i965/fs: Fix and enable the instruction scheduler for 16-wide.

Most of the work of the scheduler is agnostic to wide dispatch.  It
operates on our virtual GRF file, which means instructions are
generally referring to 8 or 16 wide naturally.  For the MRF file
management we're trying to track the actual hardware MRF file, so we
need to watch if an instruction writes multiple MRFs.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

diff --git a/src/mesa/drivers/dri/i965/brw_fs_schedule_instructions.cpp b/src/mesa/drivers/dri/i965/brw_fs_schedule_instructions.cpp
index 400452d..fb1192c 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_fs_schedule_instructions.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_schedule_instructions.cpp
@@ -145,6 +145,8 @@ public:
    void calculate_deps();
    void schedule_instructions(fs_inst *next_block_header);
 
+   bool is_compressed(fs_inst *inst);
+
    void *mem_ctx;
 
    int instructions_to_schedule;
@@ -234,6 +236,17 @@ instruction_scheduler::add_barrier_deps(schedule_node *n)
    }
 }
 
+/* instruction scheduling needs to be aware of when an MRF write
+ * actually writes 2 MRFs.
+ */
+bool
+instruction_scheduler::is_compressed(fs_inst *inst)
+{
+   return (v->c->dispatch_width == 16 &&
+          !inst->force_uncompressed &&
+          !inst->force_sechalf);
+}
+
 void
 instruction_scheduler::calculate_deps()
 {
@@ -297,11 +310,24 @@ instruction_scheduler::calculate_deps()
         }
         last_grf_write[inst->dst.reg] = n;
       } else if (inst->dst.file == MRF) {
-        if (last_mrf_write[inst->dst.hw_reg]) {
-           add_dep(last_mrf_write[inst->dst.hw_reg], n,
-                   last_mrf_write[inst->dst.hw_reg]->latency);
+        int reg = inst->dst.hw_reg & ~BRW_MRF_COMPR4;
+
+        if (last_mrf_write[reg]) {
+           add_dep(last_mrf_write[reg], n,
+                   last_mrf_write[reg]->latency);
+        }
+        last_mrf_write[reg] = n;
+        if (is_compressed(inst)) {
+           if (inst->dst.hw_reg & BRW_MRF_COMPR4)
+              reg += 4;
+           else
+              reg++;
+           if (last_mrf_write[reg]) {
+              add_dep(last_mrf_write[reg], n,
+                      last_mrf_write[reg]->latency);
+           }
+           last_mrf_write[reg] = n;
         }
-        last_mrf_write[inst->dst.hw_reg] = n;
       } else if (inst->dst.file != BAD_FILE) {
         add_barrier_deps(n);
       }
@@ -369,7 +395,18 @@ instruction_scheduler::calculate_deps()
       if (inst->dst.file == GRF) {
         last_grf_write[inst->dst.reg] = n;
       } else if (inst->dst.file == MRF) {
-        last_mrf_write[inst->dst.hw_reg] = n;
+        int reg = inst->dst.hw_reg & ~BRW_MRF_COMPR4;
+
+        last_mrf_write[reg] = n;
+
+        if (is_compressed(inst)) {
+           if (inst->dst.hw_reg & BRW_MRF_COMPR4)
+              reg += 4;
+           else
+              reg++;
+
+           last_mrf_write[reg] = n;
+        }
       } else if (inst->dst.file != BAD_FILE) {
         add_barrier_deps(n);
       }
@@ -463,9 +500,6 @@ fs_visitor::schedule_instructions()
    fs_inst *next_block_header = (fs_inst *)instructions.head;
    instruction_scheduler sched(this, mem_ctx, this->virtual_grf_next);
 
-   if (c->dispatch_width == 16)
-      return;
-
    while (!next_block_header->is_tail_sentinel()) {
       /* Add things to be scheduled until we get to a new BB. */
       while (!next_block_header->is_tail_sentinel()) {