1 From: Felix Fietkau <nbd@nbd.name>
2 Subject: [PATCH] mips: allow the compiler to optimize memset, memcmp, memcpy for better performance and (in some instances) smaller code
4 lede-commit: 07e59c7bc7f375f792ec9734be42fe4fa391a8bb
5 Signed-off-by: Felix Fietkau <nbd@nbd.name>
7 arch/mips/boot/compressed/Makefile | 3 ++-
8 arch/mips/include/asm/string.h | 38 ++++++++++++++++++++++++++++++++++++++
9 arch/mips/lib/Makefile | 2 +-
10 arch/mips/lib/memcmp.c | 22 ++++++++++++++++++++++
11 4 files changed, 63 insertions(+), 2 deletions(-)
12 create mode 100644 arch/mips/lib/memcmp.c
14 --- a/arch/mips/boot/compressed/Makefile
15 +++ b/arch/mips/boot/compressed/Makefile
16 @@ -23,7 +23,8 @@ KBUILD_CFLAGS := $(shell echo $(KBUILD_C
17 KBUILD_CFLAGS := $(filter-out -fstack-protector, $(KBUILD_CFLAGS))
19 KBUILD_CFLAGS := $(LINUXINCLUDE) $(KBUILD_CFLAGS) -D__KERNEL__ \
20 - -DBOOT_HEAP_SIZE=$(BOOT_HEAP_SIZE) -D"VMLINUX_LOAD_ADDRESS_ULL=$(VMLINUX_LOAD_ADDRESS)ull"
21 + -DBOOT_HEAP_SIZE=$(BOOT_HEAP_SIZE) -D"VMLINUX_LOAD_ADDRESS_ULL=$(VMLINUX_LOAD_ADDRESS)ull" \
24 KBUILD_AFLAGS := $(LINUXINCLUDE) $(KBUILD_AFLAGS) -D__ASSEMBLY__ \
25 -DBOOT_HEAP_SIZE=$(BOOT_HEAP_SIZE) \
26 --- a/arch/mips/include/asm/string.h
27 +++ b/arch/mips/include/asm/string.h
28 @@ -140,4 +140,42 @@ extern void *memcpy(void *__to, __const_
29 #define __HAVE_ARCH_MEMMOVE
30 extern void *memmove(void *__dest, __const__ void *__src, size_t __n);
33 +#define memset(__s, __c, len) \
35 + size_t __len = (len); \
37 + if (__builtin_constant_p(len) && __len >= 64) \
38 + __ret = memset((__s), (__c), __len); \
40 + __ret = __builtin_memset((__s), (__c), __len); \
44 +#define memcpy(dst, src, len) \
46 + size_t __len = (len); \
48 + if (__builtin_constant_p(len) && __len >= 64) \
49 + __ret = memcpy((dst), (src), __len); \
51 + __ret = __builtin_memcpy((dst), (src), __len); \
55 +#define memmove(dst, src, len) \
57 + size_t __len = (len); \
59 + if (__builtin_constant_p(len) && __len >= 64) \
60 + __ret = memmove((dst), (src), __len); \
62 + __ret = __builtin_memmove((dst), (src), __len); \
66 +#define __HAVE_ARCH_MEMCMP
67 +#define memcmp(src1, src2, len) __builtin_memcmp((src1), (src2), (len))
70 #endif /* _ASM_STRING_H */
71 --- a/arch/mips/lib/Makefile
72 +++ b/arch/mips/lib/Makefile
75 lib-y += bitops.o csum_partial.o delay.o memcpy.o memset.o \
76 mips-atomic.o strlen_user.o strncpy_user.o \
77 - strnlen_user.o uncached.o
78 + strnlen_user.o uncached.o memcmp.o
81 obj-$(CONFIG_PCI) += iomap-pci.o
83 +++ b/arch/mips/lib/memcmp.c
86 + * copied from linux/lib/string.c
88 + * Copyright (C) 1991, 1992 Linus Torvalds
91 +#include <linux/module.h>
92 +#include <linux/string.h>
95 +int memcmp(const void *cs, const void *ct, size_t count)
97 + const unsigned char *su1, *su2;
100 + for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
101 + if ((res = *su1 - *su2) != 0)
105 +EXPORT_SYMBOL(memcmp);