OPF_RMD = (1 << 0), /* removed or optimized out */
OPF_DATA = (1 << 1), /* data processing - writes to dst opr */
OPF_FLAGS = (1 << 2), /* sets flags */
- OPF_JMP = (1 << 3), /* branches, ret and call */
- OPF_CC = (1 << 4), /* uses flags */
- OPF_TAIL = (1 << 5), /* ret or tail call */
- OPF_RSAVE = (1 << 6), /* push/pop is local reg save/load */
- OPF_REP = (1 << 7), /* prefixed by rep */
- OPF_REPZ = (1 << 8), /* rep is repe/repz */
- OPF_REPNZ = (1 << 9), /* rep is repne/repnz */
- OPF_FARG = (1 << 10), /* push collected as func arg (no reuse) */
- OPF_EBP_S = (1 << 11), /* ebp used as scratch here, not BP */
+ OPF_JMP = (1 << 3), /* branch, call */
+ OPF_CJMP = (1 << 4), /* cond. branch (cc or jecxz) */
+ OPF_CC = (1 << 5), /* uses flags */
+ OPF_TAIL = (1 << 6), /* ret or tail call */
+ OPF_RSAVE = (1 << 7), /* push/pop is local reg save/load */
+ OPF_REP = (1 << 8), /* prefixed by rep */
+ OPF_REPZ = (1 << 9), /* rep is repe/repz */
+ OPF_REPNZ = (1 << 10), /* rep is repne/repnz */
+ OPF_FARG = (1 << 11), /* push collected as func arg (no reuse) */
+ OPF_EBP_S = (1 << 12), /* ebp used as scratch here, not BP */
+ OPF_DF = (1 << 13), /* DF flag set */
};
enum op_op {
OP_NOP,
OP_PUSH,
OP_POP,
+ OP_LEAVE,
OP_MOV,
OP_LEA,
OP_MOVZX,
OP_STOS,
OP_MOVS,
OP_CMPS,
+ OP_SCAS,
+ OP_STD,
+ OP_CLD,
OP_RET,
OP_ADD,
OP_SUB,
OP_CMP,
OP_CALL,
OP_JMP,
+ OP_JECXZ,
OP_JO,
OP_JNO,
OP_JC,
// datap:
// OP_CALL - parser proto hint (str), ptr to struct parsed_proto
// (OPF_CC) - point to one of (OPF_FLAGS) that affects cc op
+// OP_POP - point to OP_PUSH in push/pop pair
struct parsed_equ {
char name[64];
// must be a number after esp+, already converted to 0x..
s = name + 4;
if (!('0' <= *s && *s <= '9')) {
- aerr("%s nan?\n", __func__);
+ aerr("%s nan?\n", __func__);
return NULL;
}
if (s[0] == '0' && s[1] == 'x')
{ "repnz", OPF_REP|OPF_REPNZ },
};
+#define OPF_CJMP_CC (OPF_JMP|OPF_CJMP|OPF_CC)
+
static const struct {
const char *name;
enum op_op op;
{ "nop", OP_NOP, 0, 0, 0 },
{ "push", OP_PUSH, 1, 1, 0 },
{ "pop", OP_POP, 1, 1, OPF_DATA },
+ { "leave",OP_LEAVE, 0, 0, OPF_DATA },
{ "mov" , OP_MOV, 2, 2, OPF_DATA },
{ "lea", OP_LEA, 2, 2, OPF_DATA },
{ "movzx",OP_MOVZX, 2, 2, OPF_DATA },
{ "cmpsb",OP_CMPS, 0, 0, OPF_DATA|OPF_FLAGS },
{ "cmpsw",OP_CMPS, 0, 0, OPF_DATA|OPF_FLAGS },
{ "cmpsd",OP_CMPS, 0, 0, OPF_DATA|OPF_FLAGS },
+ { "scasb",OP_SCAS, 0, 0, OPF_DATA|OPF_FLAGS },
+ { "scasw",OP_SCAS, 0, 0, OPF_DATA|OPF_FLAGS },
+ { "scasd",OP_SCAS, 0, 0, OPF_DATA|OPF_FLAGS },
+ { "std", OP_STD, 0, 0, OPF_DATA }, // special flag
+ { "cld", OP_CLD, 0, 0, OPF_DATA },
{ "add", OP_ADD, 2, 2, OPF_DATA|OPF_FLAGS },
{ "sub", OP_SUB, 2, 2, OPF_DATA|OPF_FLAGS },
