add likely to hot path in non-simd sto-alg so "Branch Mispredict" goe…

…s down by 2%
MacroModel · Dec 17, 2024 · c5d0343 · c5d0343
1 parent 3a1fafb
commit c5d0343
Showing 1 changed file with 10 additions and 10 deletions.
diff --git a/include/fast_io_core_impl/integers/sto/sto_contiguous.h b/include/fast_io_core_impl/integers/sto/sto_contiguous.h
@@ -571,7 +571,7 @@ runtime_scan_int_contiguous_none_simd_space_part_define_impl(char_type const *fi
 						constexpr ::std::uint_least64_t mask{0x000000FF000000FF};
 						constexpr ::std::uint_least64_t fullmask{baseval * 0x80};
 
-						while (static_cast<::std::size_t>(first_phase_last - first) >= sizeof(::std::uint_least64_t))
+						while (static_cast<::std::size_t>(first_phase_last - first) >= sizeof(::std::uint_least64_t)) [[likely]]
 						{
 							::std::uint_least64_t val;
 							::fast_io::freestanding::my_memcpy(__builtin_addressof(val), first, sizeof(::std::uint_least64_t));
@@ -581,7 +581,7 @@ runtime_scan_int_contiguous_none_simd_space_part_define_impl(char_type const *fi
 								val = ::fast_io::little_endian(val);
 							}
 
-							if (::std::uint_least64_t const cval{((val + first_bound) | (val - zero_lower_bound)) & fullmask}; cval)
+							if (::std::uint_least64_t const cval{((val + first_bound) | (val - zero_lower_bound)) & fullmask}; cval) [[likely]]
 							{
 								auto ctrz_cval{::std::countr_zero(cval)};
 								auto const valid_bits{ctrz_cval & -8};
@@ -636,7 +636,7 @@ runtime_scan_int_contiguous_none_simd_space_part_define_impl(char_type const *fi
 								val = ::fast_io::little_endian(val);
 							}
 
-							if (::std::uint_least32_t const cval{((val + first_bound) | (val - 0x30303030)) & 0x80808080}; cval)
+							if (::std::uint_least32_t const cval{((val + first_bound) | (val - 0x30303030)) & 0x80808080}; cval) [[likely]]
 							{
 								auto ctrz_cval{::std::countr_zero(cval)};
 								auto const valid_bits{ctrz_cval & -8};
@@ -686,7 +686,7 @@ runtime_scan_int_contiguous_none_simd_space_part_define_impl(char_type const *fi
 					constexpr ::std::uint_least64_t first_bound{0x7fc67fc67fc67fc6 + 0x0001000100010001 * (10 - base)};
 					if constexpr (max_size >= u64_size_of_c16)
 					{
-						while (static_cast<::std::size_t>(first_phase_last - first) >= u64_size_of_c16)
+						while (static_cast<::std::size_t>(first_phase_last - first) >= u64_size_of_c16) [[likely]]
 						{
 							::std::uint_least64_t val;
 							::fast_io::freestanding::my_memcpy(__builtin_addressof(val), first, sizeof(::std::uint_least64_t));
@@ -696,7 +696,7 @@ runtime_scan_int_contiguous_none_simd_space_part_define_impl(char_type const *fi
 								val = ::fast_io::little_endian(val);
 							}
 
-							if (::std::uint_least64_t const cval{((val + first_bound) | (val - 0x0030003000300030)) & 0x8000800080008000}; cval)
+							if (::std::uint_least64_t const cval{((val + first_bound) | (val - 0x0030003000300030)) & 0x8000800080008000}; cval) [[likely]]
 							{
 								auto ctrz_cval{::std::countr_zero(cval)};
 								auto const valid_bits{ctrz_cval & -16};
@@ -751,7 +751,7 @@ runtime_scan_int_contiguous_none_simd_space_part_define_impl(char_type const *fi
 						constexpr ::std::uint_least64_t mask{0x000000FF000000FF};
 						constexpr ::std::uint_least64_t mul1{pow_base_sizeof_base_2 + (pow_base_sizeof_base_6 << 32)};
 						constexpr ::std::uint_least64_t mul2{1 + (pow_base_sizeof_base_4 << 32)};
-						while (static_cast<::std::size_t>(first_phase_last - first) >= sizeof(::std::uint_least64_t))
+						while (static_cast<::std::size_t>(first_phase_last - first) >= sizeof(::std::uint_least64_t)) [[likely]]
 						{
 							::std::uint_least64_t val;
 							::fast_io::freestanding::my_memcpy(__builtin_addressof(val), first, sizeof(::std::uint_least64_t));
@@ -767,7 +767,7 @@ runtime_scan_int_contiguous_none_simd_space_part_define_impl(char_type const *fi
 																  ~(((val + 0x3f3f3f3f3f3f3f3f) | (val - 0x4040404040404040)) &
 																	((val + 0x1f1f1f1f1f1f1f1f) | (val - 0x6060606060606060)))) &
 																 0x8080808080808080};
-								cval)
+								cval) [[likely]]
 							{
 								auto ctrz_cval{::std::countr_zero(cval)};
 								auto const valid_bits{ctrz_cval & -8};
@@ -824,14 +824,14 @@ runtime_scan_int_contiguous_none_simd_space_part_define_impl(char_type const *fi
 
 						constexpr ::std::uint_least32_t pow_base_sizeof_base_2{::fast_io::details::compile_pow_n<::std::uint_least32_t, base_char_type, 2>};
 						constexpr ::std::uint_least32_t mask{0x000000FF};
-						while (static_cast<::std::size_t>(first_phase_last - first) >= sizeof(::std::uint_least32_t))
+						while (static_cast<::std::size_t>(first_phase_last - first) >= sizeof(::std::uint_least32_t)) [[likely]]
 						{
 							::std::uint_least32_t val;
 							::fast_io::freestanding::my_memcpy(__builtin_addressof(val), first, sizeof(::std::uint_least32_t));
 
 							val = ::fast_io::little_endian(val);
 
-							if (::std::uint_least32_t const cval{((val + first_bound) | (val - 0x30303030)) & 0x80808080}; cval) [[unlikely]]
+							if (::std::uint_least32_t const cval{((val + first_bound) | (val - 0x30303030)) & 0x80808080}; cval) [[likely]]
 							{
 								auto ctrz_cval{::std::countr_zero(cval)};
 								auto const valid_bits{ctrz_cval & -8};
@@ -874,7 +874,7 @@ runtime_scan_int_contiguous_none_simd_space_part_define_impl(char_type const *fi
 		}
 	}
 
-	for (; first != first_phase_last; ++first)
+	for (; first != first_phase_last; ++first) [[likely]]
 	{
 		unsigned_char_type ch{static_cast<unsigned_char_type>(*first)};
 		if (char_digit_to_literal<base, char_type>(ch)) [[unlikely]]