resolver: Deterministic constant ID allocation

Use global declaration order for allocating implicit
pipeline-overridable constant IDs, instead of iterating over an
unordered_map.

Bug: tint:1155
Change-Id: Ia5ff534c617b0d57e45fc20dd0a5a591854e6473
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/65522
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
This commit is contained in:
James Price 2021-09-30 17:29:50 +00:00
parent 5ffae32177
commit ee23c17345
3 changed files with 79 additions and 58 deletions

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@ -14,16 +14,26 @@
#include "src/resolver/resolver.h"
#include "gmock/gmock.h"
#include "src/resolver/resolver_test_helper.h"
using ::testing::UnorderedElementsAre;
namespace tint {
namespace resolver {
namespace {
using ResolverPipelineOverridableConstantTest = ResolverTest;
class ResolverPipelineOverridableConstantTest : public ResolverTest {
protected:
/// Verify that the AST node `var` was resolved to an overridable constant
/// with an ID equal to `id`.
/// @param var the overridable constant AST node
/// @param id the expected constant ID
void ExpectConstantId(const ast::Variable* var, uint16_t id) {
auto* sem = Sem().Get<sem::GlobalVariable>(var);
ASSERT_NE(sem, nullptr);
EXPECT_EQ(sem->Declaration(), var);
EXPECT_TRUE(sem->IsPipelineConstant());
EXPECT_EQ(sem->ConstantId(), id);
}
};
TEST_F(ResolverPipelineOverridableConstantTest, NonOverridable) {
auto* a = GlobalConst("a", ty.f32(), Construct(ty.f32()));
@ -41,11 +51,7 @@ TEST_F(ResolverPipelineOverridableConstantTest, WithId) {
EXPECT_TRUE(r()->Resolve()) << r()->error();
auto* sem_a = Sem().Get<sem::GlobalVariable>(a);
ASSERT_NE(sem_a, nullptr);
EXPECT_EQ(sem_a->Declaration(), a);
EXPECT_TRUE(sem_a->IsPipelineConstant());
EXPECT_EQ(sem_a->ConstantId(), 7u);
ExpectConstantId(a, 7u);
}
TEST_F(ResolverPipelineOverridableConstantTest, WithoutId) {
@ -53,37 +59,27 @@ TEST_F(ResolverPipelineOverridableConstantTest, WithoutId) {
EXPECT_TRUE(r()->Resolve()) << r()->error();
auto* sem_a = Sem().Get<sem::GlobalVariable>(a);
ASSERT_NE(sem_a, nullptr);
EXPECT_EQ(sem_a->Declaration(), a);
EXPECT_TRUE(sem_a->IsPipelineConstant());
EXPECT_EQ(sem_a->ConstantId(), 0u);
ExpectConstantId(a, 0u);
}
TEST_F(ResolverPipelineOverridableConstantTest, WithAndWithoutIds) {
std::vector<ast::Variable*> variables;
variables.push_back(
GlobalConst("a", ty.f32(), Construct(ty.f32()), {Override()}));
variables.push_back(
GlobalConst("b", ty.f32(), Construct(ty.f32()), {Override()}));
variables.push_back(
GlobalConst("c", ty.f32(), Construct(ty.f32()), {Override(2u)}));
variables.push_back(
GlobalConst("d", ty.f32(), Construct(ty.f32()), {Override(4u)}));
variables.push_back(
GlobalConst("e", ty.f32(), Construct(ty.f32()), {Override()}));
variables.push_back(
GlobalConst("f", ty.f32(), Construct(ty.f32()), {Override(1u)}));
auto* a = GlobalConst("a", ty.f32(), Construct(ty.f32()), {Override()});
auto* b = GlobalConst("b", ty.f32(), Construct(ty.f32()), {Override()});
auto* c = GlobalConst("c", ty.f32(), Construct(ty.f32()), {Override(2u)});
auto* d = GlobalConst("d", ty.f32(), Construct(ty.f32()), {Override(4u)});
auto* e = GlobalConst("e", ty.f32(), Construct(ty.f32()), {Override()});
auto* f = GlobalConst("f", ty.f32(), Construct(ty.f32()), {Override(1u)});
EXPECT_TRUE(r()->Resolve()) << r()->error();
std::vector<uint16_t> constant_ids;
for (auto* var : variables) {
auto* sem = Sem().Get<sem::GlobalVariable>(var);
ASSERT_NE(sem, nullptr);
constant_ids.push_back(static_cast<uint16_t>(sem->ConstantId()));
}
EXPECT_THAT(constant_ids, UnorderedElementsAre(0u, 3u, 2u, 4u, 5u, 1u));
// Verify that constant id allocation order is deterministic.
ExpectConstantId(a, 0u);
ExpectConstantId(b, 3u);
ExpectConstantId(c, 2u);
ExpectConstantId(d, 4u);
ExpectConstantId(e, 5u);
ExpectConstantId(f, 1u);
}
TEST_F(ResolverPipelineOverridableConstantTest, DuplicateIds) {

