diff options
Diffstat (limited to 'src/glsl/lower_instructions.cpp')
| -rw-r--r-- | src/glsl/lower_instructions.cpp | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/src/glsl/lower_instructions.cpp b/src/glsl/lower_instructions.cpp index 49316d0020e..176070c8781 100644 --- a/src/glsl/lower_instructions.cpp +++ b/src/glsl/lower_instructions.cpp @@ -39,6 +39,8 @@ * - MOD_TO_FRACT * - LDEXP_TO_ARITH * - BITFIELD_INSERT_TO_BFM_BFI + * - CARRY_TO_ARITH + * - BORROW_TO_ARITH * * SUB_TO_ADD_NEG: * --------------- @@ -94,6 +96,14 @@ * Many GPUs implement the bitfieldInsert() built-in from ARB_gpu_shader_5 * with a pair of instructions. * + * CARRY_TO_ARITH: + * --------------- + * Converts ir_carry into (x + y) < x. + * + * BORROW_TO_ARITH: + * ---------------- + * Converts ir_borrow into (x < y). + * */ #include "main/core.h" /* for M_LOG2E */ @@ -127,6 +137,8 @@ private: void log_to_log2(ir_expression *); void bitfield_insert_to_bfm_bfi(ir_expression *); void ldexp_to_arith(ir_expression *); + void carry_to_arith(ir_expression *); + void borrow_to_arith(ir_expression *); }; } /* anonymous namespace */ @@ -436,6 +448,42 @@ lower_instructions_visitor::ldexp_to_arith(ir_expression *ir) this->progress = true; } +void +lower_instructions_visitor::carry_to_arith(ir_expression *ir) +{ + /* Translates + * ir_binop_carry x y + * into + * sum = ir_binop_add x y + * bcarry = ir_binop_less sum x + * carry = ir_unop_b2i bcarry + */ + + ir_rvalue *x_clone = ir->operands[0]->clone(ir, NULL); + ir->operation = ir_unop_i2u; + ir->operands[0] = b2i(less(add(ir->operands[0], ir->operands[1]), x_clone)); + ir->operands[1] = NULL; + + this->progress = true; +} + +void +lower_instructions_visitor::borrow_to_arith(ir_expression *ir) +{ + /* Translates + * ir_binop_borrow x y + * into + * bcarry = ir_binop_less x y + * carry = ir_unop_b2i bcarry + */ + + ir->operation = ir_unop_i2u; + ir->operands[0] = b2i(less(ir->operands[0], ir->operands[1])); + ir->operands[1] = NULL; + + this->progress = true; +} + ir_visitor_status lower_instructions_visitor::visit_leave(ir_expression *ir) { @@ -482,6 +530,16 @@ lower_instructions_visitor::visit_leave(ir_expression *ir) ldexp_to_arith(ir); break; + case ir_binop_carry: + if (lowering(CARRY_TO_ARITH)) + carry_to_arith(ir); + break; + + case ir_binop_borrow: + if (lowering(BORROW_TO_ARITH)) + borrow_to_arith(ir); + break; + default: return visit_continue; } |