| /* |
| * Copyright © 2010 Intel Corporation |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the next |
| * paragraph) shall be included in all copies or substantial portions of the |
| * Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
| * DEALINGS IN THE SOFTWARE. |
| */ |
| |
| /** |
| * \file lower_instructions.cpp |
| * |
| * Many GPUs lack native instructions for certain expression operations, and |
| * must replace them with some other expression tree. This pass lowers some |
| * of the most common cases, allowing the lowering code to be implemented once |
| * rather than in each driver backend. |
| * |
| * Currently supported transformations: |
| * - SUB_TO_ADD_NEG |
| * - DIV_TO_MUL_RCP |
| * - INT_DIV_TO_MUL_RCP |
| * - EXP_TO_EXP2 |
| * - POW_TO_EXP2 |
| * - LOG_TO_LOG2 |
| * - MOD_TO_FLOOR |
| * - LDEXP_TO_ARITH |
| * - DFREXP_TO_ARITH |
| * - BITFIELD_INSERT_TO_BFM_BFI |
| * - CARRY_TO_ARITH |
| * - BORROW_TO_ARITH |
| * - SAT_TO_CLAMP |
| * - DOPS_TO_DFRAC |
| * |
| * SUB_TO_ADD_NEG: |
| * --------------- |
| * Breaks an ir_binop_sub expression down to add(op0, neg(op1)) |
| * |
| * This simplifies expression reassociation, and for many backends |
| * there is no subtract operation separate from adding the negation. |
| * For backends with native subtract operations, they will probably |
| * want to recognize add(op0, neg(op1)) or the other way around to |
| * produce a subtract anyway. |
| * |
| * DIV_TO_MUL_RCP and INT_DIV_TO_MUL_RCP: |
| * -------------------------------------- |
| * Breaks an ir_binop_div expression down to op0 * (rcp(op1)). |
| * |
| * Many GPUs don't have a divide instruction (945 and 965 included), |
| * but they do have an RCP instruction to compute an approximate |
| * reciprocal. By breaking the operation down, constant reciprocals |
| * can get constant folded. |
| * |
| * DIV_TO_MUL_RCP only lowers floating point division; INT_DIV_TO_MUL_RCP |
| * handles the integer case, converting to and from floating point so that |
| * RCP is possible. |
| * |
| * EXP_TO_EXP2 and LOG_TO_LOG2: |
| * ---------------------------- |
| * Many GPUs don't have a base e log or exponent instruction, but they |
| * do have base 2 versions, so this pass converts exp and log to exp2 |
| * and log2 operations. |
| * |
| * POW_TO_EXP2: |
| * ----------- |
| * Many older GPUs don't have an x**y instruction. For these GPUs, convert |
| * x**y to 2**(y * log2(x)). |
| * |
| * MOD_TO_FLOOR: |
| * ------------- |
| * Breaks an ir_binop_mod expression down to (op0 - op1 * floor(op0 / op1)) |
| * |
| * Many GPUs don't have a MOD instruction (945 and 965 included), and |
| * if we have to break it down like this anyway, it gives an |
| * opportunity to do things like constant fold the (1.0 / op1) easily. |
| * |
| * Note: before we used to implement this as op1 * fract(op / op1) but this |
| * implementation had significant precision errors. |
| * |
| * LDEXP_TO_ARITH: |
| * ------------- |
| * Converts ir_binop_ldexp to arithmetic and bit operations for float sources. |
| * |
| * DFREXP_DLDEXP_TO_ARITH: |
| * --------------- |
| * Converts ir_binop_ldexp, ir_unop_frexp_sig, and ir_unop_frexp_exp to |
| * arithmetic and bit ops for double arguments. |
| * |
| * BITFIELD_INSERT_TO_BFM_BFI: |
| * --------------------------- |
| * Breaks ir_quadop_bitfield_insert into ir_binop_bfm (bitfield mask) and |
| * ir_triop_bfi (bitfield insert). |
| * |
| * 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). |
| * |
| * SAT_TO_CLAMP: |
| * ------------- |
| * Converts ir_unop_saturate into min(max(x, 0.0), 1.0) |
| * |
| * DOPS_TO_DFRAC: |
| * -------------- |
| * Converts double trunc, ceil, floor, round to fract |
| */ |
| |
| #include "c99_math.h" |
| #include "program/prog_instruction.h" /* for swizzle */ |
| #include "glsl_types.h" |
| #include "ir.h" |
| #include "ir_builder.h" |
| #include "ir_optimization.h" |
| |
| using namespace ir_builder; |
| |
| namespace { |
| |
| class lower_instructions_visitor : public ir_hierarchical_visitor { |
| public: |
| lower_instructions_visitor(unsigned lower) |
| : progress(false), lower(lower) { } |
| |
| ir_visitor_status visit_leave(ir_expression *); |
| |
| bool progress; |
| |
| private: |
