ufbx_old_fast_ascii.c

static const uint32_t ufbxi_number_start_mask =
	(((1u << 10) - 1) << ((uint32_t)'0' - 32u)) |
	(1u << ((uint32_t)'-' - 32u)) |
	(1u << ((uint32_t)'+' - 32u)) |
	(1u << ((uint32_t)'.' - 32u)) ;

ufbx_static_assert(ufbxi_number_start_codepoint,
	((uint32_t)'9' - (uint32_t)'0') == 9 &&
	(uint32_t)'0' >= 32u && (uint32_t)'0' < 64u &&
	(uint32_t)'-' >= 32u && (uint32_t)'-' < 64u &&
	(uint32_t)'+' >= 32u && (uint32_t)'+' < 64u &&
	(uint32_t)'.' >= 32u && (uint32_t)'.' < 64u);

static ufbxi_forceinline bool ufbxi_is_number_start(char c)
{
	uint32_t v = (uint32_t)(uint8_t)c - 32u;
	return v < 32 && ((ufbxi_number_start_mask >> v) & 0x1) != 0;
}



// We can safely skip over anything of the pattern:
	// (\s*[0-9\-+\.][0-9\-+\.eE]*\s*,)*

#if 0
	uint32_t num_deferred = 0;
	{
		__m128i c_digit_lo = _mm_set1_epi8('0' - 1);
		__m128i c_digit_hi = _mm_set1_epi8('9' + 1);
		__m128i c_minus = _mm_set1_epi8('-');
		__m128i c_plus = _mm_set1_epi8('+');
		__m128i c_dot = _mm_set1_epi8('.');
		__m128i c_e = _mm_set1_epi8('e');
		__m128i c_lowercase = _mm_set1_epi8(0x20);

		const char *src_next = src;
		const char *src_defer = src;
		for (;;) {
			while (src_defer != end && ufbxi_is_space(*src_defer)) src_defer++;
			if (src_defer == end || *src_defer != ',') break;
			src_defer++;
			while (src_defer != end && ufbxi_is_space(*src_defer)) src_defer++;
			src_next = src_defer;
			num_deferred += 1;

			char c = *src_defer;
			if (!ufbxi_is_number_start(c)) break;

			uint32_t count = 0;
			for (;;) {
				if (ufbxi_to_size(end - src_defer) <= 16) break;
				__m128i a = _mm_loadu_si128((const __m128i*)src_defer);
				__m128i eq;
				eq = _mm_and_si128(_mm_cmpgt_epi8(a, c_digit_lo), _mm_cmplt_epi8(a, c_digit_hi));
				eq = _mm_or_si128(eq, _mm_cmpeq_epi8(_mm_or_si128(a, c_lowercase), c_e));
				eq = _mm_or_si128(eq, _mm_cmpeq_epi8(a, c_minus));
				eq = _mm_or_si128(eq, _mm_cmpeq_epi8(a, c_plus));
				eq = _mm_or_si128(eq, _mm_cmpeq_epi8(a, c_dot));
				uint32_t mask = _mm_movemask_epi8(eq);
				count = ufbxi_tzcnt32(~mask);

				if (count < 16) break;
				src_defer += 16;
			}
			src_defer += count;
		}

		if (num_deferred > 1) {
			if (type == 'd') {
				double *v = ufbxi_push(&uc->tmp_stack, double, num_deferred);
				ufbxi_check(v);
				*v = (double)val;
			} else if (type == 'f') {
				float *v = ufbxi_push(&uc->tmp_stack, float, num_deferred);
				ufbxi_check(v);
				*v = (float)val;
			}

			size_t length = src_next - src;
			ufbxi_float_span *span = ufbxi_push(&uc->tmp_ascii_spans, ufbxi_float_span, 1);
			ufbxi_check(span);

			span->count = num_deferred - 1;
			span->source_length = length;
			if (ua->src_is_retained || !uc->read_fn) {
				span->source = src;
			} else {
				span->source = ufbxi_push_copy(tmp_buf, char, length, src);
			}
			span->offset = num_values + 1;
			ufbxi_check(span->source);

			ua->retain_buf = tmp_buf;
			ua->src = src_next;
			ufbxi_check(ufbxi_ascii_next_token(uc, &ua->token));
			ua->retain_buf = NULL;

			*p_num_read = num_deferred;
			return 1;
		}
	}
#endif