From: Steinar H. Gunderson <sgunderson@bigfoot.com>
Date: Tue, 22 Sep 2015 23:31:36 +0000 (+0200)
Subject: Yet more small AVX2 tweaks.
X-Git-Tag: 0.4~68
X-Git-Url: https://git.sesse.net/?p=bmusb;a=commitdiff_plain;h=03d475289549453b606c1c04d21e2929abef1e90

Yet more small AVX2 tweaks.
---

diff --git a/bmusb.cpp b/bmusb.cpp
index 45d1d66..1b4628e 100644
--- a/bmusb.cpp
+++ b/bmusb.cpp
@@ -335,10 +335,10 @@ const uint8_t *add_to_frame_fastpath(FrameAllocator::Frame *current_frame, const
 #if __AVX2__
 	const __m256i needle = _mm256_set1_epi8(sync_char);
 
-	const __m256i *in = (const __m256i *)aligned_start;
+	const __restrict __m256i *in = (const __m256i *)aligned_start;
 	if (current_frame->interleaved) {
-		__m256i *out1 = (__m256i *)(current_frame->data + (current_frame->len + 1) / 2);
-		__m256i *out2 = (__m256i *)(current_frame->data2 + current_frame->len / 2);
+		__restrict __m256i *out1 = (__m256i *)(current_frame->data + (current_frame->len + 1) / 2);
+		__restrict __m256i *out2 = (__m256i *)(current_frame->data2 + current_frame->len / 2);
 		if (current_frame->len % 2 == 1) {
 			swap(out1, out2);
 		}
@@ -348,11 +348,12 @@ const uint8_t *add_to_frame_fastpath(FrameAllocator::Frame *current_frame, const
 			15, 13, 11, 9, 7, 5, 3, 1, 14, 12, 10, 8, 6, 4, 2, 0);
 		while (in < (const __m256i *)limit) {
 			// Note: For brevity, comments show lanes as if they were 2x64-bit (they're actually 2x128).
-			__m256i data1 = _mm256_load_si256(in);                // AaBbCcDd EeFfGgHh
-			__m256i data2 = _mm256_load_si256(in + 1);            // IiJjKkLl MmNnOoPp
+			__m256i data1 = _mm256_stream_load_si256(in);         // AaBbCcDd EeFfGgHh
+			__m256i data2 = _mm256_stream_load_si256(in + 1);     // IiJjKkLl MmNnOoPp
 
 			__m256i found1 = _mm256_cmpeq_epi8(data1, needle);
 			__m256i found2 = _mm256_cmpeq_epi8(data2, needle);
+			__m256i found = _mm256_or_si256(found1, found2);
 
 			data1 = _mm256_shuffle_epi8(data1, shuffle_cw);       // ABCDabcd EFGHefgh
 			data2 = _mm256_shuffle_epi8(data2, shuffle_cw);       // IJKLijkl MNOPmnop
@@ -366,8 +367,7 @@ const uint8_t *add_to_frame_fastpath(FrameAllocator::Frame *current_frame, const
 			_mm256_storeu_si256(out1, lo);  // Store as early as possible, even if the data isn't used.
 			_mm256_storeu_si256(out2, hi);
 
-			if (!_mm256_testz_si256(found1, found1) ||
-			    !_mm256_testz_si256(found2, found2)) {
+			if (!_mm256_testz_si256(found, found)) {
 				break;
 			}