artemist/mes
1
0
Fork 0
Code Issues Pull requests Packages Projects Releases Wiki Activity

ldiv: Make rem < 0 if a < 0.

Browse source 
* lib/mes/div.c (ldiv): Make rem < 0 if a < 0.
This commit is contained in:
Danny Milosavljevic 2019-07-01 23:02:19 +02:00 committed by Jan Nieuwenhuizen
parent 21bd2c1e90
commit 3943155a64
No known key found for this signature in database
GPG key ID: F3C1A0D9C1D65273
1 changed files with 8 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

11
lib/mes/div.c
View file

@ -60,7 +60,9 @@ unsigned long __mesabi_uldiv(unsigned long a, unsigned long b, unsigned long* re
} }
} }
/* Note: Rounds towards zero */ /* Note: Rounds towards zero.
Maintainer: Be careful to satisfy quot * b + rem == a.
That means that rem can be negative. */
ldiv_t ldiv(long a, long b) ldiv_t ldiv(long a, long b)
{ {
ldiv_t result; ldiv_t result;
@ -68,13 +70,16 @@ ldiv_t ldiv(long a, long b)
assert(b != LONG_MIN); assert(b != LONG_MIN);
if (a != LONG_MIN) if (a != LONG_MIN)
{ {
if (a < 0) int negative_a = (a < 0);
if (negative_a)
a = -a; a = -a;
if (b < 0) if (b < 0)
b = -b; b = -b;
result.quot = __mesabi_uldiv(a, b, &result.rem); result.quot = __mesabi_uldiv(a, b, &result.rem);
if (negate_result) if (negate_result)
result.quot = -result.quot; result.quot = -result.quot;
if (negative_a)
result.rem = -result.rem;
return result; return result;
} }
else else
@ -95,7 +100,7 @@ ldiv_t ldiv(long a, long b)
long x; long x;
for (x = 0; a <= -b; a += b) for (x = 0; a <= -b; a += b)
++x; ++x;
result.rem = -a; result.rem = a; /* negative */
result.quot = x; result.quot = x;
} }
if (negate_result) if (negate_result)