x86: don't reload after cmpxchg in unsafe_atomic_op2() loop

lock cmpxchg leaves the current value in eax; no need to reload it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/arch/x86/include/asm/futex.h b/arch/x86/include/asm/futex.h
index 53c07ab..5ff7626 100644 (file)
--- a/arch/x86/include/asm/futex.h
+++ b/arch/x86/include/asm/futex.h
@@ -34,17 +34,17 @@ do {                                                                \
 do {                                                           \
        int oldval = 0, ret, tem;                               \
        asm volatile("1:\tmovl  %2, %0\n"                       \
-                    "\tmovl\t%0, %3\n"                         \
+                    "2:\tmovl\t%0, %3\n"                       \
                     "\t" insn "\n"                             \
-                    "2:\t" LOCK_PREFIX "cmpxchgl %3, %2\n"     \
-                    "\tjnz\t1b\n"                              \
-                    "3:\n"                                     \
+                    "3:\t" LOCK_PREFIX "cmpxchgl %3, %2\n"     \
+                    "\tjnz\t2b\n"                              \
+                    "4:\n"                                     \
                     "\t.section .fixup,\"ax\"\n"               \
-                    "4:\tmov\t%5, %1\n"                        \
-                    "\tjmp\t3b\n"                              \
+                    "5:\tmov\t%5, %1\n"                        \
+                    "\tjmp\t4b\n"                              \
                     "\t.previous\n"                            \
-                    _ASM_EXTABLE_UA(1b, 4b)                    \
-                    _ASM_EXTABLE_UA(2b, 4b)                    \
+                    _ASM_EXTABLE_UA(1b, 5b)                    \
+                    _ASM_EXTABLE_UA(3b, 5b)                    \
                     : "=&a" (oldval), "=&r" (ret),             \
                       "+m" (*uaddr), "=&r" (tem)               \
                     : "r" (oparg), "i" (-EFAULT), "1" (0));    \