From: Matt Turner Date: Wed, 23 Oct 2013 23:42:34 +0000 (-0700) Subject: glsl: Optimize (not A) and (not B) into not (A or B). X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=64c081e8b788ba87c9edc505127b87c3fba47599;p=mesa.git glsl: Optimize (not A) and (not B) into not (A or B). No shader-db changes, but seems like a good idea. Reviewed-by: Eric Anholt --- diff --git a/src/glsl/opt_algebraic.cpp b/src/glsl/opt_algebraic.cpp index 22d2dbfe6e3..1351904488b 100644 --- a/src/glsl/opt_algebraic.cpp +++ b/src/glsl/opt_algebraic.cpp @@ -401,6 +401,15 @@ ir_algebraic_visitor::handle_expression(ir_expression *ir) } else if (is_vec_zero(op_const[0]) || is_vec_zero(op_const[1])) { this->progress = true; return ir_constant::zero(mem_ctx, ir->type); + } else if (op_expr[0] && op_expr[0]->operation == ir_unop_logic_not && + op_expr[1] && op_expr[1]->operation == ir_unop_logic_not) { + /* De Morgan's Law: + * (not A) and (not B) === not (A or B) + */ + temp = logic_not(logic_or(op_expr[0]->operands[0], + op_expr[1]->operands[0])); + this->progress = true; + return swizzle_if_required(ir, temp); } break;