Hi, Xuerui, On Fri, Jun 23, 2023 at 9:44 PM WANG Xuerui <kernel@xxxxxxxxxx> wrote: > > From: WANG Xuerui <git@xxxxxxxxxx> > > LLVM/Clang does not see FCSRs as GPRs, so make use of compiler > built-ins instead for better maintainability with less code. > > The existing version cannot be wholly removed though, because the > built-ins, while available on GCC too, is predicated TARGET_HARD_FLOAT, > which means soft-float code cannot make use of them. > > Signed-off-by: WANG Xuerui <git@xxxxxxxxxx> > --- > arch/loongarch/include/asm/loongarch.h | 19 +++++++++++++------ > 1 file changed, 13 insertions(+), 6 deletions(-) > > diff --git a/arch/loongarch/include/asm/loongarch.h b/arch/loongarch/include/asm/loongarch.h > index ac83e60c60d1..eedc313b5241 100644 > --- a/arch/loongarch/include/asm/loongarch.h > +++ b/arch/loongarch/include/asm/loongarch.h > @@ -1445,12 +1445,6 @@ __BUILD_CSR_OP(tlbidx) > #define EXCCODE_INT_START 64 > #define EXCCODE_INT_END (EXCCODE_INT_START + EXCCODE_INT_NUM - 1) > > -/* FPU register names */ > -#define LOONGARCH_FCSR0 $r0 > -#define LOONGARCH_FCSR1 $r1 > -#define LOONGARCH_FCSR2 $r2 > -#define LOONGARCH_FCSR3 $r3 > - > /* FPU Status Register Values */ > #define FPU_CSR_RSVD 0xe0e0fce0 > > @@ -1487,6 +1481,18 @@ __BUILD_CSR_OP(tlbidx) > #define FPU_CSR_RU 0x200 /* towards +Infinity */ > #define FPU_CSR_RD 0x300 /* towards -Infinity */ > > +#ifdef CONFIG_CC_IS_CLANG > +#define LOONGARCH_FCSR0 0 > +#define LOONGARCH_FCSR1 1 > +#define LOONGARCH_FCSR2 2 > +#define LOONGARCH_FCSR3 3 > +#define read_fcsr(source) __movfcsr2gr(source) > +#define write_fcsr(dest, val) __movgr2fcsr(dest, val) > +#else /* CONFIG_CC_IS_CLANG */ > +#define LOONGARCH_FCSR0 $r0 > +#define LOONGARCH_FCSR1 $r1 > +#define LOONGARCH_FCSR2 $r2 > +#define LOONGARCH_FCSR3 $r3 > #define read_fcsr(source) \ > ({ \ > unsigned int __res; \ Now the latest binutils also supports $fcsr, so I suggest to always use inline asm, and change CONFIG_CC_IS_CLANG to CONFIG_AS_HAS_FCSR_CLASS. And of course, Patch3 and Patch4 can be merged then. Huacai > @@ -1503,5 +1509,6 @@ do { \ > " movgr2fcsr "__stringify(dest)", %0 \n" \ > : : "r" (val)); \ > } while (0) > +#endif /* CONFIG_CC_IS_CLANG */ > > #endif /* _ASM_LOONGARCH_H */ > -- > 2.40.0 >