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lib/string_helpers.c:string_get_size(): use 32 bit arithmetic when po…
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…ssible

The remainder from do_div is always a u32, and after size has been reduced
to be below 1000 (or 1024), it certainly fits in u32.  So both remainder
and sf_cap can be made u32s, the format specifiers can be simplified (%lld
wasn't the right thing to use for _unsigned_ long long anyway), and we can
replace a do_div with an ordinary 32/32 bit division.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Villemoes authored and torvalds committed Feb 13, 2015
1 parent 7eed8fd commit 84b9fbe
Showing 1 changed file with 4 additions and 5 deletions.
9 changes: 4 additions & 5 deletions lib/string_helpers.c
Original file line number Diff line number Diff line change
Expand Up @@ -42,7 +42,7 @@ int string_get_size(u64 size, const enum string_size_units units,
[STRING_UNITS_2] = 1024,
};
int i, j;
u64 remainder = 0, sf_cap;
u32 remainder = 0, sf_cap;
char tmp[8];

tmp[0] = '\0';
Expand All @@ -59,14 +59,13 @@ int string_get_size(u64 size, const enum string_size_units units,

if (j) {
remainder *= 1000;
do_div(remainder, divisor[units]);
snprintf(tmp, sizeof(tmp), ".%03lld",
(unsigned long long)remainder);
remainder /= divisor[units];
snprintf(tmp, sizeof(tmp), ".%03u", remainder);
tmp[j+1] = '\0';
}
}

snprintf(buf, len, "%lld%s %s", (unsigned long long)size,
snprintf(buf, len, "%u%s %s", (u32)size,
tmp, units_str[units][i]);

return 0;
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