From 8935c129372c02c56005463bb8b7182e0aeefd65 Mon Sep 17 00:00:00 2001 From: Abdiel Janulgue Date: Thu, 12 Jun 2014 14:59:30 -0700 Subject: [PATCH] glsl: Add a pass to lower ir_unop_saturate to clamp(x, 0, 1) Signed-off-by: Abdiel Janulgue Reviewed-by: Matt Turner Reviewed-by: Ian Romanick --- src/glsl/ir_optimization.h | 1 + src/glsl/lower_instructions.cpp | 29 +++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/src/glsl/ir_optimization.h b/src/glsl/ir_optimization.h index b83c2259234..1c6f72b544f 100644 --- a/src/glsl/ir_optimization.h +++ b/src/glsl/ir_optimization.h @@ -40,6 +40,7 @@ #define LDEXP_TO_ARITH 0x100 #define CARRY_TO_ARITH 0x200 #define BORROW_TO_ARITH 0x400 +#define SAT_TO_CLAMP 0x800 /** * \see class lower_packing_builtins_visitor diff --git a/src/glsl/lower_instructions.cpp b/src/glsl/lower_instructions.cpp index 176070c8781..684285350d0 100644 --- a/src/glsl/lower_instructions.cpp +++ b/src/glsl/lower_instructions.cpp @@ -41,6 +41,7 @@ * - BITFIELD_INSERT_TO_BFM_BFI * - CARRY_TO_ARITH * - BORROW_TO_ARITH + * - SAT_TO_CLAMP * * SUB_TO_ADD_NEG: * --------------- @@ -104,6 +105,10 @@ * ---------------- * Converts ir_borrow into (x < y). * + * SAT_TO_CLAMP: + * ------------- + * Converts ir_unop_saturate into min(max(x, 0.0), 1.0) + * */ #include "main/core.h" /* for M_LOG2E */ @@ -139,6 +144,7 @@ private: void ldexp_to_arith(ir_expression *); void carry_to_arith(ir_expression *); void borrow_to_arith(ir_expression *); + void sat_to_clamp(ir_expression *); }; } /* anonymous namespace */ @@ -484,6 +490,24 @@ lower_instructions_visitor::borrow_to_arith(ir_expression *ir) this->progress = true; } +void +lower_instructions_visitor::sat_to_clamp(ir_expression *ir) +{ + /* Translates + * ir_unop_saturate x + * into + * ir_binop_min (ir_binop_max(x, 0.0), 1.0) + */ + + ir->operation = ir_binop_min; + ir->operands[0] = new(ir) ir_expression(ir_binop_max, ir->operands[0]->type, + ir->operands[0], + new(ir) ir_constant(0.0f)); + ir->operands[1] = new(ir) ir_constant(1.0f); + + this->progress = true; +} + ir_visitor_status lower_instructions_visitor::visit_leave(ir_expression *ir) { @@ -540,6 +564,11 @@ lower_instructions_visitor::visit_leave(ir_expression *ir) borrow_to_arith(ir); break; + case ir_unop_saturate: + if (lowering(SAT_TO_CLAMP)) + sat_to_clamp(ir); + break; + default: return visit_continue; } -- 2.30.2