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@ -264,6 +264,8 @@ bool Resolver::ResolveInternal() {
}
}
AllocateOverridableConstantIds();
if (!ValidatePipelineStages()) {
return false;
}
@ -576,6 +578,46 @@ ast::Access Resolver::DefaultAccessForStorageClass(
return ast::Access::kReadWrite;
}
void Resolver::AllocateOverridableConstantIds() {
// The next pipeline constant ID to try to allocate.
uint16_t next_constant_id = 0;
// Allocate constant IDs in global declaration order, so that they are
// deterministic.
// TODO(crbug.com/tint/1192): If a transform changes the order or removes an
// unused constant, the allocation may change on the next Resolver pass.
for (auto* decl : builder_->AST().GlobalDeclarations()) {
auto* var = decl->As<ast::Variable>();
if (!var) {
continue;
}
auto* override_deco =
ast::GetDecoration<ast::OverrideDecoration>(var->decorations());
if (!override_deco) {
continue;
}
uint16_t constant_id;
if (override_deco->HasValue()) {
constant_id = static_cast<uint16_t>(override_deco->value());
} else {
// No ID was specified, so allocate the next available ID.
constant_id = next_constant_id;
while (constant_ids_.count(constant_id)) {
if (constant_id == UINT16_MAX) {
TINT_ICE(Resolver, builder_->Diagnostics())
<< "no more pipeline constant IDs available";
return;
}
constant_id++;
}
next_constant_id = constant_id + 1;
}
variable_to_info_[var]->constant_id = constant_id;
}
}
bool Resolver::ValidateVariableConstructor(const ast::Variable* var,
ast::StorageClass storage_class,
const sem::Type* storage_type,
@ -3709,9 +3751,6 @@ void Resolver::CreateSemanticNodes() const {
}
}
// The next pipeline constant ID to try to allocate.
uint16_t next_constant_id = 0;
// Create semantic nodes for all ast::Variables
std::unordered_map<const tint::ast::Variable*, sem::Parameter*> sem_params;
for (auto it : variable_to_info_) {
@ -3720,28 +3759,10 @@ void Resolver::CreateSemanticNodes() const {
sem::Variable* sem_var = nullptr;
if (auto* override_deco =
ast::GetDecoration<ast::OverrideDecoration>(var->decorations())) {
if (ast::HasDecoration<ast::OverrideDecoration>(var->decorations())) {
// Create a pipeline overridable constant.
uint16_t constant_id;
if (override_deco->HasValue()) {
constant_id = static_cast<uint16_t>(override_deco->value());
} else {
// No ID was specified, so allocate the next available ID.
constant_id = next_constant_id;
while (constant_ids_.count(constant_id)) {
if (constant_id == UINT16_MAX) {
TINT_ICE(Resolver, builder_->Diagnostics())
<< "no more pipeline constant IDs available";
return;
}
constant_id++;
}
next_constant_id = constant_id + 1;
}
sem_var =
builder_->create<sem::GlobalVariable>(var, info->type, constant_id);
sem_var = builder_->create<sem::GlobalVariable>(var, info->type,
info->constant_id);
} else {
switch (info->kind) {
case VariableKind::kGlobal:

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@ -116,6 +116,7 @@ class Resolver {
sem::BindingPoint binding_point;
VariableKind kind;
uint32_t index = 0; // Parameter index, if kind == kParameter
uint16_t constant_id = 0;
};
struct IntrinsicCallInfo {
@ -268,7 +269,7 @@ class Resolver {
/// root node, and ending with leaf nodes
/// @return true on success, false on error
bool TraverseExpressions(ast::Expression* root,
std::vector<ast::Expression*>& out);
std::vector<ast::Expression*>& out);
// AST and Type validation methods
// Each return true on success, false on failure.
@ -391,6 +392,9 @@ class Resolver {
/// @returns the default access control for the given storage class
ast::Access DefaultAccessForStorageClass(ast::StorageClass storage_class);
/// Allocate constant IDs for pipeline-overridable constants.
void AllocateOverridableConstantIds();
/// @returns the resolved type of the ast::Expression `expr`
/// @param expr the expression
sem::Type* TypeOf(const ast::Expression* expr);