Looks good to me! Thanks!
在 2022/10/12 下午10:23, Xi Ruoyao 写道:
LoongArch always support clz and ctz instructions, so we can always use __builtin_{clz,ctz} for count_{leading,trailing}_zeros. This improves the code of libgcc, and also benefits Glibc once we merge longlong.h there. Bootstrapped and regtested on loongarch64-linux-gnu. include/ChangeLog: * longlong.h [__loongarch__] (count_leading_zeros): Define. [__loongarch__] (count_trailing_zeros): Likewise. [__loongarch__] (COUNT_LEADING_ZEROS_0): Likewise. --- include/longlong.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/include/longlong.h b/include/longlong.h index 64a7b10f9b2..c3a6f1e7eaa 100644 --- a/include/longlong.h +++ b/include/longlong.h @@ -593,6 +593,18 @@ extern UDItype __umulsidi3 (USItype, USItype); #define UMUL_TIME 14 #endif+#ifdef __loongarch__+# if W_TYPE_SIZE == 32 +# define count_leading_zeros(count, x) ((count) = __builtin_clz (x)) +# define count_trailing_zeros(count, x) ((count) = __builtin_ctz (x)) +# define COUNT_LEADING_ZEROS_0 32 +# elif W_TYPE_SIZE == 64 +# define count_leading_zeros(count, x) ((count) = __builtin_clzll (x)) +# define count_trailing_zeros(count, x) ((count) = __builtin_ctzll (x)) +# define COUNT_LEADING_ZEROS_0 64 +# endif +#endif + #if defined (__M32R__) && W_TYPE_SIZE == 32 #define add_ssaaaa(sh, sl, ah, al, bh, bl) \ /* The cmp clears the condition bit. */ \