{ "and", OP_AND, 2, 2, OPF_DATA|OPF_FLAGS },
{ "retn", OP_RET, 0, 1, OPF_TAIL },
{ "call", OP_CALL, 1, 1, OPF_JMP|OPF_DATA|OPF_FLAGS },
{ "jmp", OP_JMP, 1, 1, OPF_JMP },
- { "jo", OP_JO, 1, 1, OPF_JMP|OPF_CC }, // 70 OF=1
- { "jno", OP_JNO, 1, 1, OPF_JMP|OPF_CC }, // 71 OF=0
- { "jc", OP_JC, 1, 1, OPF_JMP|OPF_CC }, // 72 CF=1
- { "jb", OP_JC, 1, 1, OPF_JMP|OPF_CC }, // 72
- { "jnc", OP_JNC, 1, 1, OPF_JMP|OPF_CC }, // 73 CF=0
- { "jnb", OP_JNC, 1, 1, OPF_JMP|OPF_CC }, // 73
- { "jae", OP_JNC, 1, 1, OPF_JMP|OPF_CC }, // 73
- { "jz", OP_JZ, 1, 1, OPF_JMP|OPF_CC }, // 74 ZF=1
- { "je", OP_JZ, 1, 1, OPF_JMP|OPF_CC }, // 74
- { "jnz", OP_JNZ, 1, 1, OPF_JMP|OPF_CC }, // 75 ZF=0
- { "jne", OP_JNZ, 1, 1, OPF_JMP|OPF_CC }, // 75
- { "jbe", OP_JBE, 1, 1, OPF_JMP|OPF_CC }, // 76 CF=1 || ZF=1
- { "jna", OP_JBE, 1, 1, OPF_JMP|OPF_CC }, // 76
- { "ja", OP_JA, 1, 1, OPF_JMP|OPF_CC }, // 77 CF=0 && ZF=0
- { "jnbe", OP_JA, 1, 1, OPF_JMP|OPF_CC }, // 77
- { "js", OP_JS, 1, 1, OPF_JMP|OPF_CC }, // 78 SF=1
- { "jns", OP_JNS, 1, 1, OPF_JMP|OPF_CC }, // 79 SF=0
- { "jp", OP_JP, 1, 1, OPF_JMP|OPF_CC }, // 7a PF=1
- { "jpe", OP_JP, 1, 1, OPF_JMP|OPF_CC }, // 7a
- { "jnp", OP_JNP, 1, 1, OPF_JMP|OPF_CC }, // 7b PF=0
- { "jpo", OP_JNP, 1, 1, OPF_JMP|OPF_CC }, // 7b
- { "jl", OP_JL, 1, 1, OPF_JMP|OPF_CC }, // 7c SF!=OF
- { "jnge", OP_JL, 1, 1, OPF_JMP|OPF_CC }, // 7c
- { "jge", OP_JGE, 1, 1, OPF_JMP|OPF_CC }, // 7d SF=OF
- { "jnl", OP_JGE, 1, 1, OPF_JMP|OPF_CC }, // 7d
- { "jle", OP_JLE, 1, 1, OPF_JMP|OPF_CC }, // 7e ZF=1 || SF!=OF
- { "jng", OP_JLE, 1, 1, OPF_JMP|OPF_CC }, // 7e
- { "jg", OP_JG, 1, 1, OPF_JMP|OPF_CC }, // 7f ZF=0 && SF=OF
- { "jnle", OP_JG, 1, 1, OPF_JMP|OPF_CC }, // 7f
+ { "jecxz",OP_JECXZ, 1, 1, OPF_JMP|OPF_CJMP },
+ { "jo", OP_JO, 1, 1, OPF_CJMP_CC }, // 70 OF=1
+ { "jno", OP_JNO, 1, 1, OPF_CJMP_CC }, // 71 OF=0
+ { "jc", OP_JC, 1, 1, OPF_CJMP_CC }, // 72 CF=1
+ { "jb", OP_JC, 1, 1, OPF_CJMP_CC }, // 72
+ { "jnc", OP_JNC, 1, 1, OPF_CJMP_CC }, // 73 CF=0
+ { "jnb", OP_JNC, 1, 1, OPF_CJMP_CC }, // 73
+ { "jae", OP_JNC, 1, 1, OPF_CJMP_CC }, // 73
+ { "jz", OP_JZ, 1, 1, OPF_CJMP_CC }, // 74 ZF=1
+ { "je", OP_JZ, 1, 1, OPF_CJMP_CC }, // 74
+ { "jnz", OP_JNZ, 1, 1, OPF_CJMP_CC }, // 75 ZF=0
+ { "jne", OP_JNZ, 1, 1, OPF_CJMP_CC }, // 75
+ { "jbe", OP_JBE, 1, 1, OPF_CJMP_CC }, // 76 CF=1 || ZF=1
+ { "jna", OP_JBE, 1, 1, OPF_CJMP_CC }, // 76
+ { "ja", OP_JA, 1, 1, OPF_CJMP_CC }, // 77 CF=0 && ZF=0
+ { "jnbe", OP_JA, 1, 1, OPF_CJMP_CC }, // 77
+ { "js", OP_JS, 1, 1, OPF_CJMP_CC }, // 78 SF=1
+ { "jns", OP_JNS, 1, 1, OPF_CJMP_CC }, // 79 SF=0
+ { "jp", OP_JP, 1, 1, OPF_CJMP_CC }, // 7a PF=1
+ { "jpe", OP_JP, 1, 1, OPF_CJMP_CC }, // 7a