| unsigned lower; /** Bitfield of which operations to lower */ |
| |
| void sub_to_add_neg(ir_expression *); |
| void div_to_mul_rcp(ir_expression *); |
| void int_div_to_mul_rcp(ir_expression *); |
| void mod_to_floor(ir_expression *); |
| void exp_to_exp2(ir_expression *); |
| void pow_to_exp2(ir_expression *); |
| void log_to_log2(ir_expression *); |
| void bitfield_insert_to_bfm_bfi(ir_expression *); |
| void ldexp_to_arith(ir_expression *); |
| void dldexp_to_arith(ir_expression *); |
| void dfrexp_sig_to_arith(ir_expression *); |
| void dfrexp_exp_to_arith(ir_expression *); |
| void carry_to_arith(ir_expression *); |
| void borrow_to_arith(ir_expression *); |
| void sat_to_clamp(ir_expression *); |
| void double_dot_to_fma(ir_expression *); |
| void double_lrp(ir_expression *); |
| void dceil_to_dfrac(ir_expression *); |
| void dfloor_to_dfrac(ir_expression *); |
| void dround_even_to_dfrac(ir_expression *); |
| void dtrunc_to_dfrac(ir_expression *); |
| void dsign_to_csel(ir_expression *); |
| }; |
| |
| } /* anonymous namespace */ |
| |
| /** |
| * Determine if a particular type of lowering should occur |
| */ |
| #define lowering(x) (this->lower & x) |
| |
| bool |
| lower_instructions(exec_list *instructions, unsigned what_to_lower) |
| { |
| lower_instructions_visitor v(what_to_lower); |
| |
| visit_list_elements(&v, instructions); |
| return v.progress; |
| } |
| |
| void |
| lower_instructions_visitor::sub_to_add_neg(ir_expression *ir) |
| { |
| ir->operation = ir_binop_add; |
| ir->operands[1] = new(ir) ir_expression(ir_unop_neg, ir->operands[1]->type, |
| ir->operands[1], NULL); |
| this->progress = true; |
| } |
| |
| void |
| lower_instructions_visitor::div_to_mul_rcp(ir_expression *ir) |
| { |
| assert(ir->operands[1]->type->is_float() || ir->operands[1]->type->is_double()); |
| |
| /* New expression for the 1.0 / op1 */ |
| ir_rvalue *expr; |
| expr = new(ir) ir_expression(ir_unop_rcp, |
| ir->operands[1]->type, |
| ir->operands[1]); |
| |
| /* op0 / op1 -> op0 * (1.0 / op1) */ |
| ir->operation = ir_binop_mul; |
| ir->operands[1] = expr; |
| |
| this->progress = true; |
| } |
| |
| void |
| lower_instructions_visitor::int_div_to_mul_rcp(ir_expression *ir) |
| { |
| assert(ir->operands[1]->type->is_integer()); |
| |
| /* Be careful with integer division -- we need to do it as a |
| * float and re-truncate, since rcp(n > 1) of an integer would |
| * just be 0. |
| */ |
| ir_rvalue *op0, *op1; |
| const struct glsl_type *vec_type; |
| |
| vec_type = glsl_type::get_instance(GLSL_TYPE_FLOAT, |
| ir->operands[1]->type->vector_elements, |
| ir->operands[1]->type->matrix_columns); |
| |
| if (ir->operands[1]->type->base_type == GLSL_TYPE_INT) |
| op1 = new(ir) ir_expression(ir_unop_i2f, vec_type, ir->operands[1], NULL); |
| else |
| op1 = new(ir) ir_expression(ir_unop_u2f, vec_type, ir->operands[1], NULL); |
| |
| op1 = new(ir) ir_expression(ir_unop_rcp, op1->type, op1, NULL); |
| |
| vec_type = glsl_type::get_instance(GLSL_TYPE_FLOAT, |
| ir->operands[0]->type->vector_elements, |
| ir->operands[0]->type->matrix_columns); |
| |
| if (ir->operands[0]->type->base_type == GLSL_TYPE_INT) |
| op0 = new(ir) ir_expression(ir_unop_i2f, vec_type, ir->operands[0], NULL); |
| else |
| op0 = new(ir) ir_expression(ir_unop_u2f, vec_type, ir->operands[0], NULL); |
| |
| vec_type = glsl_type::get_instance(GLSL_TYPE_FLOAT, |
| ir->type->vector_elements, |
| ir->type->matrix_columns); |
| |
| op0 = new(ir) ir_expression(ir_binop_mul, vec_type, op0, op1); |
| |
| if (ir->operands[1]->type->base_type == GLSL_TYPE_INT) { |
| ir->operation = ir_unop_f2i; |
| ir->operands[0] = op0; |
| } else { |
| ir->operation = ir_unop_i2u; |
| ir->operands[0] = new(ir) ir_expression(ir_unop_f2i, op0); |
| } |
| ir->operands[1] = NULL; |
| |
| this->progress = true; |
| } |
| |
| void |
| lower_instructions_visitor::exp_to_exp2(ir_expression *ir) |
| { |
| ir_constant *log2_e = new(ir) ir_constant(float(M_LOG2E)); |
| |
| ir->operation = ir_unop_exp2; |
| ir->operands[0] = new(ir) ir_expression(ir_binop_mul, ir->operands[0]->type, |
| ir->operands[0], log2_e); |
| this->progress = true; |
| } |
| |
| void |
| lower_instructions_visitor::pow_to_exp2(ir_expression *ir) |
| { |
