From 8c31bc704826d46cad65c4d65b4b70de7144205a Mon Sep 17 00:00:00 2001 From: Bryan Cain Date: Wed, 17 Aug 2011 10:01:30 -0500 Subject: [PATCH] glsl_to_tgsi: implement ir_unop_logic_not using 1-x Since our logic values are 0.0 (false) and 1.0 (true), 1.0 - x accurately implements logical not. This is a port of commit 6ad08989d7c1 to glsl_to_tgsi. --- src/mesa/state_tracker/st_glsl_to_tgsi.cpp | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp index 886a1776210..73a647efe34 100644 --- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp +++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp @@ -1336,7 +1336,17 @@ glsl_to_tgsi_visitor::visit(ir_expression *ir) switch (ir->operation) { case ir_unop_logic_not: - emit(ir, TGSI_OPCODE_SEQ, result_dst, op[0], st_src_reg_for_type(result_dst.type, 0)); + if (result_dst.type != GLSL_TYPE_FLOAT) + emit(ir, TGSI_OPCODE_SEQ, result_dst, op[0], st_src_reg_for_type(result_dst.type, 0)); + else { + /* Previously 'SEQ dst, src, 0.0' was used for this. However, many + * older GPUs implement SEQ using multiple instructions (i915 uses two + * SGE instructions and a MUL instruction). Since our logic values are + * 0.0 and 1.0, 1-x also implements !x. + */ + op[0].negate = ~op[0].negate; + emit(ir, TGSI_OPCODE_ADD, result_dst, op[0], st_src_reg_for_float(1.0)); + } break; case ir_unop_neg: assert(result_dst.type == GLSL_TYPE_FLOAT || result_dst.type == GLSL_TYPE_INT); -- 2.30.2