+ { "jnp", OP_JNP, 1, 1, OPF_CJMP_CC }, // 7b PF=0
+ { "jpo", OP_JNP, 1, 1, OPF_CJMP_CC }, // 7b
+ { "jl", OP_JL, 1, 1, OPF_CJMP_CC }, // 7c SF!=OF
+ { "jnge", OP_JL, 1, 1, OPF_CJMP_CC }, // 7c
+ { "jge", OP_JGE, 1, 1, OPF_CJMP_CC }, // 7d SF=OF
+ { "jnl", OP_JGE, 1, 1, OPF_CJMP_CC }, // 7d
+ { "jle", OP_JLE, 1, 1, OPF_CJMP_CC }, // 7e ZF=1 || SF!=OF
+ { "jng", OP_JLE, 1, 1, OPF_CJMP_CC }, // 7e
+ { "jg", OP_JG, 1, 1, OPF_CJMP_CC }, // 7f ZF=0 && SF=OF
+ { "jnle", OP_JG, 1, 1, OPF_CJMP_CC }, // 7f
{ "seto", OP_JO, 1, 1, OPF_DATA|OPF_CC },
{ "setno", OP_JNO, 1, 1, OPF_DATA|OPF_CC },
{ "setc", OP_JC, 1, 1, OPF_DATA|OPF_CC },
break;
case OP_STOS:
+ case OP_SCAS:
if (op->operand_cnt != 0)
break;
- if (IS(words[op_w], "stosb"))
+ if (words[op_w][4] == 'b')
lmod = OPLM_BYTE;
- else if (IS(words[op_w], "stosw"))
+ else if (words[op_w][4] == 'w')
lmod = OPLM_WORD;
- else if (IS(words[op_w], "stosd"))
+ else if (words[op_w][4] == 'd')
lmod = OPLM_DWORD;
op->operand_cnt = 3;
setup_reg_opr(&op->operand[0], xDI, lmod, &op->regmask_src);
op->regmask_dst = op->regmask_src;
break;
+ case OP_JECXZ:
+ op->operand_cnt = 1;
+ op->regmask_src = 1 << xCX;
+ op->operand[0].type = OPT_REG;
+ op->operand[0].reg = xCX;
+ op->operand[0].lmod = OPLM_DWORD;
+ break;
+
case OP_IMUL:
if (op->operand_cnt != 1)
break;
}
static char *out_src_opr(char *buf, size_t buf_size,
- struct parsed_op *po, struct parsed_opr *popr, const char *cast,
+ struct parsed_op *po, struct parsed_opr *popr, const char *cast,
int is_lea)
{
char tmp1[256], tmp2[256];
// last op in stream - unconditional branch or ret
#define LAST_OP(_i) ((ops[_i].flags & OPF_TAIL) \
- || (ops[_i].flags & (OPF_JMP|OPF_CC)) == OPF_JMP)
+ || (ops[_i].flags & (OPF_JMP|OPF_CJMP)) == OPF_JMP)
static int scan_for_pop(int i, int opcnt, const char *reg,
int magic, int depth, int *maxdepth, int do_flags)
return -1;
}
- if (po->flags & OPF_CC) {
+ if (po->flags & OPF_CJMP) {
ret |= scan_for_pop(po->bt_i, opcnt, reg, magic,
depth, maxdepth, do_flags);
if (ret < 0)
return found ? 0 : -1;
}
+static void scan_propagate_df(int i, int opcnt)
+{
+ struct parsed_op *po = &ops[i];
+ int j;
+
+ for (; i < opcnt; i++) {
+ po = &ops[i];
+ if (po->flags & OPF_DF)
+ return; // already resolved
+ po->flags |= OPF_DF;
+
+ if (po->op == OP_CALL)
+ ferr(po, "call with DF set?\n");
+
+ if (po->flags & OPF_JMP) {
+ if (po->btj != NULL) {
+ // jumptable
+ for (j = 0; j < po->btj->count; j++)
+ scan_propagate_df(po->btj->d[j].bt_i, opcnt);
+ return;
+ }
+
+ if (po->bt_i < 0) {
+ ferr(po, "dead branch\n");
+ return;
+ }
+
+ if (po->flags & OPF_CJMP)
+ scan_propagate_df(po->bt_i, opcnt);
+ else
+ i = po->bt_i - 1;
