[PATCH V2] LoongArch: Cleanup __builtin_constant_p() checking for cpu_has_*

From: Huacai Chen
Date: Tue Jul 18 2023 - 04:54:14 EST


In the current configuration, cpu_has_lsx and cpu_has_lasx cannot be
constants. So cleanup the __builtin_constant_p() checking to reduce the
complexity.

Reviewed-by: WANG Xuerui <git@xxxxxxxxxx>
Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
---
V2: Update commit message.

arch/loongarch/include/asm/fpu.h | 15 ++++-----------
1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/arch/loongarch/include/asm/fpu.h b/arch/loongarch/include/asm/fpu.h
index e4193d637f66..b541f6248837 100644
--- a/arch/loongarch/include/asm/fpu.h
+++ b/arch/loongarch/include/asm/fpu.h
@@ -218,15 +218,8 @@ static inline void restore_lsx(struct task_struct *t)

static inline void init_lsx_upper(void)
{
- /*
- * Check cpu_has_lsx only if it's a constant. This will allow the
- * compiler to optimise out code for CPUs without LSX without adding
- * an extra redundant check for CPUs with LSX.
- */
- if (__builtin_constant_p(cpu_has_lsx) && !cpu_has_lsx)
- return;
-
- _init_lsx_upper();
+ if (cpu_has_lsx)
+ _init_lsx_upper();
}

static inline void restore_lsx_upper(struct task_struct *t)
@@ -294,7 +287,7 @@ static inline void restore_lasx_upper(struct task_struct *t) {}

static inline int thread_lsx_context_live(void)
{
- if (__builtin_constant_p(cpu_has_lsx) && !cpu_has_lsx)
+ if (!cpu_has_lsx)
return 0;

return test_thread_flag(TIF_LSX_CTX_LIVE);
@@ -302,7 +295,7 @@ static inline int thread_lsx_context_live(void)

static inline int thread_lasx_context_live(void)
{
- if (__builtin_constant_p(cpu_has_lasx) && !cpu_has_lasx)
+ if (!cpu_has_lasx)
return 0;

return test_thread_flag(TIF_LASX_CTX_LIVE);
--
2.39.3