand(3).getImm();
// rldicr RA, RS, SH, 63-SH == sldi RA, RS, SH
if (63-SH == ME) {
O << "\tsldi ";
printOperand(MI, 0, O);
O << ", ";
printOperand(MI, 1, O);
O << ", " << (unsigned int)SH;
printAnnotation(O, Annot);
return;
}
}
printInstruction(MI, O);
printAnnotation(O, Annot);
}
void PPCInstPrinter::printPredicateOperand(const MCInst *MI, unsigned OpNo,
raw_ostream &O,
const char *Modifier) {
unsigned Code = MI->getOperand(OpNo).getImm();
if (!Modifier) {
unsigned CCReg = MI->getOperand(OpNo+1).getReg();
unsigned RegNo;
switch (CCReg) {
default: llvm_unreachable("Unknown CR register");
case PPC::CR0: RegNo = 0; break;
case PPC::CR1: RegNo = 1; break;
case PPC::CR2: RegNo = 2; break;
case PPC::CR3: RegNo = 3; break;
case PPC::CR4: RegNo = 4; break;
case PPC::CR5: RegNo = 5; break;
case PPC::CR6: RegNo = 6; break;
case PPC::CR7: RegNo = 7; break;
}
// Print the CR bit number. The Code is ((BI << 5) | BO) for a
// BCC, but we must have the positive form here (BO == 12)
unsigned BI = Code >> 5;
assert((Code & 0xF) == 12 &&
"BO in predicate bit must have the positive form");
unsigned Value = 4*RegNo + BI;
O << Value;
return;
}
if (StringRef(Modifier) == "cc") {
switch ((PPC::Predicate)Code) {
case PPC::PRED_ALWAYS: return; // Don't print anything for always.
case PPC::PRED_LT: O << "lt"; return;
case PPC::PRED_LE: O << "le"; return;
case PPC::PRED_EQ: O << "eq"; return;
case PPC::PRED_GE: O << "ge"; return;
case PPC::PRED_GT: O << "gt"; return;
case PPC::PRED_NE: O << "ne"; return;
case PPC::PRED_UN: O << "un"; return;
case PPC::PRED_NU: O << "nu"; return;
}
}
assert(StringRef(Modifier) == "reg" &&
"Need to specify 'cc' or 'reg' as predicate op modifier!");
// Don't print the register for 'always'.
if (Code == PPC::PRED_ALWAYS) return;
printOperand(MI, OpNo+1, O);
}
void PPCInstPrinter::printS5ImmOperand(const MCInst *MI, unsigned OpNo,
raw_ostream &O) {
char Value = MI->getOperand(OpNo).getImm();
Value = (Value << (32-5)) >> (32-5);
O << (int)Value;
}
void PPCInstPrinter::printU5ImmOperand(const MCInst *MI, unsigned OpNo,
raw_ostream &O) {
unsigned char Value = MI->getOperand(OpNo).getImm();
assert(Value <= 31 && "Invalid u5imm argument!");
O << (unsigned int)Value;
}
void PPCInstPrinter::printU6ImmOperand(const MCInst *MI, unsigned OpNo,
raw_ostream &O) {
unsigned char Value = MI->getOperand(OpNo).getImm();
assert(Value <= 63 && "Invalid u6imm argument!");
O << (unsigned int)Value;
}
void PPCInstPrinter::printS16ImmOperand(const MCInst *MI, unsigned OpNo,
raw_ostream &O) {
O << (short)MI->getOperand(OpNo).getImm();
}
void PPCInstPrinter::printU16ImmOperand(const MCInst *MI, unsigned OpNo,
raw_ostream &O) {
O << (unsigned short)MI->getOperand(OpNo).getImm();
}
void PPCInstPrinter::printS16X4ImmOperand(const MCInst *MI, unsigned OpNo,
raw_ostream &O) {
if (MI->getOperand(OpNo).isImm())
O << (short)(MI->getOperand(OpNo).getImm()*4);
else
printOperand(MI, OpNo, O);
}
void PPCInstPrinter::printBranchOperand(const MCInst *MI, unsigned OpNo,
raw_ostream &O) {
if (!MI->getOperand(OpNo).isImm())
return printOperand(MI, OpNo, O);
// Branches can take an immediate operand. This is used by the branch
// selection pass to print $+8, an eight byte displacement from the PC.
