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lavu/riscv: use Zbb CLZ/CTZ/CLZW/CTZW at run-time

Zbb static    Zbb dynamic   I baseline
clz       0.668032642   1.336072283   19.552376803
clzl      0.668092643   1.336181786   26.110855571
ctz       1.336208533   3.340209702   26.054869008
ctzl      1.336247784   3.340362457   26.055266290
(seconds for 1 billion iterations on a SiFive-U74 core)
This commit is contained in:
Rémi Denis-Courmont 2024-06-08 13:27:10 +03:00
parent 98db140910
commit f6d0a41c8c

View File

@ -73,6 +73,107 @@ static av_always_inline av_const int av_clip_intp2_rvi(int a, int p)
}
#if defined (__GNUC__) || defined (__clang__)
static inline av_const int ff_ctz_rv(int x)
{
#if HAVE_RV && !defined(__riscv_zbb)
if (!__builtin_constant_p(x) &&
__builtin_expect(ff_rv_zbb_support(), true)) {
int y;
__asm__ (
".option push\n"
".option arch, +zbb\n"
#if __riscv_xlen >= 64
"ctzw %0, %1\n"
#else
"ctz %0, %1\n"
#endif
".option pop" : "=r" (y) : "r" (x));
if (y > 32)
__builtin_unreachable();
return y;
}
#endif
return __builtin_ctz(x);
}
#define ff_ctz ff_ctz_rv
static inline av_const int ff_ctzll_rv(long long x)
{
#if HAVE_RV && !defined(__riscv_zbb) && __riscv_xlen == 64
if (!__builtin_constant_p(x) &&
__builtin_expect(ff_rv_zbb_support(), true)) {
int y;
__asm__ (
".option push\n"
".option arch, +zbb\n"
"ctz %0, %1\n"
".option pop" : "=r" (y) : "r" (x));
if (y > 64)
__builtin_unreachable();
return y;
}
#endif
return __builtin_ctzll(x);
}
#define ff_ctzll ff_ctzll_rv
static inline av_const int ff_clz_rv(int x)
{
#if HAVE_RV && !defined(__riscv_zbb)
if (!__builtin_constant_p(x) &&
__builtin_expect(ff_rv_zbb_support(), true)) {
int y;
__asm__ (
".option push\n"
".option arch, +zbb\n"
#if __riscv_xlen >= 64
"clzw %0, %1\n"
#else
"clz %0, %1\n"
#endif
".option pop" : "=r" (y) : "r" (x));
if (y > 32)
__builtin_unreachable();
return y;
}
#endif
return __builtin_clz(x);
}
#define ff_clz ff_clz_rv
#if __riscv_xlen == 64
static inline av_const int ff_clzll_rv(long long x)
{
#if HAVE_RV && !defined(__riscv_zbb)
if (!__builtin_constant_p(x) &&
__builtin_expect(ff_rv_zbb_support(), true)) {
int y;
__asm__ (
".option push\n"
".option arch, +zbb\n"
"clz %0, %1\n"
".option pop" : "=r" (y) : "r" (x));
if (y > 64)
__builtin_unreachable();
return y;
}
#endif
return __builtin_clzll(x);
}
#define ff_clz ff_clz_rv
#endif
static inline av_const int ff_log2_rv(unsigned int x)
{
return 31 - ff_clz_rv(x | 1);
}
#define ff_log2 ff_log2_rv
#define ff_log2_16bit ff_log2_rv
static inline av_const int av_popcount_rv(unsigned int x)
{
#if HAVE_RV && !defined(__riscv_zbb)