| ir_expression *const log2_x = |
| new(ir) ir_expression(ir_unop_log2, ir->operands[0]->type, |
| ir->operands[0]); |
| |
| ir->operation = ir_unop_exp2; |
| ir->operands[0] = new(ir) ir_expression(ir_binop_mul, ir->operands[1]->type, |
| ir->operands[1], log2_x); |
| ir->operands[1] = NULL; |
| this->progress = true; |
| } |
| |
| void |
| lower_instructions_visitor::log_to_log2(ir_expression *ir) |
| { |
| ir->operation = ir_binop_mul; |
| ir->operands[0] = new(ir) ir_expression(ir_unop_log2, ir->operands[0]->type, |
| ir->operands[0], NULL); |
| ir->operands[1] = new(ir) ir_constant(float(1.0 / M_LOG2E)); |
| this->progress = true; |
| } |
| |
| void |
| lower_instructions_visitor::mod_to_floor(ir_expression *ir) |
| { |
| ir_variable *x = new(ir) ir_variable(ir->operands[0]->type, "mod_x", |
| ir_var_temporary); |
| ir_variable *y = new(ir) ir_variable(ir->operands[1]->type, "mod_y", |
| ir_var_temporary); |
| this->base_ir->insert_before(x); |
| this->base_ir->insert_before(y); |
| |
| ir_assignment *const assign_x = |
| new(ir) ir_assignment(new(ir) ir_dereference_variable(x), |
| ir->operands[0], NULL); |
| ir_assignment *const assign_y = |
| new(ir) ir_assignment(new(ir) ir_dereference_variable(y), |
| ir->operands[1], NULL); |
| |
| this->base_ir->insert_before(assign_x); |
| this->base_ir->insert_before(assign_y); |
| |
| ir_expression *const div_expr = |
| new(ir) ir_expression(ir_binop_div, x->type, |
| new(ir) ir_dereference_variable(x), |
| new(ir) ir_dereference_variable(y)); |
| |
| /* Don't generate new IR that would need to be lowered in an additional |
| * pass. |
| */ |
| if (lowering(DIV_TO_MUL_RCP) && (ir->type->is_float() || ir->type->is_double())) |
| div_to_mul_rcp(div_expr); |
| |
| ir_expression *const floor_expr = |
| new(ir) ir_expression(ir_unop_floor, x->type, div_expr); |
| |
| if (lowering(DOPS_TO_DFRAC) && ir->type->is_double()) |
| dfloor_to_dfrac(floor_expr); |
| |
| ir_expression *const mul_expr = |
| new(ir) ir_expression(ir_binop_mul, |
| new(ir) ir_dereference_variable(y), |
| floor_expr); |
| |
| ir->operation = ir_binop_sub; |
| ir->operands[0] = new(ir) ir_dereference_variable(x); |
| ir->operands[1] = mul_expr; |
| this->progress = true; |
| } |
| |
| void |
| lower_instructions_visitor::bitfield_insert_to_bfm_bfi(ir_expression *ir) |
| { |
| /* Translates |
| * ir_quadop_bitfield_insert base insert offset bits |
| * into |
| * ir_triop_bfi (ir_binop_bfm bits offset) insert base |
| */ |
| |
| ir_rvalue *base_expr = ir->operands[0]; |
| |
| ir->operation = ir_triop_bfi; |
| ir->operands[0] = new(ir) ir_expression(ir_binop_bfm, |
| ir->type->get_base_type(), |
| ir->operands[3], |
| ir->operands[2]); |
| /* ir->operands[1] is still the value to insert. */ |
| ir->operands[2] = base_expr; |
| ir->operands[3] = NULL; |
| |
| this->progress = true; |
| } |
| |
| void |
| lower_instructions_visitor::ldexp_to_arith(ir_expression *ir) |
| { |
| /* Translates |
| * ir_binop_ldexp x exp |
| * into |
| * |
| * extracted_biased_exp = rshift(bitcast_f2i(abs(x)), exp_shift); |
| * resulting_biased_exp = extracted_biased_exp + exp; |
| * |
| * if (resulting_biased_exp < 1) { |
| * return copysign(0.0, x); |
| * } |
| * |
| * return bitcast_u2f((bitcast_f2u(x) & sign_mantissa_mask) | |
| * lshift(i2u(resulting_biased_exp), exp_shift)); |
| * |
| * which we can't actually implement as such, since the GLSL IR doesn't |
| * have vectorized if-statements. We actually implement it without branches |
| * using conditional-select: |
| * |
| * extracted_biased_exp = rshift(bitcast_f2i(abs(x)), exp_shift); |
| * resulting_biased_exp = extracted_biased_exp + exp; |
| * |
| * is_not_zero_or_underflow = gequal(resulting_biased_exp, 1); |
| * x = csel(is_not_zero_or_underflow, x, copysign(0.0f, x)); |
| * resulting_biased_exp = csel(is_not_zero_or_underflow, |
| * resulting_biased_exp, 0); |
| * |
| * return bitcast_u2f((bitcast_f2u(x) & sign_mantissa_mask) | |
| * lshift(i2u(resulting_biased_exp), exp_shift)); |
| */ |
| |
| const unsigned vec_elem = ir->type->vector_elements; |
| |
| /* Types */ |
| const glsl_type *ivec = glsl_type::get_instance(GLSL_TYPE_INT, vec_elem, 1); |
| const glsl_type *bvec = glsl_type::get_instance(GLSL_TYPE_BOOL, vec_elem, 1); |
