diff options
-rw-r--r-- | src/mesa/drivers/dri/i965/brw_fs.cpp | 85 |
1 files changed, 83 insertions, 2 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp index 4de64f0927..b00930d5cf 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp @@ -417,6 +417,8 @@ public: this->virtual_grf_sizes = NULL; this->virtual_grf_next = 1; this->virtual_grf_array_size = 0; + this->virtual_grf_def = NULL; + this->virtual_grf_use = NULL; } ~fs_visitor() { @@ -450,6 +452,8 @@ public: void assign_urb_setup(); void assign_regs(); void assign_regs_trivial(); + void calculate_live_intervals(); + bool virtual_grf_interferes(int a, int b); void generate_code(); void generate_fb_write(fs_inst *inst); void generate_linterp(fs_inst *inst, struct brw_reg dst, @@ -483,6 +487,8 @@ public: int *virtual_grf_sizes; int virtual_grf_next; int virtual_grf_array_size; + int *virtual_grf_def; + int *virtual_grf_use; struct hash_table *variable_ht; ir_variable *frag_color, *frag_data, *frag_depth; @@ -2042,6 +2048,8 @@ fs_visitor::assign_regs() int class_sizes[base_reg_count]; int class_count = 0; + calculate_live_intervals(); + /* Set up the register classes. * * The base registers store a scalar value. For texture samples, @@ -2115,7 +2123,6 @@ fs_visitor::assign_regs() */ ra_set_node_class(g, 0, classes[0]); - /* FINISHME: Proper interference (live interval analysis) */ for (int i = 1; i < this->virtual_grf_next; i++) { for (int c = 0; c < class_count; c++) { if (class_sizes[c] == this->virtual_grf_sizes[i]) { @@ -2125,7 +2132,9 @@ fs_visitor::assign_regs() } for (int j = 1; j < i; j++) { - ra_add_node_interference(g, i, j); + if (virtual_grf_interferes(i, j)) { + ra_add_node_interference(g, i, j); + } } } @@ -2173,6 +2182,78 @@ fs_visitor::assign_regs() talloc_free(regs); } +void +fs_visitor::calculate_live_intervals() +{ + int num_vars = this->virtual_grf_next; + int *def = talloc_array(mem_ctx, int, num_vars); + int *use = talloc_array(mem_ctx, int, num_vars); + int loop_depth = 0; + int loop_start = 0; + + for (int i = 0; i < num_vars; i++) { + def[i] = 1 << 30; + use[i] = 0; + } + + int ip = 0; + foreach_iter(exec_list_iterator, iter, this->instructions) { + fs_inst *inst = (fs_inst *)iter.get(); + + 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) { + /* FINISHME: + * + * Patches up any vars marked for use within the loop as + * live until the end. This is conservative, as there + * will often be variables defined and used inside the + * loop but dead at the end of the loop body. + */ + for (int i = 0; i < num_vars; i++) { + if (use[i] == loop_start) { + use[i] = ip; + } + } + } + } else { + int eip = ip; + + if (loop_depth) + eip = loop_start; + + for (unsigned int i = 0; i < 3; i++) { + if (inst->src[i].file == GRF && inst->src[i].reg != 0) { + def[inst->src[i].reg] = MIN2(def[inst->src[i].reg], eip); + use[inst->src[i].reg] = MAX2(use[inst->src[i].reg], eip); + } + } + if (inst->dst.file == GRF && inst->dst.reg != 0) { + def[inst->dst.reg] = MIN2(def[inst->dst.reg], eip); + use[inst->dst.reg] = MAX2(use[inst->dst.reg], eip); + } + } + + ip++; + } + + this->virtual_grf_def = def; + this->virtual_grf_use = use; +} + +bool +fs_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]); + + return start <= end; +} + static struct brw_reg brw_reg_from_fs_reg(fs_reg *reg) { struct brw_reg brw_reg; |