diff options
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_fs.cpp | 21 | ||||
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_fs.h | 4 | ||||
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_fs_cse.cpp | 2 | ||||
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_fs_live_variables.cpp | 76 | ||||
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp | 3 | ||||
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_fs_visitor.cpp | 4 |
6 files changed, 38 insertions, 72 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp index 778a69e7091..baaa25c1347 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp @@ -1456,8 +1456,8 @@ fs_visitor::compact_virtual_grfs() remap_table[i] = new_index; virtual_grf_sizes[new_index] = virtual_grf_sizes[i]; if (live_intervals_valid) { - virtual_grf_use[new_index] = virtual_grf_use[i]; - virtual_grf_def[new_index] = virtual_grf_def[i]; + virtual_grf_start[new_index] = virtual_grf_start[i]; + virtual_grf_end[new_index] = virtual_grf_end[i]; } ++new_index; } @@ -1771,10 +1771,8 @@ fs_visitor::opt_algebraic() } /** - * Must be called after calculate_live_intervales() to remove unused - * writes to registers -- register allocation will fail otherwise - * because something deffed but not used won't be considered to - * interfere with other regs. + * Removes any instructions writing a VGRF where that VGRF is not used by any + * later instruction. */ bool fs_visitor::dead_code_eliminate() @@ -1787,9 +1785,12 @@ fs_visitor::dead_code_eliminate() foreach_list_safe(node, &this->instructions) { fs_inst *inst = (fs_inst *)node; - if (inst->dst.file == GRF && this->virtual_grf_use[inst->dst.reg] <= pc) { - inst->remove(); - progress = true; + if (inst->dst.file == GRF) { + assert(this->virtual_grf_end[inst->dst.reg] >= pc); + if (this->virtual_grf_end[inst->dst.reg] == pc) { + inst->remove(); + progress = true; + } } pc++; @@ -2201,7 +2202,7 @@ fs_visitor::compute_to_mrf() /* Can't compute-to-MRF this GRF if someone else was going to * read it later. */ - if (this->virtual_grf_use[inst->src[0].reg] > ip) + if (this->virtual_grf_end[inst->src[0].reg] > ip) continue; /* Found a move of a GRF to a MRF. Let's see if we can go diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h index 9a2bcc07685..3d44daf8545 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.h +++ b/src/mesa/drivers/dri/i965/brw_fs.h @@ -430,8 +430,8 @@ public: int *virtual_grf_sizes; int virtual_grf_count; int virtual_grf_array_size; - int *virtual_grf_def; - int *virtual_grf_use; + int *virtual_grf_start; + int *virtual_grf_end; bool live_intervals_valid; /* This is the map from UNIFORM hw_reg + reg_offset as generated by diff --git a/src/mesa/drivers/dri/i965/brw_fs_cse.cpp b/src/mesa/drivers/dri/i965/brw_fs_cse.cpp index b5c220090cf..9b60d9be41b 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_cse.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_cse.cpp @@ -194,7 +194,7 @@ fs_visitor::opt_cse_local(bblock_t *block, exec_list *aeb) /* Kill any AEB entries using registers that don't get reused any * more -- a sure sign they'll fail operands_match(). */ - if (src_reg->file == GRF && virtual_grf_use[src_reg->reg] < ip) { + if (src_reg->file == GRF && virtual_grf_end[src_reg->reg] < ip) { entry->remove(); ralloc_free(entry); break; diff --git a/src/mesa/drivers/dri/i965/brw_fs_live_variables.cpp b/src/mesa/drivers/dri/i965/brw_fs_live_variables.cpp index fdcfac61194..3daf8fa7786 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_live_variables.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_live_variables.cpp @@ -167,16 +167,16 @@ fs_visitor::calculate_live_intervals() if (this->live_intervals_valid) return; - int *def = ralloc_array(mem_ctx, int, num_vars); - int *use = ralloc_array(mem_ctx, int, num_vars); - ralloc_free(this->virtual_grf_def); - ralloc_free(this->virtual_grf_use); - this->virtual_grf_def = def; - this->virtual_grf_use = use; + int *start = ralloc_array(mem_ctx, int, num_vars); + int *end = ralloc_array(mem_ctx, int, num_vars); + ralloc_free(this->virtual_grf_start); + ralloc_free(this->virtual_grf_end); + this->virtual_grf_start = start; + this->virtual_grf_end = end; for (int i = 0; i < num_vars; i++) { - def[i] = MAX_INSTRUCTION; - use[i] = -1; + start[i] = MAX_INSTRUCTION; + end[i] = -1; } /* Start by setting up the intervals with no knowledge of control @@ -189,8 +189,7 @@ fs_visitor::calculate_live_intervals() for (unsigned int i = 0; i < 3; i++) { if (inst->src[i].file == GRF) { int reg = inst->src[i].reg; - - use[reg] = ip; + int end_ip = ip; /* In most cases, a register can be written over safely by the * same instruction that is its last use. For a single @@ -220,15 +219,19 @@ fs_visitor::calculate_live_intervals() if (dispatch_width == 16 && (inst->src[i].smear || (this->pixel_x.reg == reg || this->pixel_y.reg == reg))) { - use[reg]++; + end_ip++; } + + start[reg] = MIN2(start[reg], ip); + end[reg] = MAX2(end[reg], end_ip); } } if (inst->dst.file == GRF) { int reg = inst->dst.reg; - def[reg] = MIN2(def[reg], ip); + start[reg] = MIN2(start[reg], ip); + end[reg] = MAX2(end[reg], ip); } ip++; @@ -241,60 +244,23 @@ fs_visitor::calculate_live_intervals() for (int b = 0; b < cfg.num_blocks; b++) { for (int i = 0; i < num_vars; i++) { if (BITSET_TEST(livevars.bd[b].livein, i)) { - def[i] = MIN2(def[i], cfg.blocks[b]->start_ip); - use[i] = MAX2(use[i], cfg.blocks[b]->start_ip); + start[i] = MIN2(start[i], cfg.blocks[b]->start_ip); + end[i] = MAX2(end[i], cfg.blocks[b]->start_ip); } if (BITSET_TEST(livevars.bd[b].liveout, i)) { - def[i] = MIN2(def[i], cfg.blocks[b]->end_ip); - use[i] = MAX2(use[i], cfg.blocks[b]->end_ip); + start[i] = MIN2(start[i], cfg.blocks[b]->end_ip); + end[i] = MAX2(end[i], cfg.blocks[b]->end_ip); } } } this->live_intervals_valid = true; - - /* Note in the non-control-flow code above, that we only take def[] as the - * first store, and use[] as the last use. We use this in dead code - * elimination, to determine when a store never gets used. However, we - * also use these arrays to answer the virtual_grf_interferes() question - * (live interval analysis), which is used for register coalescing and - * register allocation. - * - * So, there's a conflict over what the array should mean: if use[] - * considers a def after the last use, then the dead code elimination pass - * never does anything (and it's an important pass!). But if we don't - * include dead code, then virtual_grf_interferes() lies and we'll do - * horrible things like coalesce the register that is dead-code-written - * into another register that was live across the dead write (causing the - * use of the second register to take the dead write's source value instead - * of the coalesced MOV's source value). - * - * To resolve the conflict, immediately after calculating live intervals, - * detect dead code, nuke it, and if we changed anything, calculate again - * before returning to the caller. Now we happen to produce def[] and - * use[] arrays that will work for virtual_grf_interferes(). - */ - if (dead_code_eliminate()) - calculate_live_intervals(); } bool fs_visitor::virtual_grf_interferes(int a, int b) { - int a_def = this->virtual_grf_def[a], a_use = this->virtual_grf_use[a]; - int b_def = this->virtual_grf_def[b], b_use = this->virtual_grf_use[b]; - - /* If there's dead code (def but not use), it would break our test - * unless we consider it used. - */ - if ((a_use == -1 && a_def != MAX_INSTRUCTION) || - (b_use == -1 && b_def != MAX_INSTRUCTION)) { - return true; - } - - int start = MAX2(a_def, b_def); - int end = MIN2(a_use, b_use); - - return start < end; + return !(virtual_grf_end[a] <= virtual_grf_start[b] || + virtual_grf_end[b] <= virtual_grf_start[a]); } diff --git a/src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp b/src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp index fa1a93820d2..acd98466860 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp @@ -316,8 +316,7 @@ fs_visitor::setup_payload_interference(struct ra_graph *g, * in order to not have to worry about the uniform issue described in * calculate_live_intervals(). */ - if (this->virtual_grf_def[j] <= payload_last_use_ip[i] || - this->virtual_grf_use[j] <= payload_last_use_ip[i]) { + if (this->virtual_grf_start[j] <= payload_last_use_ip[i]) { ra_add_node_interference(g, first_payload_node + i, j); } } diff --git a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp index d2bac2a3def..b7bbaabf699 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp @@ -2451,8 +2451,8 @@ fs_visitor::fs_visitor(struct brw_context *brw, this->virtual_grf_sizes = NULL; this->virtual_grf_count = 0; this->virtual_grf_array_size = 0; - this->virtual_grf_def = NULL; - this->virtual_grf_use = NULL; + this->virtual_grf_start = NULL; + this->virtual_grf_end = NULL; this->live_intervals_valid = false; this->force_uncompressed_stack = 0; |