Mesa (master): i965/fs: Replace ud_reg_to_w() with a more general helper function.

[Francisco Jerez]

Module: Mesa
Branch: master
Commit: 509f58740c721e1a8cc8ec4e556af3ed993f927e
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=509f58740c721e1a8cc8ec4e556af3ed993f927e

Author: Francisco Jerez <currojerez at riseup.net>
Date:   Wed Feb  4 17:58:49 2015 +0200

i965/fs: Replace ud_reg_to_w() with a more general helper function.

Reviewed-by: Matt Turner <mattst88 at gmail.com>

---

 src/mesa/drivers/dri/i965/brw_fs_generator.cpp |   27 +++---------------------
 src/mesa/drivers/dri/i965/brw_reg.h            |   22 +++++++++++++++++++
 2 files changed, 25 insertions(+), 24 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
index 3475b31..86cc667 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
@@ -1399,27 +1399,6 @@ fs_generator::generate_set_sample_id(fs_inst *inst,
    brw_pop_insn_state(p);
 }
 
-/**
- * Change the register's data type from UD to W, doubling the strides in order
- * to compensate for halving the data type width.
- */
-static struct brw_reg
-ud_reg_to_w(struct brw_reg r)
-{
-   assert(r.type == BRW_REGISTER_TYPE_UD);
-   r.type = BRW_REGISTER_TYPE_W;
-
-   /* The BRW_*_STRIDE enums are defined so that incrementing the field
-    * doubles the real stride.
-    */
-   if (r.hstride != 0)
-      ++r.hstride;
-   if (r.vstride != 0)
-      ++r.vstride;
-
-   return r;
-}
-
 void
 fs_generator::generate_pack_half_2x16_split(fs_inst *inst,
                                             struct brw_reg dst,
@@ -1440,9 +1419,9 @@ fs_generator::generate_pack_half_2x16_split(fs_inst *inst,
     *   (HorzStride) of 2. The 16-bit result is stored in the lower word of
     *   each destination channel and the upper word is not modified.
     */
-   struct brw_reg dst_w = ud_reg_to_w(dst);
+   struct brw_reg dst_w = spread(retype(dst, BRW_REGISTER_TYPE_W), 2);
 
-   /* Give each 32-bit channel of dst the form below , where "." means
+   /* Give each 32-bit channel of dst the form below, where "." means
     * unchanged.
     *   0x....hhhh
     */
@@ -1474,7 +1453,7 @@ fs_generator::generate_unpack_half_2x16_split(fs_inst *inst,
     *   the source data type must be Word (W). The destination type must be
     *   F (Float).
     */
-   struct brw_reg src_w = ud_reg_to_w(src);
+   struct brw_reg src_w = spread(retype(src, BRW_REGISTER_TYPE_W), 2);
 
    /* Each channel of src has the form of unpackHalf2x16's input: 0xhhhhllll.
     * For the Y case, we wish to access only the upper word; therefore
diff --git a/src/mesa/drivers/dri/i965/brw_reg.h b/src/mesa/drivers/dri/i965/brw_reg.h
index 782cae1..eaf6620 100644
--- a/src/mesa/drivers/dri/i965/brw_reg.h
+++ b/src/mesa/drivers/dri/i965/brw_reg.h
@@ -45,6 +45,7 @@
 #include <stdbool.h>
 #include "main/imports.h"
 #include "main/compiler.h"
+#include "main/macros.h"
 #include "program/prog_instruction.h"
 #include "brw_defines.h"
 
@@ -720,6 +721,27 @@ stride(struct brw_reg reg, unsigned vstride, unsigned width, unsigned hstride)
    return reg;
 }
 
+/**
+ * Multiply the vertical and horizontal stride of a register by the given
+ * factor \a s.
+ */
+static inline struct brw_reg
+spread(struct brw_reg reg, unsigned s)
+{
+   if (s) {
+      assert(is_power_of_two(s));
+
+      if (reg.hstride)
+         reg.hstride += cvt(s) - 1;
+
+      if (reg.vstride)
+         reg.vstride += cvt(s) - 1;
+
+      return reg;
+   } else {
+      return stride(reg, 0, 1, 0);
+   }
+}
 
 static inline struct brw_reg
 vec16(struct brw_reg reg)