vk: Add four unit tests for our lock-free data-structures

[mesa.git] / src / mesa / drivers / dri / i965 / brw_fs_saturate_propagation.cpp

diff --git a/src/mesa/drivers/dri/i965/brw_fs_saturate_propagation.cpp b/src/mesa/drivers/dri/i965/brw_fs_saturate_propagation.cpp
index 35e677401374f94642251c1dc53c0f9a8d397baa..e406c2899e89c954b257364ad1da979f70de42d9 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_fs_saturate_propagation.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_saturate_propagation.cpp
@@ -26,18 +26,30 @@
 #include "brw_cfg.h"
 
 /** @file brw_fs_saturate_propagation.cpp
+ *
+ * Implements a pass that propagates the SAT modifier from a MOV.SAT into the
+ * instruction that produced the source of the MOV.SAT, thereby allowing the
+ * MOV's src and dst to be coalesced and the MOV removed.
+ *
+ * For instance,
+ *
+ *    ADD     tmp, src0, src1
+ *    MOV.SAT dst, tmp
+ *
+ * would be transformed into
+ *
+ *    ADD.SAT tmp, src0, src1
+ *    MOV     dst, tmp
  */
 
 static bool
 opt_saturate_propagation_local(fs_visitor *v, bblock_t *block)
 {
    bool progress = false;
-   int ip = block->start_ip - 1;
+   int ip = block->end_ip + 1;
 
-   for (fs_inst *inst = (fs_inst *)block->start;
-        inst != block->end->next;
-        inst = (fs_inst *) inst->next) {
-      ip++;
+   foreach_inst_in_block_reverse(fs_inst, inst, block) {
+      ip--;
 
       if (inst->opcode != BRW_OPCODE_MOV ||
           inst->dst.file != GRF ||
@@ -47,35 +59,38 @@ opt_saturate_propagation_local(fs_visitor *v, bblock_t *block)
           !inst->saturate)
          continue;
 
-      int src_var = v->live_intervals->var_from_reg(&inst->src[0]);
+      int src_var = v->live_intervals->var_from_reg(inst->src[0]);
       int src_end_ip = v->live_intervals->end[src_var];
-      if (src_end_ip > ip && !inst->dst.equals(inst->src[0]))
-         continue;
 
-      int scan_ip = ip;
       bool interfered = false;
-      for (fs_inst *scan_inst = (fs_inst *) inst->prev;
-           scan_inst != block->start->prev;
-           scan_inst = (fs_inst *) scan_inst->prev) {
-         scan_ip--;
+      foreach_inst_in_block_reverse_starting_from(fs_inst, scan_inst, inst, block) {
+         if (scan_inst->overwrites_reg(inst->src[0])) {
+            if (scan_inst->is_partial_write())
+               break;
 
-         if (scan_inst->dst.file == GRF &&
-             scan_inst->dst.reg == inst->src[0].reg &&
-             scan_inst->dst.reg_offset == inst->src[0].reg_offset &&
-             !scan_inst->is_partial_write()) {
-            if (scan_inst->can_do_saturate()) {
-               scan_inst->saturate = true;
+            if (scan_inst->saturate) {
                inst->saturate = false;
                progress = true;
+            } else if (src_end_ip <= ip || inst->dst.equals(inst->src[0])) {
+               if (scan_inst->can_do_saturate()) {
+                  scan_inst->saturate = true;
+                  inst->saturate = false;
+                  progress = true;
+               }
             }
             break;
          }
-         for (int i = 0; i < 3; i++) {
+         for (int i = 0; i < scan_inst->sources; i++) {
             if (scan_inst->src[i].file == GRF &&
                 scan_inst->src[i].reg == inst->src[0].reg &&
                 scan_inst->src[i].reg_offset == inst->src[0].reg_offset) {
-               interfered = true;
-               break;
+               if (scan_inst->opcode != BRW_OPCODE_MOV ||
+                   !scan_inst->saturate ||
+                   scan_inst->src[0].abs ||
+                   scan_inst->src[0].negate) {
+                  interfered = true;
+                  break;
+               }
             }
          }
 
@@ -94,15 +109,11 @@ fs_visitor::opt_saturate_propagation()
 
    calculate_live_intervals();
 
-   cfg_t cfg(&instructions);
-
-   for (int b = 0; b < cfg.num_blocks; b++) {
-      progress = opt_saturate_propagation_local(this, cfg.blocks[b])
-                 || progress;
+   foreach_block (block, cfg) {
+      progress = opt_saturate_propagation_local(this, block) || progress;
    }
 
-   if (progress)
-      invalidate_live_intervals();
+   /* Live intervals are still valid. */
 
    return progress;
 }