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bc: only check for ^C in bc_program_exec() main loop

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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 <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2018-12-02 19:43:34 +01:00
parent df51539ed0
commit 71e1fc6b37
1 changed files with 21 additions and 49 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

70
miscutils/bc.c
View File

@ -1338,12 +1338,12 @@ static BcStatus bc_read_line(BcVec *vec, const char *prompt)
#if ENABLE_FEATURE_BC_SIGNALS #if ENABLE_FEATURE_BC_SIGNALS
if (bb_got_signal) { /* ^C was pressed */ if (bb_got_signal) { /* ^C was pressed */
intr: intr:
bb_got_signal = 0; /* resets G_interrupt to zero */
fputs(IS_BC fputs(IS_BC
? "\ninterrupt (type \"quit\" to exit)\n" ? "\ninterrupt (type \"quit\" to exit)\n"
: "\ninterrupt (type \"q\" to exit)\n" : "\ninterrupt (type \"q\" to exit)\n"
, stderr); , stderr);
} }
bb_got_signal = 0; /* resets G_interrupt to zero */
#endif #endif
if (G.ttyin && !G_posix) if (G.ttyin && !G_posix)
fputs(prompt, stderr); fputs(prompt, stderr);
@ -1458,25 +1458,23 @@ static void bc_num_ten(BcNum *n)
n->num[1] = 1; 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 len)
{ {
size_t i, j; size_t i, j;
for (i = 0; !G_interrupt && i < len; ++i) { for (i = 0; i < len; ++i) {
for (a[i] -= b[i], j = 0; !G_interrupt && a[i + j] < 0;) { for (a[i] -= b[i], j = 0; a[i + j] < 0;) {
a[i + j++] += 10; a[i + j++] += 10;
a[i + j] -= 1; 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) static ssize_t bc_num_compare(BcDig *restrict a, BcDig *restrict b, size_t len)
{ {
size_t i; size_t i;
int c = 0; 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); 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); cmp = bc_num_compare(max_num, min_num, b_int + min);
if (cmp != 0) return BC_NUM_NEG(cmp, (!a_max) != neg); 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); 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; 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; in = ((int) ptr_a[i]) + ((int) ptr_b[i]) + carry;
carry = in / 10; carry = in / 10;
ptr_c[i] = (BcDig)(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; in = ((int) ptr[i]) + carry;
carry = in / 10; carry = in / 10;
ptr_c[i] = (BcDig)(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; if (carry != 0) c->num[c->len++] = (BcDig) carry;
///move ^C detection to bc_num_binary() return BC_STATUS_SUCCESS; // can't make void, see bc_num_binary()
return G_interrupt ? BC_STATUS_EXEC_SIGNAL : BC_STATUS_SUCCESS;
} }
static BcStatus bc_num_s(BcNum *a, BcNum *b, BcNum *restrict c, size_t sub) static BcStatus bc_num_s(BcNum *a, BcNum *b, BcNum *restrict c, size_t sub)
{ {
BcStatus s;
ssize_t cmp; ssize_t cmp;
BcNum *minuend, *subtrahend; BcNum *minuend, *subtrahend;
size_t start; size_t start;
@ -1755,11 +1751,11 @@ static BcStatus bc_num_s(BcNum *a, BcNum *b, BcNum *restrict c, size_t sub)
else else
start = c->rdx - subtrahend->rdx; 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); 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, 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; BcNum l1, h1, l2, h2, m2, m1, z0, z1, z2, temp;
bool aone = BC_NUM_ONE(a); 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) { if (a->len == 0 || b->len == 0) {
bc_num_zero(c); bc_num_zero(c);
return BC_STATUS_SUCCESS; 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); memset(c->num, 0, sizeof(BcDig) * c->cap);
c->len = carry = len = 0; 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]; int in = (int) c->num[i + j];
in += ((int) a->num[j]) * ((int) b->num[i]) + carry; in += ((int) a->num[j]) * ((int) b->num[i]) + carry;
carry = in / 10; carry = in / 10;
@ -1806,8 +1800,7 @@ static BcStatus bc_num_k(BcNum *restrict a, BcNum *restrict b,
c->len = len; c->len = len;
///move ^C detection to bc_num_binary() return BC_STATUS_SUCCESS;
return G_interrupt ? BC_STATUS_EXEC_SIGNAL : BC_STATUS_SUCCESS;
} }
bc_num_init(&l1, max); 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; c->len = cp.len;
p = b->num; 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; n = cp.num + i;
for (q = 0; (!s && n[len] != 0) || bc_num_compare(n, p, len) >= 0; ++q) 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; 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); 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, 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; b->neg = neg;
for (powrdx = a->rdx; !G_interrupt && !(pow & 1); pow >>= 1) { for (powrdx = a->rdx; !(pow & 1); pow >>= 1) {
powrdx <<= 1; powrdx <<= 1;
s = bc_num_mul(&copy, &copy, &copy, powrdx); s = bc_num_mul(&copy, &copy, &copy, powrdx);
if (s) goto err; 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, &copy); bc_num_copy(c, &copy);
for (resrdx = powrdx, pow >>= 1; !G_interrupt && pow != 0; pow >>= 1) { for (resrdx = powrdx, pow >>= 1; pow != 0; pow >>= 1) {
powrdx <<= 1; powrdx <<= 1;
s = bc_num_mul(&copy, &copy, &copy, powrdx); s = bc_num_mul(&copy, &copy, &copy, 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 (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); if (c->rdx > scale) bc_num_truncate(c, c->rdx - scale);
// We can't use bc_num_clean() here. // 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); if (init) bc_num_free(&num2);
///move ^C detection here:
// if (s == 0 && G_interrupt) s = BC_STATUS_EXEC_SIGNAL;
return s; return s;
} }
@ -2644,8 +2623,7 @@ static BcStatus bc_num_sqrt(BcNum *a, BcNum *restrict b, size_t scale)
resrdx = scale + 2; resrdx = scale + 2;
len = BC_NUM_INT(x0) + resrdx - 1; len = BC_NUM_INT(x0) + resrdx - 1;
///move ^C detection to callers while (cmp != 0 || digs < len) {
while (!G_interrupt && (cmp != 0 || digs < len)) {
s = bc_num_div(a, x0, &f, resrdx); s = bc_num_div(a, x0, &f, resrdx);
if (s) goto err; if (s) goto err;
@ -2673,12 +2651,6 @@ static BcStatus bc_num_sqrt(BcNum *a, BcNum *restrict b, size_t scale)
x1 = temp; x1 = temp;
} }
if (G_interrupt) {
///move ^C detection to callers
s = BC_STATUS_EXEC_SIGNAL;
goto err;
}
bc_num_copy(b, x0); bc_num_copy(b, x0);
scale -= 1; scale -= 1;
if (b->rdx > scale) bc_num_truncate(b, b->rdx - scale); if (b->rdx > scale) bc_num_truncate(b, b->rdx - scale);