| |
| /* Constants */ |
| ir_constant *zeroi = ir_constant::zero(ir, ivec); |
| |
| ir_constant *sign_mask = new(ir) ir_constant(0x80000000u, vec_elem); |
| |
| ir_constant *exp_shift = new(ir) ir_constant(23); |
| ir_constant *exp_width = new(ir) ir_constant(8); |
| |
| /* Temporary variables */ |
| ir_variable *x = new(ir) ir_variable(ir->type, "x", ir_var_temporary); |
| ir_variable *exp = new(ir) ir_variable(ivec, "exp", ir_var_temporary); |
| |
| ir_variable *zero_sign_x = new(ir) ir_variable(ir->type, "zero_sign_x", |
| ir_var_temporary); |
| |
| ir_variable *extracted_biased_exp = |
| new(ir) ir_variable(ivec, "extracted_biased_exp", ir_var_temporary); |
| ir_variable *resulting_biased_exp = |
| new(ir) ir_variable(ivec, "resulting_biased_exp", ir_var_temporary); |
| |
| ir_variable *is_not_zero_or_underflow = |
| new(ir) ir_variable(bvec, "is_not_zero_or_underflow", ir_var_temporary); |
| |
| ir_instruction &i = *base_ir; |
| |
| /* Copy <x> and <exp> arguments. */ |
| i.insert_before(x); |
| i.insert_before(assign(x, ir->operands[0])); |
| i.insert_before(exp); |
| i.insert_before(assign(exp, ir->operands[1])); |
| |
| /* Extract the biased exponent from <x>. */ |
| i.insert_before(extracted_biased_exp); |
| i.insert_before(assign(extracted_biased_exp, |
| rshift(bitcast_f2i(abs(x)), exp_shift))); |
| |
| i.insert_before(resulting_biased_exp); |
| i.insert_before(assign(resulting_biased_exp, |
| add(extracted_biased_exp, exp))); |
| |
| /* Test if result is ±0.0, subnormal, or underflow by checking if the |
| * resulting biased exponent would be less than 0x1. If so, the result is |
| * 0.0 with the sign of x. (Actually, invert the conditions so that |
| * immediate values are the second arguments, which is better for i965) |
| */ |
| i.insert_before(zero_sign_x); |
| i.insert_before(assign(zero_sign_x, |
| bitcast_u2f(bit_and(bitcast_f2u(x), sign_mask)))); |
| |
| i.insert_before(is_not_zero_or_underflow); |
| i.insert_before(assign(is_not_zero_or_underflow, |
| gequal(resulting_biased_exp, |
| new(ir) ir_constant(0x1, vec_elem)))); |
| i.insert_before(assign(x, csel(is_not_zero_or_underflow, |
| x, zero_sign_x))); |
| i.insert_before(assign(resulting_biased_exp, |
| csel(is_not_zero_or_underflow, |
| resulting_biased_exp, zeroi))); |
| |
| /* We could test for overflows by checking if the resulting biased exponent |
| * would be greater than 0xFE. Turns out we don't need to because the GLSL |
| * spec says: |
| * |
| * "If this product is too large to be represented in the |
| * floating-point type, the result is undefined." |
| */ |
| |
| ir_constant *exp_shift_clone = exp_shift->clone(ir, NULL); |
| ir->operation = ir_unop_bitcast_i2f; |
| ir->operands[0] = bitfield_insert(bitcast_f2i(x), resulting_biased_exp, |
| exp_shift_clone, exp_width); |
| ir->operands[1] = NULL; |
| |
| /* Don't generate new IR that would need to be lowered in an additional |
| * pass. |
| */ |
| if (lowering(BITFIELD_INSERT_TO_BFM_BFI)) |
| bitfield_insert_to_bfm_bfi(ir->operands[0]->as_expression()); |
| |
| this->progress = true; |
| } |
| |
| void |
| lower_instructions_visitor::dldexp_to_arith(ir_expression *ir) |
| { |
| /* See ldexp_to_arith for structure. Uses frexp_exp to extract the exponent |
| * from the significand. |
| */ |
| |
| const unsigned vec_elem = ir->type->vector_elements; |
| |
| /* Types */ |
| const glsl_type *ivec = glsl_type::get_instance(GLSL_TYPE_INT, vec_elem, 1); |
| const glsl_type *bvec = glsl_type::get_instance(GLSL_TYPE_BOOL, vec_elem, 1); |
| |
| /* Constants */ |
| ir_constant *zeroi = ir_constant::zero(ir, ivec); |
| |
| ir_constant *sign_mask = new(ir) ir_constant(0x80000000u); |
| |
| ir_constant *exp_shift = new(ir) ir_constant(20); |
| ir_constant *exp_width = new(ir) ir_constant(11); |
| ir_constant *exp_bias = new(ir) ir_constant(1022, vec_elem); |
| |
| /* Temporary variables */ |
| ir_variable *x = new(ir) ir_variable(ir->type, "x", ir_var_temporary); |
| ir_variable *exp = new(ir) ir_variable(ivec, "exp", ir_var_temporary); |
| |
| ir_variable *zero_sign_x = new(ir) ir_variable(ir->type, "zero_sign_x", |
| ir_var_temporary); |
| |
| ir_variable *extracted_biased_exp = |
