[git commit] bc: only check for ^C in bc_program_exec() main loop
Denys Vlasenko
vda.linux at googlemail.com
Wed Dec 5 14:43:35 UTC 2018
commit: https://git.busybox.net/busybox/commit/?id=71e1fc6b376e1fde2c3b0dbcf94c4261eed9c6c5
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master
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 at googlemail.com>
---
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);
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