forked from DavidKinder/Git
/
opcodes.c
508 lines (421 loc) · 16.8 KB
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opcodes.c
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// $Id: opcodes.c,v 1.20 2004/12/22 12:40:07 iain Exp $
#include "git.h"
#include "opcodes.h"
static void parseModeNibbles (git_uint32* pc, int numModes, int * modeBuffer)
{
int * mode = modeBuffer;
while (numModes > 0)
{
// Load byte.
git_uint32 byte = memRead8((*pc)++);
// Load low nibble.
*mode++ = byte & 0x0f;
--numModes;
// Check whether we need to load any more.
if (numModes == 0)
break;
// Load high nibble.
*mode++ = (byte >> 4) & 0x0f;
--numModes;
}
}
static void parseLS (git_uint32* pc, Label op)
{
int modes [2];
parseModeNibbles (pc, 2, modes);
parseLoad (pc, reg_L1, modes [0], size32, NULL);
emitCode (op);
parseStore (pc, reg_S1, modes [1], size32);
}
static void parseLLS (git_uint32* pc, Label op)
{
int modes [3];
parseModeNibbles (pc, 3, modes);
parseLoad (pc, reg_L1, modes [0], size32, NULL);
parseLoad (pc, reg_L2, modes [1], size32, NULL);
emitCode (op);
parseStore (pc, reg_S1, modes [2], size32);
}
static void parseLLSS (git_uint32* pc, Label op)
{
int modes [4];
parseModeNibbles (pc, 4, modes);
parseLoad (pc, reg_L1, modes [0], size32, NULL);
parseLoad (pc, reg_L2, modes [1], size32, NULL);
emitCode (op);
parseStore (pc, reg_S1, modes [2], size32);
parseStore (pc, reg_S2, modes [3], size32);
}
static void parseL (git_uint32* pc, Label op)
{
int modes [1];
parseModeNibbles (pc, 1, modes);
parseLoad (pc, reg_L1, modes [0], size32, NULL);
emitCode (op);
}
static void parseLL (git_uint32* pc, Label op)
{
int modes [2];
parseModeNibbles (pc, 2, modes);
parseLoad (pc, reg_L1, modes [0], size32, NULL);
parseLoad (pc, reg_L2, modes [1], size32, NULL);
emitCode (op);
}
static void parse_finish_branch (git_uint32* pc, Label op, LoadReg reg, int mode)
{
git_sint32 val;
if (parseLoad (pc, reg, mode, size32, &val))
{
// The branch offset is a constant, so we can
// check for the special values 0 and 1 right here.
if (val == 0)
{
emitCode (op - label_jeq_var + label_jeq_return0);
}
else if (val == 1)
{
emitCode (op - label_jeq_var + label_jeq_return1);
}
else
{
// Calculate the destination address and
// emit a constant branch opcode.
emitConstBranch (op - label_jeq_var + label_jeq_const, *pc + val - 2);
}
}
else
{
// The branch offset isn't a constant, so just
// emit the normal opcode plus the current PC.
emitCode (op);
emitData(*pc);
}
}
static void parseLLLL_branch (git_uint32* pc, Label op)
{
int modes [4];
parseModeNibbles (pc, 4, modes);
parseLoad (pc, reg_L1, modes [0], size32, NULL);
parseLoad (pc, reg_L2, modes [1], size32, NULL);
parseLoad (pc, reg_L3, modes [2], size32, NULL);
parse_finish_branch (pc, op, reg_L4, modes [3]);
}
static void parseLLL_branch (git_uint32* pc, Label op)
{
int modes [3];
parseModeNibbles (pc, 3, modes);
parseLoad (pc, reg_L1, modes [0], size32, NULL);
parseLoad (pc, reg_L2, modes [1], size32, NULL);
parse_finish_branch (pc, op, reg_L3, modes [2]);
}
static void parseLL_branch (git_uint32* pc, Label op)
{
int modes [2];
parseModeNibbles (pc, 2, modes);
parseLoad (pc, reg_L1, modes [0], size32, NULL);
parse_finish_branch (pc, op, reg_L2, modes [1]);
}
static void parseL_branch (git_uint32* pc, Label op)
{
int modes [1];
parseModeNibbles (pc, 1, modes);
parse_finish_branch (pc, op, reg_L1, modes [0]);
}
static void parseLLL (git_uint32* pc, Label op)
{
int modes [3];
parseModeNibbles (pc, 3, modes);
parseLoad (pc, reg_L1, modes [0], size32, NULL);
parseLoad (pc, reg_L2, modes [1], size32, NULL);
parseLoad (pc, reg_L3, modes [2], size32, NULL);
emitCode (op);
}
static void parseS (git_uint32* pc, Label op)
{
int modes [1];
parseModeNibbles (pc, 1, modes);
emitCode (op);
parseStore (pc, reg_S1, modes [0], size32);
}
static void parseSS (git_uint32* pc, Label op)
{
int modes [2];
parseModeNibbles (pc, 2, modes);
emitCode (op);
parseStore (pc, reg_S1, modes [0], size32);
parseStore (pc, reg_S2, modes [1], size32);
}
static void parseCatch (git_uint32 * pc)
{
int modes [2];
parseModeNibbles (pc, 2, modes);
parseCatchStub (pc, modes);
}
void parseInstruction (git_uint32* pc, int * done)
{
git_uint32 pcStart = *pc;
int modes [8];
git_uint32 opcode;
static int ops = 0;
++ops;
// Fetch the opcode.
