Mesa (master): llvmpipe: Fix bug with blend factor in complementary optimisations.

[Jose Fonseca]

Module: Mesa
Branch: master
Commit: e253175c9c8034bfc13ecc3e16ab72007bde744a
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=e253175c9c8034bfc13ecc3e16ab72007bde744a

Author: James Benton <jbenton at vmware.com>
Date:   Tue Jul 17 12:08:02 2012 +0100

llvmpipe: Fix bug with blend factor in complementary optimisations.

Fixes fdo 52168.

Reviewed-by: José Fonseca <jfonseca at vmware.com>

---

 src/gallium/drivers/llvmpipe/lp_bld_blend.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/gallium/drivers/llvmpipe/lp_bld_blend.c b/src/gallium/drivers/llvmpipe/lp_bld_blend.c
index a87a220..75309dd 100644
--- a/src/gallium/drivers/llvmpipe/lp_bld_blend.c
+++ b/src/gallium/drivers/llvmpipe/lp_bld_blend.c
@@ -152,20 +152,22 @@ lp_build_blend(struct lp_build_context *bld,
             }
          } else if(bld->type.floating && func == PIPE_BLEND_SUBTRACT) {
             result = lp_build_add(bld, src, dst);
-            result = lp_build_mul(bld, result, src_factor);
 
             if (factor_src < factor_dst) {
+               result = lp_build_mul(bld, result, src_factor);
                return lp_build_sub(bld, result, dst);
             } else {
+               result = lp_build_mul(bld, result, dst_factor);
                return lp_build_sub(bld, src, result);
             }
          } else if(bld->type.floating && func == PIPE_BLEND_REVERSE_SUBTRACT) {
             result = lp_build_add(bld, src, dst);
-            result = lp_build_mul(bld, result, src_factor);
 
             if (factor_src < factor_dst) {
+               result = lp_build_mul(bld, result, src_factor);
                return lp_build_sub(bld, dst, result);
             } else {
+               result = lp_build_mul(bld, result, dst_factor);
                return lp_build_sub(bld, result, src);
             }
          }