+ continue;
+ }
+
+ if (po->flags & OPF_TAIL)
+ break;
+
+ if (po->op == OP_CLD) {
+ po->flags |= OPF_RMD;
+ return;
+ }
+ }
+
+ ferr(po, "missing DF clear?\n");
+}
+
// is operand 'opr' modified by parsed_op 'po'?
static int is_opr_modified(const struct parsed_opr *opr,
const struct parsed_op *po)
return 0;
}
- if ((ops[i].flags & OPF_JMP) && !(ops[i].flags & OPF_CC))
+ if ((ops[i].flags & (OPF_JMP|OPF_CJMP)) == OPF_JMP)
return -1;
}
return i;
}
else if (po->op == OP_PUSH) {
- if (first_pop == -1)
- first_pop = -2; // none
+ //if (first_pop == -1)
+ // first_pop = -2; // none
*adj -= lmod_bytes(po, po->operand[0].lmod);
}
- else if (po->op == OP_POP) {
- if (first_pop == -1)
+ else if (po->op == OP_POP && !(po->flags & OPF_RMD)) {
+ if (first_pop == -1 && *adj >= 0)
first_pop = i;
*adj += lmod_bytes(po, po->operand[0].lmod);
}
}
}
- if (*adj == 4 && first_pop >= 0 && ops[first_pop].op == OP_POP
+ if (*adj <= 8 && first_pop >= 0 && ops[first_pop].op == OP_POP
&& ops[first_pop].operand[0].type == OPT_REG
&& ops[first_pop].operand[0].reg == xCX)
{
}
scan_fwd_set_flags(po->bt_i, opcnt, magic, flags);
- if (!(po->flags & OPF_CC))
+ if (!(po->flags & OPF_CJMP))
return;
}
if (po->flags & OPF_TAIL)
if (lr->next != NULL)
need_op_saving = 1;
for (; lr->next; lr = lr->next) {
- if ((ops[lr->i].flags & (OPF_JMP|OPF_CC)) != OPF_JMP)
+ if ((ops[lr->i].flags & (OPF_JMP|OPF_CJMP)) != OPF_JMP)
may_reuse = 1;
ret = collect_call_args_r(po, lr->i, pp, regmask, save_arg_vars,
arg, magic, need_op_saving, may_reuse);
return ret;
}
- if ((ops[lr->i].flags & (OPF_JMP|OPF_CC)) != OPF_JMP)
+ if ((ops[lr->i].flags & (OPF_JMP|OPF_CJMP)) != OPF_JMP)
may_reuse = 1;
if (j > 0 && LAST_OP(j - 1)) {
// follow last branch in reverse
ferr(po, "arg collect %d/%d hit pop\n", arg, pp->argc);
}
- else if ((ops[j].flags & (OPF_JMP|OPF_CC)) == (OPF_JMP|OPF_CC))
+ else if (ops[j].flags & OPF_CJMP)
{
if (pp->is_unresolved)
break;
if (i == opcnt && (ops[i - 1].flags & OPF_JMP) && found)
break;
- if (ops[i - 1].op == OP_POP && IS(opr_name(&ops[i - 1], 0), "ebp"))
+ if ((ops[i - 1].op == OP_POP && IS(opr_name(&ops[i - 1], 0), "ebp"))
+ || ops[i - 1].op == OP_LEAVE)
+ {
ops[i - 1].flags |= OPF_RMD;
+ }
else if (!(g_ida_func_attr & IDAFA_NORETURN))
ferr(&ops[i - 1], "'pop ebp' expected\n");
{
ops[i - 2].flags |= OPF_RMD;
}
- else if (!(g_ida_func_attr & IDAFA_NORETURN))
+ else if (ops[i - 1].op != OP_LEAVE
+ && !(g_ida_func_attr & IDAFA_NORETURN))
+ {
ferr(&ops[i - 2], "esp restore expected\n");
+ }
if (ecx_push && ops[i - 3].op == OP_POP
&& IS(opr_name(&ops[i - 3], 0), "ecx"))
tmpname, pp->argc_stack * 4, j);
ops[ret].flags |= OPF_RMD;
- // a bit of a hack, but deals with use of
