trunk/sljit/sljitNativeX86_64.c

/*
 *    Stack-less Just-In-Time compiler
 *
 *    Copyright 2009-2012 Zoltan Herczeg (hzmester@freemail.hu). All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright notice, this list of
 *      conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright notice, this list
 *      of conditions and the following disclaimer in the documentation and/or other materials
 *      provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) AND CONTRIBUTORS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE COPYRIGHT HOLDER(S) OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/* x86 64-bit arch dependent functions. */

static sljit_si emit_load_imm64(struct sljit_compiler *compiler, sljit_si reg, sljit_sw imm)
{
        sljit_ub *inst;

        inst = (sljit_ub*)ensure_buf(compiler, 1 + 2 + sizeof(sljit_sw));
        FAIL_IF(!inst);
        INC_SIZE(2 + sizeof(sljit_sw));
        *inst++ = REX_W | ((reg_map[reg] <= 7) ? 0 : REX_B);
        *inst++ = MOV_r_i32 + (reg_map[reg] & 0x7);
        *(sljit_sw*)inst = imm;
        return SLJIT_SUCCESS;
}

static sljit_ub* generate_far_jump_code(struct sljit_jump *jump, sljit_ub *code_ptr, sljit_si type)
{
        if (type < SLJIT_JUMP) {
                /* Invert type. */
                *code_ptr++ = get_jump_code(type ^ 0x1) - 0x10;
                *code_ptr++ = 10 + 3;
        }

        SLJIT_COMPILE_ASSERT(reg_map[TMP_REG3] == 9, tmp3_is_9_first);
        *code_ptr++ = REX_W | REX_B;
        *code_ptr++ = MOV_r_i32 + 1;
        jump->addr = (sljit_uw)code_ptr;

        if (jump->flags & JUMP_LABEL)
                jump->flags |= PATCH_MD;
        else
                *(sljit_sw*)code_ptr = jump->u.target;

        code_ptr += sizeof(sljit_sw);
        *code_ptr++ = REX_B;
        *code_ptr++ = GROUP_FF;
        *code_ptr++ = (type >= SLJIT_FAST_CALL) ? (MOD_REG | CALL_rm | 1) : (MOD_REG | JMP_rm | 1);

        return code_ptr;
}

static sljit_ub* generate_fixed_jump(sljit_ub *code_ptr, sljit_sw addr, sljit_si type)
{
        sljit_sw delta = addr - ((sljit_sw)code_ptr + 1 + sizeof(sljit_si));

        if (delta <= SLJIT_W(0x7fffffff) && delta >= SLJIT_W(-0x80000000)) {
                *code_ptr++ = (type == 2) ? CALL_i32 : JMP_i32;
                *(sljit_sw*)code_ptr = delta;
        }
        else {
                SLJIT_COMPILE_ASSERT(reg_map[TMP_REG3] == 9, tmp3_is_9_second);
                *code_ptr++ = REX_W | REX_B;
                *code_ptr++ = MOV_r_i32 + 1;
                *(sljit_sw*)code_ptr = addr;
                code_ptr += sizeof(sljit_sw);
                *code_ptr++ = REX_B;
                *code_ptr++ = GROUP_FF;
                *code_ptr++ = (type == 2) ? (MOD_REG | CALL_rm | 1) : (MOD_REG | JMP_rm | 1);
        }

        return code_ptr;
}

SLJIT_API_FUNC_ATTRIBUTE sljit_si sljit_emit_enter(struct sljit_compiler *compiler, sljit_si args, sljit_si scratches, sljit_si saveds, sljit_si local_size)
{
        sljit_si size, pushed_size;
        sljit_ub *inst;

        CHECK_ERROR();
        check_sljit_emit_enter(compiler, args, scratches, saveds, local_size);

        compiler->scratches = scratches;
        compiler->saveds = saveds;
        compiler->flags_saved = 0;
#if (defined SLJIT_DEBUG && SLJIT_DEBUG)
        compiler->logical_local_size = local_size;
#endif

        size = saveds;
        /* Including the return address saved by the call instruction. */
        pushed_size = (saveds + 1) * sizeof(sljit_sw);
#ifndef _WIN64
        if (saveds >= 2)
                size += saveds - 1;
#else
        if (saveds >= 4)
                size += saveds - 3;
        if (scratches >= 5) {
                size += (5 - 4) * 2;
                pushed_size += sizeof(sljit_sw);
        }
#endif
        size += args * 3;
        if (size > 0) {
                inst = (sljit_ub*)ensure_buf(compiler, 1 + size);
                FAIL_IF(!inst);

