From 71e1fc6b376e1fde2c3b0dbcf94c4261eed9c6c5 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sun, 2 Dec 2018 19:43:34 +0100 Subject: [PATCH] bc: only check for ^C in bc_program_exec() main loop Checking it in individual operations such as SQRT is not necessary since they usually do not take very long to complete. We repeatedly return to main loop. TODO: re-add more fine-grained ^C checks - but only with examples where it is actually needed. E.g. I suspect simplest ops like addition or compare won't need it. function old new delta bc_program_index 66 64 -2 bc_num_s 258 246 -12 bc_num_cmp 294 275 -19 bc_num_compare 84 59 -25 bc_num_subArrays 74 47 -27 bc_num_a 474 445 -29 bc_program_exec 4530 4500 -30 bc_num_p 518 472 -46 bc_num_d 604 558 -46 bc_num_k 1005 957 -48 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 0/10 up/down: 0/-284) Total: -284 bytes text data bss dec hex filename 988601 485 7296 996382 f341e busybox_old 988317 485 7296 996098 f3302 busybox_unstripped Signed-off-by: Denys Vlasenko --- miscutils/bc.c | 70 +++++++++++++++----------------------------------- 1 file changed, 21 insertions(+), 49 deletions(-) diff --git a/miscutils/bc.c b/miscutils/bc.c index 7e72ab28f..63b745dc7 100644 --- a/miscutils/bc.c +++ b/miscutils/bc.c @@ -1338,12 +1338,12 @@ static BcStatus bc_read_line(BcVec *vec, const char *prompt) #if ENABLE_FEATURE_BC_SIGNALS if (bb_got_signal) { /* ^C was pressed */ intr: + bb_got_signal = 0; /* resets G_interrupt to zero */ fputs(IS_BC ? "\ninterrupt (type \"quit\" to exit)\n" : "\ninterrupt (type \"q\" to exit)\n" , stderr); } - bb_got_signal = 0; /* resets G_interrupt to zero */ #endif if (G.ttyin && !G_posix) fputs(prompt, stderr); @@ -1458,25 +1458,23 @@ static void bc_num_ten(BcNum *n) n->num[1] = 1; } -static BcStatus bc_num_subArrays(BcDig *restrict a, BcDig *restrict b, +static void bc_num_subArrays(BcDig *restrict a, BcDig *restrict b, size_t len) { size_t i, j; - for (i = 0; !G_interrupt && i < len; ++i) { - for (a[i] -= b[i], j = 0; !G_interrupt && a[i + j] < 0;) { + for (i = 0; i < len; ++i) { + for (a[i] -= b[i], j = 0; a[i + j] < 0;) { a[i + j++] += 10; a[i + j] -= 1; } } -///move ^C detection to bc_num_binary() (can make bc_num_s() return void) - return G_interrupt ? BC_STATUS_EXEC_SIGNAL : BC_STATUS_SUCCESS; } static ssize_t bc_num_compare(BcDig *restrict a, BcDig *restrict b, size_t len) { size_t i; int c = 0; - for (i = len - 1; !G_interrupt && i < len && !(c = a[i] - b[i]); --i); + for (i = len - 1; i < len && !(c = a[i] - b[i]); --i); return BC_NUM_NEG(i + 1, c < 0); } @@ -1522,7 +1520,7 @@ static ssize_t bc_num_cmp(BcNum *a, BcNum *b) cmp = bc_num_compare(max_num, min_num, b_int + min); if (cmp != 0) return BC_NUM_NEG(cmp, (!a_max) != neg); - for (max_num -= diff, i = diff - 1; !G_interrupt && i < diff; --i) { + for (max_num -= diff, i = diff - 1; i < diff; --i) { if (max_num[i]) return BC_NUM_NEG(1, (!a_max) != neg); } @@ -1681,13 +1679,13 @@ static BcStatus bc_num_a(BcNum *a, BcNum *b, BcNum *restrict c, size_t sub) ptr = ptr_b; } - for (carry = 0, i = 0; !G_interrupt && i < min_rdx + min_int; ++i, ++c->len) { + for (carry = 0, i = 0; i < min_rdx + min_int; ++i, ++c->len) { in = ((int) ptr_a[i]) + ((int) ptr_b[i]) + carry; carry = in / 10; ptr_c[i] = (BcDig)(in % 10); } - for (; !G_interrupt && i < max + min_rdx; ++i, ++c->len) { + for (; i < max + min_rdx; ++i, ++c->len) { in = ((int) ptr[i]) + carry; carry = in / 10; ptr_c[i] = (BcDig)(in % 10); @@ -1695,13 +1693,11 @@ static BcStatus bc_num_a(BcNum *a, BcNum *b, BcNum *restrict c, size_t sub) if (carry != 0) c->num[c->len++] = (BcDig) carry; -///move ^C detection to bc_num_binary() - return G_interrupt ? BC_STATUS_EXEC_SIGNAL : BC_STATUS_SUCCESS; + return BC_STATUS_SUCCESS; // can't make void, see bc_num_binary() } static BcStatus bc_num_s(BcNum *a, BcNum *b, BcNum *restrict c, size_t sub) { - BcStatus s; ssize_t cmp; BcNum *minuend, *subtrahend; size_t start; @@ -1755,11 +1751,11 @@ static BcStatus bc_num_s(BcNum *a, BcNum *b, BcNum *restrict c, size_t sub) else start = c->rdx - subtrahend->rdx; - s = bc_num_subArrays(c->num + start, subtrahend->num, subtrahend->len); + bc_num_subArrays(c->num + start, subtrahend->num, subtrahend->len); bc_num_clean(c); - return s; + return BC_STATUS_SUCCESS; // can't make void, see bc_num_binary() } static BcStatus bc_num_k(BcNum *restrict a, BcNum *restrict b, @@ -1771,8 +1767,6 @@ static BcStatus bc_num_k(BcNum *restrict a, BcNum *restrict b, BcNum l1, h1, l2, h2, m2, m1, z0, z1, z2, temp; bool aone = BC_NUM_ONE(a); -///move ^C detection to bc_num_binary() - if (G_interrupt) return BC_STATUS_EXEC_SIGNAL; if (a->len == 0 || b->len == 0) { bc_num_zero(c); return BC_STATUS_SUCCESS; @@ -1790,9 +1784,9 @@ static BcStatus bc_num_k(BcNum *restrict a, BcNum *restrict b, memset(c->num, 0, sizeof(BcDig) * c->cap); c->len = carry = len = 0; - for (i = 0; !G_interrupt && i < b->len; ++i) { + for (i = 0; i < b->len; ++i) { - for (j = 0; !G_interrupt && j < a->len; ++j) { + for (j = 0; j < a->len; ++j) { int in = (int) c->num[i + j]; in += ((int) a->num[j]) * ((int) b->num[i]) + carry; carry = in / 10; @@ -1806,8 +1800,7 @@ static BcStatus bc_num_k(BcNum *restrict a, BcNum *restrict b, c->len = len; -///move ^C detection to bc_num_binary() - return G_interrupt ? BC_STATUS_EXEC_SIGNAL : BC_STATUS_SUCCESS; + return BC_STATUS_SUCCESS; } bc_num_init(&l1, max); @@ -1957,17 +1950,17 @@ static BcStatus bc_num_d(BcNum *a, BcNum *b, BcNum *restrict c, size_t scale) c->len = cp.len; p = b->num; - for (i = end - 1; !G_interrupt && !s && i < end; --i) { + for (i = end - 1; !s && i < end; --i) { n = cp.num + i; for (q = 0; (!s && n[len] != 0) || bc_num_compare(n, p, len) >= 0; ++q) - s = bc_num_subArrays(n, p, len); + bc_num_subArrays(n, p, len); c->num[i] = q; } - if (!s) bc_num_retireMul(c, scale, a->neg, b->neg); + bc_num_retireMul(c, scale, a->neg, b->neg); bc_num_free(&cp); - return s; + return BC_STATUS_SUCCESS; // can't make void, see bc_num_binary() } static BcStatus bc_num_r(BcNum *a, BcNum *b, BcNum *restrict c, @@ -2057,21 +2050,15 @@ static BcStatus bc_num_p(BcNum *a, BcNum *b, BcNum *restrict c, size_t scale) b->neg = neg; - for (powrdx = a->rdx; !G_interrupt && !(pow & 1); pow >>= 1) { + for (powrdx = a->rdx; !(pow & 1); pow >>= 1) { powrdx <<= 1; s = bc_num_mul(©, ©, ©, powrdx); if (s) goto err; } - if (G_interrupt) { -///move ^C detection to bc_num_binary() - s = BC_STATUS_EXEC_SIGNAL; - goto err; - } - bc_num_copy(c, ©); - for (resrdx = powrdx, pow >>= 1; !G_interrupt && pow != 0; pow >>= 1) { + for (resrdx = powrdx, pow >>= 1; pow != 0; pow >>= 1) { powrdx <<= 1; s = bc_num_mul(©, ©, ©, powrdx); @@ -2089,12 +2076,6 @@ static BcStatus bc_num_p(BcNum *a, BcNum *b, BcNum *restrict c, size_t scale) if (s) goto err; } - if (G_interrupt) { -///move ^C detection to bc_num_binary() - s = BC_STATUS_EXEC_SIGNAL; - goto err; - } - if (c->rdx > scale) bc_num_truncate(c, c->rdx - scale); // We can't use bc_num_clean() here. @@ -2140,8 +2121,6 @@ static BcStatus bc_num_binary(BcNum *a, BcNum *b, BcNum *c, size_t scale, if (init) bc_num_free(&num2); -///move ^C detection here: -// if (s == 0 && G_interrupt) s = BC_STATUS_EXEC_SIGNAL; return s; } @@ -2644,8 +2623,7 @@ static BcStatus bc_num_sqrt(BcNum *a, BcNum *restrict b, size_t scale) resrdx = scale + 2; len = BC_NUM_INT(x0) + resrdx - 1; -///move ^C detection to callers - while (!G_interrupt && (cmp != 0 || digs < len)) { + while (cmp != 0 || digs < len) { s = bc_num_div(a, x0, &f, resrdx); if (s) goto err; @@ -2673,12 +2651,6 @@ static BcStatus bc_num_sqrt(BcNum *a, BcNum *restrict b, size_t scale) x1 = temp; } - if (G_interrupt) { -///move ^C detection to callers - s = BC_STATUS_EXEC_SIGNAL; - goto err; - } - bc_num_copy(b, x0); scale -= 1; if (b->rdx > scale) bc_num_truncate(b, b->rdx - scale); -- 2.25.1