#include "nir_builder.h"
#include "c99_math.h"
+#include <float.h>
+
/*
* Lowers some unsupported double operations, using only:
*
set_exponent(nir_builder *b, nir_ssa_def *src, nir_ssa_def *exp)
{
/* Split into bits 0-31 and 32-63 */
- nir_ssa_def *lo = nir_unpack_double_2x32_split_x(b, src);
- nir_ssa_def *hi = nir_unpack_double_2x32_split_y(b, src);
+ nir_ssa_def *lo = nir_unpack_64_2x32_split_x(b, src);
+ nir_ssa_def *hi = nir_unpack_64_2x32_split_y(b, src);
/* The exponent is bits 52-62, or 20-30 of the high word, so set the exponent
* to 1023
*/
nir_ssa_def *new_hi = nir_bfi(b, nir_imm_int(b, 0x7ff00000), exp, hi);
/* recombine */
- return nir_pack_double_2x32_split(b, lo, new_hi);
+ return nir_pack_64_2x32_split(b, lo, new_hi);
}
static nir_ssa_def *
get_exponent(nir_builder *b, nir_ssa_def *src)
{
/* get bits 32-63 */
- nir_ssa_def *hi = nir_unpack_double_2x32_split_y(b, src);
+ nir_ssa_def *hi = nir_unpack_64_2x32_split_y(b, src);
/* extract bits 20-30 of the high word */
return nir_ubitfield_extract(b, hi, nir_imm_int(b, 20), nir_imm_int(b, 11));
static nir_ssa_def *
get_signed_inf(nir_builder *b, nir_ssa_def *zero)
{
- nir_ssa_def *zero_hi = nir_unpack_double_2x32_split_y(b, zero);
+ nir_ssa_def *zero_hi = nir_unpack_64_2x32_split_y(b, zero);
/* The bit pattern for infinity is 0x7ff0000000000000, where the sign bit
* is the highest bit. Only the sign bit can be non-zero in the passed in
* bits and then pack it together with zero low 32 bits.
*/
nir_ssa_def *inf_hi = nir_ior(b, nir_imm_int(b, 0x7ff00000), zero_hi);
- return nir_pack_double_2x32_split(b, nir_imm_int(b, 0), inf_hi);
+ return nir_pack_64_2x32_split(b, nir_imm_int(b, 0), inf_hi);
}
/*
/* cast to float, do an rcp, and then cast back to get an approximate
* result
*/
- nir_ssa_def *ra = nir_f2d(b, nir_frcp(b, nir_d2f(b, src_norm)));
+ nir_ssa_def *ra = nir_f2f64(b, nir_frcp(b, nir_f2f32(b, src_norm)));
/* Fixup the exponent of the result - note that we check if this is too
* small below.
* See https://en.wikipedia.org/wiki/Division_algorithm for more details.
*/
- ra = nir_ffma(b, ra, nir_ffma(b, ra, src, nir_imm_double(b, -1)), ra);
- ra = nir_ffma(b, ra, nir_ffma(b, ra, src, nir_imm_double(b, -1)), ra);
+ ra = nir_ffma(b, nir_fneg(b, ra), nir_ffma(b, ra, src, nir_imm_double(b, -1)), ra);
+ ra = nir_ffma(b, nir_fneg(b, ra), nir_ffma(b, ra, src, nir_imm_double(b, -1)), ra);
return fix_inv_result(b, ra, src, new_exp);
}
nir_iadd(b, nir_imm_int(b, 1023),
even));
- nir_ssa_def *ra = nir_f2d(b, nir_frsq(b, nir_d2f(b, src_norm)));
+ nir_ssa_def *ra = nir_f2f64(b, nir_frsq(b, nir_f2f32(b, src_norm)));
nir_ssa_def *new_exp = nir_isub(b, get_exponent(b, ra), half);
ra = set_exponent(b, ra, new_exp);
* (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots).