                INC_SIZE(size);
                if (saveds >= 5) {
                        SLJIT_COMPILE_ASSERT(reg_map[SLJIT_SAVED_EREG2] >= 8, saved_ereg2_is_hireg);
                        *inst++ = REX_B;
                        PUSH_REG(reg_lmap[SLJIT_SAVED_EREG2]);
                }
                if (saveds >= 4) {
                        SLJIT_COMPILE_ASSERT(reg_map[SLJIT_SAVED_EREG1] >= 8, saved_ereg1_is_hireg);
                        *inst++ = REX_B;
                        PUSH_REG(reg_lmap[SLJIT_SAVED_EREG1]);
                }
                if (saveds >= 3) {
#ifndef _WIN64
                        SLJIT_COMPILE_ASSERT(reg_map[SLJIT_SAVED_REG3] >= 8, saved_reg3_is_hireg);
                        *inst++ = REX_B;
#else
                        SLJIT_COMPILE_ASSERT(reg_map[SLJIT_SAVED_REG3] < 8, saved_reg3_is_loreg);
#endif
                        PUSH_REG(reg_lmap[SLJIT_SAVED_REG3]);
                }
                if (saveds >= 2) {
#ifndef _WIN64
                        SLJIT_COMPILE_ASSERT(reg_map[SLJIT_SAVED_REG2] >= 8, saved_reg2_is_hireg);
                        *inst++ = REX_B;
#else
                        SLJIT_COMPILE_ASSERT(reg_map[SLJIT_SAVED_REG2] < 8, saved_reg2_is_loreg);
#endif
                        PUSH_REG(reg_lmap[SLJIT_SAVED_REG2]);
                }
                if (saveds >= 1) {
                        SLJIT_COMPILE_ASSERT(reg_map[SLJIT_SAVED_REG1] < 8, saved_reg1_is_loreg);
                        PUSH_REG(reg_lmap[SLJIT_SAVED_REG1]);
                }
#ifdef _WIN64
                if (scratches >= 5) {
                        SLJIT_COMPILE_ASSERT(reg_map[SLJIT_TEMPORARY_EREG2] >= 8, temporary_ereg2_is_hireg);
                        *inst++ = REX_B;
                        PUSH_REG(reg_lmap[SLJIT_TEMPORARY_EREG2]);
                }
#endif

#ifndef _WIN64
                if (args > 0) {
                        *inst++ = REX_W;
                        *inst++ = MOV_r_rm;
                        *inst++ = MOD_REG | (reg_map[SLJIT_SAVED_REG1] << 3) | 0x7 /* rdi */;
                }
                if (args > 1) {
                        *inst++ = REX_W | REX_R;
                        *inst++ = MOV_r_rm;
                        *inst++ = MOD_REG | (reg_lmap[SLJIT_SAVED_REG2] << 3) | 0x6 /* rsi */;
                }
                if (args > 2) {
                        *inst++ = REX_W | REX_R;
                        *inst++ = MOV_r_rm;
                        *inst++ = MOD_REG | (reg_lmap[SLJIT_SAVED_REG3] << 3) | 0x2 /* rdx */;
                }
#else
                if (args > 0) {
                        *inst++ = REX_W;
                        *inst++ = MOV_r_rm;
                        *inst++ = MOD_REG | (reg_map[SLJIT_SAVED_REG1] << 3) | 0x1 /* rcx */;
                }
                if (args > 1) {
                        *inst++ = REX_W;
                        *inst++ = MOV_r_rm;
                        *inst++ = MOD_REG | (reg_map[SLJIT_SAVED_REG2] << 3) | 0x2 /* rdx */;
                }
                if (args > 2) {
                        *inst++ = REX_W | REX_B;
                        *inst++ = MOV_r_rm;
                        *inst++ = MOD_REG | (reg_map[SLJIT_SAVED_REG3] << 3) | 0x0 /* r8 */;
                }
#endif
        }

