From 6c8f1f483a999005cae1da5b54cc8ca1904e7ce7 Mon Sep 17 00:00:00 2001 From: Ian Romanick Date: Mon, 18 Jul 2011 18:51:25 -0700 Subject: [PATCH] glsl: Compare vector indices in blocks Just like the non-constant array index lowering pass, compare all N indices at once. For accesses to a vec4, this saves 3 comparison instructions on a vector architecture. Reviewed-by: Eric Anholt --- src/glsl/lower_vec_index_to_cond_assign.cpp | 62 +++++++++++++-------- 1 file changed, 39 insertions(+), 23 deletions(-) diff --git a/src/glsl/lower_vec_index_to_cond_assign.cpp b/src/glsl/lower_vec_index_to_cond_assign.cpp index 15992e27288..fce9c3424a1 100644 --- a/src/glsl/lower_vec_index_to_cond_assign.cpp +++ b/src/glsl/lower_vec_index_to_cond_assign.cpp @@ -71,8 +71,6 @@ ir_vec_index_to_cond_assign_visitor::convert_vec_index_to_cond_assign(ir_rvalue ir_assignment *assign; ir_variable *index, *var; ir_dereference *deref; - ir_expression *condition; - ir_swizzle *swizzle; int i; if (!orig_deref) @@ -86,39 +84,52 @@ ir_vec_index_to_cond_assign_visitor::convert_vec_index_to_cond_assign(ir_rvalue assert(orig_deref->array_index->type->base_type == GLSL_TYPE_INT); + exec_list list; + /* Store the index to a temporary to avoid reusing its tree. */ index = new(base_ir) ir_variable(glsl_type::int_type, "vec_index_tmp_i", ir_var_temporary); - base_ir->insert_before(index); + list.push_tail(index); deref = new(base_ir) ir_dereference_variable(index); assign = new(base_ir) ir_assignment(deref, orig_deref->array_index, NULL); - base_ir->insert_before(assign); + list.push_tail(assign); /* Temporary where we store whichever value we swizzle out. */ var = new(base_ir) ir_variable(ir->type, "vec_index_tmp_v", ir_var_temporary); - base_ir->insert_before(var); + list.push_tail(var); + + /* Generate a single comparison condition "mask" for all of the components + * in the vector. + */ + ir_rvalue *const cond_deref = + compare_index_block(&list, index, 0, + orig_deref->array->type->vector_elements, + mem_ctx); /* Generate a conditional move of each vector element to the temp. */ for (i = 0; i < orig_deref->array->type->vector_elements; i++) { - deref = new(base_ir) ir_dereference_variable(index); - condition = new(base_ir) ir_expression(ir_binop_equal, - glsl_type::bool_type, - deref, - new(base_ir) ir_constant(i)); + ir_rvalue *condition_swizzle = + new(base_ir) ir_swizzle(cond_deref->clone(ir, NULL), i, 0, 0, 0, 1); /* Just clone the rest of the deref chain when trying to get at the * underlying variable. */ - swizzle = new(base_ir) ir_swizzle(orig_deref->array->clone(mem_ctx, NULL), - i, 0, 0, 0, 1); + ir_rvalue *swizzle = + new(base_ir) ir_swizzle(orig_deref->array->clone(mem_ctx, NULL), + i, 0, 0, 0, 1); deref = new(base_ir) ir_dereference_variable(var); - assign = new(base_ir) ir_assignment(deref, swizzle, condition); - base_ir->insert_before(assign); + assign = new(base_ir) ir_assignment(deref, swizzle, condition_swizzle); + list.push_tail(assign); } + /* Put all of the new instructions in the IR stream before the old + * instruction. + */ + base_ir->insert_before(&list); + this->progress = true; return new(base_ir) ir_dereference_variable(var); } @@ -189,24 +200,29 @@ ir_vec_index_to_cond_assign_visitor::visit_leave(ir_assignment *ir) assign = new(ir) ir_assignment(deref, ir->rhs, NULL); list.push_tail(assign); + /* Generate a single comparison condition "mask" for all of the components + * in the vector. + */ + ir_rvalue *const cond_deref = + compare_index_block(&list, index, 0, + orig_deref->array->type->vector_elements, + mem_ctx); + /* Generate a conditional move of each vector element to the temp. */ for (i = 0; i < orig_deref->array->type->vector_elements; i++) { - ir_rvalue *condition, *swizzle; + ir_rvalue *condition_swizzle = + new(ir) ir_swizzle(cond_deref->clone(ir, NULL), i, 0, 0, 0, 1); - deref = new(ir) ir_dereference_variable(index); - condition = new(ir) ir_expression(ir_binop_equal, - glsl_type::bool_type, - deref, - new(ir) ir_constant(i)); /* Just clone the rest of the deref chain when trying to get at the * underlying variable. */ - swizzle = new(ir) ir_swizzle(orig_deref->array->clone(mem_ctx, NULL), - i, 0, 0, 0, 1); + ir_rvalue *swizzle = + new(ir) ir_swizzle(orig_deref->array->clone(mem_ctx, NULL), + i, 0, 0, 0, 1); deref = new(ir) ir_dereference_variable(var); - assign = new(ir) ir_assignment(swizzle, deref, condition); + assign = new(ir) ir_assignment(swizzle, deref, condition_swizzle); list.push_tail(assign); } -- 2.30.2