O << "$+";
printAbsAddrOperand(MI, OpNo, O);
}
void PPCInstPrinter::printAbsAddrOperand(const MCInst *MI, unsigned OpNo,
raw_ostream &O) {
O << (int)MI->getOperand(OpNo).getImm()*4;
}
void PPCInstPrinter::printcrbitm(const MCInst *MI, unsigned OpNo,
raw_ostream &O) {
unsigned CCReg = MI->getOperand(OpNo).getReg();
unsigned RegNo;
switch (CCReg) {
default: llvm_unreachable("Unknown CR register");
case PPC::CR0: RegNo = 0; break;
case PPC::CR1: RegNo = 1; break;
case PPC::CR2: RegNo = 2; break;
case PPC::CR3: RegNo = 3; break;
case PPC::CR4: RegNo = 4; break;
case PPC::CR5: RegNo = 5; break;
case PPC::CR6: RegNo = 6; break;
case PPC::CR7: RegNo = 7; break;
}
O << (0x80 >> RegNo);
}
void PPCInstPrinter::printMemRegImm(const MCInst *MI, unsigned OpNo,
raw_ostream &O) {
printSymbolLo(MI, OpNo, O);
O << '(';
if (MI->getOperand(OpNo+1).getReg() == PPC::R0)
O << "0";
else
printOperand(MI, OpNo+1, O);
O << ')';
}
void PPCInstPrinter::printMemRegImmShifted(const MCInst *MI, unsigned OpNo,
raw_ostream &O) {
if (MI->getOperand(OpNo).isImm())
printS16X4ImmOperand(MI, OpNo, O);
else
printSymbolLo(MI, OpNo, O);
O << '(';
if (MI->getOperand(OpNo+1).getReg() == PPC::R0)
O << "0";
else
printOperand(MI, OpNo+1, O);
O << ')';
}
void PPCInstPrinter::printMemRegReg(const MCInst *MI, unsigned OpNo,
raw_ostream &O) {
// When used as the base register, r0 reads constant zero rather than
// the value contained in the register. For this reason, the darwin
// assembler requires that we print r0 as 0 (no r) when used as the base.
if (MI->getOperand(OpNo).getReg() == PPC::R0)
O << "0";
else
printOperand(MI, OpNo, O);
O << ", ";
printOperand(MI, OpNo+1, O);
}
/// stripRegisterPrefix - This method strips the character prefix from a
/// register name so that only the number is left. Used by for linux asm.
static const char *stripRegisterPrefix(const char *RegName) {
switch (RegName[0]) {
case 'r':
case 'f':
case 'v': return RegName + 1;
case 'c': if (RegName[1] == 'r') return RegName + 2;
}
return RegName;
}
void PPCInstPrinter::printOperand(const MCInst *MI, unsigned OpNo,
raw_ostream &O) {
const MCOperand &Op = MI->getOperand(OpNo);
if (Op.isReg()) {
const char *RegName = getRegisterName(Op.getReg());
// The linux and AIX assembler does not take register prefixes.
if (!isDarwinSyntax())
RegName = stripRegisterPrefix(RegName);
O << RegName;
return;
}
if (Op.isImm()) {
O << Op.getImm();
return;
}
assert(Op.isExpr() && "unknown operand kind in printOperand");
O << *Op.getExpr();
}
void PPCInstPrinter::printSymbolLo(const MCInst *MI, unsigned OpNo,
raw_ostream &O) {
if (MI->getOperand(OpNo).isImm())
return printS16ImmOperand(MI, OpNo, O);
// FIXME: This is a terrible hack because we can't encode lo16() as an operand
// flag of a subtraction. See the FIXME in GetSymbolRef in PPCMCInstLower.
if (MI->getOperand(OpNo).isExpr() &&
isa<MCBinaryExpr>(MI->getOperand(OpNo).getExpr())) {
O << "lo16(";
printOperand(MI, OpNo, O);
O << ')';
} else {
printOperand(MI, OpNo, O);
}
}
void PPCInstPrinter::printSymbolHi(const MCInst *MI, unsigned OpNo,
raw_ostream &O) {
if (MI->getOperand(OpNo).isImm())
return printS16ImmOperand(MI, OpNo, O);
// FIXME: This is a terrible hack because we can't encode lo16() as an operand
// flag of a subtraction. See the FIXME in GetSymbolRef in PPCMCInstLower.
if (MI->getOperand(OpNo).isExpr() &&
isa<MCBinaryExpr>(MI->getOperand(OpNo).getExpr())) {
O << "ha16(";
printOperand(MI, OpNo, O);
O << ')';
} else {
printOperand(MI, OpNo, O);
}
}