        local_size = ((local_size + FIXED_LOCALS_OFFSET + pushed_size + 16 - 1) & ~(16 - 1)) - pushed_size;
        compiler->local_size = local_size;
#ifdef _WIN64
        if (local_size > 1024) {
                /* Allocate stack for the callback, which grows the stack. */
                inst = (sljit_ub*)ensure_buf(compiler, 1 + 4 + (3 + sizeof(sljit_si)));
                FAIL_IF(!inst);
                INC_SIZE(4 + (3 + sizeof(sljit_si)));
                *inst++ = REX_W;
                *inst++ = GROUP_BINARY_83;
                *inst++ = MOD_REG | SUB | 4;
                /* Pushed size must be divisible by 8. */
                SLJIT_ASSERT(!(pushed_size & 0x7));
                if (pushed_size & 0x8) {
                        *inst++ = 5 * sizeof(sljit_sw);
                        local_size -= 5 * sizeof(sljit_sw);
                } else {
                        *inst++ = 4 * sizeof(sljit_sw);
                        local_size -= 4 * sizeof(sljit_sw);
                }
                /* Second instruction */
                SLJIT_COMPILE_ASSERT(reg_map[SLJIT_SCRATCH_REG1] < 8, temporary_reg1_is_loreg);
                *inst++ = REX_W;
                *inst++ = MOV_rm_i32;
                *inst++ = MOD_REG | reg_lmap[SLJIT_SCRATCH_REG1];
                *(sljit_si*)inst = local_size;
#if (defined SLJIT_VERBOSE && SLJIT_VERBOSE) || (defined SLJIT_DEBUG && SLJIT_DEBUG)
                compiler->skip_checks = 1;
#endif
                FAIL_IF(sljit_emit_ijump(compiler, SLJIT_CALL1, SLJIT_IMM, SLJIT_FUNC_OFFSET(sljit_grow_stack)));
        }
#endif
        SLJIT_ASSERT(local_size > 0);
        if (local_size <= 127) {
                inst = (sljit_ub*)ensure_buf(compiler, 1 + 4);
                FAIL_IF(!inst);
                INC_SIZE(4);
                *inst++ = REX_W;
                *inst++ = GROUP_BINARY_83;
                *inst++ = MOD_REG | SUB | 4;
                *inst++ = local_size;
        }
        else {
                inst = (sljit_ub*)ensure_buf(compiler, 1 + 7);
                FAIL_IF(!inst);
                INC_SIZE(7);
                *inst++ = REX_W;
                *inst++ = GROUP_BINARY_81;
                *inst++ = MOD_REG | SUB | 4;
                *(sljit_si*)inst = local_size;
                inst += sizeof(sljit_si);
        }
#ifdef _WIN64
        /* Save xmm6 with MOVAPS instruction. */
        inst = (sljit_ub*)ensure_buf(compiler, 1 + 5);
        FAIL_IF(!inst);
        INC_SIZE(5);
        *inst++ = GROUP_0F;
        *(sljit_si*)inst = 0x20247429;
#endif

        return SLJIT_SUCCESS;
}

SLJIT_API_FUNC_ATTRIBUTE void sljit_set_context(struct sljit_compiler *compiler, sljit_si args, sljit_si scratches, sljit_si saveds, sljit_si local_size)
{
        sljit_si pushed_size;

        CHECK_ERROR_VOID();
        check_sljit_set_context(compiler, args, scratches, saveds, local_size);

        compiler->scratches = scratches;
        compiler->saveds = saveds;
#if (defined SLJIT_DEBUG && SLJIT_DEBUG)
        compiler->logical_local_size = local_size;
#endif

        /* Including the return address saved by the call instruction. */
        pushed_size = (saveds + 1) * sizeof(sljit_sw);
#ifdef _WIN64
        if (scratches >= 5)
                pushed_size += sizeof(sljit_sw);
#endif
        compiler->local_size = ((local_size + FIXED_LOCALS_OFFSET + pushed_size + 16 - 1) & ~(16 - 1)) - pushed_size;
}

SLJIT_API_FUNC_ATTRIBUTE sljit_si sljit_emit_return(struct sljit_compiler *compiler, sljit_si op, sljit_si src, sljit_sw srcw)
{
        sljit_si size;
        sljit_ub *inst;