| new(ir) ir_variable(ivec, "extracted_biased_exp", ir_var_temporary); |
| ir_variable *resulting_biased_exp = |
| new(ir) ir_variable(ivec, "resulting_biased_exp", ir_var_temporary); |
| |
| ir_variable *is_not_zero_or_underflow = |
| new(ir) ir_variable(bvec, "is_not_zero_or_underflow", ir_var_temporary); |
| |
| ir_instruction &i = *base_ir; |
| |
| /* Copy <x> and <exp> arguments. */ |
| i.insert_before(x); |
| i.insert_before(assign(x, ir->operands[0])); |
| i.insert_before(exp); |
| i.insert_before(assign(exp, ir->operands[1])); |
| |
| ir_expression *frexp_exp = expr(ir_unop_frexp_exp, x); |
| if (lowering(DFREXP_DLDEXP_TO_ARITH)) |
| dfrexp_exp_to_arith(frexp_exp); |
| |
| /* Extract the biased exponent from <x>. */ |
| i.insert_before(extracted_biased_exp); |
| i.insert_before(assign(extracted_biased_exp, add(frexp_exp, exp_bias))); |
| |
| i.insert_before(resulting_biased_exp); |
| i.insert_before(assign(resulting_biased_exp, |
| add(extracted_biased_exp, exp))); |
| |
| /* Test if result is ±0.0, subnormal, or underflow by checking if the |
| * resulting biased exponent would be less than 0x1. If so, the result is |
| * 0.0 with the sign of x. (Actually, invert the conditions so that |
| * immediate values are the second arguments, which is better for i965) |
| * TODO: Implement in a vector fashion. |
| */ |
| i.insert_before(zero_sign_x); |
| for (unsigned elem = 0; elem < vec_elem; elem++) { |
| ir_variable *unpacked = |
| new(ir) ir_variable(glsl_type::uvec2_type, "unpacked", ir_var_temporary); |
| i.insert_before(unpacked); |
| i.insert_before( |
| assign(unpacked, |
| expr(ir_unop_unpack_double_2x32, swizzle(x, elem, 1)))); |
| i.insert_before(assign(unpacked, bit_and(swizzle_y(unpacked), sign_mask->clone(ir, NULL)), |
| WRITEMASK_Y)); |
| i.insert_before(assign(unpacked, ir_constant::zero(ir, glsl_type::uint_type), WRITEMASK_X)); |
| i.insert_before(assign(zero_sign_x, |
| expr(ir_unop_pack_double_2x32, unpacked), |
| 1 << elem)); |
| } |
| i.insert_before(is_not_zero_or_underflow); |
| i.insert_before(assign(is_not_zero_or_underflow, |
| gequal(resulting_biased_exp, |
| new(ir) ir_constant(0x1, vec_elem)))); |
| i.insert_before(assign(x, csel(is_not_zero_or_underflow, |
| x, zero_sign_x))); |
| i.insert_before(assign(resulting_biased_exp, |
| csel(is_not_zero_or_underflow, |
| resulting_biased_exp, zeroi))); |
| |
| /* We could test for overflows by checking if the resulting biased exponent |
| * would be greater than 0xFE. Turns out we don't need to because the GLSL |
| * spec says: |
| * |
| * "If this product is too large to be represented in the |
| * floating-point type, the result is undefined." |
| */ |
| |
| ir_rvalue *results[4] = {NULL}; |
| for (unsigned elem = 0; elem < vec_elem; elem++) { |
| ir_variable *unpacked = |
| new(ir) ir_variable(glsl_type::uvec2_type, "unpacked", ir_var_temporary); |
| i.insert_before(unpacked); |
| i.insert_before( |
| assign(unpacked, |
| expr(ir_unop_unpack_double_2x32, swizzle(x, elem, 1)))); |
| |
| ir_expression *bfi = bitfield_insert( |
| swizzle_y(unpacked), |
| i2u(swizzle(resulting_biased_exp, elem, 1)), |
| exp_shift->clone(ir, NULL), |
| exp_width->clone(ir, NULL)); |
| |
| if (lowering(BITFIELD_INSERT_TO_BFM_BFI)) |
| bitfield_insert_to_bfm_bfi(bfi); |
| |
| i.insert_before(assign(unpacked, bfi, WRITEMASK_Y)); |
| |
| results[elem] = expr(ir_unop_pack_double_2x32, unpacked); |
| } |
| |
| ir->operation = ir_quadop_vector; |
| ir->operands[0] = results[0]; |
| ir->operands[1] = results[1]; |
| ir->operands[2] = results[2]; |
| ir->operands[3] = results[3]; |
| |
| /* Don't generate new IR that would need to be lowered in an additional |
| * pass. |
| */ |
| |
| this->progress = true; |
| } |
| |
| void |
| lower_instructions_visitor::dfrexp_sig_to_arith(ir_expression *ir) |
| { |
| const unsigned vec_elem = ir->type->vector_elements; |
| const glsl_type *bvec = glsl_type::get_instance(GLSL_TYPE_BOOL, vec_elem, 1); |
| |
| /* Double-precision floating-point values are stored as |
| * 1 sign bit; |
| * 11 exponent bits; |
| * 52 mantissa bits. |
| * |
| * We're just extracting the significand here, so we only need to modify |
| * the upper 32-bit uint. Unfortunately we must extract each double |
