[Mesa-dev] [PATCH] r600g: Support TGSI_SEMANTIC_HELPER_INVOCATION
Glenn Kennard
glenn.kennard at gmail.com
Fri Nov 13 15:11:38 PST 2015
On Fri, 13 Nov 2015 18:57:28 +0100, Nicolai Hähnle <nhaehnle at gmail.com>
wrote:
> On 13.11.2015 00:14, Glenn Kennard wrote:
>> Signed-off-by: Glenn Kennard <glenn.kennard at gmail.com>
>> ---
>> Maybe there is a better way to check if a thread is a helper invocation?
>
> Is ctx->face_gpr guaranteed to be initialized when
> load_helper_invocation is called?
>
allocate_system_value_inputs() sets that if needed, and is called before
parsing any opcodes.
> Aside, I'm not sure I understand correctly what this is supposed to do.
> The values you're querying are related to multi-sampling, but my
> understanding has always been that helper invocations can also happen
> without multi-sampling: you always want to process 2x2 quads of pixels
> at a time to be able to compute derivatives for texture sampling. When
> the boundary of primitive intersects such a quad, you get helper
> invocations outside the primitive.
>
Non-MSAA buffers act just like 1 sample buffers with regards to the
coverage mask supplied by the hardware, so helper invocations which have
no coverage get a 0 for the mask value, and normal fragments get 1. Works
with the piglit test case posted at least...
> Cheers,
> Nicolai
>
>> src/gallium/drivers/r600/r600_shader.c | 83
>> +++++++++++++++++++++++++++++-----
>> 1 file changed, 72 insertions(+), 11 deletions(-)
>>
>> diff --git a/src/gallium/drivers/r600/r600_shader.c
>> b/src/gallium/drivers/r600/r600_shader.c
>> index 560197c..a227d78 100644
>> --- a/src/gallium/drivers/r600/r600_shader.c
>> +++ b/src/gallium/drivers/r600/r600_shader.c
>> @@ -530,7 +530,8 @@ static int r600_spi_sid(struct r600_shader_io * io)
>> name == TGSI_SEMANTIC_PSIZE ||
>> name == TGSI_SEMANTIC_EDGEFLAG ||
>> name == TGSI_SEMANTIC_FACE ||
>> - name == TGSI_SEMANTIC_SAMPLEMASK)
>> + name == TGSI_SEMANTIC_SAMPLEMASK ||
>> + name == TGSI_SEMANTIC_HELPER_INVOCATION)
>> index = 0;
>> else {
>> if (name == TGSI_SEMANTIC_GENERIC) {
>> @@ -734,7 +735,8 @@ static int tgsi_declaration(struct r600_shader_ctx
>> *ctx)
>> case TGSI_FILE_SYSTEM_VALUE:
>> if (d->Semantic.Name == TGSI_SEMANTIC_SAMPLEMASK ||
>> d->Semantic.Name == TGSI_SEMANTIC_SAMPLEID ||
>> - d->Semantic.Name == TGSI_SEMANTIC_SAMPLEPOS) {
>> + d->Semantic.Name == TGSI_SEMANTIC_SAMPLEPOS ||
>> + d->Semantic.Name == TGSI_SEMANTIC_HELPER_INVOCATION) {
>> break; /* Already handled from allocate_system_value_inputs */
>> } else if (d->Semantic.Name == TGSI_SEMANTIC_INSTANCEID) {
>> if (!ctx->native_integers) {
>> @@ -776,13 +778,14 @@ static int allocate_system_value_inputs(struct
>> r600_shader_ctx *ctx, int gpr_off
>> struct {
>> boolean enabled;
>> int *reg;
>> - unsigned name, alternate_name;
>> + unsigned associated_semantics[3];
>> } inputs[2] = {
>> - { false, &ctx->face_gpr, TGSI_SEMANTIC_SAMPLEMASK, ~0u }, /* lives
>> in Front Face GPR.z */
>> -
>> - { false, &ctx->fixed_pt_position_gpr, TGSI_SEMANTIC_SAMPLEID,
>> TGSI_SEMANTIC_SAMPLEPOS } /* SAMPLEID is in Fixed Point Position GPR.w
>> */
>> + { false, &ctx->face_gpr, { TGSI_SEMANTIC_SAMPLEMASK /* lives in
>> Front Face GPR.z */,
>> + TGSI_SEMANTIC_HELPER_INVOCATION, ~0u } },
>> + { false, &ctx->fixed_pt_position_gpr, { TGSI_SEMANTIC_SAMPLEID /*
>> in Fixed Point Position GPR.w */,