*/
- nir_ssa_def *one_half = nir_imm_double(b, 0.5);
- nir_ssa_def *h_0 = nir_fmul(b, one_half, ra);
- nir_ssa_def *g_0 = nir_fmul(b, src, ra);
- nir_ssa_def *r_0 = nir_ffma(b, nir_fneg(b, h_0), g_0, one_half);
- nir_ssa_def *h_1 = nir_ffma(b, h_0, r_0, h_0);
- nir_ssa_def *res;
- if (sqrt) {
- nir_ssa_def *g_1 = nir_ffma(b, g_0, r_0, g_0);
- nir_ssa_def *r_1 = nir_ffma(b, nir_fneg(b, g_1), g_1, src);
- res = nir_ffma(b, h_1, r_1, g_1);
- } else {
- nir_ssa_def *y_1 = nir_fmul(b, nir_imm_double(b, 2.0), h_1);
- nir_ssa_def *r_1 = nir_ffma(b, nir_fneg(b, y_1), nir_fmul(b, h_1, src),
- one_half);
- res = nir_ffma(b, y_1, r_1, y_1);
- }
-
- if (sqrt) {
- /* Here, the special cases we need to handle are
- * 0 -> 0 and
- * +inf -> +inf
- */
- res = nir_bcsel(b, nir_ior(b, nir_feq(b, src, nir_imm_double(b, 0.0)),
- nir_feq(b, src, nir_imm_double(b, INFINITY))),
- src, res);
- } else {
- res = fix_inv_result(b, res, src, new_exp);
- }
-
- return res;
+ nir_ssa_def *one_half = nir_imm_double(b, 0.5);
+ nir_ssa_def *h_0 = nir_fmul(b, one_half, ra);
+ nir_ssa_def *g_0 = nir_fmul(b, src, ra);
+ nir_ssa_def *r_0 = nir_ffma(b, nir_fneg(b, h_0), g_0, one_half);
+ nir_ssa_def *h_1 = nir_ffma(b, h_0, r_0, h_0);
+ nir_ssa_def *res;
+ if (sqrt) {
+ nir_ssa_def *g_1 = nir_ffma(b, g_0, r_0, g_0);
+ nir_ssa_def *r_1 = nir_ffma(b, nir_fneg(b, g_1), g_1, src);
+ res = nir_ffma(b, h_1, r_1, g_1);
+ } else {
+ nir_ssa_def *y_1 = nir_fmul(b, nir_imm_double(b, 2.0), h_1);
+ nir_ssa_def *r_1 = nir_ffma(b, nir_fneg(b, y_1), nir_fmul(b, h_1, src),
+ one_half);
+ res = nir_ffma(b, y_1, r_1, y_1);
+ }
+
+ if (sqrt) {
+ /* Here, the special cases we need to handle are
+ * 0 -> 0 and
+ * +inf -> +inf
+ */
+ const bool preserve_denorms =
+ b->shader->info.float_controls_execution_mode &
+ FLOAT_CONTROLS_DENORM_PRESERVE_FP64;
+ nir_ssa_def *src_flushed = src;
+ if (!preserve_denorms) {
+ src_flushed = nir_bcsel(b,
+ nir_flt(b, nir_fabs(b, src),
+ nir_imm_double(b, DBL_MIN)),
+ nir_imm_double(b, 0.0),
+ src);
+ }
+ res = nir_bcsel(b, nir_ior(b, nir_feq(b, src_flushed, nir_imm_double(b, 0.0)),
+ nir_feq(b, src, nir_imm_double(b, INFINITY))),
+ src_flushed, res);
+ } else {
+ res = fix_inv_result(b, res, src, new_exp);
+ }
+
+ return res;
}
static nir_ssa_def *
nir_imm_int(b, ~0),
nir_isub(b, frac_bits, nir_imm_int(b, 32))));
- nir_ssa_def *src_lo = nir_unpack_double_2x32_split_x(b, src);
- nir_ssa_def *src_hi = nir_unpack_double_2x32_split_y(b, src);
+ nir_ssa_def *src_lo = nir_unpack_64_2x32_split_x(b, src);
+ nir_ssa_def *src_hi = nir_unpack_64_2x32_split_y(b, src);
return
nir_bcsel(b,
nir_imm_double(b, 0.0),
nir_bcsel(b, nir_ige(b, unbiased_exp, nir_imm_int(b, 53)),
src,
- nir_pack_double_2x32_split(b,
- nir_iand(b, mask_lo, src_lo),
- nir_iand(b, mask_hi, src_hi))));
+ nir_pack_64_2x32_split(b,
+ nir_iand(b, mask_lo, src_lo),
+ nir_iand(b, mask_hi, src_hi))));
}
-static void
