From 2c4d0fb104306339e8692852478f7021914c24de 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) Cc: "10.5" Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89180 --- src/glsl/opt_algebraic.cpp | 75 ++++++++++++++++++++++++++++------------------ 1 file changed, 46 insertions(+), 29 deletions(-) diff --git a/src/glsl/opt_algebraic.cpp b/src/glsl/opt_algebraic.cpp index 6784242..c3f3842 100644 --- a/src/glsl/opt_algebraic.cpp +++ b/src/glsl/opt_algebraic.cpp @@ -744,48 +744,65 @@ 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); - - /* 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); - - if (!inner_val_b->as_constant()) - continue; - - 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); - - /* 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); + /* 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); + + /* 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); + + /* 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)); + + /* 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)); + + /* 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)); } } -- 2.0.5