diff options
| -rw-r--r-- | clippy_lints/src/floating_point_arithmetic.rs | 69 | ||||
| -rw-r--r-- | tests/ui/floating_point_powi.fixed | 10 | ||||
| -rw-r--r-- | tests/ui/floating_point_powi.rs | 4 | ||||
| -rw-r--r-- | tests/ui/floating_point_powi.stderr | 38 |
4 files changed, 75 insertions, 46 deletions
diff --git a/clippy_lints/src/floating_point_arithmetic.rs b/clippy_lints/src/floating_point_arithmetic.rs index beb0b234408..11bd0ae23aa 100644 --- a/clippy_lints/src/floating_point_arithmetic.rs +++ b/clippy_lints/src/floating_point_arithmetic.rs @@ -294,37 +294,56 @@ fn check_powf(cx: &LateContext<'_>, expr: &Expr<'_>, args: &[Expr<'_>]) { } fn check_powi(cx: &LateContext<'_>, expr: &Expr<'_>, args: &[Expr<'_>]) { - // Check argument if let Some((value, _)) = constant(cx, cx.tables(), &args[1]) { - // TODO: need more specific check. this is too wide. remember also to include tests - if let Some(parent) = get_parent_expr(cx, expr) { - if let Some(grandparent) = get_parent_expr(cx, parent) { - if let ExprKind::MethodCall(PathSegment { ident: method_name, .. }, _, args, _) = grandparent.kind { - if method_name.as_str() == "sqrt" && detect_hypot(cx, args).is_some() { - return; + if value == Int(2) { + if let Some(parent) = get_parent_expr(cx, expr) { + if let Some(grandparent) = get_parent_expr(cx, parent) { + if let ExprKind::MethodCall(PathSegment { ident: method_name, .. }, _, args, _) = grandparent.kind { + if method_name.as_str() == "sqrt" && detect_hypot(cx, args).is_some() { + return; + } } } + + if let ExprKind::Binary( + Spanned { + node: BinOpKind::Add, .. + }, + ref lhs, + ref rhs, + ) = parent.kind + { + let other_addend = if lhs.hir_id == expr.hir_id { rhs } else { lhs }; + + span_lint_and_sugg( + cx, + SUBOPTIMAL_FLOPS, + parent.span, + "square can be computed more efficiently", + "consider using", + format!( + "{}.mul_add({}, {})", + Sugg::hir(cx, &args[0], ".."), + Sugg::hir(cx, &args[0], ".."), + Sugg::hir(cx, &other_addend, ".."), + ), + Applicability::MachineApplicable, + ); + + return; + } } - } - let (lint, help, suggestion) = match value { - Int(2) => ( - IMPRECISE_FLOPS, - "square can be computed more accurately", + span_lint_and_sugg( + cx, + SUBOPTIMAL_FLOPS, + expr.span, + "square can be computed more efficiently", + "consider using", format!("{} * {}", Sugg::hir(cx, &args[0], ".."), Sugg::hir(cx, &args[0], "..")), - ), - _ => return, - }; - - span_lint_and_sugg( - cx, - lint, - expr.span, - help, - "consider using", - suggestion, - Applicability::MachineApplicable, - ); + Applicability::MachineApplicable, + ); + } } } diff --git a/tests/ui/floating_point_powi.fixed b/tests/ui/floating_point_powi.fixed index 98766e68aaf..56762400593 100644 --- a/tests/ui/floating_point_powi.fixed +++ b/tests/ui/floating_point_powi.fixed @@ -1,5 +1,5 @@ // run-rustfix -#![warn(clippy::imprecise_flops)] +#![warn(clippy::suboptimal_flops)] fn main() { let one = 1; @@ -8,10 +8,12 @@ fn main() { let _ = x * x; let y = 4f32; - let _ = (x * x + y).sqrt(); - let _ = (x + y * y).sqrt(); + let _ = x.mul_add(x, y); + let _ = y.mul_add(y, x); + let _ = x.mul_add(x, y).sqrt(); + let _ = y.mul_add(y, x).sqrt(); // Cases where the lint shouldn't be applied let _ = x.powi(3); let _ = x.powi(one + 1); - let _ = x.hypot(y); + let _ = (x.powi(2) + y.powi(2)).sqrt(); } diff --git a/tests/ui/floating_point_powi.rs b/tests/ui/floating_point_powi.rs index 3c4b636a3d8..1f800e4628d 100644 --- a/tests/ui/floating_point_powi.rs +++ b/tests/ui/floating_point_powi.rs @@ -1,5 +1,5 @@ // run-rustfix -#![warn(clippy::imprecise_flops)] +#![warn(clippy::suboptimal_flops)] fn main() { let one = 1; @@ -8,6 +8,8 @@ fn main() { let _ = x.powi(1 + 1); let y = 4f32; + let _ = x.powi(2) + y; + let _ = x + y.powi(2); let _ = (x.powi(2) + y).sqrt(); let _ = (x + y.powi(2)).sqrt(); // Cases where the lint shouldn't be applied diff --git a/tests/ui/floating_point_powi.stderr b/tests/ui/floating_point_powi.stderr index f370e24bf05..d5a5f1bcca1 100644 --- a/tests/ui/floating_point_powi.stderr +++ b/tests/ui/floating_point_powi.stderr @@ -1,34 +1,40 @@ -error: square can be computed more accurately +error: square can be computed more efficiently --> $DIR/floating_point_powi.rs:7:13 | LL | let _ = x.powi(2); | ^^^^^^^^^ help: consider using: `x * x` | - = note: `-D clippy::imprecise-flops` implied by `-D warnings` + = note: `-D clippy::suboptimal-flops` implied by `-D warnings` -error: square can be computed more accurately +error: square can be computed more efficiently --> $DIR/floating_point_powi.rs:8:13 | LL | let _ = x.powi(1 + 1); | ^^^^^^^^^^^^^ help: consider using: `x * x` -error: square can be computed more accurately - --> $DIR/floating_point_powi.rs:11:14 +error: square can be computed more efficiently + --> $DIR/floating_point_powi.rs:11:13 | -LL | let _ = (x.powi(2) + y).sqrt(); - | ^^^^^^^^^ help: consider using: `x * x` +LL | let _ = x.powi(2) + y; + | ^^^^^^^^^^^^^ help: consider using: `x.mul_add(x, y)` -error: square can be computed more accurately - --> $DIR/floating_point_powi.rs:12:18 +error: square can be computed more efficiently + --> $DIR/floating_point_powi.rs:12:13 | -LL | let _ = (x + y.powi(2)).sqrt(); - | ^^^^^^^^^ help: consider using: `y * y` +LL | let _ = x + y.powi(2); + | ^^^^^^^^^^^^^ help: consider using: `y.mul_add(y, x)` + +error: square can be computed more efficiently + --> $DIR/floating_point_powi.rs:13:13 + | +LL | let _ = (x.powi(2) + y).sqrt(); + | ^^^^^^^^^^^^^^^ help: consider using: `x.mul_add(x, y)` -error: hypotenuse can be computed more accurately - --> $DIR/floating_point_powi.rs:16:13 +error: square can be computed more efficiently + --> $DIR/floating_point_powi.rs:14:13 | -LL | let _ = (x.powi(2) + y.powi(2)).sqrt(); - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.hypot(y)` +LL | let _ = (x + y.powi(2)).sqrt(); + | ^^^^^^^^^^^^^^^ help: consider using: `y.mul_add(y, x)` -error: aborting due to 5 previous errors +error: aborting due to 6 previous errors |