From 3432d0a3e53896348d840176722be46d080ad439 Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Mon, 12 Oct 2020 15:17:42 +0200 Subject: [PATCH] pan/bi: Special-case BLEND instruction emission for blend shaders Blend shaders shouldn't use the blend descriptors stored in the FAU RAM since this is what triggered the blend shader call in the first place. The descriptor is instead extracted from the compiler inputs and passed as a constant to the blend instruction. Signed-off-by: Boris Brezillon Reviewed-by: Alyssa Rosenzweig Part-of: --- src/panfrost/bifrost/bifrost_compile.c | 38 ++++++++++++++++++++++---- 1 file changed, 32 insertions(+), 6 deletions(-) diff --git a/src/panfrost/bifrost/bifrost_compile.c b/src/panfrost/bifrost/bifrost_compile.c index 1dbfa4361cf..07a4bfefdf4 100644 --- a/src/panfrost/bifrost/bifrost_compile.c +++ b/src/panfrost/bifrost/bifrost_compile.c @@ -168,7 +168,7 @@ bi_emit_ld_vary(bi_context *ctx, nir_intrinsic_instr *instr) static void bi_emit_frag_out(bi_context *ctx, nir_intrinsic_instr *instr) { - if (!ctx->emitted_atest) { + if (!ctx->emitted_atest && !ctx->is_blend) { bi_instruction ins = { .type = BI_ATEST, .src = { @@ -197,29 +197,55 @@ bi_emit_frag_out(bi_context *ctx, nir_intrinsic_instr *instr) .src = { pan_src_index(&instr->src[0]), BIR_INDEX_REGISTER | 60 /* Can this be arbitrary? */, - /* Blend descriptor */ - BIR_INDEX_BLEND | BIFROST_SRC_FAU_LO, - BIR_INDEX_BLEND | BIFROST_SRC_FAU_HI, }, .src_types = { nir_intrinsic_src_type(instr), - nir_type_uint32 + nir_type_uint32, + nir_type_uint32, + nir_type_uint32, }, .swizzle = { { 0, 1, 2, 3 }, { 0 } }, - .dest = BIR_INDEX_REGISTER | 48 /* Looks like magic */, .dest_type = nir_type_uint32, .vector_channels = 4 }; + if (ctx->is_blend) { + /* Blend descriptor comes from the compile inputs */ + blend.src[2] = BIR_INDEX_CONSTANT | 0; + blend.src[3] = BIR_INDEX_CONSTANT | 32; + blend.constant.u64 = ctx->blend_desc; + + /* Put the result in r0 */ + blend.dest = BIR_INDEX_REGISTER | 0; + } else { + /* Blend descriptor comes from the FAU RAM */ + blend.src[2] = BIR_INDEX_BLEND | BIFROST_SRC_FAU_LO; + blend.src[3] = BIR_INDEX_BLEND | BIFROST_SRC_FAU_HI; + + /* By convention, the return address is stored in r48 and will + * be used by the blend shader to jump back to the fragment + * shader when it's done. + */ + blend.dest = BIR_INDEX_REGISTER | 48; + } + assert(blend.blend_location < 8); assert(ctx->blend_types); assert(blend.src_types[0]); ctx->blend_types[blend.blend_location] = blend.src_types[0]; bi_emit(ctx, blend); + + if (ctx->is_blend) { + /* Jump back to the fragment shader, return address is stored + * in r48 (see above). + */ + bi_instruction *ret = bi_emit_branch(ctx); + ret->src[2] = BIR_INDEX_REGISTER | 48; + } } static bi_instruction