        CHECK_ERROR();
        check_sljit_emit_return(compiler, op, src, srcw);

        compiler->flags_saved = 0;
        FAIL_IF(emit_mov_before_return(compiler, op, src, srcw));

#ifdef _WIN64
        /* Restore xmm6 with MOVAPS instruction. */
        inst = (sljit_ub*)ensure_buf(compiler, 1 + 5);
        FAIL_IF(!inst);
        INC_SIZE(5);
        *inst++ = GROUP_0F;
        *(sljit_si*)inst = 0x20247428;
#endif
        SLJIT_ASSERT(compiler->local_size > 0);
        if (compiler->local_size <= 127) {
                inst = (sljit_ub*)ensure_buf(compiler, 1 + 4);
                FAIL_IF(!inst);
                INC_SIZE(4);
                *inst++ = REX_W;
                *inst++ = GROUP_BINARY_83;
                *inst++ = MOD_REG | ADD | 4;
                *inst = compiler->local_size;
        }
        else {
                inst = (sljit_ub*)ensure_buf(compiler, 1 + 7);
                FAIL_IF(!inst);
                INC_SIZE(7);
                *inst++ = REX_W;
                *inst++ = GROUP_BINARY_81;
                *inst++ = MOD_REG | ADD | 4;
                *(sljit_si*)inst = compiler->local_size;
        }

        size = 1 + compiler->saveds;
#ifndef _WIN64
        if (compiler->saveds >= 2)
                size += compiler->saveds - 1;
#else
        if (compiler->saveds >= 4)
                size += compiler->saveds - 3;
        if (compiler->scratches >= 5)
                size += (5 - 4) * 2;
#endif
        inst = (sljit_ub*)ensure_buf(compiler, 1 + size);
        FAIL_IF(!inst);

        INC_SIZE(size);

#ifdef _WIN64
        if (compiler->scratches >= 5) {
                *inst++ = REX_B;
                POP_REG(reg_lmap[SLJIT_TEMPORARY_EREG2]);
        }
#endif
        if (compiler->saveds >= 1)
                POP_REG(reg_map[SLJIT_SAVED_REG1]);
        if (compiler->saveds >= 2) {
#ifndef _WIN64
                *inst++ = REX_B;
#endif
                POP_REG(reg_lmap[SLJIT_SAVED_REG2]);
        }
        if (compiler->saveds >= 3) {
#ifndef _WIN64
                *inst++ = REX_B;
#endif
                POP_REG(reg_lmap[SLJIT_SAVED_REG3]);
        }
        if (compiler->saveds >= 4) {
                *inst++ = REX_B;
                POP_REG(reg_lmap[SLJIT_SAVED_EREG1]);
        }
        if (compiler->saveds >= 5) {
                *inst++ = REX_B;
                POP_REG(reg_lmap[SLJIT_SAVED_EREG2]);
        }

        RET();
        return SLJIT_SUCCESS;
}

/* --------------------------------------------------------------------- */
/*  Operators                                                            */
/* --------------------------------------------------------------------- */

static sljit_si emit_do_imm32(struct sljit_compiler *compiler, sljit_ub rex, sljit_ub opcode, sljit_sw imm)
{
        sljit_ub *inst;
        sljit_si length = 1 + (rex ? 1 : 0) + sizeof(sljit_si);

        inst = (sljit_ub*)ensure_buf(compiler, 1 + length);
        FAIL_IF(!inst);
        INC_SIZE(length);
        if (rex)
                *inst++ = rex;
        *inst++ = opcode;
        *(sljit_si*)inst = imm;
        return SLJIT_SUCCESS;
}

static sljit_ub* emit_x86_instruction(struct sljit_compiler *compiler, sljit_si size,
        /* The register or immediate operand. */
        sljit_si a, sljit_sw imma,
        /* The general operand (not immediate). */
        sljit_si b, sljit_sw immb)
{
        sljit_ub *inst;
        sljit_ub *buf_ptr;
        sljit_ub rex = 0;
        sljit_si flags = size & ~0xf;
        sljit_si inst_size;

