From 2483a9a08cae6935e84fab3580ed285c6c68fb75 Mon Sep 17 00:00:00 2001 From: Ian Romanick Date: Wed, 13 Apr 2016 11:43:23 -0700 Subject: [PATCH] ir_to_mesa: Emit smarter ir_binop_logic_or for vertex programs Continue using ADD in the other case because a fragment shader backend could fuse the ADD with a MUL to generate a MAD for ((x && y) || z). Signed-off-by: Ian Romanick Reviewed-by: Matt Turner --- src/mesa/program/ir_to_mesa.cpp | 26 +++++++++++--------------- 1 file changed, 11 insertions(+), 15 deletions(-) diff --git a/src/mesa/program/ir_to_mesa.cpp b/src/mesa/program/ir_to_mesa.cpp index d5b3693661c..7f24a9e16e4 100644 --- a/src/mesa/program/ir_to_mesa.cpp +++ b/src/mesa/program/ir_to_mesa.cpp @@ -1212,24 +1212,20 @@ ir_to_mesa_visitor::visit(ir_expression *ir) break; case ir_binop_logic_or: { - /* After the addition, the value will be an integer on the - * range [0,2]. Zero stays zero, and positive values become 1.0. - */ - ir_to_mesa_instruction *add = - emit(ir, OPCODE_ADD, result_dst, op[0], op[1]); if (this->prog->Target == GL_FRAGMENT_PROGRAM_ARB) { - /* The clamping to [0,1] can be done for free in the fragment - * shader with a saturate. - */ + /* After the addition, the value will be an integer on the + * range [0,2]. Zero stays zero, and positive values become 1.0. + */ + ir_to_mesa_instruction *add = + emit(ir, OPCODE_ADD, result_dst, op[0], op[1]); add->saturate = true; } else { - /* Negating the result of the addition gives values on the range - * [-2, 0]. Zero stays zero, and negative values become 1.0. This - * is achieved using SLT. - */ - src_reg slt_src = result_src; - slt_src.negate = ~slt_src.negate; - emit(ir, OPCODE_SLT, result_dst, slt_src, src_reg_for_float(0.0)); + /* The Boolean arguments are stored as float 0.0 and 1.0. If either + * value is 1.0, the result of the logcal-or should be 1.0. If both + * values are 0.0, the result should be 0.0. This is exactly what + * MAX does. + */ + emit(ir, OPCODE_MAX, result_dst, op[0], op[1]); } break; } -- 2.30.2