76 lines
3.0 KiB
C
76 lines
3.0 KiB
C
|
/*
|
|||
|
* Copyright © 2020 Microsoft 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.
|
|||
|
*/
|
|||
|
|
|||
|
#include "nir.h"
|
|||
|
#include "nir_builder.h"
|
|||
|
|
|||
|
static bool
|
|||
|
nir_scale_fdiv_instr(nir_builder *b, nir_instr *instr, UNUSED void *_data)
|
|||
|
{
|
|||
|
if (instr->type != nir_instr_type_alu)
|
|||
|
return false;
|
|||
|
|
|||
|
nir_alu_instr *alu = nir_instr_as_alu(instr);
|
|||
|
if (alu->op != nir_op_fdiv || alu->src[0].src.ssa->bit_size != 32)
|
|||
|
return false;
|
|||
|
|
|||
|
b->cursor = nir_before_instr(&alu->instr);
|
|||
|
|
|||
|
nir_ssa_def *fabs = nir_fabs(b, alu->src[1].src.ssa);
|
|||
|
nir_ssa_def *big = nir_flt(b, nir_imm_int(b, 0x7e800000), fabs);
|
|||
|
nir_ssa_def *small = nir_flt(b, fabs, nir_imm_int(b, 0x00800000));
|
|||
|
|
|||
|
nir_ssa_def *scaled_down_a = nir_fmul_imm(b, alu->src[0].src.ssa, 0.25);
|
|||
|
nir_ssa_def *scaled_down_b = nir_fmul_imm(b, alu->src[1].src.ssa, 0.25);
|
|||
|
nir_ssa_def *scaled_up_a = nir_fmul_imm(b, alu->src[0].src.ssa, 16777216.0);
|
|||
|
nir_ssa_def *scaled_up_b = nir_fmul_imm(b, alu->src[1].src.ssa, 16777216.0);
|
|||
|
|
|||
|
nir_ssa_def *final_a =
|
|||
|
nir_bcsel(b, big, scaled_down_a,
|
|||
|
(nir_bcsel(b, small, scaled_up_a, alu->src[0].src.ssa)));
|
|||
|
nir_ssa_def *final_b =
|
|||
|
nir_bcsel(b, big, scaled_down_b,
|
|||
|
(nir_bcsel(b, small, scaled_up_b, alu->src[1].src.ssa)));
|
|||
|
|
|||
|
nir_instr_rewrite_src_ssa(instr, &alu->src[0].src, final_a);
|
|||
|
nir_instr_rewrite_src_ssa(instr, &alu->src[1].src, final_b);
|
|||
|
|
|||
|
return true;
|
|||
|
}
|
|||
|
|
|||
|
/** Scale both sides of an fdiv if needed to prevent denorm flushing
|
|||
|
*
|
|||
|
* This may be needed to satisfy the precision requirements of OpenCL. When
|
|||
|
* fdiv is lowered to frcp+fmul, denorm flushing may cause the frcp to return
|
|||
|
* zero even for finite floats. This multiplies both sides of an fdiv by a
|
|||
|
* constant, if needed, to prevent such flushing.
|
|||
|
*/
|
|||
|
bool
|
|||
|
nir_scale_fdiv(nir_shader *shader)
|
|||
|
{
|
|||
|
return nir_shader_instructions_pass(shader, nir_scale_fdiv_instr,
|
|||
|
nir_metadata_block_index |
|
|||
|
nir_metadata_dominance,
|
|||
|
NULL);
|
|||
|
}
|