[Mesa-dev] [PATCH 14/16] i965: Compute the number of live registers at each IP.

[Matt Turner]

From: Kenneth Graunke <kenneth at whitecape.org>

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
 src/mesa/drivers/dri/i965/brw_fs.cpp         | 18 ++++++++++++++++++
 src/mesa/drivers/dri/i965/brw_fs.h           |  3 +++
 src/mesa/drivers/dri/i965/brw_fs_visitor.cpp |  1 +
 3 files changed, 22 insertions(+)

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index 12b6d4a..2c7b3ae 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -3219,6 +3219,24 @@ fs_visitor::assign_binding_table_offsets()
    assign_common_binding_table_offsets(next_binding_table_offset);
 }
 
+void
+fs_visitor::calculate_register_pressure()
+{
+   calculate_live_intervals();
+
+   int num_instructions = 0;
+   foreach_list(node, &this->instructions) {
+      ++num_instructions;
+   }
+
+   regs_live_at_ip = rzalloc_array(mem_ctx, int, num_instructions);
+
+   for (int reg = 0; reg < virtual_grf_count; reg++) {
+      for (int ip = virtual_grf_start[reg]; ip <= virtual_grf_end[reg]; ip++)
+         regs_live_at_ip[ip] += virtual_grf_sizes[reg];
+   }
+}
+
 bool
 fs_visitor::run()
 {
diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h
index 07360ae..bee8cdf 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.h
+++ b/src/mesa/drivers/dri/i965/brw_fs.h
@@ -309,6 +309,7 @@ public:
    void setup_pull_constants();
    void invalidate_live_intervals();
    void calculate_live_intervals();
+   void calculate_register_pressure();
    bool opt_algebraic();
    bool opt_cse();
    bool opt_cse_local(bblock_t *block, exec_list *aeb);
@@ -447,6 +448,8 @@ public:
    int *virtual_grf_end;
    brw::fs_live_variables *live_intervals;
 
+   int *regs_live_at_ip;
+
    /* This is the map from UNIFORM hw_reg + reg_offset as generated by
     * the visitor to the packed uniform number after
     * remove_dead_constants() that represents the actual uploaded
diff --git a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
index 869b636..c5bacc2 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
@@ -2933,6 +2933,7 @@ fs_visitor::fs_visitor(struct brw_context *brw,
    this->virtual_grf_start = NULL;
    this->virtual_grf_end = NULL;
    this->live_intervals = NULL;
+   this->regs_live_at_ip = NULL;
 
    this->params_remap = NULL;
    this->nr_params_remap = 0;
-- 
1.8.3.2