opcode = memRead8((*pc)++);
// Check for multi-byte opcode.
if (opcode & 0x80)
{
if (opcode & 0x40)
{
// Four-byte opcode.
opcode &= 0x3F;
opcode = (opcode << 8) | memRead8((*pc)++);
opcode = (opcode << 8) | memRead8((*pc)++);
opcode = (opcode << 8) | memRead8((*pc)++);
}
else
{
// Two-byte opcode.
opcode &= 0x7F;
opcode = (opcode << 8) | memRead8((*pc)++);
}
}
if (gDebug)
{
emitCode (label_debug_step);
emitData (pcStart);
emitData (opcode);
}
// printf (" opcode=0x%x", opcode);
// Now we have an opcode number,
// parse the operands and emit code.
switch (opcode)
{
case op_nop: emitCode (label_nop); break;
// Arithmetic and logic
case op_add: parseLLS (pc, label_add_discard); break;
case op_sub: parseLLS (pc, label_sub_discard); break;
case op_mul: parseLLS (pc, label_mul_discard); break;
case op_div: parseLLS (pc, label_div_discard); break;
case op_mod: parseLLS (pc, label_mod_discard); break;
case op_bitand: parseLLS (pc, label_bitand_discard); break;
case op_bitor: parseLLS (pc, label_bitor_discard); break;
case op_bitxor: parseLLS (pc, label_bitxor_discard); break;
case op_neg: parseLS (pc, label_neg_discard); break;
case op_bitnot: parseLS (pc, label_bitnot_discard); break;
case op_shiftl: parseLLS (pc, label_shiftl_discard); break;
case op_ushiftr: parseLLS (pc, label_ushiftr_discard); break;
case op_sshiftr: parseLLS (pc, label_sshiftr_discard); break;
// Branches
case op_jump: parseL_branch (pc, label_jump_var); *done = 1; break;
case op_jz: parseLL_branch (pc, label_jz_var); break;
case op_jnz: parseLL_branch (pc, label_jnz_var); break;
case op_jeq: parseLLL_branch (pc, label_jeq_var); break;
case op_jne: parseLLL_branch (pc, label_jne_var); break;
case op_jlt: parseLLL_branch (pc, label_jlt_var); break;
case op_jgt: parseLLL_branch (pc, label_jgt_var); break;
case op_jle: parseLLL_branch (pc, label_jle_var); break;
case op_jge: parseLLL_branch (pc, label_jge_var); break;
case op_jltu: parseLLL_branch (pc, label_jltu_var); break;
case op_jgtu: parseLLL_branch (pc, label_jgtu_var); break;
case op_jleu: parseLLL_branch (pc, label_jleu_var); break;
case op_jgeu: parseLLL_branch (pc, label_jgeu_var); break;
case op_jumpabs: parseL (pc, label_jumpabs); *done = 1; break;
// Moving data
case op_copy:
parseModeNibbles (pc, 2, modes);
parseLoad (pc, reg_L1, modes [0], size32, NULL);
parseStore (pc, reg_S1, modes [1], size32);
break;
case op_copys:
parseModeNibbles (pc, 2, modes);
parseLoad (pc, reg_L1, modes [0], size16, NULL);
emitCode (label_copys_discard);
parseStore (pc, reg_S1, modes [1], size16);
break;
case op_copyb:
parseModeNibbles (pc, 2, modes);
parseLoad (pc, reg_L1, modes [0], size8, NULL);
emitCode (label_copyb_discard);
parseStore (pc, reg_S1, modes [1], size8);
break;
case op_sexs: parseLS (pc, label_sexs_discard); break;
case op_sexb: parseLS (pc, label_sexb_discard); break;
// Array data
case op_aload: parseLLS (pc, label_aload_discard); break;
case op_aloads: parseLLS (pc, label_aloads_discard); break;
case op_aloadb: parseLLS (pc, label_aloadb_discard); break;
case op_aloadbit: parseLLS (pc, label_aloadbit_discard); break;
case op_astore: parseLLL (pc, label_astore); break;
case op_astores: parseLLL (pc, label_astores); break;
case op_astoreb: parseLLL (pc, label_astoreb); break;