        /* The immediate operand must be 32 bit. */
        SLJIT_ASSERT(!(a & SLJIT_IMM) || compiler->mode32 || IS_HALFWORD(imma));
        /* Both cannot be switched on. */
        SLJIT_ASSERT((flags & (EX86_BIN_INS | EX86_SHIFT_INS)) != (EX86_BIN_INS | EX86_SHIFT_INS));
        /* Size flags not allowed for typed instructions. */
        SLJIT_ASSERT(!(flags & (EX86_BIN_INS | EX86_SHIFT_INS)) || (flags & (EX86_BYTE_ARG | EX86_HALF_ARG)) == 0);
        /* Both size flags cannot be switched on. */
        SLJIT_ASSERT((flags & (EX86_BYTE_ARG | EX86_HALF_ARG)) != (EX86_BYTE_ARG | EX86_HALF_ARG));
#if (defined SLJIT_SSE2 && SLJIT_SSE2)
        /* SSE2 and immediate is not possible. */
        SLJIT_ASSERT(!(a & SLJIT_IMM) || !(flags & EX86_SSE2));
        SLJIT_ASSERT((flags & (EX86_PREF_F2 | EX86_PREF_F3)) != (EX86_PREF_F2 | EX86_PREF_F3)
                && (flags & (EX86_PREF_F2 | EX86_PREF_66)) != (EX86_PREF_F2 | EX86_PREF_66)
                && (flags & (EX86_PREF_F3 | EX86_PREF_66)) != (EX86_PREF_F3 | EX86_PREF_66));
#endif

        size &= 0xf;
        inst_size = size;

        if ((b & SLJIT_MEM) && !(b & 0xf0) && NOT_HALFWORD(immb)) {
                if (emit_load_imm64(compiler, TMP_REG3, immb))
                        return NULL;
                immb = 0;
                if (b & 0xf)
                        b |= TMP_REG3 << 4;
                else
                        b |= TMP_REG3;
        }

        if (!compiler->mode32 && !(flags & EX86_NO_REXW))
                rex |= REX_W;
        else if (flags & EX86_REX)
                rex |= REX;

#if (defined SLJIT_SSE2 && SLJIT_SSE2)
        if (flags & (EX86_PREF_F2 | EX86_PREF_F3))
                inst_size++;
#endif
        if (flags & EX86_PREF_66)
                inst_size++;

        /* Calculate size of b. */
        inst_size += 1; /* mod r/m byte. */
        if (b & SLJIT_MEM) {
                if ((b & 0x0f) == SLJIT_UNUSED)
                        inst_size += 1 + sizeof(sljit_si); /* SIB byte required to avoid RIP based addressing. */
                else {
                        if (reg_map[b & 0x0f] >= 8)
                                rex |= REX_B;
                        if (immb != 0 && !(b & 0xf0)) {
                                /* Immediate operand. */
                                if (immb <= 127 && immb >= -128)
                                        inst_size += sizeof(sljit_sb);
                                else
                                        inst_size += sizeof(sljit_si);
                        }
                }

                if ((b & 0xf) == SLJIT_LOCALS_REG && !(b & 0xf0))
                        b |= SLJIT_LOCALS_REG << 4;

                if ((b & 0xf0) != SLJIT_UNUSED) {
                        inst_size += 1; /* SIB byte. */
                        if (reg_map[(b >> 4) & 0x0f] >= 8)
                                rex |= REX_X;
                }
        }
#if (defined SLJIT_SSE2 && SLJIT_SSE2)
        else if (!(flags & EX86_SSE2) && reg_map[b] >= 8)
                rex |= REX_B;
#else
        else if (reg_map[b] >= 8)
                rex |= REX_B;
#endif

        if (a & SLJIT_IMM) {
                if (flags & EX86_BIN_INS) {
                        if (imma <= 127 && imma >= -128) {
                                inst_size += 1;
                                flags |= EX86_BYTE_ARG;
                        } else
                                inst_size += 4;
                }
                else if (flags & EX86_SHIFT_INS) {
                        imma &= compiler->mode32 ? 0x1f : 0x3f;
                        if (imma != 1) {
                                inst_size ++;
                                flags |= EX86_BYTE_ARG;
                        }
                } else if (flags & EX86_BYTE_ARG)
                        inst_size++;
                else if (flags & EX86_HALF_ARG)
                        inst_size += sizeof(short);
                else
                        inst_size += sizeof(sljit_si);
        }
        else {
                SLJIT_ASSERT(!(flags & EX86_SHIFT_INS) || a == SLJIT_PREF_SHIFT_REG);
                /* reg_map[SLJIT_PREF_SHIFT_REG] is less than 8. */
#if (defined SLJIT_SSE2 && SLJIT_SSE2)
                if (!(flags & EX86_SSE2) && reg_map[a] >= 8)
                        rex |= REX_R;
#else
                if (reg_map[a] >= 8)
                        rex |= REX_R;
#endif
        }

        if (rex)
                inst_size++;

        inst = (sljit_ub*)ensure_buf(compiler, 1 + inst_size);
        PTR_FAIL_IF(!inst);

