[Mesa-dev] [PATCH 3/4] st_glsl_to_tgsi: rewrite rename registers to use array fully.

[Dave Airlie]

From: Dave Airlie <airlied at redhat.com>

Instead of having to search the whole array, just use the whole
thing and store a valid bit in there with the rename.

Removes this from the profile on some of the fp64 tests
---
 src/mesa/state_tracker/st_glsl_to_tgsi.cpp | 51 +++++++++++++++---------------
 1 file changed, 25 insertions(+), 26 deletions(-)

diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index 8835dc2..0e59aca 100644
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -388,7 +388,7 @@ find_array_type(struct inout_decl *decls, unsigned count, unsigned array_id)
 }
 
 struct rename_reg_pair {
-   int old_reg;
+   bool valid;
    int new_reg;
 };
 
@@ -556,7 +556,7 @@ public:
 
    void simplify_cmp(void);
 
-   void rename_temp_registers(int num_renames, struct rename_reg_pair *renames);
+   void rename_temp_registers(struct rename_reg_pair *renames);
    void get_first_temp_read(int *first_reads);
    void get_last_temp_read_first_temp_write(int *last_reads, int *first_writes);
    void get_last_temp_write(int *last_writes);
@@ -4746,30 +4746,32 @@ glsl_to_tgsi_visitor::simplify_cmp(void)
 
 /* Replaces all references to a temporary register index with another index. */
 void
-glsl_to_tgsi_visitor::rename_temp_registers(int num_renames, struct rename_reg_pair *renames)
+glsl_to_tgsi_visitor::rename_temp_registers(struct rename_reg_pair *renames)
 {
    foreach_in_list(glsl_to_tgsi_instruction, inst, &this->instructions) {
       unsigned j;
-      int k;
       for (j = 0; j < num_inst_src_regs(inst); j++) {
-         if (inst->src[j].file == PROGRAM_TEMPORARY)
-            for (k = 0; k < num_renames; k++)
-               if (inst->src[j].index == renames[k].old_reg)
-                  inst->src[j].index = renames[k].new_reg;
+         if (inst->src[j].file == PROGRAM_TEMPORARY) {
+            int old_idx = inst->src[j].index;
+            if (renames[old_idx].valid)
+               inst->src[j].index = renames[old_idx].new_reg;
+         }
       }
 
       for (j = 0; j < inst->tex_offset_num_offset; j++) {
-         if (inst->tex_offsets[j].file == PROGRAM_TEMPORARY)
-            for (k = 0; k < num_renames; k++)
-               if (inst->tex_offsets[j].index == renames[k].old_reg)
-                  inst->tex_offsets[j].index = renames[k].new_reg;
+         if (inst->tex_offsets[j].file == PROGRAM_TEMPORARY) {
+            int old_idx = inst->tex_offsets[j].index;
+            if (renames[old_idx].valid)
+               inst->tex_offsets[j].index = renames[old_idx].new_reg;
+         }
       }
 
       for (j = 0; j < num_inst_dst_regs(inst); j++) {
-         if (inst->dst[j].file == PROGRAM_TEMPORARY)
-             for (k = 0; k < num_renames; k++)
-                if (inst->dst[j].index == renames[k].old_reg)
-                   inst->dst[j].index = renames[k].new_reg;
+         if (inst->dst[j].file == PROGRAM_TEMPORARY) {
+            int old_idx = inst->dst[j].index;
+            if (renames[old_idx].valid)
+               inst->dst[j].index = renames[old_idx].new_reg;
+         }
       }
    }
 }
@@ -5402,7 +5404,6 @@ glsl_to_tgsi_visitor::merge_registers(void)
    int *first_writes = rzalloc_array(mem_ctx, int, this->next_temp);
    struct rename_reg_pair *renames = rzalloc_array(mem_ctx, struct rename_reg_pair, this->next_temp);
    int i, j;
-   int num_renames = 0;
 
    /* Read the indices of the last read and first write to each temp register
     * into an array so that we don't have to traverse the instruction list as
@@ -5429,9 +5430,8 @@ glsl_to_tgsi_visitor::merge_registers(void)
           * as the register at index j. */
          if (first_writes[i] <= first_writes[j] &&
              last_reads[i] <= first_writes[j]) {
-            renames[num_renames].old_reg = j;
-            renames[num_renames].new_reg = i;
-            num_renames++;
+            renames[j].new_reg = i;
+            renames[j].valid = true;
 
             /* Update the first_writes and last_reads arrays with the new
              * values for the merged register index, and mark the newly unused
@@ -5444,7 +5444,7 @@ glsl_to_tgsi_visitor::merge_registers(void)
       }
    }
 
-   rename_temp_registers(num_renames, renames);
+   rename_temp_registers(renames);
    ralloc_free(renames);
    ralloc_free(last_reads);
    ralloc_free(first_writes);
@@ -5459,7 +5459,7 @@ glsl_to_tgsi_visitor::renumber_registers(void)
    int new_index = 0;
    int *first_reads = rzalloc_array(mem_ctx, int, this->next_temp);
    struct rename_reg_pair *renames = rzalloc_array(mem_ctx, struct rename_reg_pair, this->next_temp);
-   int num_renames = 0;
+
    for (i = 0; i < this->next_temp; i++) {
       first_reads[i] = -1;
    }
@@ -5468,14 +5468,13 @@ glsl_to_tgsi_visitor::renumber_registers(void)
    for (i = 0; i < this->next_temp; i++) {
       if (first_reads[i] < 0) continue;
       if (i != new_index) {
-         renames[num_renames].old_reg = i;
-         renames[num_renames].new_reg = new_index;
-         num_renames++;
+         renames[i].new_reg = new_index;
+         renames[i].valid = true;
       }
       new_index++;
    }
 
-   rename_temp_registers(num_renames, renames);
+   rename_temp_registers(renames);
    this->next_temp = new_index;
    ralloc_free(renames);
    ralloc_free(first_reads);
-- 
2.1.0