From 3ee2daf23dc91b8dfc017b5c89c10ab1376ba4df Mon Sep 17 00:00:00 2001 From: Francisco Jerez Date: Fri, 10 Jul 2015 19:18:39 +0300 Subject: [PATCH] i965: Implement b2f and b2i using negation. Booleans are represented as 0/-1 on modern hardware which means we can just negate them to convert them into a numeric type. Negation has the benefit that it can be implemented using a source modifier which can easily be propagated into some other instruction. shader-db results on HSW: total instructions in shared programs: 6349082 -> 6346693 (-0.04%) instructions in affected programs: 40948 -> 38559 (-5.83%) helped: 123 HURT: 1 GAINED: 1 LOST: 0 Reviewed-by: Matt Turner --- src/mesa/drivers/dri/i965/brw_fs_nir.cpp | 4 +--- src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp | 7 +------ 2 files changed, 2 insertions(+), 9 deletions(-) diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp index 10903a1..1987032 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp @@ -968,10 +968,8 @@ fs_visitor::nir_emit_alu(const fs_builder &bld, nir_alu_instr *instr) break; case nir_op_b2i: - bld.AND(result, op[0], fs_reg(1)); - break; case nir_op_b2f: - bld.AND(retype(result, BRW_REGISTER_TYPE_UD), op[0], fs_reg(0x3f800000u)); + bld.MOV(result, negate(op[0])); break; case nir_op_f2b: diff --git a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp index 67f2b5c..8a352d3 100644 --- a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp +++ b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp @@ -1733,16 +1733,11 @@ vec4_visitor::visit(ir_expression *ir) emit(MOV(result_dst, op[0])); break; case ir_unop_b2i: - emit(AND(result_dst, op[0], src_reg(1))); - break; case ir_unop_b2f: if (devinfo->gen <= 5) { resolve_bool_comparison(ir->operands[0], &op[0]); } - op[0].type = BRW_REGISTER_TYPE_D; - result_dst.type = BRW_REGISTER_TYPE_D; - emit(AND(result_dst, op[0], src_reg(0x3f800000u))); - result_dst.type = BRW_REGISTER_TYPE_F; + emit(MOV(result_dst, negate(op[0]))); break; case ir_unop_f2b: emit(CMP(result_dst, op[0], src_reg(0.0f), BRW_CONDITIONAL_NZ)); -- 2.7.4