Skip to content

[mypyc] feat: support constant folding in try_optimize_int_floor_divide [1/1] #19973

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

Merged
merged 2 commits into from
Oct 2, 2025
+4 −4
Merged

[mypyc] feat: support constant folding in try_optimize_int_floor_divide [1/1] #19973

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
6b6cf1e
[mypyc] feat: support constant folding in `try_optimize_int_floor_div…
BobTheBuidler Oct 2, 2025
a07ae62
Update expression.py
BobTheBuidler Oct 2, 2025
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
8 changes: 4 additions & 4 deletions mypyc/irbuild/expression.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -558,7 +558,7 @@ def transform_op_expr(builder: IRBuilder, expr: OpExpr) -> Value:
# Special case some int ops to allow borrowing operands.
if is_int_rprimitive(ltype) and is_int_rprimitive(rtype):
if expr.op == "//":
expr = try_optimize_int_floor_divide(expr)
expr = try_optimize_int_floor_divide(builder, expr)
if expr.op in int_borrow_friendly_op:
borrow_left = is_borrow_friendly_expr(builder, expr.right)
borrow_right = True
Expand All @@ -571,11 +571,11 @@ def transform_op_expr(builder: IRBuilder, expr: OpExpr) -> Value:
return builder.binary_op(left, right, expr.op, expr.line)


def try_optimize_int_floor_divide(expr: OpExpr) -> OpExpr:
def try_optimize_int_floor_divide(builder: IRBuilder, expr: OpExpr) -> OpExpr:
"""Replace // with a power of two with a right shift, if possible."""
if not isinstance(expr.right, IntExpr):
divisor = constant_fold_expr(builder, expr.right)
if not isinstance(divisor, int):
return expr
divisor = expr.right.value
shift = divisor.bit_length() - 1
if 0 < shift < 28 and divisor == (1 << shift):
return OpExpr(">>", expr.left, IntExpr(shift))
Expand Down