        /* Encoding the byte. */
        INC_SIZE(inst_size);
#if (defined SLJIT_SSE2 && SLJIT_SSE2)
        if (flags & EX86_PREF_F2)
                *inst++ = 0xf2;
        if (flags & EX86_PREF_F3)
                *inst++ = 0xf3;
#endif
        if (flags & EX86_PREF_66)
                *inst++ = 0x66;
        if (rex)
                *inst++ = rex;
        buf_ptr = inst + size;

        /* Encode mod/rm byte. */
        if (!(flags & EX86_SHIFT_INS)) {
                if ((flags & EX86_BIN_INS) && (a & SLJIT_IMM))
                        *inst = (flags & EX86_BYTE_ARG) ? GROUP_BINARY_83 : GROUP_BINARY_81;

                if ((a & SLJIT_IMM) || (a == 0))
                        *buf_ptr = 0;
#if (defined SLJIT_SSE2 && SLJIT_SSE2)
                else if (!(flags & EX86_SSE2))
                        *buf_ptr = reg_lmap[a] << 3;
                else
                        *buf_ptr = a << 3;
#else
                else
                        *buf_ptr = reg_lmap[a] << 3;
#endif
        }
        else {
                if (a & SLJIT_IMM) {
                        if (imma == 1)
                                *inst = GROUP_SHIFT_1;
                        else
                                *inst = GROUP_SHIFT_N;
                } else
                        *inst = GROUP_SHIFT_CL;
                *buf_ptr = 0;
        }

        if (!(b & SLJIT_MEM))
#if (defined SLJIT_SSE2 && SLJIT_SSE2)
                *buf_ptr++ |= MOD_REG + ((!(flags & EX86_SSE2)) ? reg_lmap[b] : b);
#else
                *buf_ptr++ |= MOD_REG + reg_lmap[b];
#endif
        else if ((b & 0x0f) != SLJIT_UNUSED) {
                if ((b & 0xf0) == SLJIT_UNUSED || (b & 0xf0) == (SLJIT_LOCALS_REG << 4)) {
                        if (immb != 0) {
                                if (immb <= 127 && immb >= -128)
                                        *buf_ptr |= 0x40;
                                else
                                        *buf_ptr |= 0x80;
                        }

                        if ((b & 0xf0) == SLJIT_UNUSED)
                                *buf_ptr++ |= reg_lmap[b & 0x0f];
                        else {
                                *buf_ptr++ |= 0x04;
                                *buf_ptr++ = reg_lmap[b & 0x0f] | (reg_lmap[(b >> 4) & 0x0f] << 3);
                        }

                        if (immb != 0) {
                                if (immb <= 127 && immb >= -128)
                                        *buf_ptr++ = immb; /* 8 bit displacement. */
                                else {
                                        *(sljit_si*)buf_ptr = immb; /* 32 bit displacement. */
                                        buf_ptr += sizeof(sljit_si);
                                }
                        }
                }
                else {
                        *buf_ptr++ |= 0x04;
                        *buf_ptr++ = reg_lmap[b & 0x0f] | (reg_lmap[(b >> 4) & 0x0f] << 3) | (immb << 6);
                }
        }
        else {
                *buf_ptr++ |= 0x04;
                *buf_ptr++ = 0x25;
                *(sljit_si*)buf_ptr = immb; /* 32 bit displacement. */
                buf_ptr += sizeof(sljit_si);
        }

        if (a & SLJIT_IMM) {
                if (flags & EX86_BYTE_ARG)
                        *buf_ptr = imma;
                else if (flags & EX86_HALF_ARG)
                        *(short*)buf_ptr = imma;
                else if (!(flags & EX86_SHIFT_INS))
                        *(sljit_si*)buf_ptr = imma;
        }

        return !(flags & EX86_SHIFT_INS) ? inst : (inst + 1);
}

/* --------------------------------------------------------------------- */
/*  Call / return instructions                                           */
/* --------------------------------------------------------------------- */

static SLJIT_INLINE sljit_si call_with_args(struct sljit_compiler *compiler, sljit_si type)
{
        sljit_ub *inst;

