From c3bb07f875075b08a0b13f47be95e0c49edb6555 Mon Sep 17 00:00:00 2001 From: Ian Romanick Date: Fri, 22 Mar 2013 17:42:38 -0700 Subject: [PATCH] glsl: Use vector-insert and vector-extract on elements of gl_ClipDistanceMESA Variable indexing into vectors using ir_dereference_array is being removed, so this lowering pass has to generate something different. v2: Convert tabs to spaces. Suggested by Eric. v3: Simplify code slightly by assuming that elements of gl_ClipDistanceMESA will always be vec4. Suggested by Paul. v4: Fairly substantial rewrite based on the rewrite of "glsl: Convert lower_clip_distance_visitor to be an ir_rvalue_visitor" Signed-off-by: Ian Romanick Reviewed-by: Kenneth Graunke Reviewed-by: Paul Berry --- src/glsl/lower_clip_distance.cpp | 66 +++++++++++++++++++++++++++++--- 1 file changed, 60 insertions(+), 6 deletions(-) diff --git a/src/glsl/lower_clip_distance.cpp b/src/glsl/lower_clip_distance.cpp index 129375d6659..d6cf944388b 100644 --- a/src/glsl/lower_clip_distance.cpp +++ b/src/glsl/lower_clip_distance.cpp @@ -48,6 +48,7 @@ #include "glsl_symbol_table.h" #include "ir_rvalue_visitor.h" #include "ir.h" +#include "program/prog_instruction.h" /* For WRITEMASK_* */ class lower_clip_distance_visitor : public ir_rvalue_visitor { public: @@ -65,6 +66,8 @@ public: virtual void handle_rvalue(ir_rvalue **rvalue); + void fix_lhs(ir_assignment *); + bool progress; /** @@ -199,12 +202,45 @@ lower_clip_distance_visitor::handle_rvalue(ir_rvalue **rv) ir_rvalue *swizzle_index; this->create_indices(array_deref->array_index, array_index, swizzle_index); void *mem_ctx = ralloc_parent(array_deref); - array_deref->array = new(mem_ctx) ir_dereference_array( - this->new_clip_distance_var, array_index); - array_deref->array_index = swizzle_index; + + ir_dereference_array *const ClipDistanceMESA_deref = + new(mem_ctx) ir_dereference_array(this->new_clip_distance_var, + array_index); + + ir_expression *const expr = + new(mem_ctx) ir_expression(ir_binop_vector_extract, + ClipDistanceMESA_deref, + swizzle_index); + + *rv = expr; } } +void +lower_clip_distance_visitor::fix_lhs(ir_assignment *ir) +{ + if (ir->lhs->ir_type == ir_type_expression) { + void *mem_ctx = ralloc_parent(ir); + ir_expression *const expr = (ir_expression *) ir->lhs; + + /* The expression must be of the form: + * + * (vector_extract gl_ClipDistanceMESA[i], j). + */ + assert(expr->operation == ir_binop_vector_extract); + assert(expr->operands[0]->ir_type == ir_type_dereference_array); + assert(expr->operands[0]->type == glsl_type::vec4_type); + + ir_dereference *const new_lhs = (ir_dereference *) expr->operands[0]; + ir->rhs = new(mem_ctx) ir_expression(ir_triop_vector_insert, + glsl_type::vec4_type, + new_lhs->clone(mem_ctx, NULL), + ir->rhs, + expr->operands[1]); + ir->set_lhs(new_lhs); + ir->write_mask = WRITEMASK_XYZW; + } +} /** * Replace any assignment having gl_ClipDistance (undereferenced) as its LHS @@ -234,12 +270,24 @@ lower_clip_distance_visitor::visit_leave(ir_assignment *ir) for (int i = 0; i < array_size; ++i) { ir_dereference_array *new_lhs = new(ctx) ir_dereference_array( ir->lhs->clone(ctx, NULL), new(ctx) ir_constant(i)); - this->handle_rvalue((ir_rvalue **) &new_lhs); ir_dereference_array *new_rhs = new(ctx) ir_dereference_array( ir->rhs->clone(ctx, NULL), new(ctx) ir_constant(i)); this->handle_rvalue((ir_rvalue **) &new_rhs); - this->base_ir->insert_before( - new(ctx) ir_assignment(new_lhs, new_rhs)); + + /* Handle the LHS after creating the new assignment. This must + * happen in this order because handle_rvalue may replace the old LHS + * with an ir_expression of ir_binop_vector_extract. Since this is + * not a valide l-value, this will cause an assertion in the + * ir_assignment constructor to fail. + * + * If this occurs, replace the mangled LHS with a dereference of the + * vector, and replace the RHS with an ir_triop_vector_insert. + */ + ir_assignment *const assign = new(ctx) ir_assignment(new_lhs, new_rhs); + this->handle_rvalue((ir_rvalue **) &assign->lhs); + this->fix_lhs(assign); + + this->base_ir->insert_before(assign); } ir->remove(); @@ -249,8 +297,14 @@ lower_clip_distance_visitor::visit_leave(ir_assignment *ir) /* Handle the LHS as if it were an r-value. Normally * rvalue_visit(ir_assignment *) only visits the RHS, but we need to lower * expressions in the LHS as well. + * + * This may cause the LHS to get replaced with an ir_expression of + * ir_binop_vector_extract. If this occurs, replace it with a dereference + * of the vector, and replace the RHS with an ir_triop_vector_insert. */ handle_rvalue((ir_rvalue **)&ir->lhs); + this->fix_lhs(ir); + return rvalue_visit(ir); } -- 2.30.2