-lower_doubles_instr(nir_alu_instr *instr, nir_lower_doubles_options options)
+static nir_ssa_def *
+lower_floor(nir_builder *b, nir_ssa_def *src)
{
- assert(instr->dest.dest.is_ssa);
- if (instr->dest.dest.ssa.bit_size != 64)
- return;
+ /*
+ * For x >= 0, floor(x) = trunc(x)
+ * For x < 0,
+ * - if x is integer, floor(x) = x
+ * - otherwise, floor(x) = trunc(x) - 1
+ */
+ nir_ssa_def *tr = nir_ftrunc(b, src);
+ nir_ssa_def *positive = nir_fge(b, src, nir_imm_double(b, 0.0));
+ return nir_bcsel(b,
+ nir_ior(b, positive, nir_feq(b, src, tr)),
+ tr,
+ nir_fsub(b, tr, nir_imm_double(b, 1.0)));
+}
- switch (instr->op) {
- case nir_op_frcp:
- if (!(options & nir_lower_drcp))
- return;
- break;
+static nir_ssa_def *
+lower_ceil(nir_builder *b, nir_ssa_def *src)
+{
+ /* if x < 0, ceil(x) = trunc(x)
+ * else if (x - trunc(x) == 0), ceil(x) = x
+ * else, ceil(x) = trunc(x) + 1
+ */
+ nir_ssa_def *tr = nir_ftrunc(b, src);
+ nir_ssa_def *negative = nir_flt(b, src, nir_imm_double(b, 0.0));
+ return nir_bcsel(b,
+ nir_ior(b, negative, nir_feq(b, src, tr)),
+ tr,
+ nir_fadd(b, tr, nir_imm_double(b, 1.0)));
+}
- case nir_op_fsqrt:
- if (!(options & nir_lower_dsqrt))
- return;
- break;
+static nir_ssa_def *
+lower_fract(nir_builder *b, nir_ssa_def *src)
+{
+ return nir_fsub(b, src, nir_ffloor(b, src));
+}
- case nir_op_frsq:
- if (!(options & nir_lower_drsq))
- return;
- break;
+static nir_ssa_def *
+lower_round_even(nir_builder *b, nir_ssa_def *src)
+{
+ /* Add and subtract 2**52 to round off any fractional bits. */
+ nir_ssa_def *two52 = nir_imm_double(b, (double)(1ull << 52));
+ nir_ssa_def *sign = nir_iand(b, nir_unpack_64_2x32_split_y(b, src),
+ nir_imm_int(b, 1ull << 31));
+
+ b->exact = true;
+ nir_ssa_def *res = nir_fsub(b, nir_fadd(b, nir_fabs(b, src), two52), two52);
+ b->exact = false;
+
+ return nir_bcsel(b, nir_flt(b, nir_fabs(b, src), two52),
+ nir_pack_64_2x32_split(b, nir_unpack_64_2x32_split_x(b, res),
+ nir_ior(b, nir_unpack_64_2x32_split_y(b, res), sign)), src);
+}
- case nir_op_ftrunc:
- if (!(options & nir_lower_dtrunc))
- return;
- break;
+static nir_ssa_def *
+lower_mod(nir_builder *b, nir_ssa_def *src0, nir_ssa_def *src1)
+{
+ /* mod(x,y) = x - y * floor(x/y)
+ *
+ * If the division is lowered, it could add some rounding errors that make
+ * floor() to return the quotient minus one when x = N * y. If this is the
+ * case, we should return zero because mod(x, y) output value is [0, y).
+ * But fortunately Vulkan spec allows this kind of errors; from Vulkan
+ * spec, appendix A (Precision and Operation of SPIR-V instructions:
+ *
+ * "The OpFRem and OpFMod instructions use cheap approximations of
+ * remainder, and the error can be large due to the discontinuity in
+ * trunc() and floor(). This can produce mathematically unexpected
+ * results in some cases, such as FMod(x,x) computing x rather than 0,
+ * and can also cause the result to have a different sign than the
+ * infinitely precise result."
