diff options
| -rw-r--r-- | tccgen.c | 74 |
1 files changed, 51 insertions, 23 deletions
@@ -4888,6 +4888,52 @@ static int case_cmp(const void *pa, const void *pb) return a < b ? -1 : a > b; } +static void gcase(struct case_t **base, int len, int case_reg, int *bsym) +{ + struct case_t *p; + int e; + if (len <= 4) { + while (len--) { + p = *base++; + vseti(case_reg, 0); + vpushi(p->v2); + if (p->v1 == p->v2) { + gen_op(TOK_EQ); + gtst_addr(0, p->sym); + } else { + gen_op(TOK_LE); + e = gtst(1, 0); + vseti(case_reg, 0); + vpushi(p->v1); + gen_op(TOK_GE); + gtst_addr(0, p->sym); + gsym(e); + } + } + } else { + p = base[len/2]; + /* mid */ + vseti(case_reg, 0); + vpushi(p->v2); + gen_op(TOK_LE); + e = gtst(1, 0); + vseti(case_reg, 0); + vpushi(p->v1); + gen_op(TOK_GE); + gtst_addr(0, p->sym); + /* left */ + gcase(base, len/2, case_reg, bsym); + if (cur_switch->def_sym) + gjmp_addr(cur_switch->def_sym); + else + *bsym = gjmp(*bsym); + /* right */ + gsym(e); + e = len/2 + 1; + gcase(base + e, len - e, case_reg, bsym); + } +} + static void block(int *bsym, int *csym, int is_expr) { int a, b, c, d; @@ -5166,35 +5212,17 @@ static void block(int *bsym, int *csym, int is_expr) sw.p = NULL; sw.n = 0; sw.def_sym = 0; saved = cur_switch; cur_switch = &sw; block(&a, csym, 0); - cur_switch = saved; a = gjmp(a); /* add implicit break */ + /* case lookup */ gsym(b); - qsort(sw.p, sw.n, sizeof(void*), case_cmp); - for (b = 0; b < sw.n; b++) { - int v = sw.p[b]->v1; - if (b && v <= d) + for (b = 1; b < sw.n; b++) + if (sw.p[b - 1]->v2 >= sw.p[b]->v1) tcc_error("duplicate case value"); - d = sw.p[b]->v2; - - vseti(c, 0); - vpushi(v); - if (v == d) { - gen_op(TOK_EQ); - gtst_addr(0, sw.p[b]->sym); - } else { - int e; - gen_op(TOK_GE); - e = gtst(1, 0); - vseti(c, 0); - vpushi(d); - gen_op(TOK_LE); - gtst_addr(0, sw.p[b]->sym); - gsym(e); - } - } + gcase(sw.p, sw.n, c, &a); if (sw.def_sym) gjmp_addr(sw.def_sym); + cur_switch = saved; /* break label */ gsym(a); } else |