Mesa (master): i965: Set CMP's destination type to src0's type.

[Matt Turner]

Module: Mesa
Branch: master
Commit: 6b3a301f611c9aabc090522951eda589e8302562
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=6b3a301f611c9aabc090522951eda589e8302562

Author: Matt Turner <mattst88 at gmail.com>
Date:   Wed Jan  7 11:52:05 2015 -0800

i965: Set CMP's destination type to src0's type.

Allows CMP instructions with float sources to be compacted and coissued.

Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>

---

 src/mesa/drivers/dri/i965/brw_fs.cpp           |   16 ++++++----------
 src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp |   20 ++++++++++++--------
 2 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index 0ada583..2046eba 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -339,17 +339,13 @@ fs_visitor::CMP(fs_reg dst, fs_reg src0, fs_reg src1,
     *
     * Original gen4 does type conversion to the destination type before
     * comparison, producing garbage results for floating point comparisons.
-    * gen5 does the comparison on the execution type (resolved source types),
-    * so dst type doesn't matter.  gen6 does comparison and then uses the
-    * result as if it was the dst type with no conversion, which happens to
-    * mostly work out for float-interpreted-as-int since our comparisons are
-    * for >0, =0, <0.
+    *
+    * The destination type doesn't matter on newer generations, so we set the
+    * type to match src0 so we can compact the instruction.
     */
-   if (brw->gen == 4) {
-      dst.type = src0.type;
-      if (dst.file == HW_REG)
-	 dst.fixed_hw_reg.type = dst.type;
-   }
+   dst.type = src0.type;
+   if (dst.file == HW_REG)
+      dst.fixed_hw_reg.type = dst.type;
 
    resolve_ud_negate(&src0);
    resolve_ud_negate(&src1);
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
index 8129118..e6a7ed0 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
@@ -222,15 +222,19 @@ vec4_visitor::CMP(dst_reg dst, src_reg src0, src_reg src1,
 {
    vec4_instruction *inst;
 
-   /* original gen4 does type conversion to the destination type
-    * before before comparison, producing garbage results for floating
-    * point comparisons.
+   /* Take the instruction:
+    *
+    * CMP null<d> src0<f> src1<f>
+    *
+    * Original gen4 does type conversion to the destination type before
+    * comparison, producing garbage results for floating point comparisons.
+    *
+    * The destination type doesn't matter on newer generations, so we set the
+    * type to match src0 so we can compact the instruction.
     */
-   if (brw->gen == 4) {
-      dst.type = src0.type;
-      if (dst.file == HW_REG)
-	 dst.fixed_hw_reg.type = dst.type;
-   }
+   dst.type = src0.type;
+   if (dst.file == HW_REG)
+      dst.fixed_hw_reg.type = dst.type;
 
    resolve_ud_negate(&src0);
    resolve_ud_negate(&src1);