+ *
+ * In practice this means the output value is actually in the interval
+ * [0, y].
+ *
+ * While Vulkan states this behaviour explicitly, OpenGL does not, and thus
+ * we need to assume that value should be in range [0, y); but on the other
+ * hand, mod(a,b) is defined as "a - b * floor(a/b)" and OpenGL allows for
+ * some error in division, so a/a could actually end up being 1.0 - 1ULP;
+ * so in this case floor(a/a) would end up as 0, and hence mod(a,a) == a.
+ *
+ * In summary, in the practice mod(a,a) can be "a" both for OpenGL and
+ * Vulkan.
+ */
+ nir_ssa_def *floor = nir_ffloor(b, nir_fdiv(b, src0, src1));
- default:
- return;
- }
+ return nir_fsub(b, src0, nir_fmul(b, src1, floor));
+}
- nir_builder bld;
- nir_builder_init(&bld, nir_cf_node_get_function(&instr->instr.block->cf_node));
- bld.cursor = nir_before_instr(&instr->instr);
+static nir_ssa_def *
+lower_doubles_instr_to_soft(nir_builder *b, nir_alu_instr *instr,
+ const nir_shader *softfp64,
+ nir_lower_doubles_options options)
+{
+ if (!(options & nir_lower_fp64_full_software))
+ return NULL;
- nir_ssa_def *src = nir_fmov_alu(&bld, instr->src[0],
- instr->dest.dest.ssa.num_components);
+ assert(instr->dest.dest.is_ssa);
- nir_ssa_def *result;
+ const char *name;
+ const struct glsl_type *return_type = glsl_uint64_t_type();
switch (instr->op) {
- case nir_op_frcp:
- result = lower_rcp(&bld, src);
+ case nir_op_f2i64:
+ if (instr->src[0].src.ssa->bit_size == 64)
+ name = "__fp64_to_int64";
+ else
+ name = "__fp32_to_int64";
+ return_type = glsl_int64_t_type();
break;
- case nir_op_fsqrt:
- result = lower_sqrt_rsq(&bld, src, true);
+ case nir_op_f2u64:
+ if (instr->src[0].src.ssa->bit_size == 64)
+ name = "__fp64_to_uint64";
+ else
+ name = "__fp32_to_uint64";
break;
- case nir_op_frsq:
- result = lower_sqrt_rsq(&bld, src, false);
+ case nir_op_f2f64:
+ name = "__fp32_to_fp64";
+ break;
+ case nir_op_f2f32:
+ name = "__fp64_to_fp32";
+ return_type = glsl_float_type();
+ break;
+ case nir_op_f2i32:
+ name = "__fp64_to_int";
+ return_type = glsl_int_type();
+ break;
+ case nir_op_f2u32:
+ name = "__fp64_to_uint";
+ return_type = glsl_uint_type();
+ break;
+ case nir_op_f2b1:
+ case nir_op_f2b32:
+ name = "__fp64_to_bool";
+ return_type = glsl_bool_type();
+ break;
+ case nir_op_b2f64:
+ name = "__bool_to_fp64";
+ break;
+ case nir_op_i2f32:
+ if (instr->src[0].src.ssa->bit_size != 64)
+ return false;
+ name = "__int64_to_fp32";
+ return_type = glsl_float_type();
+ break;
+ case nir_op_u2f32:
+ if (instr->src[0].src.ssa->bit_size != 64)
+ return false;
+ name = "__uint64_to_fp32";
+ return_type = glsl_float_type();
+ break;
+ case nir_op_i2f64:
+ if (instr->src[0].src.ssa->bit_size == 64)
+ name = "__int64_to_fp64";
+ else
+ name = "__int_to_fp64";
+ break;
+ case nir_op_u2f64:
+ if (instr->src[0].src.ssa->bit_size == 64)
+ name = "__uint64_to_fp64";
+ else
+ name = "__uint_to_fp64";
+ break;
+ case nir_op_fabs:
+ name = "__fabs64";
+ break;
+ case nir_op_fneg:
+ name = "__fneg64";
+ break;
+ case nir_op_fround_even:
+ name = "__fround64";
break;
case nir_op_ftrunc:
- result = lower_trunc(&bld, src);
+ name = "__ftrunc64";
+ break;
+ case nir_op_ffloor:
