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xtensa: use "m" constraint instead of "r" in futex.h assembly 

Use "m" constraint instead of "r" for the address, as "m" allows
compiler to access adjacent locations using base + offset, while "r"
requires updating the base register every time.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
This commit is contained in:
Max Filippov 2019-10-16 00:49:54 -07:00
parent cf3b3baa71
commit 5eff6ca2e3
1 changed files with 5 additions and 5 deletions
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10
arch/xtensa/include/asm/futex.h
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@ -43,10 +43,10 @@
#elif XCHAL_HAVE_S32C1I
#define __futex_atomic_op(insn, ret, old, uaddr, arg) \
__asm__ __volatile( \
"1: l32i %[oldval], %[addr], 0\n" \
"1: l32i %[oldval], %[mem]\n" \
insn "\n" \
" wsr %[oldval], scompare1\n" \
"2: s32c1i %[newval], %[addr], 0\n" \
"2: s32c1i %[newval], %[mem]\n" \
" bne %[newval], %[oldval], 1b\n" \
" movi %[newval], 0\n" \
"3:\n" \
@ -60,9 +60,9 @@
" .section __ex_table,\"a\"\n" \
" .long 1b, 5b, 2b, 5b\n" \
" .previous\n" \
: [oldval] "=&r" (old), [newval] "=&r" (ret) \
: [addr] "r" (uaddr), [oparg] "r" (arg), \
[fault] "I" (-EFAULT) \
: [oldval] "=&r" (old), [newval] "=&r" (ret), \
[mem] "+m" (*(uaddr)) \
: [oparg] "r" (arg), [fault] "I" (-EFAULT) \
: "memory")
#endif