From d92394c5d88c77f7ff9676b6ade935f922e377a4 Mon Sep 17 00:00:00 2001 From: Abdiel Janulgue Date: Thu, 19 Jun 2014 22:17:20 -0700 Subject: [PATCH] glsl: Optimize clamp(x, 0.0, b), where b < 1.0 as min(saturate(x),b) v2: - Output min(saturate(x),b) instead of saturate(min(x,b)) suggested by Ilia Mirkin - Make sure we do component-wise comparison for vectors (Ian Romanick) v3: - Add missing condition where the outer constant value is zero and inner constant is < 1 - Fix comments to reflect we are doing a commutative operation (Matt Turner) Reviewed-by: Ian Romanick Signed-off-by: Abdiel Janulgue --- src/glsl/opt_algebraic.cpp | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/src/glsl/opt_algebraic.cpp b/src/glsl/opt_algebraic.cpp index 4b052933..6dfb681 100644 --- a/src/glsl/opt_algebraic.cpp +++ b/src/glsl/opt_algebraic.cpp @@ -110,6 +110,33 @@ is_vec_basis(ir_constant *ir) return (ir == NULL) ? false : ir->is_basis(); } +static inline bool +is_valid_vec_const(ir_constant *ir) +{ + if (ir == NULL) + return false; + + if (!ir->type->is_scalar() && !ir->type->is_vector()) + return false; + + return true; +} + +static inline bool +is_less_than_one(ir_constant *ir) +{ + if (!is_valid_vec_const(ir)) + return false; + + unsigned component = 0; + for (int c = 0; c < ir->type->vector_elements; c++) { + if (ir->get_float_component(c) < 1.0f) + component++; + } + + return (component == ir->type->vector_elements); +} + static void update_type(ir_expression *ir) { @@ -645,6 +672,18 @@ ir_algebraic_visitor::handle_expression(ir_expression *ir) 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); } } -- 2.7.4