case op_astorebit: parseLLL (pc, label_astorebit); break;
// The stack
case op_stkcount: parseS (pc, label_stkcount); break;
case op_stkpeek: parseLS (pc, label_stkpeek); break;
case op_stkswap: emitCode (label_stkswap); break;
case op_stkcopy: parseL (pc, label_stkcopy); break;
case op_stkroll: parseLL (pc, label_stkroll); break;
// Functions
case op_call:
parseModeNibbles (pc, 3, modes);
parseLoad (pc, reg_L1, modes [0], size32, NULL);
parseLoad (pc, reg_L2, modes [1], size32, NULL);
emitCode (label_args_stack);
parseCallStub (pc, modes [2]);
break;
case op_callf:
parseModeNibbles (pc, 2, modes);
parseLoad (pc, reg_L1, modes [0], size32, NULL);
emitCode (label_args_0);
parseCallStub (pc, modes [1]);
break;
case op_callfi:
parseModeNibbles (pc, 3, modes);
parseLoad (pc, reg_L1, modes [0], size32, NULL);
parseLoad (pc, reg_L2, modes [1], size32, NULL);
emitCode (label_args_1);
parseCallStub (pc, modes [2]);
break;
case op_callfii:
parseModeNibbles (pc, 4, modes);
parseLoad (pc, reg_L1, modes [0], size32, NULL);
parseLoad (pc, reg_L2, modes [1], size32, NULL);
parseLoad (pc, reg_L3, modes [2], size32, NULL);
emitCode (label_args_2);
parseCallStub (pc, modes [3]);
break;
case op_callfiii:
parseModeNibbles (pc, 5, modes);
parseLoad (pc, reg_L1, modes [0], size32, NULL);
parseLoad (pc, reg_L2, modes [1], size32, NULL);
parseLoad (pc, reg_L3, modes [2], size32, NULL);
parseLoad (pc, reg_L4, modes [3], size32, NULL);
emitCode (label_args_3);
parseCallStub (pc, modes [4]);
break;
case op_return:
parseL (pc, label_return);
*done = 1;
break;
case op_tailcall:
parseModeNibbles (pc, 2, modes);
parseLoad (pc, reg_L1, modes [0], size32, NULL);
parseLoad (pc, reg_L2, modes [1], size32, NULL);
emitCode (label_args_stack);
emitCode (label_tailcall);
*done = 1;
break;
// Continuations
case op_catch: parseCatch (pc); break;
case op_throw:
parseLL (pc, label_throw);
*done = 1;
break;
case op_random: parseLS (pc, label_random); break;
case op_setrandom: parseL (pc, label_setrandom); break;
case op_getmemsize: parseS (pc, label_getmemsize); break;
case op_setmemsize: parseLS (pc, label_setmemsize); break;
case op_quit:
emitCode (label_quit);
*done = 1;
break;
case op_restart:
emitCode (label_restart);
*done = 1;
break;
case op_restore: parseLS (pc, label_restore); break;
case op_restoreundo: parseS (pc, label_restoreundo); break;
case op_protect: parseLL (pc, label_protect); break;
case op_verify: parseS (pc, label_verify); break;
case op_save:
parseModeNibbles (pc, 2, modes);
parseLoad (pc, reg_L1, modes [0], size32, NULL);
parseSaveStub (pc, modes [1]);
break;
case op_saveundo:
parseModeNibbles (pc, 1, modes);
parseUndoStub (pc, modes [0]);
break;
case op_getiosys: parseSS (pc, label_getiosys); break;
case op_setiosys: parseLL (pc, label_setiosys); break;
case op_getstringtbl: parseS (pc, label_getstringtbl); break;
case op_setstringtbl: parseL (pc, label_setstringtbl); break;
case op_streamchar: parseL (pc, label_streamchar); emitData(*pc); break;
case op_streamnum: parseL (pc, label_streamnum); emitData(*pc); break;
case op_streamstr: parseL (pc, label_streamstr); emitData(*pc); break;
case op_streamunichar: parseL (pc, label_streamunichar); emitData(*pc); break;
