shader: fold reads through empty scalar descriptor tables

Co-authored-by: fxpw <fxpw@outlook.com>
This commit is contained in:
nmzik
2026-10-14 15:17:03 +02:00
parent 4b549b9cb3
commit f3c017b168
4 changed files with 170 additions and 9 deletions
+110
View File
@@ -1024,6 +1024,115 @@ void TestCyclicControlPredicatesRemainUnknown() {
"cyclic control lost a possible branch during reachability");
}
void TestEmptyScalarBufferSpecialization() {
using namespace Libs::Graphics::ShaderRecompiler::IR;
struct Fixture {
Program program;
std::vector<std::pair<Inst *, Type>> uses;
Inst *nonnull = nullptr;
};
const auto make_fixture = [] {
Fixture fixture;
auto &program = fixture.program;
program.stage = Libs::Graphics::ShaderType::Compute;
program.srt_plan_complete = program.resource_tracking_complete = true;
program.user_data_count = 4u;
auto &block = AddValueBlock(program);
DescriptorSource source;
source.dword_count = 4u;
for (uint32_t word = 0; word < 4u; ++word)
source.dwords[word] = Value(&block.AppendNewInst(ValueOpcode::GetUserData,
{Value(static_cast<ScalarReg>(word))}));
program.descriptor_sources.push_back(source);
program.info.buffers.push_back({.source = 0u, .read = true, .scalar = true});
const auto table = Value(&block.AppendNewInst(ValueOpcode::GetBufferResource,
{source.dwords[0], source.dwords[1], source.dwords[2], source.dwords[3]}));
std::array<Value, 4> words;
for (uint32_t word = 0; word < 4u; ++word) {
program.memory_info.push_back({.kind = ResourceKind::ScalarBuffer, .resource = 0u,
.offset = word * 4u});
auto &read = block.AppendNewInst(ValueOpcode::ReadConstBuffer, {table, Value(0u)});
read.SetFlags(MemoryFlags{.index = word});
words[word] = Value(&read);
}
const auto handle = Value(&block.AppendNewInst(ValueOpcode::GetBufferResource,
{words[0], words[1], words[2], words[3]}));
for (const auto opcode : {ValueOpcode::ReadConstBuffer, ValueOpcode::LoadBufferU8,
ValueOpcode::LoadBufferU16, ValueOpcode::LoadBufferU32,
ValueOpcode::LoadBufferU32x2, ValueOpcode::LoadBufferU32x3,
ValueOpcode::LoadBufferU32x4}) {
const auto index = static_cast<uint32_t>(program.memory_info.size());
program.memory_info.push_back({.kind = ResourceKind::IndirectBuffer, .resource = UINT32_MAX,
.data_dwords = BufferComponentCount(opcode),
.data_bits = opcode == ValueOpcode::LoadBufferU8 ? 8u : opcode == ValueOpcode::LoadBufferU16 ? 16u : 32u,
.formatted = opcode == ValueOpcode::LoadBufferU32});
auto &read = opcode == ValueOpcode::ReadConstBuffer
? block.AppendNewInst(opcode, {handle, Value(0u)})
: block.AppendNewInst(opcode, {handle, Value(0u), Value(0u), Value(0u), Value(true)});
read.SetFlags(MemoryFlags{.index = index});
fixture.uses.emplace_back(&block.AppendNewInst(ValueOpcode::Identity, {Value(&read)}), read.GetType());
}
const auto nonnull = Value(&block.AppendNewInst(ValueOpcode::GetBufferResource,
{words[0], words[1], words[2], Value(1u)}));
auto &read = block.AppendNewInst(ValueOpcode::ReadConstBuffer, {nonnull, Value(0u)});
read.SetFlags(MemoryFlags{.index = 4u});
fixture.nonnull = &block.AppendNewInst(ValueOpcode::Identity, {Value(&read)});
return fixture;
};
auto fixture = make_fixture();
auto plan = ExtractResourcePlan(fixture.program);
std::array<uint32_t, 4> descriptor{0x1000u, 8u << 16u, 0u, 3u << 28u};
uint32_t reads = 0u;
const SrtRuntime runtime{.user_data = descriptor, .read_memory = RejectSpecializationRead,
.userdata = &reads, .read_specialization_memory = RejectSpecializationRead};
ResourceSnapshot snapshot;
ResourceSpecialization specialization, empty, populated;
for (const uint32_t records : {0u, 1u, 0x20000000u, 0u}) {
descriptor[2] = records;
Check(MaterializeResources(plan, runtime, snapshot, specialization) && reads == 0u &&
specialization.buffers[0].scalar_empty == (records == 0u),
"scalar emptiness read table contents or truncated its 64-bit byte size");
if (records == 0u) {
if (empty.buffers.empty()) empty = specialization;
