From 3d581f99963dea7e93a2f8fd819410da02c1cb7f Mon Sep 17 00:00:00 2001 From: Matt Turner Date: Fri, 19 Dec 2014 21:35:56 -0800 Subject: [PATCH] i965/vec4: Emit MADs from (x + -(y * z)). Same as commit c4fab711 to the fs backend. total instructions in shared programs: 5945998 -> 5945788 (-0.00%) instructions in affected programs: 74665 -> 74455 (-0.28%) helped: 399 HURT: 180 It hurts some programs because we make no attempts in the vec4 backend to avoid MADs if they have constant (or vector uniform) arguments. Reviewed-by: Kenneth Graunke --- src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp index 432c2182d3d..2a988d0a0c6 100644 --- a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp +++ b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp @@ -1161,10 +1161,21 @@ vec4_visitor::try_emit_mad(ir_expression *ir) ir_rvalue *nonmul = ir->operands[1]; ir_expression *mul = ir->operands[0]->as_expression(); + bool mul_negate = false; + if (mul && mul->operation == ir_unop_neg) { + mul = mul->operands[0]->as_expression(); + mul_negate = true; + } + if (!mul || mul->operation != ir_binop_mul) { nonmul = ir->operands[0]; mul = ir->operands[1]->as_expression(); + if (mul && mul->operation == ir_unop_neg) { + mul = mul->operands[0]->as_expression(); + mul_negate = true; + } + if (!mul || mul->operation != ir_binop_mul) return false; } @@ -1174,6 +1185,7 @@ vec4_visitor::try_emit_mad(ir_expression *ir) mul->operands[0]->accept(this); src_reg src1 = fix_3src_operand(this->result); + src1.negate ^= mul_negate; mul->operands[1]->accept(this); src_reg src2 = fix_3src_operand(this->result); -- 2.30.2