void x86_jcc( struct x86_function *p,
enum x86_cc cc,
int label )
{
int offset = label - (x86_get_label(p) + 2);
DUMP_I(cc);
if (offset < 0) {
/*assert(p->csr - p->store > -offset);*/
if (p->csr - p->store <= -offset) {
/* probably out of memory (using the error_overflow buffer) */
return;
}
}
if (offset <= 127 && offset >= -128) {
emit_1ub(p, 0x70 + cc);
emit_1b(p, (char) offset);
}
else {
offset = label - (x86_get_label(p) + 6);
emit_2ub(p, 0x0f, 0x80 + cc);
emit_1i(p, offset);
}
}
void x86_jcc( struct x86_function *p,
enum x86_cc cc,
unsigned char *label )
{
int offset = label - (x86_get_label(p) + 2);
if (offset <= 127 && offset >= -128) {
emit_1ub(p, 0x70 + cc);
emit_1b(p, (char) offset);
}
else {
offset = label - (x86_get_label(p) + 6);
emit_2ub(p, 0x0f, 0x80 + cc);
emit_1i(p, offset);
}
}
/**
* Immediate group 1 instructions.
*/
static INLINE void
x86_group1_imm( struct x86_function *p,
unsigned op, struct x86_reg dst, int imm )
{
assert(dst.file == file_REG32);
assert(dst.mod == mod_REG);
if(-0x80 <= imm && imm < 0x80) {
emit_1ub(p, 0x83);
emit_modrm_noreg(p, op, dst);
emit_1b(p, (char)imm);
}
else {
emit_1ub(p, 0x81);
emit_modrm_noreg(p, op, dst);
emit_1i(p, imm);
}
}
/* Build a modRM byte + possible displacement. No treatment of SIB
* indexing. BZZT - no way to encode an absolute address.
*
* This is the "/r" field in the x86 manuals...
*/
static void emit_modrm( struct x86_function *p,
struct x86_reg reg,
struct x86_reg regmem )
{
unsigned char val = 0;
assert(reg.mod == mod_REG);
/* TODO: support extended x86-64 registers */
assert(reg.idx < 8);
assert(regmem.idx < 8);
val |= regmem.mod << 6; /* mod field */
val |= reg.idx << 3; /* reg field */
val |= regmem.idx; /* r/m field */
emit_1ub(p, val);
/* Oh-oh we've stumbled into the SIB thing.
*/
if (regmem.file == file_REG32 &&
regmem.idx == reg_SP &&
regmem.mod != mod_REG) {
emit_1ub(p, 0x24); /* simplistic! */
}
switch (regmem.mod) {
case mod_REG:
case mod_INDIRECT:
break;
case mod_DISP8:
emit_1b(p, (char) regmem.disp);
break;
case mod_DISP32:
emit_1i(p, regmem.disp);
break;
default:
assert(0);
break;
}
}