else Check(specialization == empty, "returning to an empty scalar table changed its specialization");
}
else if (records == 1u) populated = specialization;
else Check(specialization == populated, "nonempty scalar size created a shader permutation");
auto current = make_fixture();
ApplyResourceSpecialization(current.program, specialization);
for (const auto &[use, type] : current.uses) {
const auto value = use->Arg(0).Resolve();
Check(value.GetType() == type, "empty scalar-table folding changed the load result type");
if (records != 0u) {
Check(value.TryInstruction() != nullptr && BufferAccessOf(value.Instruction()->GetOpcode()) == BufferAccess::Read,
"nonempty scalar table lost a runtime buffer load");
} else if (value.IsImmediate()) {
Check(value == Value(uint8_t{0}) || value == Value(uint16_t{0}) || value == Value(0u),
"empty scalar table did not produce a typed zero");
} else {
for (size_t component = 0; component < value.Instruction()->NumArgs(); ++component)
Check(value.Instruction()->Arg(component) == Value(0u),
"empty scalar table retained a nonzero vector component");
}
}
Check(current.nonnull->Arg(0).Resolve().TryInstruction() != nullptr,
"a partly nonzero indirect descriptor was treated as unbound");
}
Check(empty != populated, "empty-to-populated scalar transition reused the folded specialization");
plan.info.buffers[0].scalar = false;
Check(MaterializeResources(plan, runtime, snapshot, specialization) &&
!specialization.buffers[0].scalar_empty,
"vector-only resource acquired scalar-empty specialization");
empty.buffers[0].indirect_root = 0u;
empty.buffers.push_back(empty.buffers[0]);
empty.buffers[1].scalar_empty = false;
ApplyResourceSpecialization(fixture.program, empty);
for (const auto &[use, type] : fixture.uses)
Check(use->Arg(0).GetType() == type && use->Arg(0).Resolve().TryInstruction() != nullptr &&
BufferAccessOf(use->Arg(0).ResolveInstruction()->GetOpcode()) == BufferAccess::Read,
"empty root folded a scalar read with nonempty candidates");
}
void TestMixedSamplerVariantsShareRuntimeDescriptor() {
using namespace Libs::Graphics::ShaderRecompiler::IR;
auto program = MixedSamplerProgram();
@@ -1145,6 +1254,7 @@ int main() {
for (const bool independent_mask : {false, true})
TestEmptyTraversalSkipsUnmappedDescriptor(independent_mask);
TestCyclicControlPredicatesRemainUnknown();
TestEmptyScalarBufferSpecialization();
TestMixedSamplerVariantsShareRuntimeDescriptor();
for (const bool mixed : {false, true}) TestIndirectImageSamplerClasses(mixed);
std::puts("ResourceMaterializationTests: all cases passed");
+31 -5
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@@ -36778,12 +36778,12 @@ void CheckGpuSelectedRecordBufferAccess(VulkanHarness &vulkan) {
for (const u32 table_bytes : {0u, 536u, 544u}) {
TestCase test;
test.name = wave == 32u ? "GpuSelectedRecordBufferAccess32" : "GpuSelectedRecordBufferAccess64";
test.initial.assign((slot * 13u + keys.size() * wave * 8u) / 4u, 0xdeadbeefu);
test.initial.assign((slot * 13u + keys.size() * wave * 16u) / 4u, 0xdeadbeefu);
test.has_user_data = test.has_compute_info = true;
const std::array<u32, 8> descriptors{selectors, 12u << 16u, keys.size(), 0x5204u,
table, 0u, table_bytes, 0x5204u};
std::copy(descriptors.begin(), descriptors.end(), test.user_data.begin());
const std::array<u32, 4> output{slot * 13u, 8u << 16u, u32(keys.size()) * wave, 0x5204u};
const std::array<u32, 4> output{slot * 13u, 16u << 16u, u32(keys.size()) * wave, 0x5204u};
std::copy(output.begin(), output.end(), test.user_data.begin() + 16u);
test.compute_info.wave_size = wave;
test.compute_info.threads_num[0] = wave;
@@ -36793,17 +36793,21 @@ void CheckGpuSelectedRecordBufferAccess(VulkanHarness &vulkan) {
test.compute_info.workgroup_register = 24u;
test.compute_info.lds_size_dwords = 0;
test.dispatch_x = keys.size();
test.bda_mappings = {{0u, 0u}};
auto &code = test.code;
code.insert(code.end(), {EncodeSop2(0x26, 32, 24, InlineU32(12)),
EncodeSmem0(0x08, 32, 0), EncodeSmem1(0u, 32), EncodeSopp(0x0c, 0),
