mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-29 13:53:33 +00:00
Code Issues Releases Wiki Activity

tools/nolibc/stdlib: avoid a 64-bit shift in u64toh_r()

Browse source 
The build of printf() on mips requires libgcc for functions __ashldi3 and
__lshrdi3 due to 64-bit shifts when scanning the input number. These are
not really needed in fact since we scan the number 4 bits at a time. Let's
arrange the loop to perform two 32-bit shifts instead on 32-bit platforms.

Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit is contained in:
Willy Tarreau 2022-02-07 17:23:37 +01:00 committed by Paul E. McKenney
parent a7604ba149
commit ac90226d53
1 changed files with 11 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

18
tools/include/nolibc/stdlib.h
View file

@ -200,14 +200,18 @@ int u64toh_r(uint64_t in, char *buffer)
int dig;
do {
dig = in >> pos;
in -= (uint64_t)dig << pos;
pos -= 4;
if (dig || digits || pos < 0) {
if (dig > 9)
dig += 'a' - '0' - 10;
buffer[digits++] = '0' + dig;
if (sizeof(long) >= 8) {
dig = (in >> pos) & 0xF;
} else {
/* 32-bit platforms: avoid a 64-bit shift */
uint32_t d = (pos >= 32) ? (in >> 32) : in;
dig = (d >> (pos & 31)) & 0xF;
}
if (dig > 9)
dig += 'a' - '0' - 10;
pos -= 4;
if (dig || digits || pos < 0)
buffer[digits++] = '0' + dig;
} while (pos >= 0);
buffer[digits] = 0;