#ifndef _WIN64
        SLJIT_COMPILE_ASSERT(reg_map[SLJIT_SCRATCH_REG2] == 6 && reg_map[SLJIT_SCRATCH_REG1] < 8 && reg_map[SLJIT_SCRATCH_REG3] < 8, args_registers);

        inst = (sljit_ub*)ensure_buf(compiler, 1 + ((type < SLJIT_CALL3) ? 3 : 6));
        FAIL_IF(!inst);
        INC_SIZE((type < SLJIT_CALL3) ? 3 : 6);
        if (type >= SLJIT_CALL3) {
                *inst++ = REX_W;
                *inst++ = MOV_r_rm;
                *inst++ = MOD_REG | (0x2 /* rdx */ << 3) | reg_lmap[SLJIT_SCRATCH_REG3];
        }
        *inst++ = REX_W;
        *inst++ = MOV_r_rm;
        *inst++ = MOD_REG | (0x7 /* rdi */ << 3) | reg_lmap[SLJIT_SCRATCH_REG1];
#else
        SLJIT_COMPILE_ASSERT(reg_map[SLJIT_SCRATCH_REG2] == 2 && reg_map[SLJIT_SCRATCH_REG1] < 8 && reg_map[SLJIT_SCRATCH_REG3] < 8, args_registers);

        inst = (sljit_ub*)ensure_buf(compiler, 1 + ((type < SLJIT_CALL3) ? 3 : 6));
        FAIL_IF(!inst);
        INC_SIZE((type < SLJIT_CALL3) ? 3 : 6);
        if (type >= SLJIT_CALL3) {
                *inst++ = REX_W | REX_R;
                *inst++ = MOV_r_rm;
                *inst++ = MOD_REG | (0x0 /* r8 */ << 3) | reg_lmap[SLJIT_SCRATCH_REG3];
        }
        *inst++ = REX_W;
        *inst++ = MOV_r_rm;
        *inst++ = MOD_REG | (0x1 /* rcx */ << 3) | reg_lmap[SLJIT_SCRATCH_REG1];
#endif
        return SLJIT_SUCCESS;
}

SLJIT_API_FUNC_ATTRIBUTE sljit_si sljit_emit_fast_enter(struct sljit_compiler *compiler, sljit_si dst, sljit_sw dstw)
{
        sljit_ub *inst;

        CHECK_ERROR();
        check_sljit_emit_fast_enter(compiler, dst, dstw);
        ADJUST_LOCAL_OFFSET(dst, dstw);

        /* For UNUSED dst. Uncommon, but possible. */
        if (dst == SLJIT_UNUSED)
                dst = TMP_REGISTER;

        if (dst <= TMP_REGISTER) {
                if (reg_map[dst] < 8) {
                        inst = (sljit_ub*)ensure_buf(compiler, 1 + 1);
                        FAIL_IF(!inst);
                        INC_SIZE(1);
                        POP_REG(reg_lmap[dst]);
                        return SLJIT_SUCCESS;
                }

                inst = (sljit_ub*)ensure_buf(compiler, 1 + 2);
                FAIL_IF(!inst);
                INC_SIZE(2);
                *inst++ = REX_B;
                POP_REG(reg_lmap[dst]);
                return SLJIT_SUCCESS;
        }

        /* REX_W is not necessary (src is not immediate). */
        compiler->mode32 = 1;
        inst = emit_x86_instruction(compiler, 1, 0, 0, dst, dstw);
        FAIL_IF(!inst);
        *inst++ = POP_rm;
        return SLJIT_SUCCESS;
}

SLJIT_API_FUNC_ATTRIBUTE sljit_si sljit_emit_fast_return(struct sljit_compiler *compiler, sljit_si src, sljit_sw srcw)
{
        sljit_ub *inst;