>> + TGSI_SEMANTIC_SAMPLEPOS, TGSI_SEMANTIC_HELPER_INVOCATION } }
>> };
>> - int i, k, num_regs = 0;
>> + int i, k, l, num_regs = 0;
>>
>> if (tgsi_parse_init(&parse, ctx->tokens) != TGSI_PARSE_OK) {
>> return 0;
>> @@ -818,9 +821,11 @@ static int allocate_system_value_inputs(struct
>> r600_shader_ctx *ctx, int gpr_off
>> struct tgsi_full_declaration *d = &parse.FullToken.FullDeclaration;
>> if (d->Declaration.File == TGSI_FILE_SYSTEM_VALUE) {
>> for (k = 0; k < Elements(inputs); k++) {
>> - if (d->Semantic.Name == inputs[k].name ||
>> - d->Semantic.Name == inputs[k].alternate_name) {
>> - inputs[k].enabled = true;
>> + for (l = 0; l < 3; l++) {
>> + if (d->Semantic.Name == inputs[k].associated_semantics[l]) {
>> + inputs[k].enabled = true;
>> + break;
>> + }
>> }
>> }
>> }
>> @@ -832,7 +837,7 @@ static int allocate_system_value_inputs(struct
>> r600_shader_ctx *ctx, int gpr_off
>> for (i = 0; i < Elements(inputs); i++) {
>> boolean enabled = inputs[i].enabled;
>> int *reg = inputs[i].reg;
>> - unsigned name = inputs[i].name;
>> + unsigned name = inputs[i].associated_semantics[0];
>>
>> if (enabled) {
>> int gpr = gpr_offset + num_regs++;
>> @@ -985,6 +990,56 @@ static int load_sample_position(struct
>> r600_shader_ctx *ctx, struct r600_shader_
>> return t1;
>> }
>>
>> +static int load_helper_invocation(struct r600_shader_ctx *ctx,
>> + int mask_gpr, int mask_chan, int id_gpr, int id_chan)
>> +{
>> + // sample (mask >> sampleid) & 1
>> + struct r600_bytecode_alu alu;
>> + int r, t = r600_get_temp(ctx);
>> +
>> + memset(&alu, 0, sizeof(struct r600_bytecode_alu));
>> + alu.op = ALU_OP2_LSHR_INT;
>> + alu.src[0].sel = mask_gpr;
>> + alu.src[0].chan = mask_chan;
>> + alu.src[1].sel = id_gpr;
>> + alu.src[1].chan = id_chan;
>> + alu.dst.sel = t;
>> + alu.dst.chan = 0;
>> + alu.dst.write = 1;
>> + alu.last = 1;
>> + r = r600_bytecode_add_alu(ctx->bc, &alu);
>> + if (r)
>> + return r;
>> +
>> + memset(&alu, 0, sizeof(struct r600_bytecode_alu));
>> + alu.op = ALU_OP2_AND_INT;
>> + alu.src[0].sel = t;
>> + alu.src[0].chan = 0;
>> + alu.src[1].sel = V_SQ_ALU_SRC_1_INT;
>> + alu.dst.sel = t;
>> + alu.dst.chan = 0;
>> + alu.dst.write = 1;
>> + alu.last = 1;
>> + r = r600_bytecode_add_alu(ctx->bc, &alu);
>> + if (r)
>> + return r;
>> +
>> + memset(&alu, 0, sizeof(struct r600_bytecode_alu));
>> + alu.op = ALU_OP2_SUB_INT;
>> + alu.src[0].sel = t;
>> + alu.src[0].chan = 0;
>> + alu.src[1].sel = V_SQ_ALU_SRC_1_INT;
>> + alu.dst.sel = t;
>> + alu.dst.chan = 0;
>> + alu.dst.write = 1;
>> + alu.last = 1;
>> + r = r600_bytecode_add_alu(ctx->bc, &alu);
>> + if (r)
>> + return r;
>> +
>> + return t;
>> +}
>> +
>> static void tgsi_src(struct r600_shader_ctx *ctx,
>> const struct tgsi_full_src_register *tgsi_src,
>> struct r600_shader_src *r600_src)
>> @@ -1048,6 +1103,12 @@ static void tgsi_src(struct r600_shader_ctx *ctx,
>> r600_src->swizzle[2] = 3;
>> r600_src->swizzle[3] = 3;
>> r600_src->sel = 1;
>> + } else if
>> (ctx->info.system_value_semantic_name[tgsi_src->Register.Index] ==
>> TGSI_SEMANTIC_HELPER_INVOCATION) {
>> + r600_src->swizzle[0] = 0;
>> + r600_src->swizzle[1] = 0;
>> + r600_src->swizzle[2] = 0;
>> + r600_src->swizzle[3] = 0;
>> + r600_src->sel = load_helper_invocation(ctx, ctx->face_gpr, 2,
>> ctx->fixed_pt_position_gpr, 3);
>> }
>> } else {
>> if (tgsi_src->Register.Indirect)
>>
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