| * independently as there is no vector version of unpackDouble. |
| */ |
| |
| ir_instruction &i = *base_ir; |
| |
| ir_variable *is_not_zero = |
| new(ir) ir_variable(bvec, "is_not_zero", ir_var_temporary); |
| ir_rvalue *results[4] = {NULL}; |
| |
| ir_constant *dzero = new(ir) ir_constant(0.0, vec_elem); |
| i.insert_before(is_not_zero); |
| i.insert_before( |
| assign(is_not_zero, |
| nequal(abs(ir->operands[0]->clone(ir, NULL)), dzero))); |
| |
| /* TODO: Remake this as more vector-friendly when int64 support is |
| * available. |
| */ |
| for (unsigned elem = 0; elem < vec_elem; elem++) { |
| ir_constant *zero = new(ir) ir_constant(0u, 1); |
| ir_constant *sign_mantissa_mask = new(ir) ir_constant(0x800fffffu, 1); |
| |
| /* Exponent of double floating-point values in the range [0.5, 1.0). */ |
| ir_constant *exponent_value = new(ir) ir_constant(0x3fe00000u, 1); |
| |
| ir_variable *bits = |
| new(ir) ir_variable(glsl_type::uint_type, "bits", ir_var_temporary); |
| ir_variable *unpacked = |
| new(ir) ir_variable(glsl_type::uvec2_type, "unpacked", ir_var_temporary); |
| |
| ir_rvalue *x = swizzle(ir->operands[0]->clone(ir, NULL), elem, 1); |
| |
| i.insert_before(bits); |
| i.insert_before(unpacked); |
| i.insert_before(assign(unpacked, expr(ir_unop_unpack_double_2x32, x))); |
| |
| /* Manipulate the high uint to remove the exponent and replace it with |
| * either the default exponent or zero. |
| */ |
| i.insert_before(assign(bits, swizzle_y(unpacked))); |
| i.insert_before(assign(bits, bit_and(bits, sign_mantissa_mask))); |
| i.insert_before(assign(bits, bit_or(bits, |
| csel(swizzle(is_not_zero, elem, 1), |
| exponent_value, |
| zero)))); |
| i.insert_before(assign(unpacked, bits, WRITEMASK_Y)); |
| results[elem] = expr(ir_unop_pack_double_2x32, unpacked); |
| } |
| |
| /* Put the dvec back together */ |
| ir->operation = ir_quadop_vector; |
| ir->operands[0] = results[0]; |
| ir->operands[1] = results[1]; |
| ir->operands[2] = results[2]; |
| ir->operands[3] = results[3]; |
| |
| this->progress = true; |
| } |
| |
| void |
| lower_instructions_visitor::dfrexp_exp_to_arith(ir_expression *ir) |
| { |
| const unsigned vec_elem = ir->type->vector_elements; |
| const glsl_type *bvec = glsl_type::get_instance(GLSL_TYPE_BOOL, vec_elem, 1); |
| const glsl_type *uvec = glsl_type::get_instance(GLSL_TYPE_UINT, vec_elem, 1); |
| |
| /* Double-precision floating-point values are stored as |
| * 1 sign bit; |
| * 11 exponent bits; |
| * 52 mantissa bits. |
| * |
| * We're just extracting the exponent here, so we only care about the upper |
| * 32-bit uint. |
| */ |
| |
| ir_instruction &i = *base_ir; |
| |
| ir_variable *is_not_zero = |
| new(ir) ir_variable(bvec, "is_not_zero", ir_var_temporary); |
| ir_variable *high_words = |
| new(ir) ir_variable(uvec, "high_words", ir_var_temporary); |
| ir_constant *dzero = new(ir) ir_constant(0.0, vec_elem); |
| ir_constant *izero = new(ir) ir_constant(0, vec_elem); |
| |
| ir_rvalue *absval = abs(ir->operands[0]); |
| |
| i.insert_before(is_not_zero); |
| i.insert_before(high_words); |
| i.insert_before(assign(is_not_zero, nequal(absval->clone(ir, NULL), dzero))); |
| |
| /* Extract all of the upper uints. */ |
| for (unsigned elem = 0; elem < vec_elem; elem++) { |
| ir_rvalue *x = swizzle(absval->clone(ir, NULL), elem, 1); |
| |
| i.insert_before(assign(high_words, |
| swizzle_y(expr(ir_unop_unpack_double_2x32, x)), |
| 1 << elem)); |
| |
| } |
| ir_constant *exponent_shift = new(ir) ir_constant(20, vec_elem); |
| ir_constant *exponent_bias = new(ir) ir_constant(-1022, vec_elem); |
| |
| /* For non-zero inputs, shift the exponent down and apply bias. */ |
| ir->operation = ir_triop_csel; |
| ir->operands[0] = new(ir) ir_dereference_variable(is_not_zero); |
| ir->operands[1] = add(exponent_bias, u2i(rshift(high_words, exponent_shift))); |
| ir->operands[2] = izero; |
| |
| 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; |
| } |
| |
| 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; |
| } |
| |
| void |
| lower_instructions_visitor::double_dot_to_fma(ir_expression *ir) |
| { |
| ir_variable *temp = new(ir) ir_variable(ir->operands[0]->type->get_base_type(), "dot_res", |
| ir_var_temporary); |
| this->base_ir->insert_before(temp); |