EncodeSop2(0x26, 33, 32, 255), 192u,
EncodeSop2(0x02, 33, 33, 255), 96u,
EncodeSmem0(0x0a, 36, 2), EncodeSmem1(144u, 33),
EncodeSmem0(0x0a, 8, 2), EncodeSmem1(160u, 33),
EncodeSmem0(0x0a, 12, 2), EncodeSmem1(176u, 33), EncodeSopp(0x0c, 0),
EncodeMubuf0(0x83, 0, true, false), EncodeMubuf1(4, 2, 0),
EncodeMubuf0(0x0a, 0, true, false), EncodeMubuf1(6, 9, 0),
EncodeMubuf0(0x00, 0, true, false), EncodeMubuf1(7, 9, 0),
EncodeSopp(0x0c, 0), EncodeSop2(0x1e, 34, 24, InlineU32(std::countr_zero(wave))),
EncodeVop2(0x25, 20, 34, 0),
EncodeMubuf0(0x1d, 0, true, false), EncodeMubuf1(4, 4, 20)});
EncodeMubuf0(0x1e, 0, true, false), EncodeMubuf1(4, 4, 20)});
AppendVMovLiteral(&code, 10, 0xa5c39b72u);
AppendSMovLiteral(&code, 126, 0x55555555u);
AppendSMovLiteral(&code, 127, wave == 64u ? 0x55555555u : 0u);
@@ -36814,11 +36818,30 @@ void CheckGpuSelectedRecordBufferAccess(VulkanHarness &vulkan) {
static_cast<u32>(Prospero::BufferFormat::k16_16_16_16Float) << 12u | DstSel(4, 5, 6, 7),
slot * (row + 7u), 1u << 16u, u32(keys.size()) * wave, 0x5204u};
std::copy(record.begin(), record.end(), test.initial.begin() + (table + 192u + row * 64u) / 4u);
// BDA loads use a separate tuple, as the captured shader's record members do.
std::copy_n(record.begin(), 4u, test.initial.begin() + (table + 176u + row * 64u) / 4u);
test.initial[slot * (row + 1u) / 4u] = ((0x3800u + row) << 16u) | (0x3c00u + row);
test.initial[slot * (row + 1u) / 4u + 1u] = ((0xc000u + row) << 16u) | (0x4000u + row);
}
// Compile against poison selectors. A separate GPU dispatch writes the actual keys.
auto compiled = CompileCase(test, vulkan.SubgroupSize());
if (table_bytes == 0u)
test.forbidden_spirv = {"convert_indirect_buffer_format"};
else
test.required_spirv = {"get_bda_pointer", "convert_indirect_buffer_format"};
CheckSpirvEmission(test, compiled.spirv);
u32 bda_function = 0, bda_calls = 0;
for (size_t offset = 5; offset < compiled.spirv.size();) {
const auto words = std::span(compiled.spirv).subspan(offset, compiled.spirv[offset] >> 16u);
const auto opcode = static_cast<spv::Op>(words[0] & 0xffffu);
if (opcode == spv::OpName &&
std::string_view(reinterpret_cast<const char *>(words.data() + 2)) == "get_bda_pointer")
bda_function = words[1];
if (opcode == spv::OpFunctionCall && words[3] == bda_function) ++bda_calls;
offset += words.size();
}
Require(test.name, "empty descriptor table specialization", (bda_calls == 0u) == (table_bytes == 0u),
"empty table retained BDA reads or nonempty table lost GPU descriptor loads");
for (const auto &descriptor : compiled.resources.buffers) {
ShaderBufferResource resource{};
std::copy_n(descriptor.dwords.begin(), 4u, resource.fields);
@@ -36846,15 +36869,18 @@ void CheckGpuSelectedRecordBufferAccess(VulkanHarness &vulkan) {
const u32 dynamic = keys[group] * 192u + 96u;
const u32 row = dynamic / 64u;
for (u32 lane = 0; lane < wave; ++lane) {
const u32 out = slot * 13u / 4u + (group * wave + lane) * 2u;
const u32 out = slot * 13u / 4u + (group * wave + lane) * 4u;
const bool source = uint64_t{dynamic} + 160u + 16u <= table_bytes && lane == 0u;
test.expected[out] = source ? test.initial[slot * (row + 1u) / 4u] : 0u;
test.expected[out + 1u] = source ? test.initial[slot * (row + 1u) / 4u + 1u] : 0u;
const bool bda_source = uint64_t{dynamic} + 144u + 16u <= table_bytes && lane == 0u;
test.expected[out + 2u] = bda_source ? 0x3c00u + row : 0u;
test.expected[out + 3u] = bda_source ? 0x3f800000u + (row << 13u) : 0u;
if (uint64_t{dynamic} + 176u + 16u <= table_bytes && (lane & 1u) == 0u)
bytes[slot * (row + 7u) + group * wave + lane] = std::byte{0xc3};
}
}
auto buffer = vulkan.CreateStorageBuffer(test.name, test.initial, test.initial.size());
auto buffer = vulkan.CreateStorageBuffer(test.name, test.initial, test.initial.size(), true);
vulkan.Dispatch(producer, producer_shader, buffer);
vulkan.Dispatch(test, compiled, buffer);
CompareWords(test, "GPU selectors, wrapped offsets, partial descriptors, OOB and masked byte stores",