+ name = "__ffloor64";
+ break;
+ case nir_op_ffract:
+ name = "__ffract64";
+ break;
+ case nir_op_fsign:
+ name = "__fsign64";
+ break;
+ case nir_op_feq:
+ name = "__feq64";
+ return_type = glsl_bool_type();
+ break;
+ case nir_op_fne:
+ name = "__fne64";
+ return_type = glsl_bool_type();
+ break;
+ case nir_op_flt:
+ name = "__flt64";
+ return_type = glsl_bool_type();
+ break;
+ case nir_op_fge:
+ name = "__fge64";
+ return_type = glsl_bool_type();
+ break;
+ case nir_op_fmin:
+ name = "__fmin64";
+ break;
+ case nir_op_fmax:
+ name = "__fmax64";
+ break;
+ case nir_op_fadd:
+ name = "__fadd64";
+ break;
+ case nir_op_fmul:
+ name = "__fmul64";
+ break;
+ case nir_op_ffma:
+ name = "__ffma64";
+ break;
+ case nir_op_fsat:
+ name = "__fsat64";
break;
default:
- unreachable("unhandled opcode");
+ return false;
+ }
+
+ nir_function *func = NULL;
+ nir_foreach_function(function, softfp64) {
+ if (strcmp(function->name, name) == 0) {
+ func = function;
+ break;
+ }
+ }
+ if (!func || !func->impl) {
+ fprintf(stderr, "Cannot find function \"%s\"\n", name);
+ assert(func);
+ }
+
+ nir_ssa_def *params[4] = { NULL, };
+
+ nir_variable *ret_tmp =
+ nir_local_variable_create(b->impl, return_type, "return_tmp");
+ nir_deref_instr *ret_deref = nir_build_deref_var(b, ret_tmp);
+ params[0] = &ret_deref->dest.ssa;
+
+ assert(nir_op_infos[instr->op].num_inputs + 1 == func->num_params);
+ for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++) {
+ assert(i + 1 < ARRAY_SIZE(params));
+ params[i + 1] = nir_mov_alu(b, instr->src[i], 1);
}
- nir_ssa_def_rewrite_uses(&instr->dest.dest.ssa, nir_src_for_ssa(result));
- nir_instr_remove(&instr->instr);
+ nir_inline_function_impl(b, func->impl, params);
+
+ return nir_load_deref(b, ret_deref);
}
+nir_lower_doubles_options
+nir_lower_doubles_op_to_options_mask(nir_op opcode)
+{
+ switch (opcode) {
+ case nir_op_frcp: return nir_lower_drcp;
+ case nir_op_fsqrt: return nir_lower_dsqrt;
+ case nir_op_frsq: return nir_lower_drsq;
+ case nir_op_ftrunc: return nir_lower_dtrunc;
+ case nir_op_ffloor: return nir_lower_dfloor;
+ case nir_op_fceil: return nir_lower_dceil;
+ case nir_op_ffract: return nir_lower_dfract;
+ case nir_op_fround_even: return nir_lower_dround_even;
+ case nir_op_fmod: return nir_lower_dmod;
+ case nir_op_fsub: return nir_lower_dsub;
+ case nir_op_fdiv: return nir_lower_ddiv;
+ default: return 0;
+ }
+}
+
+struct lower_doubles_data {
+ const nir_shader *softfp64;
+ nir_lower_doubles_options options;
+};
+
static bool
-lower_doubles_block(nir_block *block, void *ctx)
+should_lower_double_instr(const nir_instr *instr, const void *_data)
{
- nir_lower_doubles_options options = *((nir_lower_doubles_options *) ctx);
+ const struct lower_doubles_data *data = _data;
+ const nir_lower_doubles_options options = data->options;
+
+ if (instr->type != nir_instr_type_alu)
+ return false;
+
+ const nir_alu_instr *alu = nir_instr_as_alu(instr);
- nir_foreach_instr_safe(block, instr) {
- if (instr->type != nir_instr_type_alu)
- continue;
+ assert(alu->dest.dest.is_ssa);
+ bool is_64 = alu->dest.dest.ssa.bit_size == 64;
- lower_doubles_instr(nir_instr_as_alu(instr), options);
+ unsigned num_srcs = nir_op_infos[alu->op].num_inputs;
