From 1aeba347b3a90a8b22f1c3eed0dcfba38bb8dbb8 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Mon, 26 Nov 2018 18:58:40 +0000 Subject: [PATCH] MIPS: Hardcode cpu_has_mips* where target ISA allows In the same vein as commit 93e01942a6eb ("MIPS: Hardcode cpu_has_* where known at compile time due to ISA"), we can use our knowledge of the ISA being targeted by the kernel build to make cpu_has_mips* macros compile-time constant in some cases. This allows the compiler greater opportunity to optimize out code which will never execute. Signed-off-by: Paul Burton Patchwork: https://patchwork.linux-mips.org/patch/21245/ Cc: linux-mips@linux-mips.org --- arch/mips/include/asm/cpu-features.h | 35 ++++++++++++++++++++++++----------- 1 file changed, 24 insertions(+), 11 deletions(-) diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h index ca34835..701e525 100644 --- a/arch/mips/include/asm/cpu-features.h +++ b/arch/mips/include/asm/cpu-features.h @@ -15,6 +15,7 @@ #include #define __ase(ase) (cpu_data[0].ases & (ase)) +#define __isa(isa) (cpu_data[0].isa_level & (isa)) #define __opt(opt) (cpu_data[0].options & (opt)) /* @@ -53,6 +54,18 @@ #define __isa_lt_and_opt(isa, opt) ((MIPS_ISA_REV < (isa)) && __opt(opt)) /* + * Similarly allow for ISA level checks that take into account knowledge of the + * ISA targeted by the kernel build, provided by MIPS_ISA_REV. + */ +#define __isa_ge_and_flag(isa, flag) ((MIPS_ISA_REV >= (isa)) && __isa(flag)) +#define __isa_ge_or_flag(isa, flag) ((MIPS_ISA_REV >= (isa)) || __isa(flag)) +#define __isa_lt_and_flag(isa, flag) ((MIPS_ISA_REV < (isa)) && __isa(flag)) +#define __isa_range(ge, lt) \ + ((MIPS_ISA_REV >= (ge)) && (MIPS_ISA_REV < (lt))) +#define __isa_range_or_flag(ge, lt, flag) \ + (__isa_range(ge, lt) || ((MIPS_ISA_REV < (lt)) && __isa(flag))) + +/* * SMP assumption: Options of CPU 0 are a superset of all processors. * This is true for all known MIPS systems. */ @@ -254,37 +267,37 @@ #endif #ifndef cpu_has_mips_1 -# define cpu_has_mips_1 (!cpu_has_mips_r6) +# define cpu_has_mips_1 (MIPS_ISA_REV < 6) #endif #ifndef cpu_has_mips_2 -# define cpu_has_mips_2 (cpu_data[0].isa_level & MIPS_CPU_ISA_II) +# define cpu_has_mips_2 __isa_lt_and_flag(6, MIPS_CPU_ISA_II) #endif #ifndef cpu_has_mips_3 -# define cpu_has_mips_3 (cpu_data[0].isa_level & MIPS_CPU_ISA_III) +# define cpu_has_mips_3 __isa_lt_and_flag(6, MIPS_CPU_ISA_III) #endif #ifndef cpu_has_mips_4 -# define cpu_has_mips_4 (cpu_data[0].isa_level & MIPS_CPU_ISA_IV) +# define cpu_has_mips_4 __isa_lt_and_flag(6, MIPS_CPU_ISA_IV) #endif #ifndef cpu_has_mips_5 -# define cpu_has_mips_5 (cpu_data[0].isa_level & MIPS_CPU_ISA_V) +# define cpu_has_mips_5 __isa_lt_and_flag(6, MIPS_CPU_ISA_V) #endif #ifndef cpu_has_mips32r1 -# define cpu_has_mips32r1 (cpu_data[0].isa_level & MIPS_CPU_ISA_M32R1) +# define cpu_has_mips32r1 __isa_range_or_flag(1, 6, MIPS_CPU_ISA_M32R1) #endif #ifndef cpu_has_mips32r2 -# define cpu_has_mips32r2 (cpu_data[0].isa_level & MIPS_CPU_ISA_M32R2) +# define cpu_has_mips32r2 __isa_range_or_flag(2, 6, MIPS_CPU_ISA_M32R2) #endif #ifndef cpu_has_mips32r6 -# define cpu_has_mips32r6 (cpu_data[0].isa_level & MIPS_CPU_ISA_M32R6) +# define cpu_has_mips32r6 __isa_ge_or_flag(6, MIPS_CPU_ISA_M32R6) #endif #ifndef cpu_has_mips64r1 -# define cpu_has_mips64r1 (cpu_data[0].isa_level & MIPS_CPU_ISA_M64R1) +# define cpu_has_mips64r1 __isa_range_or_flag(1, 6, MIPS_CPU_ISA_M64R1) #endif #ifndef cpu_has_mips64r2 -# define cpu_has_mips64r2 (cpu_data[0].isa_level & MIPS_CPU_ISA_M64R2) +# define cpu_has_mips64r2 __isa_range_or_flag(2, 6, MIPS_CPU_ISA_M64R2) #endif #ifndef cpu_has_mips64r6 -# define cpu_has_mips64r6 (cpu_data[0].isa_level & MIPS_CPU_ISA_M64R6) +# define cpu_has_mips64r6 __isa_ge_and_flag(6, MIPS_CPU_ISA_M64R6) #endif /* -- 2.7.4