- // single adj for multiple calls
- ops[ret].operand[1].val -= j;
+ if (ops[ret].op == OP_POP && j > 4) {
+ // deal with multi-pop stack adjust
+ j = pp->argc_stack;
+ while (ops[ret].op == OP_POP && j > 0 && ret < opcnt) {
+ ops[ret].flags |= OPF_RMD;
+ j--;
+ ret++;
+ }
+ }
+ else {
+ // a bit of a hack, but deals with use of
+ // single adj for multiple calls
+ ops[ret].operand[1].val -= j;
+ }
}
else if (pp->is_vararg)
ferr(po, "missing esp_adjust for vararg func '%s'\n",
// pass4:
// - find POPs for PUSHes, rm both
+ // - scan for STD/CLD, propagate DF
// - scan for all used registers
// - find flag set ops for their users
// - do unreselved calls
regmask_save |= 1 << reg;
}
- if (po->op == OP_PUSH
- && po->argnum == 0 && !(po->flags & OPF_RSAVE)
- && po->operand[0].type == OPT_REG)
+ if (po->op == OP_PUSH && po->argnum == 0
+ && !(po->flags & OPF_RSAVE))
{
- reg = po->operand[0].reg;
- if (reg < 0)
- ferr(po, "reg not set for push?\n");
-
- depth = 0;
- ret = scan_for_pop(i + 1, opcnt,
- po->operand[0].name, i + opcnt * 3, 0, &depth, 0);
- if (ret == 1) {
- if (depth > 1)
- ferr(po, "too much depth: %d\n", depth);
-
- po->flags |= OPF_RMD;
- scan_for_pop(i + 1, opcnt, po->operand[0].name,
- i + opcnt * 4, 0, &depth, 1);
- continue;
+ if (po->operand[0].type == OPT_REG)
+ {
+ reg = po->operand[0].reg;
+ if (reg < 0)
+ ferr(po, "reg not set for push?\n");
+
+ depth = 0;
+ ret = scan_for_pop(i + 1, opcnt,
+ po->operand[0].name, i + opcnt * 3, 0, &depth, 0);
+ if (ret == 1) {
+ if (depth > 1)
+ ferr(po, "too much depth: %d\n", depth);
+
+ po->flags |= OPF_RMD;
+ scan_for_pop(i + 1, opcnt, po->operand[0].name,
+ i + opcnt * 4, 0, &depth, 1);
+ continue;
+ }
+ ret = scan_for_pop_ret(i + 1, opcnt, po->operand[0].name, 0);
+ if (ret == 0) {
+ arg = OPF_RMD;
+ if (regmask & (1 << reg)) {
+ if (regmask_save & (1 << reg))
+ ferr(po, "%s already saved?\n", po->operand[0].name);
+ arg = OPF_RSAVE;
+ }
+ po->flags |= arg;
+ scan_for_pop_ret(i + 1, opcnt, po->operand[0].name, arg);
+ continue;
+ }
}
- ret = scan_for_pop_ret(i + 1, opcnt, po->operand[0].name, 0);
- if (ret == 0) {
- arg = OPF_RMD;
- if (regmask & (1 << reg)) {
- if (regmask_save & (1 << reg))
- ferr(po, "%s already saved?\n", po->operand[0].name);
- arg = OPF_RSAVE;
+ else if (po->operand[0].type == OPT_CONST) {
+ for (j = i + 1; j < opcnt; j++) {
+ if ((ops[j].flags & (OPF_JMP|OPF_TAIL|OPF_RSAVE))
+ || ops[j].op == OP_PUSH || g_labels[i][0] != 0)
+ {
+ break;
+ }
+
+ if (!(ops[j].flags & OPF_RMD) && ops[j].op == OP_POP)
+ {
+ po->flags |= OPF_RMD;
+ ops[j].datap = po;
+ break;
+ }
}
- po->flags |= arg;
- scan_for_pop_ret(i + 1, opcnt, po->operand[0].name, arg);
