From: Keith Whitwell <keithw@vmware.com>
Date: Sun, 23 Aug 2009 18:28:34 +0000 (+0100)
Subject: softpipe: use one fewer divide in sample_cube
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=fd19e8adcd82e88d0fc8d187360b528100fed244;p=mesa.git

softpipe: use one fewer divide in sample_cube

GCC won't do this for us.  Makes a bigger difference to cubemap fps
than previous set of compilcated rearrangements.
---

diff --git a/src/gallium/drivers/softpipe/sp_tex_sample.c b/src/gallium/drivers/softpipe/sp_tex_sample.c
index 3bc4599e045..50460df7cdf 100644
--- a/src/gallium/drivers/softpipe/sp_tex_sample.c
+++ b/src/gallium/drivers/softpipe/sp_tex_sample.c
@@ -1543,9 +1543,12 @@ sample_cube(struct tgsi_sampler *tgsi_sampler,
          }
       }
 
-      ssss[j] = ( sc / ma + 1.0F ) * 0.5F;
-      tttt[j] = ( tc / ma + 1.0F ) * 0.5F;
-      samp->faces[j] = face;
+      {
+	 const float ima = 1.0 / ma;
+	 ssss[j] = ( sc * ima + 1.0F ) * 0.5F;
+	 tttt[j] = ( tc * ima + 1.0F ) * 0.5F;
+	 samp->faces[j] = face;
+      }
    }
 
    /* In our little pipeline, the compare stage is next.  If compare