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| author | Heiko Carstens <hca@linux.ibm.com> | 2024-06-09 22:02:19 +0300 |
|---|---|---|
| committer | Alexander Gordeev <agordeev@linux.ibm.com> | 2024-06-24 12:12:39 +0300 |
| commit | 7c67928648188d193c9f73679f7e6aa67d088237 (patch) | |
| tree | 6fad25c850bde3014c0db794ce7f050f456ab360 /arch/s390 | |
| parent | 447360d75cf473d4b1048a7204443262f3f60758 (diff) | |
| download | linux-7c67928648188d193c9f73679f7e6aa67d088237.tar.xz | |
s390: Provide optimized __arch_hweight*() implementations
Make use of the popcnt instruction to provide optimized __arch_hweight*()
implementations. The generated code is shorter and avoids rather expensive
functions calls.
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/Kconfig | 2 | ||||
| -rw-r--r-- | arch/s390/include/asm/arch_hweight.h | 76 | ||||
| -rw-r--r-- | arch/s390/include/asm/bitops.h | 3 |
3 files changed, 79 insertions, 2 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index c59d2b54df49..9788ae5e930b 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -21,7 +21,7 @@ config ARCH_PROC_KCORE_TEXT def_bool y config GENERIC_HWEIGHT - def_bool y + def_bool !HAVE_MARCH_Z196_FEATURES config GENERIC_BUG def_bool y if BUG diff --git a/arch/s390/include/asm/arch_hweight.h b/arch/s390/include/asm/arch_hweight.h new file mode 100644 index 000000000000..50e23ce854e5 --- /dev/null +++ b/arch/s390/include/asm/arch_hweight.h @@ -0,0 +1,76 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _ASM_S390_ARCH_HWEIGHT_H +#define _ASM_S390_ARCH_HWEIGHT_H + +#include <linux/types.h> + +static __always_inline unsigned long popcnt_z196(unsigned long w) +{ + unsigned long cnt; + + asm volatile(".insn rrf,0xb9e10000,%[cnt],%[w],0,0" + : [cnt] "=d" (cnt) + : [w] "d" (w) + : "cc"); + return cnt; +} + +static __always_inline unsigned long popcnt_z15(unsigned long w) +{ + unsigned long cnt; + + asm volatile(".insn rrf,0xb9e10000,%[cnt],%[w],8,0" + : [cnt] "=d" (cnt) + : [w] "d" (w) + : "cc"); + return cnt; +} + +static __always_inline unsigned long __arch_hweight64(__u64 w) +{ + if (IS_ENABLED(CONFIG_HAVE_MARCH_Z15_FEATURES)) + return popcnt_z15(w); + if (IS_ENABLED(CONFIG_HAVE_MARCH_Z196_FEATURES)) { + w = popcnt_z196(w); + w += w >> 32; + w += w >> 16; + w += w >> 8; + return w & 0xff; + } + return __sw_hweight64(w); +} + +static __always_inline unsigned int __arch_hweight32(unsigned int w) +{ + if (IS_ENABLED(CONFIG_HAVE_MARCH_Z15_FEATURES)) + return popcnt_z15(w); + if (IS_ENABLED(CONFIG_HAVE_MARCH_Z196_FEATURES)) { + w = popcnt_z196(w); + w += w >> 16; + w += w >> 8; + return w & 0xff; + } + return __sw_hweight32(w); +} + +static __always_inline unsigned int __arch_hweight16(unsigned int w) +{ + if (IS_ENABLED(CONFIG_HAVE_MARCH_Z15_FEATURES)) + return popcnt_z15((unsigned short)w); + if (IS_ENABLED(CONFIG_HAVE_MARCH_Z196_FEATURES)) { + w = popcnt_z196(w); + w += w >> 8; + return w & 0xff; + } + return __sw_hweight16(w); +} + +static __always_inline unsigned int __arch_hweight8(unsigned int w) +{ + if (IS_ENABLED(CONFIG_HAVE_MARCH_Z196_FEATURES)) + return popcnt_z196((unsigned char)w); + return __sw_hweight8(w); +} + +#endif /* _ASM_S390_ARCH_HWEIGHT_H */ diff --git a/arch/s390/include/asm/bitops.h b/arch/s390/include/asm/bitops.h index c467dffa8c12..54a079cd39ed 100644 --- a/arch/s390/include/asm/bitops.h +++ b/arch/s390/include/asm/bitops.h @@ -379,8 +379,9 @@ static inline int fls(unsigned int word) return fls64(word); } +#include <asm/arch_hweight.h> +#include <asm-generic/bitops/const_hweight.h> #include <asm-generic/bitops/ffz.h> -#include <asm-generic/bitops/hweight.h> #include <asm-generic/bitops/sched.h> #include <asm-generic/bitops/le.h> #include <asm-generic/bitops/ext2-atomic-setbit.h> |