case op_glk: parseLLS (pc, label_glk); break;
case op_gestalt: parseLLS (pc, label_gestalt); break;
case op_binarysearch:
case op_linearsearch:
parseModeNibbles (pc, 8, modes);
parseLoad (pc, reg_L1, modes [0], size32, NULL);
parseLoad (pc, reg_L2, modes [1], size32, NULL);
parseLoad (pc, reg_L3, modes [2], size32, NULL);
parseLoad (pc, reg_L4, modes [3], size32, NULL);
parseLoad (pc, reg_L5, modes [4], size32, NULL);
parseLoad (pc, reg_L6, modes [5], size32, NULL);
parseLoad (pc, reg_L7, modes [6], size32, NULL);
emitCode (opcode == op_linearsearch ? label_linearsearch : label_binarysearch);
parseStore (pc, reg_S1, modes [7], size32);
break;
case op_linkedsearch:
parseModeNibbles (pc, 7, modes);
parseLoad (pc, reg_L1, modes [0], size32, NULL);
parseLoad (pc, reg_L2, modes [1], size32, NULL);
parseLoad (pc, reg_L3, modes [2], size32, NULL);
parseLoad (pc, reg_L4, modes [3], size32, NULL);
parseLoad (pc, reg_L5, modes [4], size32, NULL);
parseLoad (pc, reg_L6, modes [5], size32, NULL);
emitCode (label_linkedsearch);
parseStore (pc, reg_S1, modes [6], size32);
break;
case op_debugtrap:
parseL (pc, label_debugtrap);
break;
// Memory management
case op_mzero: parseLL (pc, label_mzero); break;
case op_mcopy: parseLLL (pc, label_mcopy); break;
case op_malloc: parseLS (pc, label_malloc); break;
case op_mfree: parseL (pc, label_mfree); break;
// Function acceleration
case op_accelfunc: parseLL (pc, label_accelfunc); break;
case op_accelparam: parseLL (pc, label_accelparam); break;
// Floating point
case op_numtof: parseLS (pc, label_numtof); break;
case op_ftonumz: parseLS (pc, label_ftonumz); break;
case op_ftonumn: parseLS (pc, label_ftonumn); break;
case op_ceil: parseLS (pc, label_ceil); break;
case op_floor: parseLS (pc, label_floor); break;
case op_sqrt: parseLS (pc, label_sqrt); break;
case op_exp: parseLS (pc, label_exp); break;
case op_log: parseLS (pc, label_log); break;
case op_fadd: parseLLS (pc, label_fadd_discard); break;
case op_fsub: parseLLS (pc, label_fsub_discard); break;
case op_fmul: parseLLS (pc, label_fmul_discard); break;
case op_fdiv: parseLLS (pc, label_fdiv_discard); break;
case op_pow: parseLLS (pc, label_pow); break;
case op_atan2: parseLLS (pc, label_atan2); break;
case op_fmod: parseLLSS (pc, label_fmod); break;
case op_sin: parseLS (pc, label_sin); break;
case op_cos: parseLS (pc, label_cos); break;
case op_tan: parseLS (pc, label_tan); break;
case op_asin: parseLS (pc, label_asin); break;
case op_acos: parseLS (pc, label_acos); break;
case op_atan: parseLS (pc, label_atan); break;
case op_jfeq: parseLLLL_branch (pc, label_jfeq_var); break;
case op_jfne: parseLLLL_branch (pc, label_jfne_var); break;
case op_jflt: parseLLL_branch (pc, label_jflt_var); break;
case op_jfle: parseLLL_branch (pc, label_jfle_var); break;
case op_jfgt: parseLLL_branch (pc, label_jfgt_var); break;
case op_jfge: parseLLL_branch (pc, label_jfge_var); break;
case op_jisnan: parseLL_branch (pc, label_jisnan_var); break;
case op_jisinf: parseLL_branch (pc, label_jisinf_var); break;
// Special Git opcodes
case op_git_setcacheram: parseL (pc, label_git_setcacheram); break;
case op_git_prunecache: parseLL (pc, label_git_prunecache); break;
default:
// Unknown opcode.
abortCompilation();
break;
}
}