i965: rewrite the code for handling shader subroutine calls

Previously, the prog_instruction::Data field was used to map original Mesa
instructions to brw instructions in order to resolve subroutine calls.  This
was a rather tangled mess.  Plus it's an obstacle to implementing dynamic
allocation/growing of the instruction buffer (it's still a fixed size).

Mesa's GLSL compiler emits a label for each subroutine and CAL instruction.
Now we use those labels to patch the subroutine calls after code generation
has been done.  We just keep a list of all CAL instructions that needs patching
and a list of all subroutine labels.  It's a simple matter to resolve them.

This also consolidates some redundant post-emit code between brw_vs_emit.c and
brw_wm_glsl.c and removes some loops that cleared the prog_instruction::Data
fields at the end.

Plus, a bunch of new comments.

1 files changed, 18 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_eu.h b/src/mesa/drivers/dri/i965/brw_eu.h
index 9e2b39af9b..b36a1976ef 100644
--- a/src/mesa/drivers/dri/i965/brw_eu.h
+++ b/src/mesa/drivers/dri/i965/brw_eu.h
@@ -91,6 +91,11 @@ struct brw_indirect {
 };
 
 
+struct brw_glsl_label;
+struct brw_glsl_call;
+
+
+
 #define BRW_EU_MAX_INSN_STACK 5
 #define BRW_EU_MAX_INSN 1200
 
@@ -106,9 +111,22 @@ struct brw_compile {
    GLuint flag_value;
    GLboolean single_program_flow;
    struct brw_context *brw;
+
+   struct brw_glsl_label *first_label;  /**< linked list of labels */
+   struct brw_glsl_call *first_call;    /**< linked list of CALs */
 };
 
 
+void
+brw_save_label(struct brw_compile *c, const char *name, GLuint position);
+
+void
+brw_save_call(struct brw_compile *c, const char *name, GLuint call_pos);
+
+void
+brw_resolve_cals(struct brw_compile *c);
+
+
 
 static INLINE int type_sz( GLuint type )
 {