The V3D driver has an open-coded solution for this, and we need the same thing for Panfrost, so let's add a generic way to lower TXS(LOD) into max(TXS(0) >> LOD, 1).
Signed-off-by: Boris Brezillon <[email protected]> --- src/compiler/nir/nir.h | 6 ++++ src/compiler/nir/nir_lower_tex.c | 49 ++++++++++++++++++++++++++++++++ 2 files changed, 55 insertions(+) diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h index 4270df565111..8972b4af7480 100644 --- a/src/compiler/nir/nir.h +++ b/src/compiler/nir/nir.h @@ -3426,6 +3426,12 @@ typedef struct nir_lower_tex_options { */ bool lower_txd_clamp_if_sampler_index_not_lt_16; + /** + * If true, lower nir_texop_txs with a non-0-lod into nir_texop_txs with + * 0-lod followed by a nir_ishr. + */ + bool lower_txs_lod; + /** * If true, apply a .bagr swizzle on tg4 results to handle Broadcom's * mixed-up tg4 locations. diff --git a/src/compiler/nir/nir_lower_tex.c b/src/compiler/nir/nir_lower_tex.c index 53719017a87f..c29581d9b048 100644 --- a/src/compiler/nir/nir_lower_tex.c +++ b/src/compiler/nir/nir_lower_tex.c @@ -978,6 +978,50 @@ lower_tg4_offsets(nir_builder *b, nir_tex_instr *tex) return true; } +static bool +nir_lower_txs_lod(nir_builder *b, nir_tex_instr *tex) +{ + int lod_idx = nir_tex_instr_src_index(tex, nir_tex_src_lod); + if (lod_idx < 0 || + (nir_src_is_const(tex->src[lod_idx].src) && + !nir_src_as_int(tex->src[lod_idx].src))) + return false; + + nir_ssa_def *lod = nir_ssa_for_src(b, tex->src[lod_idx].src, 1); + unsigned dest_size = nir_tex_instr_dest_size(tex); + nir_ssa_def *shift, *min, *result; + + b->cursor = nir_after_instr(&tex->instr); + + switch (dest_size) { + case 3: + shift = nir_vec3(b, lod, lod, tex->is_array ? nir_imm_int(b, 0) : lod); + min = nir_imm_ivec3(b, 1, 1, tex->is_array ? 0 : 1); + break; + case 2: + shift = nir_vec2(b, lod, tex->is_array ? nir_imm_int(b, 0) : lod); + min = nir_imm_ivec2(b, 1, tex->is_array ? 0 : 1); + break; + case 1: + shift = lod; + min = nir_imm_int(b, 1); + break; + default: + unreachable("Invalid nir_tex_instr_dest_size()\n"); + } + + /* TXS(LOD) = max(TXS(0) >> LOD, 1) */ + result = nir_imax(b, nir_ishr(b, &tex->dest.ssa, shift), min); + nir_ssa_def_rewrite_uses_after(&tex->dest.ssa, nir_src_for_ssa(result), + result->parent_instr); + + /* Replace the non-0-LOD in the initial TXS operation by a 0-LOD. */ + b->cursor = nir_before_instr(&tex->instr); + nir_instr_rewrite_src(&tex->instr, &tex->src[lod_idx].src, + nir_src_for_ssa(nir_imm_int(b, 0))); + return true; +} + static bool nir_lower_tex_block(nir_block *block, nir_builder *b, const nir_lower_tex_options *options) @@ -1132,6 +1176,11 @@ nir_lower_tex_block(nir_block *block, nir_builder *b, continue; } + if (options->lower_txs_lod && tex->op == nir_texop_txs) { + progress |= nir_lower_txs_lod(b, tex); + continue; + } + /* has to happen after all the other lowerings as the original tg4 gets * replaced by 4 tg4 instructions. */ -- 2.20.1 _______________________________________________ mesa-dev mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/mesa-dev
