tgsi: add missing functionality to support instructions with labels

Could previously emit opcodes with label arguments, but was no way to
patch them with the actual destinations of those labels.

Adds two functions:

  ureg_get_instruction_number - to get the id of the next instruction
     to be emitted

  ureg_fixup_label - to patch an emitted label to point to a given
     instruction number.

Need some more complex examples than u_simple_shader, so far this has
only been compile-tested.

src/gallium/auxiliary/tgsi/tgsi_ureg.c

@@ -103,6 +103,7 @@ struct ureg_program
 
    unsigned nr_constants;
    unsigned nr_samplers;
+   unsigned nr_instructions;
 
    struct ureg_tokens domain[2];
 };
@@ -525,7 +526,9 @@ ureg_emit_insn(struct ureg_program *ureg,
    out[0].insn.NumSrcRegs = num_src;
    out[0].insn.Padding = 0;
    out[0].insn.Extended = 0;
-
+   
+   ureg->nr_instructions++;
+   
    return ureg->domain[DOMAIN_INSN].count - 1;
 }
 
@@ -544,6 +547,31 @@ ureg_emit_label(struct ureg_program *ureg,
 
    out[0].value = 0;
    out[0].insn_ext_label.Type = TGSI_INSTRUCTION_EXT_TYPE_LABEL;
+   
+   *label_token = ureg->domain[DOMAIN_INSN].count - 1;
+}
+
+/* Will return a number which can be used in a label to point to the
+ * next instruction to be emitted.
+ */
+unsigned
+ureg_get_instruction_number( struct ureg_program *ureg )
+{
+   return ureg->nr_instructions;
+}
+
+/* Patch a given label (expressed as a token number) to point to a
+ * given instruction (expressed as an instruction number).
+ */
+void
+ureg_fixup_label(struct ureg_program *ureg,
+                 unsigned label_token,
+                 unsigned instruction_number )
+{
+   union tgsi_any_token *out = retrieve_token( ureg, DOMAIN_INSN, label_token );
+
+   assert(out->insn_ext_label.Type == TGSI_INSTRUCTION_EXT_TYPE_LABEL);
+   out->insn_ext_label.Label = instruction_number;
 }
 
 
@@ -571,6 +599,7 @@ ureg_fixup_insn_size(struct ureg_program *ureg,
 {
    union tgsi_any_token *out = retrieve_token( ureg, DOMAIN_INSN, insn );
 
+   assert(out->insn.Type == TGSI_TOKEN_TYPE_INSTRUCTION);
    out->insn.NrTokens = ureg->domain[DOMAIN_INSN].count - insn - 1;
 }
 

src/gallium/auxiliary/tgsi/tgsi_ureg.h

@@ -174,6 +174,33 @@ ureg_DECL_immediate1f( struct ureg_program *ureg,
    return ureg_DECL_immediate( ureg, v, 1 );
 }
 
+/***********************************************************************
+ * Functions for patching up labels
+ */
+
+
+/* Will return a number which can be used in a label to point to the
+ * next instruction to be emitted.
+ */
+unsigned
+ureg_get_instruction_number( struct ureg_program *ureg );
+
+
+/* Patch a given label (expressed as a token number) to point to a
+ * given instruction (expressed as an instruction number).
+ *
+ * Labels are obtained from instruction emitters, eg ureg_CAL().
+ * Instruction numbers are obtained from ureg_get_instruction_number(),
+ * above.
+ */
+void
+ureg_fixup_label(struct ureg_program *ureg,
+                 unsigned label_token,
+                 unsigned instruction_number );
+
+
+
+
 /***********************************************************************
  * Internal instruction helpers, don't call these directly:
  */