        CHECK_ERROR();
        check_sljit_emit_fast_return(compiler, src, srcw);
        ADJUST_LOCAL_OFFSET(src, srcw);

        if ((src & SLJIT_IMM) && NOT_HALFWORD(srcw)) {
                FAIL_IF(emit_load_imm64(compiler, TMP_REGISTER, srcw));
                src = TMP_REGISTER;
        }

        if (src <= TMP_REGISTER) {
                if (reg_map[src] < 8) {
                        inst = (sljit_ub*)ensure_buf(compiler, 1 + 1 + 1);
                        FAIL_IF(!inst);

                        INC_SIZE(1 + 1);
                        PUSH_REG(reg_lmap[src]);
                }
                else {
                        inst = (sljit_ub*)ensure_buf(compiler, 1 + 2 + 1);
                        FAIL_IF(!inst);

                        INC_SIZE(2 + 1);
                        *inst++ = REX_B;
                        PUSH_REG(reg_lmap[src]);
                }
        }
        else if (src & SLJIT_MEM) {
                /* REX_W is not necessary (src is not immediate). */
                compiler->mode32 = 1;
                inst = emit_x86_instruction(compiler, 1, 0, 0, src, srcw);
                FAIL_IF(!inst);
                *inst++ = GROUP_FF;
                *inst |= PUSH_rm;

                inst = (sljit_ub*)ensure_buf(compiler, 1 + 1);
                FAIL_IF(!inst);
                INC_SIZE(1);
        }
        else {
                SLJIT_ASSERT(IS_HALFWORD(srcw));
                /* SLJIT_IMM. */
                inst = (sljit_ub*)ensure_buf(compiler, 1 + 5 + 1);
                FAIL_IF(!inst);

                INC_SIZE(5 + 1);
                *inst++ = PUSH_i32;
                *(sljit_si*)inst = srcw;
                inst += sizeof(sljit_si);
        }

        RET();
        return SLJIT_SUCCESS;
}


/* --------------------------------------------------------------------- */
/*  Extend input                                                         */
/* --------------------------------------------------------------------- */

static sljit_si emit_mov_int(struct sljit_compiler *compiler, sljit_si sign,
        sljit_si dst, sljit_sw dstw,
        sljit_si src, sljit_sw srcw)
{
        sljit_ub* inst;
        sljit_si dst_r;

        compiler->mode32 = 0;

        if (dst == SLJIT_UNUSED && !(src & SLJIT_MEM))
                return SLJIT_SUCCESS; /* Empty instruction. */

        if (src & SLJIT_IMM) {
                if (dst <= TMP_REGISTER) {
                        if (sign || ((sljit_uw)srcw <= 0x7fffffff)) {
                                inst = emit_x86_instruction(compiler, 1, SLJIT_IMM, (sljit_sw)(sljit_si)srcw, dst, dstw);
                                FAIL_IF(!inst);
                                *inst = MOV_rm_i32;
                                return SLJIT_SUCCESS;
                        }
                        return emit_load_imm64(compiler, dst, srcw);
                }
                compiler->mode32 = 1;
                inst = emit_x86_instruction(compiler, 1, SLJIT_IMM, (sljit_sw)(sljit_si)srcw, dst, dstw);
                FAIL_IF(!inst);
                *inst = MOV_rm_i32;
                compiler->mode32 = 0;
                return SLJIT_SUCCESS;
        }

        dst_r = (dst <= TMP_REGISTER) ? dst : TMP_REGISTER;

        if ((dst & SLJIT_MEM) && (src <= TMP_REGISTER))
                dst_r = src;
        else {
                if (sign) {
                        inst = emit_x86_instruction(compiler, 1, dst_r, 0, src, srcw);
                        FAIL_IF(!inst);
                        *inst++ = MOVSXD_r_rm;
                } else {
                        compiler->mode32 = 1;
                        FAIL_IF(emit_mov(compiler, dst_r, 0, src, srcw));
                        compiler->mode32 = 0;
                }
        }

        if (dst & SLJIT_MEM) {
                compiler->mode32 = 1;
                inst = emit_x86_instruction(compiler, 1, dst_r, 0, dst, dstw);
                FAIL_IF(!inst);
                *inst = MOV_rm_r;
                compiler->mode32 = 0;
        }

        return SLJIT_SUCCESS;
}