diff options
Diffstat (limited to 'src/glsl/lower_instructions.cpp')
| -rw-r--r-- | src/glsl/lower_instructions.cpp | 279 |
1 files changed, 278 insertions, 1 deletions
diff --git a/src/glsl/lower_instructions.cpp b/src/glsl/lower_instructions.cpp index c63c018e247..8f8303241e2 100644 --- a/src/glsl/lower_instructions.cpp +++ b/src/glsl/lower_instructions.cpp @@ -38,6 +38,7 @@ * - LOG_TO_LOG2 * - MOD_TO_FLOOR * - LDEXP_TO_ARITH + * - DFREXP_TO_ARITH * - BITFIELD_INSERT_TO_BFM_BFI * - CARRY_TO_ARITH * - BORROW_TO_ARITH @@ -91,7 +92,12 @@ * * LDEXP_TO_ARITH: * ------------- - * Converts ir_binop_ldexp to arithmetic and bit operations. + * 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: * --------------------------- @@ -150,6 +156,9 @@ private: 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 *); @@ -483,6 +492,262 @@ lower_instructions_visitor::ldexp_to_arith(ir_expression *ir) } 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(0.0d, 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(0.0d, 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 @@ -781,6 +1046,18 @@ lower_instructions_visitor::visit_leave(ir_expression *ir) 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: |