[PATCH 2/3] lib: string_get_size: Use 32 bit arithmetic when possible

From: Rasmus Villemoes
Date: Fri Dec 12 2014 - 09:44:41 EST


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@xxxxxxxxxxxxxxxxxx>
---
lib/string_helpers.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index 0d25f7aa732c..2b3757f84b3b 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -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;
--
2.1.3

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