i965: Refactor Sandybridge implied move handling.

This was open-coded in three different places, and more are necessary.
Extract this into a function so it can be reused.

Unfortunately, not all variations were the same: in particular, one set
compression control and checked that the source register was not
ARF_NULL.  This seemed like a good idea, so all cases now do so.

diff --git a/src/mesa/drivers/dri/i965/brw_eu_emit.c b/src/mesa/drivers/dri/i965/brw_eu_emit.c
index 21ce92c917304cf959258b97fdd9e9e2fad8202c..b66359467ecc5641962bdb67ed203af7119f0925 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_eu_emit.c
+++ b/src/mesa/drivers/dri/i965/brw_eu_emit.c
@@ -52,6 +52,35 @@ static void guess_execution_size(struct brw_compile *p,
 }
 
 
+/**
+ * Prior to Sandybridge, the SEND instruction accepted non-MRF source
+ * registers, implicitly moving the operand to a message register.
+ *
+ * On Sandybridge, this is no longer the case.  This function performs the
+ * explicit move; it should be called before emitting a SEND instruction.
+ */
+static void
+gen6_resolve_implied_move(struct brw_compile *p,
+                         struct brw_reg *src,
+                         GLuint msg_reg_nr)
+{
+   struct intel_context *intel = &p->brw->intel;
+   if (intel->gen != 6)
+      return;
+
+   if (src->file == BRW_ARCHITECTURE_REGISTER_FILE && src->nr == BRW_ARF_NULL)
+      return;
+
+   brw_push_insn_state(p);
+   brw_set_mask_control(p, BRW_MASK_DISABLE);
+   brw_set_compression_control(p, BRW_COMPRESSION_NONE);
+   brw_MOV(p, retype(brw_message_reg(msg_reg_nr), BRW_REGISTER_TYPE_UD),
+          retype(*src, BRW_REGISTER_TYPE_UD));
+   brw_pop_insn_state(p);
+   *src = brw_message_reg(msg_reg_nr);
+}
+
+
 static void brw_set_dest(struct brw_compile *p,
                         struct brw_instruction *insn,
                         struct brw_reg dest)
@@ -1966,20 +1995,7 @@ void brw_SAMPLE(struct brw_compile *p,
    {
       struct brw_instruction *insn;
    
-      /* Sandybridge doesn't have the implied move for SENDs,
-       * and the first message register index comes from src0.
-       */
-      if (intel->gen >= 6) {
-        if (src0.file != BRW_ARCHITECTURE_REGISTER_FILE ||
-            src0.nr != BRW_ARF_NULL) {
-           brw_push_insn_state(p);
-           brw_set_mask_control( p, BRW_MASK_DISABLE );
-           brw_set_compression_control(p, BRW_COMPRESSION_NONE);
-           brw_MOV(p, retype(brw_message_reg(msg_reg_nr), src0.type), src0);
-           brw_pop_insn_state(p);
-        }
-        src0 = brw_message_reg(msg_reg_nr);
-      }
+      gen6_resolve_implied_move(p, &src0, msg_reg_nr);
 
       insn = next_insn(p, BRW_OPCODE_SEND);
       insn->header.predicate_control = 0; /* XXX */
@@ -2034,17 +2050,7 @@ void brw_urb_WRITE(struct brw_compile *p,
    struct intel_context *intel = &p->brw->intel;
    struct brw_instruction *insn;
 
-   /* Sandybridge doesn't have the implied move for SENDs,
-    * and the first message register index comes from src0.
-    */
-   if (intel->gen >= 6) {
-      brw_push_insn_state(p);
-      brw_set_mask_control( p, BRW_MASK_DISABLE );
-      brw_MOV(p, retype(brw_message_reg(msg_reg_nr), BRW_REGISTER_TYPE_UD),
-             retype(src0, BRW_REGISTER_TYPE_UD));
-      brw_pop_insn_state(p);
-      src0 = brw_message_reg(msg_reg_nr);
-   }
+   gen6_resolve_implied_move(p, &src0, msg_reg_nr);
 
    insn = next_insn(p, BRW_OPCODE_SEND);
 
@@ -2154,17 +2160,7 @@ void brw_ff_sync(struct brw_compile *p,
    struct intel_context *intel = &p->brw->intel;
    struct brw_instruction *insn;
 
-   /* Sandybridge doesn't have the implied move for SENDs,
-    * and the first message register index comes from src0.
-    */
-   if (intel->gen >= 6) {
-      brw_push_insn_state(p);
-      brw_set_mask_control( p, BRW_MASK_DISABLE );
-      brw_MOV(p, retype(brw_message_reg(msg_reg_nr), BRW_REGISTER_TYPE_UD),
-             retype(src0, BRW_REGISTER_TYPE_UD));
-      brw_pop_insn_state(p);
-      src0 = brw_message_reg(msg_reg_nr);
-   }
+   gen6_resolve_implied_move(p, &src0, msg_reg_nr);
 
    insn = next_insn(p, BRW_OPCODE_SEND);
    brw_set_dest(p, insn, dest);