From 296c5fd25db15a535920fc43deea2b279e11c5d6 Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Mon, 17 Jun 2019 11:43:13 +0200 Subject: [PATCH] nir/lower_tex: Add a way to lower TXS(non-0-LOD) instructions 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). Changes in v2: * Use == 0 instead of ! * Rework the minification logic as suggested by Jason * Assign cursor pos at the beginning of the function * Patch the LOD just after retrieving the old value Signed-off-by: Boris Brezillon Reviewed-by: Alyssa Rosenzweig --- src/compiler/nir/nir.h | 6 ++++++ src/compiler/nir/nir_lower_tex.c | 46 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 52 insertions(+) diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h index 4270df5..8972b4a 100644 --- a/src/compiler/nir/nir.h +++ b/src/compiler/nir/nir.h @@ -3427,6 +3427,12 @@ 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 ace8600..8a36edf 100644 --- a/src/compiler/nir/nir_lower_tex.c +++ b/src/compiler/nir/nir_lower_tex.c @@ -983,6 +983,47 @@ lower_tg4_offsets(nir_builder *b, nir_tex_instr *tex) } 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) == 0)) + return false; + + unsigned dest_size = nir_tex_instr_dest_size(tex); + + b->cursor = nir_before_instr(&tex->instr); + nir_ssa_def *lod = nir_ssa_for_src(b, tex->src[lod_idx].src, 1); + + /* Replace the non-0-LOD in the initial TXS operation by a 0-LOD. */ + nir_instr_rewrite_src(&tex->instr, &tex->src[lod_idx].src, + nir_src_for_ssa(nir_imm_int(b, 0))); + + /* TXS(LOD) = max(TXS(0) >> LOD, 1) */ + b->cursor = nir_after_instr(&tex->instr); + nir_ssa_def *minified = nir_imax(b, nir_ushr(b, &tex->dest.ssa, lod), + nir_imm_int(b, 1)); + + /* Make sure the component encoding the array size (if any) is not + * minified. + */ + if (tex->is_array) { + nir_ssa_def *comp[3]; + + for (unsigned i = 0; i < dest_size - 1; i++) + comp[i] = nir_channel(b, minified, i); + + comp[dest_size - 1] = nir_channel(b, &tex->dest.ssa, dest_size - 1); + minified = nir_vec(b, comp, dest_size); + } + + nir_ssa_def_rewrite_uses_after(&tex->dest.ssa, nir_src_for_ssa(minified), + minified->parent_instr); + return true; +} + +static bool nir_lower_tex_block(nir_block *block, nir_builder *b, const nir_lower_tex_options *options) { @@ -1135,6 +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. */ -- 2.7.4