From 4a024c771992e274f46a8451647dc86f92a90999 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sun, 9 Dec 2018 13:21:54 +0100 Subject: [PATCH] bc: simplify string-tonumber conversion code function old new delta bc_program_num 1108 983 -125 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-125) Total: -125 bytes text data bss dec hex filename 985831 477 7296 993604 f2944 busybox_old 985706 477 7296 993479 f28c7 busybox_unstripped Signed-off-by: Denys Vlasenko --- miscutils/bc.c | 88 ++++++++++++++++++++++++-------------------------- 1 file changed, 43 insertions(+), 45 deletions(-) diff --git a/miscutils/bc.c b/miscutils/bc.c index 71b419d8f..c36486414 100644 --- a/miscutils/bc.c +++ b/miscutils/bc.c @@ -2199,49 +2199,45 @@ static BcStatus bc_num_binary(BcNum *a, BcNum *b, BcNum *c, size_t scale, static bool bc_num_strValid(const char *val, size_t base) { BcDig b; - bool small, radix = false; - size_t i, len = strlen(val); - - if (!len) return true; - - small = base <= 10; - b = (BcDig)(small ? base + '0' : base - 10 + 'A'); - - for (i = 0; i < len; ++i) { - - BcDig c = val[i]; + bool radix; + b = (BcDig)(base <= 10 ? base + '0' : base - 10 + 'A'); + radix = false; + for (;;) { + BcDig c = *val++; + if (c == '\0') + break; if (c == '.') { - if (radix) return false; - radix = true; continue; } - - if (c < '0' || (small && c >= b) || (c > '9' && (c < 'A' || c >= b))) + if (c < '0' || c >= b || (c > '9' && c < 'A')) return false; } - return true; } +// Note: n is already "bc_num_zero()"ed, +// leading zeroes in "val" are removed static void bc_num_parseDecimal(BcNum *n, const char *val) { size_t len, i; const char *ptr; - bool zero = true; + bool zero; - for (i = 0; val[i] == '0'; ++i); - - val += i; len = strlen(val); - bc_num_zero(n); + if (len == 0) + return; - if (len != 0) { - for (i = 0; zero && i < len; ++i) zero = val[i] == '0' || val[i] == '.'; - bc_num_expand(n, len); + zero = true; + for (i = 0; val[i]; ++i) { + if (val[i] != '0' && val[i] != '.') { + zero = false; + break; + } } + bc_num_expand(n, len); ptr = strchr(val, '.'); @@ -2255,26 +2251,29 @@ static void bc_num_parseDecimal(BcNum *n, const char *val) } } +// Note: n is already "bc_num_zero()"ed, +// leading zeroes in "val" are removed static void bc_num_parseBase(BcNum *n, const char *val, BcNum *base) { BcStatus s; BcNum temp, mult, result; BcDig c = '\0'; - bool zero = true; unsigned long v; - size_t i, digits, len = strlen(val); + size_t i, digits; - bc_num_zero(n); - - for (i = 0; zero && i < len; ++i) zero = (val[i] == '.' || val[i] == '0'); - if (zero) return; + for (i = 0; ; ++i) { + if (val[i] == '\0') + return; + if (val[i] != '.' && val[i] != '0') + break; + } bc_num_init_DEF_SIZE(&temp); bc_num_init_DEF_SIZE(&mult); - for (i = 0; i < len; ++i) { - - c = val[i]; + for (;;) { + c = *val++; + if (c == '\0') goto int_err; if (c == '.') break; v = (unsigned long) (c <= '9' ? c - '0' : c - 'A' + 10); @@ -2286,19 +2285,15 @@ static void bc_num_parseBase(BcNum *n, const char *val, BcNum *base) if (s) goto int_err; } - if (i == len) { - c = val[i]; - if (c == 0) goto int_err; - } - bc_num_init(&result, base->len); //bc_num_zero(&result); - already is bc_num_one(&mult); - for (i += 1, digits = 0; i < len; ++i, ++digits) { - - c = val[i]; - if (c == 0) break; + digits = 0; + for (;;) { + c = *val++; + if (c == '\0') break; + digits++; v = (unsigned long) (c <= '9' ? c - '0' : c - 'A' + 10); @@ -2318,8 +2313,7 @@ static void bc_num_parseBase(BcNum *n, const char *val, BcNum *base) if (n->len != 0) { if (n->rdx < digits) bc_num_extend(n, digits - n->rdx); - } - else + } else bc_num_zero(n); err: @@ -2498,6 +2492,9 @@ static BcStatus bc_num_parse(BcNum *n, const char *val, BcNum *base, if (!bc_num_strValid(val, base_t)) return bc_error("bad number string"); + bc_num_zero(n); + while (*val == '0') val++; + if (base_t == 10) bc_num_parseDecimal(n, val); else @@ -6387,7 +6384,7 @@ static BcStatus bc_program_asciify(void) { BcStatus s; BcResult *r, res; - BcNum *num = NULL, n; + BcNum *num, n; char *str, *str2, c; size_t len = G.prog.strs.len, idx; unsigned long val; @@ -6396,6 +6393,7 @@ static BcStatus bc_program_asciify(void) return bc_error_stack_has_too_few_elements(); r = bc_vec_top(&G.prog.results); + num = NULL; // TODO: is this NULL needed? s = bc_program_num(r, &num, false); if (s) return s; -- 2.25.1