i965: Use the implied move available in most brw_wm_emit brw_math() calls.

This saves an extra message reg move in the program, though I'm not
clear on whether it will have any performance impact other than cache
footprint.  It will also fix those math calls on Sandybridge, where
the brw_eu_emit.c brw_math() support relies on the implied move being
used.

diff --git a/src/mesa/drivers/dri/i965/brw_wm_emit.c b/src/mesa/drivers/dri/i965/brw_wm_emit.c
index 053cf13a011d05eac42399da13e6b282b6ca429f..f01fffbd5c8236f6cac6c8953119f3eca92a9440 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_wm_emit.c
+++ b/src/mesa/drivers/dri/i965/brw_wm_emit.c
@@ -862,11 +862,6 @@ void emit_math1(struct brw_wm_compile *c,
 
    assert(is_power_of_two(mask & WRITEMASK_XYZW));
 
-   /* If compressed, this will write message reg 2,3 from arg0.x's 16
-    * channels.
-    */
-   brw_MOV(p, brw_message_reg(2), arg0[0]);
-
    /* Send two messages to perform all 16 operations:
     */
    brw_push_insn_state(p);
@@ -876,7 +871,7 @@ void emit_math1(struct brw_wm_compile *c,
            function,
            saturate,
            2,
-           brw_null_reg(),
+           arg0[0],
            BRW_MATH_DATA_VECTOR,
            BRW_MATH_PRECISION_FULL);
 
@@ -887,7 +882,7 @@ void emit_math1(struct brw_wm_compile *c,
               function,
               saturate,
               3,
-              brw_null_reg(),
+              sechalf(arg0[0]),
               BRW_MATH_DATA_VECTOR,
               BRW_MATH_PRECISION_FULL);
    }
@@ -915,13 +910,6 @@ void emit_math2(struct brw_wm_compile *c,
 
    brw_push_insn_state(p);
 
-   brw_set_compression_control(p, BRW_COMPRESSION_NONE);
-   brw_MOV(p, brw_message_reg(2), arg0[0]);
-   if (c->dispatch_width == 16) {
-      brw_set_compression_control(p, BRW_COMPRESSION_2NDHALF);
-      brw_MOV(p, brw_message_reg(4), sechalf(arg0[0]));
-   }
-
    brw_set_compression_control(p, BRW_COMPRESSION_NONE);
    brw_MOV(p, brw_message_reg(3), arg1[0]);
    if (c->dispatch_width == 16) {
@@ -935,7 +923,7 @@ void emit_math2(struct brw_wm_compile *c,
            function,
            saturate,
            2,
-           brw_null_reg(),
+           arg0[0],
            BRW_MATH_DATA_VECTOR,
            BRW_MATH_PRECISION_FULL);
 
@@ -948,7 +936,7 @@ void emit_math2(struct brw_wm_compile *c,
               function,
               saturate,
               4,
-              brw_null_reg(),
+              sechalf(arg0[0]),
               BRW_MATH_DATA_VECTOR,
               BRW_MATH_PRECISION_FULL);
    }