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authorJames Benton <[email protected]>2012-05-10 17:15:27 +0100
committerJosé Fonseca <[email protected]>2012-05-11 13:21:21 +0100
commit0c8a8a35e107bcb04de94154933156165fed62a8 (patch)
tree638af7f8b93f7909561f082aba310e8563b0e95c /src
parent60e7b08101295099618a3c1f879440b257265253 (diff)
llvmpipe: Change triangle rasterization comparison from < 0 to <= 0
Tested with custom rasterisation test tool added to piglit suite, reduced errors Signed-off-by: José Fonseca <[email protected]>
Diffstat (limited to 'src')
-rw-r--r--src/gallium/drivers/llvmpipe/lp_rast_tri.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/src/gallium/drivers/llvmpipe/lp_rast_tri.c b/src/gallium/drivers/llvmpipe/lp_rast_tri.c
index 71d0ddf5e75..230b80a945f 100644
--- a/src/gallium/drivers/llvmpipe/lp_rast_tri.c
+++ b/src/gallium/drivers/llvmpipe/lp_rast_tri.c
@@ -290,6 +290,10 @@ lp_rast_triangle_3_16(struct lp_rasterizer_task *task,
c = _mm_add_epi32(c, mm_mullo_epi32(dcdy, _mm_set1_epi32(y)));
rej4 = _mm_slli_epi32(rej4, 2);
+ /* Adjust so we can just check the sign bit (< 0 comparison), instead of having to do a less efficient <= 0 comparison */
+ c = _mm_sub_epi32(c, _mm_set1_epi32(1));
+ rej4 = _mm_add_epi32(rej4, _mm_set1_epi32(1));
+
dcdx2 = _mm_add_epi32(dcdx, dcdx);
dcdx3 = _mm_add_epi32(dcdx2, dcdx);
@@ -383,7 +387,7 @@ lp_rast_triangle_3_4(struct lp_rasterizer_task *task,
__m128i span_1; /* 0,dcdx,2dcdx,3dcdx for plane 1 */
__m128i span_2; /* 0,dcdx,2dcdx,3dcdx for plane 2 */
__m128i unused;
-
+
transpose4_epi32(&p0, &p1, &p2, &zero,
&c, &dcdx, &dcdy, &unused);
@@ -394,6 +398,9 @@ lp_rast_triangle_3_4(struct lp_rasterizer_task *task,
c = _mm_add_epi32(c, mm_mullo_epi32(dcdx, _mm_set1_epi32(x)));
c = _mm_add_epi32(c, mm_mullo_epi32(dcdy, _mm_set1_epi32(y)));
+ /* Adjust so we can just check the sign bit (< 0 comparison), instead of having to do a less efficient <= 0 comparison */
+ c = _mm_sub_epi32(c, _mm_set1_epi32(1));
+
dcdx2 = _mm_add_epi32(dcdx, dcdx);
dcdx3 = _mm_add_epi32(dcdx2, dcdx);