From: Eric Anholt Date: Wed, 4 May 2011 20:50:13 +0000 (-0700) Subject: i965/fs: Eliminate the magic nature of virtual GRF 0. X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=b76378d46a211521582cfab56dc05031a57502a6;p=mesa.git i965/fs: Eliminate the magic nature of virtual GRF 0. This was a debugging aid at one point -- virtual grf 0 should never be allocated, and it would be used if undefined register access occurred in codegen. However, it made the confusing register allocation code even more confusing by indexing things off of 1 all over. --- diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp index f55be022f72..d57a67cc4fc 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp @@ -181,9 +181,6 @@ fs_visitor::virtual_grf_alloc(int size) virtual_grf_array_size *= 2; virtual_grf_sizes = reralloc(mem_ctx, virtual_grf_sizes, int, virtual_grf_array_size); - - /* This slot is always unused. */ - virtual_grf_sizes[0] = 0; } virtual_grf_sizes[virtual_grf_next] = size; return virtual_grf_next++; @@ -985,7 +982,7 @@ fs_visitor::calculate_live_intervals() } } else { for (unsigned int i = 0; i < 3; i++) { - if (inst->src[i].file == GRF && inst->src[i].reg != 0) { + if (inst->src[i].file == GRF) { int reg = inst->src[i].reg; if (!loop_depth) { @@ -1001,7 +998,7 @@ fs_visitor::calculate_live_intervals() } } } - if (inst->dst.file == GRF && inst->dst.reg != 0) { + if (inst->dst.file == GRF) { int reg = inst->dst.reg; if (!loop_depth) { @@ -1715,7 +1712,7 @@ fs_visitor::run() if (0) { /* Debug of register spilling: Go spill everything. */ int virtual_grf_count = virtual_grf_next; - for (int i = 1; i < virtual_grf_count; i++) { + for (int i = 0; i < virtual_grf_count; i++) { spill_reg(i); } } diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h index 96e1420038f..0375f672bec 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.h +++ b/src/mesa/drivers/dri/i965/brw_fs.h @@ -402,7 +402,7 @@ public: this->base_ir = NULL; this->virtual_grf_sizes = NULL; - this->virtual_grf_next = 1; + this->virtual_grf_next = 0; this->virtual_grf_array_size = 0; this->virtual_grf_def = NULL; this->virtual_grf_use = NULL; 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 f246ac49660..83dd629aafb 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp @@ -50,7 +50,7 @@ extern "C" { static void assign_reg(int *reg_hw_locations, fs_reg *reg, int reg_width) { - if (reg->file == GRF && reg->reg != 0) { + if (reg->file == GRF) { assert(reg->reg_offset >= 0); reg->hw_reg = reg_hw_locations[reg->reg] + reg->reg_offset * reg_width; reg->reg = 0; @@ -60,20 +60,17 @@ assign_reg(int *reg_hw_locations, fs_reg *reg, int reg_width) void fs_visitor::assign_regs_trivial() { - int last_grf = 0; - int hw_reg_mapping[this->virtual_grf_next]; + int hw_reg_mapping[this->virtual_grf_next + 1]; int i; int reg_width = c->dispatch_width / 8; - hw_reg_mapping[0] = 0; /* Note that compressed instructions require alignment to 2 registers. */ - hw_reg_mapping[1] = ALIGN(this->first_non_payload_grf, reg_width); - for (i = 2; i < this->virtual_grf_next; i++) { + hw_reg_mapping[0] = ALIGN(this->first_non_payload_grf, reg_width); + for (i = 1; i <= this->virtual_grf_next; i++) { hw_reg_mapping[i] = (hw_reg_mapping[i - 1] + this->virtual_grf_sizes[i - 1] * reg_width); } - last_grf = hw_reg_mapping[i - 1] + (this->virtual_grf_sizes[i - 1] * - reg_width); + this->grf_used = hw_reg_mapping[this->virtual_grf_next]; foreach_list(node, &this->instructions) { fs_inst *inst = (fs_inst *)node; @@ -83,12 +80,11 @@ fs_visitor::assign_regs_trivial() assign_reg(hw_reg_mapping, &inst->src[1], reg_width); } - if (last_grf >= BRW_MAX_GRF) { + if (this->grf_used >= BRW_MAX_GRF) { fail("Ran out of regs on trivial allocator (%d/%d)\n", - last_grf, BRW_MAX_GRF); + this->grf_used, BRW_MAX_GRF); } - this->grf_used = last_grf + reg_width; } bool @@ -101,7 +97,7 @@ fs_visitor::assign_regs() * for reg_width == 2. */ int reg_width = c->dispatch_width / 8; - int hw_reg_mapping[this->virtual_grf_next + 1]; + int hw_reg_mapping[this->virtual_grf_next]; int first_assigned_grf = ALIGN(this->first_non_payload_grf, reg_width); int base_reg_count = (BRW_MAX_GRF - first_assigned_grf) / reg_width; int class_sizes[base_reg_count]; @@ -125,7 +121,7 @@ fs_visitor::assign_regs() */ class_sizes[class_count++] = 2; } - for (int r = 1; r < this->virtual_grf_next; r++) { + for (int r = 0; r < this->virtual_grf_next; r++) { int i; for (i = 0; i < class_count; i++) { @@ -195,12 +191,8 @@ fs_visitor::assign_regs() struct ra_graph *g = ra_alloc_interference_graph(regs, this->virtual_grf_next); - /* Node 0 is just a placeholder to keep virtual_grf[] mapping 1:1 - * with nodes. - */ - ra_set_node_class(g, 0, classes[0]); - for (int i = 1; i < this->virtual_grf_next; i++) { + for (int i = 0; i < this->virtual_grf_next; i++) { for (int c = 0; c < class_count; c++) { if (class_sizes[c] == this->virtual_grf_sizes[i]) { if (aligned_pair_class >= 0 && @@ -213,7 +205,7 @@ fs_visitor::assign_regs() } } - for (int j = 1; j < i; j++) { + for (int j = 0; j < i; j++) { if (virtual_grf_interferes(i, j)) { ra_add_node_interference(g, i, j); } @@ -248,8 +240,7 @@ fs_visitor::assign_regs() * numbers. */ this->grf_used = first_assigned_grf; - hw_reg_mapping[0] = 0; /* unused */ - for (int i = 1; i < this->virtual_grf_next; i++) { + for (int i = 0; i < this->virtual_grf_next; i++) { int reg = ra_get_node_reg(g, i); int hw_reg = -1; diff --git a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp index 2b769ccbba1..2e3f9be75b4 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp @@ -142,9 +142,7 @@ fs_visitor::visit(ir_dereference_array *ir) this->result.type = brw_type_for_base_type(ir->type); if (index) { - assert(this->result.file == UNIFORM || - (this->result.file == GRF && - this->result.reg != 0)); + assert(this->result.file == UNIFORM || this->result.file == GRF); this->result.reg_offset += index->value.i[0] * element_size; } else { assert(!"FINISHME: non-constant array element");