+ for (unsigned i = 0; i < num_srcs; i++) {
+ is_64 |= (nir_src_bit_size(alu->src[i].src) == 64);
}
- return true;
+ if (!is_64)
+ return false;
+
+ if (options & nir_lower_fp64_full_software)
+ return true;
+
+ return options & nir_lower_doubles_op_to_options_mask(alu->op);
}
-static void
-lower_doubles_impl(nir_function_impl *impl, nir_lower_doubles_options options)
+static nir_ssa_def *
+lower_doubles_instr(nir_builder *b, nir_instr *instr, void *_data)
{
- nir_foreach_block_call(impl, lower_doubles_block, &options);
+ const struct lower_doubles_data *data = _data;
+ const nir_lower_doubles_options options = data->options;
+ nir_alu_instr *alu = nir_instr_as_alu(instr);
+
+ nir_ssa_def *soft_def =
+ lower_doubles_instr_to_soft(b, alu, data->softfp64, options);
+ if (soft_def)
+ return soft_def;
+
+ if (!(options & nir_lower_doubles_op_to_options_mask(alu->op)))
+ return NULL;
+
+ nir_ssa_def *src = nir_mov_alu(b, alu->src[0],
+ alu->dest.dest.ssa.num_components);
+
+ switch (alu->op) {
+ case nir_op_frcp:
+ return lower_rcp(b, src);
+ case nir_op_fsqrt:
+ return lower_sqrt_rsq(b, src, true);
+ case nir_op_frsq:
+ return lower_sqrt_rsq(b, src, false);
+ case nir_op_ftrunc:
+ return lower_trunc(b, src);
+ case nir_op_ffloor:
+ return lower_floor(b, src);
+ case nir_op_fceil:
+ return lower_ceil(b, src);
+ case nir_op_ffract:
+ return lower_fract(b, src);
+ case nir_op_fround_even:
+ return lower_round_even(b, src);
+
+ case nir_op_fdiv:
+ case nir_op_fsub:
+ case nir_op_fmod: {
+ nir_ssa_def *src1 = nir_mov_alu(b, alu->src[1],
+ alu->dest.dest.ssa.num_components);
+ switch (alu->op) {
+ case nir_op_fdiv:
+ return nir_fmul(b, src, nir_frcp(b, src1));
+ case nir_op_fsub:
+ return nir_fadd(b, src, nir_fneg(b, src1));
+ case nir_op_fmod:
+ return lower_mod(b, src, src1);
+ default:
+ unreachable("unhandled opcode");
+ }
+ }
+ default:
+ unreachable("unhandled opcode");
+ }
}
-void
-nir_lower_doubles(nir_shader *shader, nir_lower_doubles_options options)
+static bool
+nir_lower_doubles_impl(nir_function_impl *impl,
+ const nir_shader *softfp64,
+ nir_lower_doubles_options options)
{
- nir_foreach_function(shader, function) {
- if (function->impl)
- lower_doubles_impl(function->impl, options);
+ struct lower_doubles_data data = {
+ .softfp64 = softfp64,
+ .options = options,
+ };
+
+ bool progress =
+ nir_function_impl_lower_instructions(impl,
+ should_lower_double_instr,
+ lower_doubles_instr,
+ &data);
+
+ if (progress && (options & nir_lower_fp64_full_software)) {
+ /* SSA and register indices are completely messed up now */
+ nir_index_ssa_defs(impl);
+ nir_index_local_regs(impl);
+
+ nir_metadata_preserve(impl, nir_metadata_none);
+
+ /* And we have deref casts we need to clean up thanks to function
+ * inlining.
+ */
+ nir_opt_deref_impl(impl);
}
+
+ return progress;
+}
+
+bool
+nir_lower_doubles(nir_shader *shader,
+ const nir_shader *softfp64,
+ nir_lower_doubles_options options)
+{
+ bool progress = false;
+
+ nir_foreach_function(function, shader) {
+ if (function->impl) {
+ progress |= nir_lower_doubles_impl(function->impl, softfp64, options);
+ }
+ }
+
+ return progress;
}
projects / mesa.git / blobdiff