Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

[Opt] Constant folding for BitExtractStmt #1307

Merged
merged 3 commits into from
Jun 23, 2020
Merged

[Opt] Constant folding for BitExtractStmt #1307

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
181196f
[Opt] Constant folding for BitExtractStmt
xumingkuan Jun 23, 2020
70f0038
fix tests
xumingkuan Jun 23, 2020
a1dcf57
Let BitExtractStmt support all integral types
xumingkuan Jun 23, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
27 changes: 25 additions & 2 deletions taichi/transforms/constant_fold.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -160,7 +160,7 @@ class ConstantFold : public BasicStmtVisitor {
auto evaluated =
Stmt::make<ConstStmt>(LaneAttribute<TypedConstant>(new_constant));
stmt->replace_with(evaluated.get());
modifier.insert_before(stmt, VecStatement(std::move(evaluated)));
modifier.insert_before(stmt, std::move(evaluated));
modifier.erase(stmt);
}
}
Expand All @@ -177,11 +177,34 @@ class ConstantFold : public BasicStmtVisitor {
auto evaluated =
Stmt::make<ConstStmt>(LaneAttribute<TypedConstant>(new_constant));
stmt->replace_with(evaluated.get());
modifier.insert_before(stmt, VecStatement(std::move(evaluated)));
modifier.insert_before(stmt, std::move(evaluated));
modifier.erase(stmt);
}
}

void visit(BitExtractStmt *stmt) override {
auto input = stmt->input->cast<ConstStmt>();
if (!input)
return;
Comment on lines +187 to +188
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Suggested change
if (!input)
return;
if (!input || input->element_type() == DataType::i32)
return;

Copy link
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Why not do constant folding when the input is i32?

if (stmt->width() != 1)
return;
std::unique_ptr<Stmt> result_stmt;
if (is_signed(input->val[0].dt)) {
auto result = (input->val[0].val_int() >> stmt->bit_begin) &
((1LL << (stmt->bit_end - stmt->bit_begin)) - 1);
result_stmt = Stmt::make<ConstStmt>(LaneAttribute<TypedConstant>(
TypedConstant(input->val[0].dt, result)));
} else {
auto result = (input->val[0].val_uint() >> stmt->bit_begin) &
((1LL << (stmt->bit_end - stmt->bit_begin)) - 1);
result_stmt = Stmt::make<ConstStmt>(LaneAttribute<TypedConstant>(
TypedConstant(input->val[0].dt, result)));
}
stmt->replace_with(result_stmt.get());
modifier.insert_before(stmt, std::move(result_stmt));
modifier.erase(stmt);
}

static bool run(IRNode *node) {
ConstantFold folder;
bool modified = false;
Expand Down
2 changes: 1 addition & 1 deletion taichi/transforms/type_check.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -371,7 +371,7 @@ class TypeCheck : public IRVisitor {
}

void visit(BitExtractStmt *stmt) {
stmt->ret_type.data_type = DataType::i32;
stmt->ret_type = stmt->input->ret_type;
}

void visit(LinearizeStmt *stmt) {
Expand Down