From 45e1443fd87b23edb00019a743a6bba38ae846b2 Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Sun, 17 Nov 2019 14:53:54 +0100 Subject: [PATCH] etnaviv: tgsi: Fix gl_FrontFacing support The GPU presents the state of the hardware front_face in internal register 0 (i0), the range of which is 0.0f..1.0f. This patch assigns the fragment shader input to this internal register. Moreover, based on the internal front_ccw state, the value of the i0 register is inverted accordingly using SET.EQ/SEQ.NE instruction before being further processed in the shader. This mimics the operation of the NIR compiler. Signed-off-by: Marek Vasut Reviewed-by: Christian Gmeiner Reviewed-by: Jonathan Marek Tested-by: Marge Bot Part-of: --- .../drivers/etnaviv/etnaviv_compiler_tgsi.c | 63 ++++++++++++++++--- 1 file changed, 53 insertions(+), 10 deletions(-) diff --git a/src/gallium/drivers/etnaviv/etnaviv_compiler_tgsi.c b/src/gallium/drivers/etnaviv/etnaviv_compiler_tgsi.c index 97750c7bd35..f153f80490a 100644 --- a/src/gallium/drivers/etnaviv/etnaviv_compiler_tgsi.c +++ b/src/gallium/drivers/etnaviv/etnaviv_compiler_tgsi.c @@ -222,6 +222,16 @@ etna_native_temp(unsigned reg) }; } +static struct etna_native_reg +etna_native_internal(unsigned reg) +{ + return (struct etna_native_reg) { + .valid = 1, + .rgroup = INST_RGROUP_INTERNAL, + .id = reg + }; +} + /** Register allocation **/ enum reg_sort_order { FIRST_USE_ASC, @@ -622,12 +632,19 @@ assign_special_inputs(struct etna_compile *c) /* never assign t0 as it is the position output, start assigning at t1 */ c->next_free_native = 1; - /* hardwire TGSI_SEMANTIC_POSITION (input and output) to t0 */ for (int idx = 0; idx < c->total_decls; ++idx) { struct etna_reg_desc *reg = &c->decl[idx]; - if (reg->active && reg->semantic.Name == TGSI_SEMANTIC_POSITION) + if (!reg->active) + continue; + + /* hardwire TGSI_SEMANTIC_POSITION (input and output) to t0 */ + if (reg->semantic.Name == TGSI_SEMANTIC_POSITION) reg->native = etna_native_temp(0); + + /* hardwire TGSI_SEMANTIC_FACE to i0 */ + if (reg->semantic.Name == TGSI_SEMANTIC_FACE) + reg->native = etna_native_internal(0); } } } @@ -824,7 +841,34 @@ emit_inst(struct etna_compile *c, struct etna_inst *inst) unsigned uni_reg = -1; for (int src = 0; src < ETNA_NUM_SRC; ++src) { - if (etna_rgroup_is_uniform(inst->src[src].rgroup)) { + if (inst->src[src].rgroup == INST_RGROUP_INTERNAL && + c->info.processor == PIPE_SHADER_FRAGMENT && + c->key->front_ccw) { + struct etna_native_reg inner_temp = etna_compile_get_inner_temp(c); + + /* + * Set temporary register to 0.0 or 1.0 based on the gl_FrontFacing + * configuration (CW or CCW). + */ + etna_assemble(&c->code[c->inst_ptr * 4], &(struct etna_inst) { + .opcode = INST_OPCODE_SET, + .cond = INST_CONDITION_NE, + .dst = etna_native_to_dst(inner_temp, INST_COMPS_X | INST_COMPS_Y | + INST_COMPS_Z | INST_COMPS_W), + .src[0] = inst->src[src], + .src[1] = alloc_imm_f32(c, 1.0f) + }); + c->inst_ptr++; + + /* Modify instruction to use temp register instead of uniform */ + inst->src[src].use = 1; + inst->src[src].rgroup = INST_RGROUP_TEMP; + inst->src[src].reg = inner_temp.id; + inst->src[src].swiz = INST_SWIZ_IDENTITY; /* swizzling happens on MOV */ + inst->src[src].neg = 0; /* negation happens on MOV */ + inst->src[src].abs = 0; /* abs happens on MOV */ + inst->src[src].amode = 0; /* amode effects happen on MOV */ + } else if (etna_rgroup_is_uniform(inst->src[src].rgroup)) { if (uni_reg == -1) { /* first unique uniform used */ uni_rgroup = inst->src[src].rgroup; uni_reg = inst->src[src].reg; @@ -2037,8 +2081,9 @@ static void permute_ps_inputs(struct etna_compile *c) { /* Special inputs: - * gl_FragCoord VARYING_SLOT_POS TGSI_SEMANTIC_POSITION - * gl_PointCoord VARYING_SLOT_PNTC TGSI_SEMANTIC_PCOORD + * gl_FragCoord VARYING_SLOT_POS TGSI_SEMANTIC_POSITION + * gl_FrontFacing VARYING_SLOT_FACE TGSI_SEMANTIC_FACE + * gl_PointCoord VARYING_SLOT_PNTC TGSI_SEMANTIC_PCOORD */ uint native_idx = 1; @@ -2047,7 +2092,9 @@ permute_ps_inputs(struct etna_compile *c) uint input_id; assert(reg->has_semantic); - if (!reg->active || reg->semantic.Name == TGSI_SEMANTIC_POSITION) + if (!reg->active || + reg->semantic.Name == TGSI_SEMANTIC_POSITION || + reg->semantic.Name == TGSI_SEMANTIC_FACE) continue; input_id = native_idx++; @@ -2347,10 +2394,6 @@ etna_compile_shader(struct etna_shader_variant *v) /* optimize outputs */ etna_compile_pass_optimize_outputs(c); - /* XXX assign special inputs: gl_FrontFacing (VARYING_SLOT_FACE) - * this is part of RGROUP_INTERNAL - */ - /* assign inputs: last usage of input should be <= first usage of temp */ /* potential optimization case: * if single MOV TEMP[y], IN[x] before which temp y is not used, and -- 2.30.2