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authorRalf Baechle <ralf@linux-mips.org>2007-02-16 17:18:50 +0000
committerRalf Baechle <ralf@linux-mips.org>2007-02-18 21:31:35 +0000
commit102fa15c3f14565f2edb9f08f08ea3f2bf123dc9 (patch)
treee4b753ec35e1cf543ab580df9b36b03086f9909c /include
parent151fd6acd94e12ef3a7d5fa0911a2590690c493f (diff)
[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>
Diffstat (limited to 'include')
-rw-r--r--include/asm-mips/bitops.h52
1 files changed, 51 insertions, 1 deletions
diff --git a/include/asm-mips/bitops.h b/include/asm-mips/bitops.h
index 06c08228a525..89436b96ad66 100644
--- a/include/asm-mips/bitops.h
+++ b/include/asm-mips/bitops.h
@@ -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;

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