| |
| int nc = ir->operands[0]->type->components(); |
| for (int i = nc - 1; i >= 1; i--) { |
| ir_assignment *assig; |
| if (i == (nc - 1)) { |
| assig = assign(temp, mul(swizzle(ir->operands[0]->clone(ir, NULL), i, 1), |
| swizzle(ir->operands[1]->clone(ir, NULL), i, 1))); |
| } else { |
| assig = assign(temp, fma(swizzle(ir->operands[0]->clone(ir, NULL), i, 1), |
| swizzle(ir->operands[1]->clone(ir, NULL), i, 1), |
| temp)); |
| } |
| this->base_ir->insert_before(assig); |
| } |
| |
| ir->operation = ir_triop_fma; |
| ir->operands[0] = swizzle(ir->operands[0], 0, 1); |
| ir->operands[1] = swizzle(ir->operands[1], 0, 1); |
| ir->operands[2] = new(ir) ir_dereference_variable(temp); |
| |
| this->progress = true; |
| |
| } |
| |
| void |
| lower_instructions_visitor::double_lrp(ir_expression *ir) |
| { |
| int swizval; |
| ir_rvalue *op0 = ir->operands[0], *op2 = ir->operands[2]; |
| ir_constant *one = new(ir) ir_constant(1.0, op2->type->vector_elements); |
| |
| switch (op2->type->vector_elements) { |
| case 1: |
| swizval = SWIZZLE_XXXX; |
| break; |
| default: |
| assert(op0->type->vector_elements == op2->type->vector_elements); |
| swizval = SWIZZLE_XYZW; |
| break; |
| } |
| |
| ir->operation = ir_triop_fma; |
| ir->operands[0] = swizzle(op2, swizval, op0->type->vector_elements); |
| ir->operands[2] = mul(sub(one, op2->clone(ir, NULL)), op0); |
| |
| this->progress = true; |
| } |
| |
| void |
| lower_instructions_visitor::dceil_to_dfrac(ir_expression *ir) |
| { |
| /* |
| * frtemp = frac(x); |
| * temp = sub(x, frtemp); |
| * result = temp + ((frtemp != 0.0) ? 1.0 : 0.0); |
| */ |
| ir_instruction &i = *base_ir; |
| ir_constant *zero = new(ir) ir_constant(0.0, ir->operands[0]->type->vector_elements); |
| ir_constant *one = new(ir) ir_constant(1.0, ir->operands[0]->type->vector_elements); |
| ir_variable *frtemp = new(ir) ir_variable(ir->operands[0]->type, "frtemp", |
| ir_var_temporary); |
| |
| i.insert_before(frtemp); |
| i.insert_before(assign(frtemp, fract(ir->operands[0]))); |
| |
| ir->operation = ir_binop_add; |
| ir->operands[0] = sub(ir->operands[0]->clone(ir, NULL), frtemp); |
| ir->operands[1] = csel(nequal(frtemp, zero), one, zero->clone(ir, NULL)); |
| |
| this->progress = true; |
| } |
| |
| void |
| lower_instructions_visitor::dfloor_to_dfrac(ir_expression *ir) |
| { |
| /* |
| * frtemp = frac(x); |
| * result = sub(x, frtemp); |
| */ |
| ir->operation = ir_binop_sub; |
| ir->operands[1] = fract(ir->operands[0]->clone(ir, NULL)); |
| |
| this->progress = true; |
| } |
| void |
| lower_instructions_visitor::dround_even_to_dfrac(ir_expression *ir) |
| { |
| /* |
| * insane but works |
| * temp = x + 0.5; |
| * frtemp = frac(temp); |
| * t2 = sub(temp, frtemp); |
| * if (frac(x) == 0.5) |
| * result = frac(t2 * 0.5) == 0 ? t2 : t2 - 1; |
| * else |
| * result = t2; |
| |
| */ |
| ir_instruction &i = *base_ir; |
| ir_variable *frtemp = new(ir) ir_variable(ir->operands[0]->type, "frtemp", |
| ir_var_temporary); |
| ir_variable *temp = new(ir) ir_variable(ir->operands[0]->type, "temp", |
| ir_var_temporary); |
| ir_variable *t2 = new(ir) ir_variable(ir->operands[0]->type, "t2", |
| ir_var_temporary); |
| ir_constant *p5 = new(ir) ir_constant(0.5, ir->operands[0]->type->vector_elements); |
| ir_constant *one = new(ir) ir_constant(1.0, ir->operands[0]->type->vector_elements); |
| ir_constant *zero = new(ir) ir_constant(0.0, ir->operands[0]->type->vector_elements); |
| |
| i.insert_before(temp); |
| i.insert_before(assign(temp, add(ir->operands[0], p5))); |
| |
| i.insert_before(frtemp); |
| i.insert_before(assign(frtemp, fract(temp))); |
| |
| i.insert_before(t2); |
| i.insert_before(assign(t2, sub(temp, frtemp))); |
| |
| ir->operation = ir_triop_csel; |
| ir->operands[0] = equal(fract(ir->operands[0]->clone(ir, NULL)), |
| p5->clone(ir, NULL)); |
| ir->operands[1] = csel(equal(fract(mul(t2, p5->clone(ir, NULL))), |
| zero), |
| t2, |
| sub(t2, one)); |
| ir->operands[2] = new(ir) ir_dereference_variable(t2); |
| |
| this->progress = true; |
| } |
| |
| void |
| lower_instructions_visitor::dtrunc_to_dfrac(ir_expression *ir) |
| { |
| /* |
| * frtemp = frac(x); |
| * temp = sub(x, frtemp); |
| * result = x >= 0 ? temp : temp + (frtemp == 0.0) ? 0 : 1; |
