bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Rename mul_add test file and add general improvements

Browse source
This commit is contained in:
Krishna Sai Veera Reddy 2020-02-23 20:48:57 -08:00
parent 4065ca9c8c
commit e94a167508
7 changed files with 82 additions and 72 deletions
Download patch file Download diff file Expand all files Collapse all files

108
clippy_lints/src/floating_point_arithmetic.rs
View file

@ -9,6 +9,8 @@ use rustc_errors::Applicability;
use rustc_hir::{BinOpKind, Expr, ExprKind, UnOp};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::source_map::Spanned;
use std::f32::consts as f32_consts;
use std::f64::consts as f64_consts;
use sugg::{format_numeric_literal, Sugg};
@ -138,26 +140,29 @@ fn check_log_base(cx: &LateContext<'_, '_>, expr: &Expr<'_>, args: &[Expr<'_>])
// TODO: Lint expressions of the form `(x + y).ln()` where y > 1 and
// suggest usage of `(x + (y - 1)).ln_1p()` instead
fn check_ln1p(cx: &LateContext<'_, '_>, expr: &Expr<'_>, args: &[Expr<'_>]) {
if_chain! {
if let ExprKind::Binary(op, ref lhs, ref rhs) = &args[0].kind;
if op.node == BinOpKind::Add;
then {
let recv = match (constant(cx, cx.tables, lhs), constant(cx, cx.tables, rhs)) {
(Some((value, _)), _) if F32(1.0) == value || F64(1.0) == value => rhs,
(_, Some((value, _))) if F32(1.0) == value || F64(1.0) == value => lhs,
_ => return,
};
if let ExprKind::Binary(
Spanned {
node: BinOpKind::Add, ..
},
lhs,
rhs,
) = &args[0].kind
{
let recv = match (constant(cx, cx.tables, lhs), constant(cx, cx.tables, rhs)) {
(Some((value, _)), _) if F32(1.0) == value || F64(1.0) == value => rhs,
(_, Some((value, _))) if F32(1.0) == value || F64(1.0) == value => lhs,
_ => return,
};
span_lint_and_sugg(
cx,
SUBOPTIMAL_FLOPS,
expr.span,
"ln(1 + x) can be computed more accurately",
"consider using",
format!("{}.ln_1p()", prepare_receiver_sugg(cx, recv)),
Applicability::MachineApplicable,
);
}
span_lint_and_sugg(
cx,
SUBOPTIMAL_FLOPS,
expr.span,
"ln(1 + x) can be computed more accurately",
"consider using",
format!("{}.ln_1p()", prepare_receiver_sugg(cx, recv)),
Applicability::MachineApplicable,
);
}
}
@ -249,8 +254,7 @@ fn check_powf(cx: &LateContext<'_, '_>, expr: &Expr<'_>, args: &[Expr<'_>]) {
// and suggest usage of `x.exp_m1() - (y - 1)` instead
fn check_expm1(cx: &LateContext<'_, '_>, expr: &Expr<'_>) {
if_chain! {
if let ExprKind::Binary(op, ref lhs, ref rhs) = expr.kind;
if op.node == BinOpKind::Sub;
if let ExprKind::Binary(Spanned { node: BinOpKind::Sub, .. }, ref lhs, ref rhs) = expr.kind;
if cx.tables.expr_ty(lhs).is_floating_point();
if let Some((value, _)) = constant(cx, cx.tables, rhs);
if F32(1.0) == value || F64(1.0) == value;
@ -276,8 +280,7 @@ fn check_expm1(cx: &LateContext<'_, '_>, expr: &Expr<'_>) {
fn is_float_mul_expr<'a>(cx: &LateContext<'_, '_>, expr: &'a Expr<'a>) -> Option<(&'a Expr<'a>, &'a Expr<'a>)> {
if_chain! {
if let ExprKind::Binary(op, ref lhs, ref rhs) = &expr.kind;
if let BinOpKind::Mul = op.node;
if let ExprKind::Binary(Spanned { node: BinOpKind::Mul, .. }, ref lhs, ref rhs) = &expr.kind;
if cx.tables.expr_ty(lhs).is_floating_point();
if cx.tables.expr_ty(rhs).is_floating_point();
then {
@ -289,34 +292,37 @@ fn is_float_mul_expr<'a>(cx: &LateContext<'_, '_>, expr: &'a Expr<'a>) -> Option
}
// TODO: Fix rust-lang/rust-clippy#4735
fn check_fma(cx: &LateContext<'_, '_>, expr: &Expr<'_>) {
if_chain! {
if let ExprKind::Binary(op, lhs, rhs) = &expr.kind;
if let BinOpKind::Add = op.node;
then {
let (recv, arg1, arg2) = if let Some((inner_lhs, inner_rhs)) = is_float_mul_expr(cx, lhs) {
(inner_lhs, inner_rhs, rhs)
} else if let Some((inner_lhs, inner_rhs)) = is_float_mul_expr(cx, rhs) {
(inner_lhs, inner_rhs, lhs)
} else {
return;
};
fn check_mul_add(cx: &LateContext<'_, '_>, expr: &Expr<'_>) {
if let ExprKind::Binary(
Spanned {
node: BinOpKind::Add, ..
},
lhs,
rhs,
) = &expr.kind
{
let (recv, arg1, arg2) = if let Some((inner_lhs, inner_rhs)) = is_float_mul_expr(cx, lhs) {
(inner_lhs, inner_rhs, rhs)
} else if let Some((inner_lhs, inner_rhs)) = is_float_mul_expr(cx, rhs) {
(inner_lhs, inner_rhs, lhs)
} else {
return;
};
span_lint_and_sugg(
cx,
SUBOPTIMAL_FLOPS,
expr.span,
"multiply and add expressions can be calculated more efficiently and accurately",
"consider using",
format!(
"{}.mul_add({}, {})",
prepare_receiver_sugg(cx, recv),
Sugg::hir(cx, arg1, ".."),
Sugg::hir(cx, arg2, ".."),
),
Applicability::MachineApplicable,
);
}
span_lint_and_sugg(
cx,
SUBOPTIMAL_FLOPS,
expr.span,
"multiply and add expressions can be calculated more efficiently and accurately",
"consider using",
format!(
"{}.mul_add({}, {})",
prepare_receiver_sugg(cx, recv),
Sugg::hir(cx, arg1, ".."),
Sugg::hir(cx, arg2, ".."),
),
Applicability::MachineApplicable,
);
}
}
@ -335,7 +341,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for FloatingPointArithmetic {
}
} else {
check_expm1(cx, expr);
check_fma(cx, expr);
check_mul_add(cx, expr);
}
}
}