From: Jason Ekstrand <jason.ekstrand@intel.com>
Date: Thu, 10 Sep 2015 23:19:42 +0000 (-0700)
Subject: i965/vec4: Don't reswizzle hardware registers
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=1037e0a84f61f4b1815093bcfd548d4b58ca106f;p=mesa.git

i965/vec4: Don't reswizzle hardware registers

Cc: "11.0 10.6" <mesa-stable@lists.freedesktop.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91719
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
---

diff --git a/src/mesa/drivers/dri/i965/brw_vec4.cpp b/src/mesa/drivers/dri/i965/brw_vec4.cpp
index c4da1a11be8..9d863c273e9 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4.cpp
@@ -954,6 +954,14 @@ vec4_instruction::can_reswizzle(int dst_writemask,
    if (mlen > 0)
       return false;
 
+   /* We can't use swizzles on the accumulator and that's really the only
+    * HW_REG we would care to reswizzle so just disallow them all.
+    */
+   for (int i = 0; i < 3; i++) {
+      if (src[i].file == HW_REG)
+         return false;
+   }
+
    return true;
 }