From 6f52686d7783f20264932419fe133626c16646cc Mon Sep 17 00:00:00 2001 From: Matt Turner Date: Tue, 24 Feb 2015 10:41:52 -0800 Subject: [PATCH] glsl: Rewrite and fix min/max to saturate optimization. There were some bugs, and the code was really difficult to follow. We would optimize min(max(x, b), 1.0) into max(sat(x), b) but not pay attention to the order of min/max and also do max(min(x, b), 1.0) into max(sat(x), b) Corrects four shaders from Champions of Regnum that do min(max(x, 1), 10) and corrects rendering of Mass Effect under VMware Workstation. Cc: "10.4 10.5" Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89180 Reviewed-by: Abdiel Janulgue Reviewed-by: Ian Romanick (cherry picked from commit cb25087c7bd5f1ad2515647278b32d3f07803f77) --- src/glsl/opt_algebraic.cpp | 67 ++++++++++++++++++++++++-------------- 1 file changed, 42 insertions(+), 25 deletions(-) diff --git a/src/glsl/opt_algebraic.cpp b/src/glsl/opt_algebraic.cpp index c6f4a9c786d..fae58c75c0e 100644 --- a/src/glsl/opt_algebraic.cpp +++ b/src/glsl/opt_algebraic.cpp @@ -696,48 +696,65 @@ ir_algebraic_visitor::handle_expression(ir_expression *ir) * a saturate operation */ for (int op = 0; op < 2; op++) { - ir_expression *minmax = op_expr[op]; + ir_expression *inner_expr = op_expr[op]; ir_constant *outer_const = op_const[1 - op]; ir_expression_operation op_cond = (ir->operation == ir_binop_max) ? ir_binop_min : ir_binop_max; - if (!minmax || !outer_const || (minmax->operation != op_cond)) + if (!inner_expr || !outer_const || (inner_expr->operation != op_cond)) continue; + /* One of these has to be a constant */ + if (!inner_expr->operands[0]->as_constant() && + !inner_expr->operands[1]->as_constant()) + break; + /* Found a min(max) combination. Now try to see if its operands * meet our conditions that we can do just a single saturate operation */ for (int minmax_op = 0; minmax_op < 2; minmax_op++) { - ir_rvalue *inner_val_a = minmax->operands[minmax_op]; - ir_rvalue *inner_val_b = minmax->operands[1 - minmax_op]; + ir_rvalue *x = inner_expr->operands[minmax_op]; + ir_rvalue *y = inner_expr->operands[1 - minmax_op]; - if (!inner_val_a || !inner_val_b) + ir_constant *inner_const = y->as_constant(); + if (!inner_const) continue; - /* Found a {min|max} ({max|min} (x, 0.0), 1.0) operation and its variations */ - if ((outer_const->is_one() && inner_val_a->is_zero()) || - (inner_val_a->is_one() && outer_const->is_zero())) - return saturate(inner_val_b); + /* min(max(x, 0.0), 1.0) is sat(x) */ + if (ir->operation == ir_binop_min && + inner_const->is_zero() && + outer_const->is_one()) + return saturate(x); - /* Found a {min|max} ({max|min} (x, 0.0), b) where b < 1.0 - * and its variations - */ - if (is_less_than_one(outer_const) && inner_val_b->is_zero()) - return expr(ir_binop_min, saturate(inner_val_a), outer_const); + /* max(min(x, 1.0), 0.0) is sat(x) */ + if (ir->operation == ir_binop_max && + inner_const->is_one() && + outer_const->is_zero()) + return saturate(x); - if (!inner_val_b->as_constant()) - continue; + /* min(max(x, 0.0), b) where b < 1.0 is sat(min(x, b)) */ + if (ir->operation == ir_binop_min && + inner_const->is_zero() && + is_less_than_one(outer_const)) + return saturate(expr(ir_binop_min, x, outer_const)); - if (is_less_than_one(inner_val_b->as_constant()) && outer_const->is_zero()) - return expr(ir_binop_min, saturate(inner_val_a), inner_val_b); + /* max(min(x, b), 0.0) where b < 1.0 is sat(min(x, b)) */ + if (ir->operation == ir_binop_max && + is_less_than_one(inner_const) && + outer_const->is_zero()) + return saturate(expr(ir_binop_min, x, inner_const)); - /* Found a {min|max} ({max|min} (x, b), 1.0), where b > 0.0 - * and its variations - */ - if (outer_const->is_one() && is_greater_than_zero(inner_val_b->as_constant())) - return expr(ir_binop_max, saturate(inner_val_a), inner_val_b); - if (inner_val_b->as_constant()->is_one() && is_greater_than_zero(outer_const)) - return expr(ir_binop_max, saturate(inner_val_a), outer_const); + /* max(min(x, 1.0), b) where b > 0.0 is sat(max(x, b)) */ + if (ir->operation == ir_binop_max && + inner_const->is_one() && + is_greater_than_zero(outer_const)) + return saturate(expr(ir_binop_max, x, outer_const)); + + /* min(max(x, b), 1.0) where b > 0.0 is sat(max(x, b)) */ + if (ir->operation == ir_binop_min && + is_greater_than_zero(inner_const) && + outer_const->is_one()) + return saturate(expr(ir_binop_max, x, inner_const)); } }