From 079b20e89d3c511716bafb3369336e2b1c165bd5 Mon Sep 17 00:00:00 2001 From: Xi Ruoyao Date: Mon, 7 Aug 2023 13:07:08 +0200 Subject: [PATCH] LoongArch: implement count_{leading,trailing}_zeros 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/ * 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 9948a58769c..32d2048d353 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. */ \ -- 2.30.2