diff options
| -rw-r--r-- | src/glsl/Makefile | 1 | ||||
| -rw-r--r-- | src/glsl/ir_div_to_mul_rcp.cpp | 77 | ||||
| -rw-r--r-- | src/glsl/ir_optimization.h | 1 | ||||
| -rw-r--r-- | src/mesa/shader/ir_to_mesa.cpp | 5 |
4 files changed, 81 insertions, 3 deletions
diff --git a/src/glsl/Makefile b/src/glsl/Makefile index a709bf7121e..30ba475d923 100644 --- a/src/glsl/Makefile +++ b/src/glsl/Makefile @@ -33,6 +33,7 @@ CXX_SOURCES = \ ir.cpp \ ir_dead_code.cpp \ ir_dead_code_local.cpp \ + ir_div_to_mul_rcp.cpp \ ir_expression_flattening.cpp \ ir_function_can_inline.cpp \ ir_function.cpp \ diff --git a/src/glsl/ir_div_to_mul_rcp.cpp b/src/glsl/ir_div_to_mul_rcp.cpp new file mode 100644 index 00000000000..ce84add2213 --- /dev/null +++ b/src/glsl/ir_div_to_mul_rcp.cpp @@ -0,0 +1,77 @@ +/* + * Copyright © 2010 Intel Corporation + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + */ + +/** + * \file ir_div_to_mul_rcp.cpp + * + * Breaks an ir_unop_div expression down to op0 * (rcp(op1)). + * + * Many GPUs don't have a divide instruction (945 and 965 included), + * but they do have an RCP instruction to compute an approximate + * reciprocal. By breaking the operation down, constant reciprocals + * can get constant folded. + */ + +#include "ir.h" + +class ir_div_to_mul_rcp_visitor : public ir_hierarchical_visitor { +public: + ir_div_to_mul_rcp_visitor() + { + this->made_progress = false; + } + + ir_visitor_status visit_leave(ir_expression *); + + bool made_progress; +}; + +bool +do_div_to_mul_rcp(exec_list *instructions) +{ + ir_div_to_mul_rcp_visitor v; + + visit_list_elements(&v, instructions); + return v.made_progress; +} + +ir_visitor_status +ir_div_to_mul_rcp_visitor::visit_leave(ir_expression *ir) +{ + if (ir->operation != ir_binop_div) + return visit_continue; + + /* New expression for the 1.0 / op1 */ + ir_rvalue *expr; + expr = new(ir) ir_expression(ir_unop_rcp, + ir->operands[1]->type, + ir->operands[1], + NULL); + + /* op0 / op1 -> op0 * (1.0 / op1) */ + ir->operation = ir_binop_mul; + ir->operands[1] = expr; + this->made_progress = true; + + return visit_continue; +} diff --git a/src/glsl/ir_optimization.h b/src/glsl/ir_optimization.h index 1a8b740566b..6d02e591c3d 100644 --- a/src/glsl/ir_optimization.h +++ b/src/glsl/ir_optimization.h @@ -37,6 +37,7 @@ bool do_dead_code(struct _mesa_glsl_parse_state *state, bool do_dead_code_local(exec_list *instructions); bool do_dead_code_unlinked(struct _mesa_glsl_parse_state *state, exec_list *instructions); +bool do_div_to_mul_rcp(exec_list *instructions); bool do_function_inlining(exec_list *instructions); bool do_if_simplification(exec_list *instructions); bool do_mod_to_fract(exec_list *instructions); diff --git a/src/mesa/shader/ir_to_mesa.cpp b/src/mesa/shader/ir_to_mesa.cpp index 7c7e368d0d5..d5664e7b91e 100644 --- a/src/mesa/shader/ir_to_mesa.cpp +++ b/src/mesa/shader/ir_to_mesa.cpp @@ -691,9 +691,7 @@ ir_to_mesa_visitor::visit(ir_expression *ir) } break; case ir_binop_div: - ir_to_mesa_emit_scalar_op1(ir, OPCODE_RCP, result_dst, op[1]); - ir_to_mesa_emit_op2(ir, OPCODE_MUL, result_dst, op[0], result_src); - break; + assert(!"not reached: should be handled by ir_div_to_mul_rcp"); case ir_binop_mod: assert(!"ir_binop_mod should have been converted to b * fract(a/b)"); break; @@ -1729,6 +1727,7 @@ _mesa_glsl_compile_shader(GLcontext *ctx, struct gl_shader *shader) /* Lowering */ do_mod_to_fract(shader->ir); + do_div_to_mul_rcp(shader->ir); /* Optimization passes */ if (!state->error && !shader->ir->is_empty()) { |