- continue;
}
}
+ if (po->op == OP_STD) {
+ po->flags |= OPF_DF | OPF_RMD;
+ scan_propagate_df(i + 1, opcnt);
+ }
+
regmask_now = po->regmask_src | po->regmask_dst;
if (regmask_now & (1 << xBP)) {
if (g_bp_frame && !(po->flags & OPF_EBP_S)) {
// to get nicer code, we try to delay test and cmp;
// if we can't because of operand modification, or if we
- // have math op, or branch, make it calculate flags explicitly
- if (tmp_op->op == OP_TEST || tmp_op->op == OP_CMP) {
+ // have arith op, or branch, make it calculate flags explicitly
+ if (tmp_op->op == OP_TEST || tmp_op->op == OP_CMP)
+ {
if (branched || scan_for_mod(tmp_op, setters[j] + 1, i, 0) >= 0)
pfomask = 1 << pfo;
}
+ else if (tmp_op->op == OP_SCAS) {
+ pfomask = 1 << pfo;
+ }
else if (tmp_op->op == OP_CMPS) {
pfomask = 1 << PFO_Z;
}
if (po->op == OP_ADC || po->op == OP_SBB)
cmp_result_vars |= 1 << PFO_C;
}
+ else if (po->op == OP_CMPS || po->op == OP_SCAS) {
+ cmp_result_vars |= 1 << PFO_Z;
+ }
else if (po->op == OP_MUL
|| (po->op == OP_IMUL && po->operand_cnt == 1))
{
break;
case OP_STOS:
- // assumes DF=0
assert_operand_cnt(3);
if (po->flags & OPF_REP) {
- fprintf(fout, " for (; ecx != 0; ecx--, edi += %d)\n",
+ fprintf(fout, " for (; ecx != 0; ecx--, edi %c= %d)\n",
+ (po->flags & OPF_DF) ? '-' : '+',
lmod_bytes(po, po->operand[0].lmod));
fprintf(fout, " %sedi = eax;",
lmod_cast_u_ptr(po, po->operand[0].lmod));
strcpy(g_comment, "rep stos");
}
else {
- fprintf(fout, " %sedi = eax; edi += %d;",
+ fprintf(fout, " %sedi = eax; edi %c= %d;",
lmod_cast_u_ptr(po, po->operand[0].lmod),
+ (po->flags & OPF_DF) ? '-' : '+',
lmod_bytes(po, po->operand[0].lmod));
strcpy(g_comment, "stos");
}
break;
case OP_MOVS:
- // assumes DF=0
assert_operand_cnt(3);
j = lmod_bytes(po, po->operand[0].lmod);
strcpy(buf1, lmod_cast_u_ptr(po, po->operand[0].lmod));
+ l = (po->flags & OPF_DF) ? '-' : '+';
if (po->flags & OPF_REP) {
fprintf(fout,
- " for (; ecx != 0; ecx--, edi += %d, esi += %d)\n",
- j, j);
+ " for (; ecx != 0; ecx--, edi %c= %d, esi %c= %d)\n",
+ l, j, l, j);
fprintf(fout,
" %sedi = %sesi;", buf1, buf1);
strcpy(g_comment, "rep movs");
}
else {
- fprintf(fout, " %sedi = %sesi; edi += %d; esi += %d;",
- buf1, buf1, j, j);
+ fprintf(fout, " %sedi = %sesi; edi %c= %d; esi %c= %d;",
+ buf1, buf1, l, j, l, j);
strcpy(g_comment, "movs");
}
break;
case OP_CMPS:
- // assumes DF=0
// repe ~ repeat while ZF=1
assert_operand_cnt(3);
j = lmod_bytes(po, po->operand[0].lmod);
strcpy(buf1, lmod_cast_u_ptr(po, po->operand[0].lmod));
+ l = (po->flags & OPF_DF) ? '-' : '+';
if (po->flags & OPF_REP) {
fprintf(fout,
- " for (; ecx != 0; ecx--, edi += %d, esi += %d)\n",
- j, j);
