diff options
| -rw-r--r-- | src/mesa/shader/slang/slang_codegen.c | 158 |
1 files changed, 88 insertions, 70 deletions
diff --git a/src/mesa/shader/slang/slang_codegen.c b/src/mesa/shader/slang/slang_codegen.c index bb1ae035690..0d72f4e5dc2 100644 --- a/src/mesa/shader/slang/slang_codegen.c +++ b/src/mesa/shader/slang/slang_codegen.c @@ -75,6 +75,11 @@ const GLuint MAX_FOR_LOOP_UNROLL_COMPLEXITY = 256; static slang_ir_node * _slang_gen_operation(slang_assemble_ctx * A, slang_operation *oper); +static void +slang_substitute(slang_assemble_ctx *A, slang_operation *oper, + GLuint substCount, slang_variable **substOld, + slang_operation **substNew, GLboolean isLHS); + /** * Retrieves type information about an operation. @@ -927,6 +932,78 @@ slang_resolve_variable(slang_operation *oper) /** + * Generate code for "return expr;" + * We return values from functions by assinging the returned value to + * the hidden __retVal variable which is an extra 'out' parameter we add + * to the function signature. + * This code basically converts "return expr;" into "__retVal = expr; return;" + * \return the new AST code. + */ +static slang_operation * +gen_return_expression(slang_assemble_ctx *A, slang_operation *oper) +{ + slang_operation *blockOper; + + blockOper = slang_operation_new(1); + blockOper->type = SLANG_OPER_BLOCK_NO_NEW_SCOPE; + blockOper->locals->outer_scope = oper->locals->outer_scope; + slang_operation_add_children(blockOper, 2); + + /* if EmitContReturn: + * if (!__returnFlag) { + * build: __retVal = expr; + * } + * otherwise: + * build: __retVal = expr; + */ + { + slang_operation *assignOper; + + if (A->UseReturnFlag) { + slang_operation *ifOper = slang_oper_child(blockOper, 0); + ifOper->type = SLANG_OPER_IF; + slang_operation_add_children(ifOper, 3); + { + slang_operation *cond = slang_oper_child(ifOper, 0); + cond->type = SLANG_OPER_IDENTIFIER; + cond->a_id = slang_atom_pool_atom(A->atoms, "__returnFlag"); + } + { + slang_operation *elseOper = slang_oper_child(ifOper, 2); + elseOper->type = SLANG_OPER_VOID; + } + assignOper = slang_oper_child(ifOper, 1); + } + else { + assignOper = slang_oper_child(blockOper, 0); + } + + assignOper->type = SLANG_OPER_ASSIGN; + slang_operation_add_children(assignOper, 2); + { + slang_operation *lhs = slang_oper_child(assignOper, 0); + lhs->type = SLANG_OPER_IDENTIFIER; + lhs->a_id = slang_atom_pool_atom(A->atoms, "__retVal"); + } + { + slang_operation *rhs = slang_oper_child(assignOper, 1); + slang_operation_copy(rhs, &oper->children[0]); + } + } + + /* build: return; (with no return value) */ + { + slang_operation *returnOper = slang_oper_child(blockOper, 1); + returnOper->type = SLANG_OPER_RETURN; /* return w/ no value */ + assert(returnOper->num_children == 0); + } + + return blockOper; +} + + + +/** * Replace particular variables (SLANG_OPER_IDENTIFIER) with new expressions. */ static void @@ -994,14 +1071,7 @@ slang_substitute(slang_assemble_ctx *A, slang_operation *oper, /* do return replacement here too */ assert(oper->num_children == 0 || oper->num_children == 1); if (oper->num_children == 1 && !_slang_is_noop(&oper->children[0])) { - /* replace: - * return expr; - * with: - * __retVal = expr; - * return; - * then do substitutions on the assignment. - */ - slang_operation *blockOper; + slang_operation *newReturn; /* check if function actually has a return type */ assert(A->CurFunction); @@ -1010,70 +1080,16 @@ slang_substitute(slang_assemble_ctx *A, slang_operation *oper, return; } - blockOper = slang_operation_new(1); - blockOper->type = SLANG_OPER_BLOCK_NO_NEW_SCOPE; - blockOper->locals->outer_scope = oper->locals->outer_scope; - slang_operation_add_children(blockOper, 2); - - /* if EmitContReturn: - * if (!__returnFlag) { - * build: __retVal = expr; - * } - * otherwise: - * build: __retVal = expr; - */ - { - slang_operation *assignOper; + /* generate new 'return' code' */ + newReturn = gen_return_expression(A, oper); - if (A->UseReturnFlag) { - slang_operation *ifOper = slang_oper_child(blockOper, 0); - ifOper->type = SLANG_OPER_IF; - slang_operation_add_children(ifOper, 3); - - { - slang_operation *cond = slang_oper_child(ifOper, 0); - cond->type = SLANG_OPER_IDENTIFIER; - cond->a_id = slang_atom_pool_atom(A->atoms, "__returnFlag"); - } - { - assignOper = slang_oper_child(ifOper, 1); - } - { - slang_operation *elseOper = slang_oper_child(ifOper, 2); - elseOper->type = SLANG_OPER_VOID; - } - } - else { - assignOper = slang_oper_child(blockOper, 0); - } + /* do substitutions on the "__retVal = expr" sub-tree */ + slang_substitute(A, slang_oper_child(newReturn, 0), + substCount, substOld, substNew, GL_FALSE); - assignOper->type = SLANG_OPER_ASSIGN; - slang_operation_add_children(assignOper, 2); - { - slang_operation *lhs = slang_oper_child(assignOper, 0); - lhs->type = SLANG_OPER_IDENTIFIER; - lhs->a_id = slang_atom_pool_atom(A->atoms, "__retVal"); - } - { - slang_operation *rhs = slang_oper_child(assignOper, 1); - slang_operation_copy(rhs, &oper->children[0]); - } - - /* do substitutions on the "__retVal = expr" sub-tree */ - slang_substitute(A, assignOper, - substCount, substOld, substNew, GL_FALSE); - } - - /* build: return; */ - { - slang_operation *returnOper = slang_oper_child(blockOper, 1); - returnOper->type = SLANG_OPER_RETURN; /* return w/ no value */ - assert(returnOper->num_children == 0); - } - - /* install new code */ - slang_operation_copy(oper, blockOper); - slang_operation_destruct(blockOper); + /* install new 'return' code */ + slang_operation_copy(oper, newReturn); + slang_operation_destruct(newReturn); } else { /* check if return value was expected */ @@ -4036,6 +4052,8 @@ _slang_gen_return(slang_assemble_ctx * A, slang_operation *oper) } #endif + /* XXX use the gen_return_expression() function here */ + assign = slang_operation_new(1); assign->type = SLANG_OPER_ASSIGN; assign->num_children = 2; |