Commit 84b9fbed authored Feb 12, 2015 by Rasmus Villemoes Committed by Linus Torvalds Feb 12, 2015

lib/string_helpers.c:string_get_size(): use 32 bit arithmetic when possible

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>

parent 7eed8fde

lib/string_helpers.c

+4 −5

Original line number	Diff line number	Diff line
		@@ -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';
		@@ -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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