From: Eric Anholt <eric@anholt.net>
Date: Sat, 1 Aug 2015 00:08:46 +0000 (-0700)
Subject: vc4: Don't bother saturating the dst color for blending.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=63eac5de8fd0e091d07f866a42584c057ca4bfa9;p=mesa.git

vc4: Don't bother saturating the dst color for blending.

Since we just pulled it out of the destination as 8-bit unorm, we know
it's in [0, 1] already.

shader-db:
total instructions in shared programs: 100040 -> 98208 (-1.83%)
instructions in affected programs:     14084 -> 12252 (-13.01%)
---

diff --git a/src/gallium/drivers/vc4/vc4_program.c b/src/gallium/drivers/vc4/vc4_program.c
index 5e2a3f448a0..d6c60739e93 100644
--- a/src/gallium/drivers/vc4/vc4_program.c
+++ b/src/gallium/drivers/vc4/vc4_program.c
@@ -1130,14 +1130,8 @@ vc4_blend(struct vc4_compile *c, struct qreg *result,
                 return;
         }
 
-        struct qreg clamped_src[4];
-        struct qreg clamped_dst[4];
-        for (int i = 0; i < 4; i++) {
-                clamped_src[i] = qir_SAT(c, src_color[i]);
-                clamped_dst[i] = qir_SAT(c, dst_color[i]);
-        }
-        src_color = clamped_src;
-        dst_color = clamped_dst;
+        for (int i = 0; i < 4; i++)
+                src_color[i] = qir_SAT(c, src_color[i]);
 
         struct qreg src_blend[4], dst_blend[4];
         for (int i = 0; i < 3; i++) {