| */ |
| ir_rvalue *arg = ir->operands[0]; |
| ir_instruction &i = *base_ir; |
| |
| ir_constant *zero = new(ir) ir_constant(0.0, arg->type->vector_elements); |
| ir_constant *one = new(ir) ir_constant(1.0, arg->type->vector_elements); |
| ir_variable *frtemp = new(ir) ir_variable(arg->type, "frtemp", |
| ir_var_temporary); |
| ir_variable *temp = new(ir) ir_variable(ir->operands[0]->type, "temp", |
| ir_var_temporary); |
| |
| i.insert_before(frtemp); |
| i.insert_before(assign(frtemp, fract(arg))); |
| i.insert_before(temp); |
| i.insert_before(assign(temp, sub(arg->clone(ir, NULL), frtemp))); |
| |
| ir->operation = ir_triop_csel; |
| ir->operands[0] = gequal(arg->clone(ir, NULL), zero); |
| ir->operands[1] = new (ir) ir_dereference_variable(temp); |
| ir->operands[2] = add(temp, |
| csel(equal(frtemp, zero->clone(ir, NULL)), |
| zero->clone(ir, NULL), |
| one)); |
| |
| this->progress = true; |
| } |
| |
| void |
| lower_instructions_visitor::dsign_to_csel(ir_expression *ir) |
| { |
| /* |
| * temp = x > 0.0 ? 1.0 : 0.0; |
| * result = x < 0.0 ? -1.0 : temp; |
| */ |
| ir_rvalue *arg = ir->operands[0]; |
| ir_constant *zero = new(ir) ir_constant(0.0, arg->type->vector_elements); |
| ir_constant *one = new(ir) ir_constant(1.0, arg->type->vector_elements); |
| ir_constant *neg_one = new(ir) ir_constant(-1.0, arg->type->vector_elements); |
| |
| ir->operation = ir_triop_csel; |
| ir->operands[0] = less(arg->clone(ir, NULL), |
| zero->clone(ir, NULL)); |
| ir->operands[1] = neg_one; |
| ir->operands[2] = csel(greater(arg, zero), |
| one, |
| zero->clone(ir, NULL)); |
| |
| this->progress = true; |
| } |
| |
| ir_visitor_status |
| lower_instructions_visitor::visit_leave(ir_expression *ir) |
| { |
| switch (ir->operation) { |
| case ir_binop_dot: |
| if (ir->operands[0]->type->is_double()) |
| double_dot_to_fma(ir); |
| break; |
| case ir_triop_lrp: |
| if (ir->operands[0]->type->is_double()) |
| double_lrp(ir); |
| break; |
| case ir_binop_sub: |
| if (lowering(SUB_TO_ADD_NEG)) |
| sub_to_add_neg(ir); |
| break; |
| |
| case ir_binop_div: |
| if (ir->operands[1]->type->is_integer() && lowering(INT_DIV_TO_MUL_RCP)) |
| int_div_to_mul_rcp(ir); |
| else if ((ir->operands[1]->type->is_float() || |
| ir->operands[1]->type->is_double()) && lowering(DIV_TO_MUL_RCP)) |
| div_to_mul_rcp(ir); |
| break; |
| |
| case ir_unop_exp: |
| if (lowering(EXP_TO_EXP2)) |
| exp_to_exp2(ir); |
| break; |
| |
| case ir_unop_log: |
| if (lowering(LOG_TO_LOG2)) |
| log_to_log2(ir); |
| break; |
| |
| case ir_binop_mod: |
| if (lowering(MOD_TO_FLOOR) && (ir->type->is_float() || ir->type->is_double())) |
| mod_to_floor(ir); |
| break; |
| |
| case ir_binop_pow: |
| if (lowering(POW_TO_EXP2)) |
| pow_to_exp2(ir); |
| break; |
| |
| case ir_quadop_bitfield_insert: |
| if (lowering(BITFIELD_INSERT_TO_BFM_BFI)) |
| bitfield_insert_to_bfm_bfi(ir); |
| break; |
| |
| case ir_binop_ldexp: |
| if (lowering(LDEXP_TO_ARITH) && ir->type->is_float()) |
| ldexp_to_arith(ir); |
| if (lowering(DFREXP_DLDEXP_TO_ARITH) && ir->type->is_double()) |
| dldexp_to_arith(ir); |
| break; |
| |
| case ir_unop_frexp_exp: |
| if (lowering(DFREXP_DLDEXP_TO_ARITH) && ir->operands[0]->type->is_double()) |
| dfrexp_exp_to_arith(ir); |
| break; |
| |
| case ir_unop_frexp_sig: |
| if (lowering(DFREXP_DLDEXP_TO_ARITH) && ir->operands[0]->type->is_double()) |
| dfrexp_sig_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; |
| |
| case ir_unop_saturate: |
| if (lowering(SAT_TO_CLAMP)) |
| sat_to_clamp(ir); |
| break; |
| |
| case ir_unop_trunc: |
| if (lowering(DOPS_TO_DFRAC) && ir->type->is_double()) |
| dtrunc_to_dfrac(ir); |
| break; |
| |
| case ir_unop_ceil: |
| if (lowering(DOPS_TO_DFRAC) && ir->type->is_double()) |
| dceil_to_dfrac(ir); |
| break; |
| |
| case ir_unop_floor: |
| if (lowering(DOPS_TO_DFRAC) && ir->type->is_double()) |
| dfloor_to_dfrac(ir); |
| break; |
| |
| case ir_unop_round_even: |
| if (lowering(DOPS_TO_DFRAC) && ir->type->is_double()) |
| dround_even_to_dfrac(ir); |
| break; |
| |
| case ir_unop_sign: |
| if (lowering(DOPS_TO_DFRAC) && ir->type->is_double()) |
| dsign_to_csel(ir); |
| break; |
| default: |
| return visit_continue; |
| } |
| |
| return visit_continue; |
| } |