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[MIPS] Use MIPS R2 instructions for bitops. 

Add R2 optimized variants of clear_bit, set_bit and test_and_clear_bit.
With gcc 4.1.1 this saves 1592 bytes on a defconfig (minus IPv6) kernel.
Turns out that R2 bitop instructions are no gain for the other bitop
functions.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Ralf Baechle 2007-02-16 17:18:50 +00:00
parent 151fd6acd9
commit 102fa15c3f
1 changed files with 51 additions and 1 deletions
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52
include/asm-mips/bitops.h
View File

@ -3,7 +3,7 @@
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 1994 - 1997, 1999, 2000, 06 Ralf Baechle (ralf@linux-mips.org)
* Copyright (c) 1994 - 1997, 99, 2000, 06, 07 Ralf Baechle (ralf@linux-mips.org)
* Copyright (c) 1999, 2000 Silicon Graphics, Inc.
*/
#ifndef _ASM_BITOPS_H
@ -24,11 +24,15 @@
#define SZLONG_MASK 31UL
#define __LL "ll "
#define __SC "sc "
#define __INS "ins "
#define __EXT "ext "
#elif (_MIPS_SZLONG == 64)
#define SZLONG_LOG 6
#define SZLONG_MASK 63UL
#define __LL "lld "
#define __SC "scd "
#define __INS "dins "
#define __EXT "dext "
#endif
/*
@ -62,6 +66,19 @@ static inline void set_bit(unsigned long nr, volatile unsigned long *addr)
" .set mips0 \n"
: "=&r" (temp), "=m" (*m)
: "ir" (1UL << (nr & SZLONG_MASK)), "m" (*m));
#ifdef CONFIG_CPU_MIPSR2
} else if (__builtin_constant_p(nr)) {
__asm__ __volatile__(
"1: " __LL "%0, %1 # set_bit \n"
" " __INS "%0, %4, %2, 1 \n"
" " __SC "%0, %1 \n"
" beqz %0, 2f \n"
" .subsection 2 \n"
"2: b 1b \n"
" .previous \n"
: "=&r" (temp), "=m" (*m)
: "ir" (nr & SZLONG_MASK), "m" (*m), "r" (~0));
#endif /* CONFIG_CPU_MIPSR2 */
} else if (cpu_has_llsc) {
__asm__ __volatile__(
" .set mips3 \n"
@ -113,6 +130,19 @@ static inline void clear_bit(unsigned long nr, volatile unsigned long *addr)
" .set mips0 \n"
: "=&r" (temp), "=m" (*m)
: "ir" (~(1UL << (nr & SZLONG_MASK))), "m" (*m));
#ifdef CONFIG_CPU_MIPSR2
} else if (__builtin_constant_p(nr)) {
__asm__ __volatile__(
"1: " __LL "%0, %1 # clear_bit \n"
" " __INS "%0, $0, %2, 1 \n"
" " __SC "%0, %1 \n"
" beqz %0, 2f \n"
" .subsection 2 \n"
"2: b 1b \n"
" .previous \n"
: "=&r" (temp), "=m" (*m)
: "ir" (nr & SZLONG_MASK), "m" (*m));
#endif /* CONFIG_CPU_MIPSR2 */
} else if (cpu_has_llsc) {
__asm__ __volatile__(
" .set mips3 \n"
@ -291,6 +321,26 @@ static inline int test_and_clear_bit(unsigned long nr,
: "memory");
return res != 0;
#ifdef CONFIG_CPU_MIPSR2
} else if (__builtin_constant_p(nr)) {
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp, res;
__asm__ __volatile__(
"1: " __LL "%0, %1 # test_and_clear_bit \n"
" " __EXT "%2, %0, %3, 1 \n"
" " __INS "%0, $0, %3, 1 \n"
" " __SC "%0, %1 \n"
" beqz %0, 2f \n"
" .subsection 2 \n"
"2: b 1b \n"
" .previous \n"
: "=&r" (temp), "=m" (*m), "=&r" (res)
: "ri" (nr & SZLONG_MASK), "m" (*m)
: "memory");
return res;
#endif
} else if (cpu_has_llsc) {
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp, res;