+ " for (; ecx != 0; ecx--, edi %c= %d, esi %c= %d)\n",
+ l, j, l, j);
fprintf(fout,
" if ((cond_z = (%sedi == %sesi)) %s 0)\n",
buf1, buf1, (po->flags & OPF_REPZ) ? "==" : "!=");
}
else {
fprintf(fout,
- " cond_z = (%sedi = %sesi); edi += %d; esi += %d;",
- buf1, buf1, j, j);
+ " cond_z = (%sedi = %sesi); edi %c= %d; esi %c= %d;",
+ buf1, buf1, l, j, l, j);
strcpy(g_comment, "cmps");
}
pfomask &= ~(1 << PFO_Z);
delayed_flag_op = NULL;
break;
+ case OP_SCAS:
+ // only does ZF (for now)
+ // repe ~ repeat while ZF=1
+ assert_operand_cnt(3);
+ j = lmod_bytes(po, po->operand[0].lmod);
+ l = (po->flags & OPF_DF) ? '-' : '+';
+ if (po->flags & OPF_REP) {
+ fprintf(fout,
+ " for (; ecx != 0; ecx--, edi %c= %d)\n", l, j);
+ fprintf(fout,
+ " if ((cond_z = (%seax == %sedi)) %s 0)\n",
+ lmod_cast_u(po, po->operand[0].lmod),
+ lmod_cast_u_ptr(po, po->operand[0].lmod),
+ (po->flags & OPF_REPZ) ? "==" : "!=");
+ fprintf(fout,
+ " break;");
+ snprintf(g_comment, sizeof(g_comment), "rep%s scas",
+ (po->flags & OPF_REPZ) ? "e" : "ne");
+ }
+ else {
+ fprintf(fout, " cond_z = (%seax = %sedi); edi %c= %d;",
+ lmod_cast_u(po, po->operand[0].lmod),
+ lmod_cast_u_ptr(po, po->operand[0].lmod), l, j);
+ strcpy(g_comment, "scas");
+ }
+ pfomask &= ~(1 << PFO_Z);
+ last_arith_dst = NULL;
+ delayed_flag_op = NULL;
+ break;
+
// arithmetic w/flags
case OP_ADD:
case OP_SUB:
// else SETcc - should already be handled
break;
+ case OP_JECXZ:
+ fprintf(fout, " if (ecx == 0)\n");
+ fprintf(fout, " goto %s;", po->operand[0].name);
+ strcat(g_comment, "jecxz");
+ break;
+
case OP_JMP:
assert_operand_cnt(1);
last_arith_dst = NULL;
fprintf(fout, " %s = s_%s;", buf1, buf1);
break;
}
+ else if (po->datap != NULL) {
+ // push/pop pair
+ tmp_op = po->datap;
+ out_dst_opr(buf1, sizeof(buf1), po, &po->operand[0]);
+ fprintf(fout, " %s = %s;", buf1,
+ out_src_opr(buf2, sizeof(buf2),
+ tmp_op, &tmp_op->operand[0],
+ po->operand[0].is_ptr ? "(void *)" : "", 0));
+ break;
+ }
ferr(po, "stray pop encountered\n");
break;
fprintf(fout, "\n");
// some sanity checking
- if ((po->flags & OPF_REP) && po->op != OP_STOS
- && po->op != OP_MOVS && po->op != OP_CMPS)
- ferr(po, "unexpected rep\n");
- if ((po->flags & (OPF_REPZ|OPF_REPNZ)) && po->op != OP_CMPS)
+ if (po->flags & OPF_REP) {
+ if (po->op != OP_STOS && po->op != OP_MOVS
+ && po->op != OP_CMPS && po->op != OP_SCAS)
+ ferr(po, "unexpected rep\n");
+ if (!(po->flags & (OPF_REPZ|OPF_REPNZ))
+ && (po->op == OP_CMPS || po->op == OP_SCAS))
+ ferr(po, "cmps/scas with plain rep\n");
+ }
+ if ((po->flags & (OPF_REPZ|OPF_REPNZ))
+ && po->op != OP_CMPS && po->op != OP_SCAS)
ferr(po, "unexpected repz/repnz\n");
if (pfomask != 0)