i965/vs: Improve live interval calculation.

This is derived from the FS visitor code for the same, but tracks each channel
separately (otherwise, some typical fill-a-channel-at-a-time patterns would
produce excessive live intervals across loops and cause spilling).

Reviewed-by: Kenneth Graunke <[email protected]>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=48375
          (crash -> failure, can turn into pass by forcing unrolling still)

1 files changed, 0 insertions, 96 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_vec4.cpp b/src/mesa/drivers/dri/i965/brw_vec4.cpp
index 727d980c314..9eed5993027 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4.cpp
@@ -265,102 +265,6 @@ src_reg::equals(src_reg *r)
 	   imm.u == r->imm.u);
 }
 
-void
-vec4_visitor::calculate_live_intervals()
-{
-   int *def = ralloc_array(mem_ctx, int, virtual_grf_count);
-   int *use = ralloc_array(mem_ctx, int, virtual_grf_count);
-   int loop_depth = 0;
-   int loop_start = 0;
-
-   if (this->live_intervals_valid)
-      return;
-
-   for (int i = 0; i < virtual_grf_count; i++) {
-      def[i] = MAX_INSTRUCTION;
-      use[i] = -1;
-   }
-
-   int ip = 0;
-   foreach_list(node, &this->instructions) {
-      vec4_instruction *inst = (vec4_instruction *)node;
-
-      if (inst->opcode == BRW_OPCODE_DO) {
-	 if (loop_depth++ == 0)
-	    loop_start = ip;
-      } else if (inst->opcode == BRW_OPCODE_WHILE) {
-	 loop_depth--;
-
-	 if (loop_depth == 0) {
-	    /* Patches up the use of vars marked for being live across
-	     * the whole loop.
-	     */
-	    for (int i = 0; i < virtual_grf_count; i++) {
-	       if (use[i] == loop_start) {
-		  use[i] = ip;
-	       }
-	    }
-	 }
-      } else {
-	 for (unsigned int i = 0; i < 3; i++) {
-	    if (inst->src[i].file == GRF) {
-	       int reg = inst->src[i].reg;
-
-	       if (!loop_depth) {
-		  use[reg] = ip;
-	       } else {
-		  def[reg] = MIN2(loop_start, def[reg]);
-		  use[reg] = loop_start;
-
-		  /* Nobody else is going to go smash our start to
-		   * later in the loop now, because def[reg] now
-		   * points before the bb header.
-		   */
-	       }
-	    }
-	 }
-	 if (inst->dst.file == GRF) {
-	    int reg = inst->dst.reg;
-
-	    if (!loop_depth) {
-	       def[reg] = MIN2(def[reg], ip);
-	    } else {
-	       def[reg] = MIN2(def[reg], loop_start);
-	    }
-	 }
-      }
-
-      ip++;
-   }
-
-   ralloc_free(this->virtual_grf_def);
-   ralloc_free(this->virtual_grf_use);
-   this->virtual_grf_def = def;
-   this->virtual_grf_use = use;
-
-   this->live_intervals_valid = true;
-}
-
-bool
-vec4_visitor::virtual_grf_interferes(int a, int b)
-{
-   int start = MAX2(this->virtual_grf_def[a], this->virtual_grf_def[b]);
-   int end = MIN2(this->virtual_grf_use[a], this->virtual_grf_use[b]);
-
-   /* We can't handle dead register writes here, without iterating
-    * over the whole instruction stream to find every single dead
-    * write to that register to compare to the live interval of the
-    * other register.  Just assert that dead_code_eliminate() has been
-    * called.
-    */
-   assert((this->virtual_grf_use[a] != -1 ||
-	   this->virtual_grf_def[a] == MAX_INSTRUCTION) &&
-	  (this->virtual_grf_use[b] != -1 ||
-	   this->virtual_grf_def[b] == MAX_INSTRUCTION));
-
-   return start < end;
-}
-
 /**
  * Must be called after calculate_live_intervales() to remove unused
  * writes to registers -- register allocation will fail otherwise