Auto merge of #9576 - TennyZhuang:unnecessary_cast_for_non_literal_expr, r=llogiq

let unnecessary_cast work for trivial non_literal expressions

Signed-off-by: TennyZhuang <zty0826@gmail.com>

---

changelog: [`unnecessary_cast`]: fix for trivial non_literal expressions

Fixes #9562

24 files changed, 141 insertions, 100 deletions

diff --git a/clippy_lints/src/casts/unnecessary_cast.rs b/clippy_lints/src/casts/unnecessary_cast.rs
index 031cedb9072..21ed7f4844c 100644
--- a/clippy_lints/src/casts/unnecessary_cast.rs
+++ b/clippy_lints/src/casts/unnecessary_cast.rs
@@ -31,8 +31,10 @@ pub(super) fn check<'tcx>(
         }
     }
 
+    let cast_str = snippet_opt(cx, cast_expr.span).unwrap_or_default();
+
     if let Some(lit) = get_numeric_literal(cast_expr) {
-        let literal_str = snippet_opt(cx, cast_expr.span).unwrap_or_default();
+        let literal_str = &cast_str;
 
         if_chain! {
             if let LitKind::Int(n, _) = lit.node;
@@ -50,12 +52,16 @@ pub(super) fn check<'tcx>(
 
         match lit.node {
             LitKind::Int(_, LitIntType::Unsuffixed) if cast_to.is_integral() => {
-                lint_unnecessary_cast(cx, expr, &literal_str, cast_from, cast_to);
+                lint_unnecessary_cast(cx, expr, literal_str, cast_from, cast_to);
+                return false;
             },
             LitKind::Float(_, LitFloatType::Unsuffixed) if cast_to.is_floating_point() => {
-                lint_unnecessary_cast(cx, expr, &literal_str, cast_from, cast_to);
+                lint_unnecessary_cast(cx, expr, literal_str, cast_from, cast_to);
+                return false;
+            },
+            LitKind::Int(_, LitIntType::Unsuffixed) | LitKind::Float(_, LitFloatType::Unsuffixed) => {
+                return false;
             },
-            LitKind::Int(_, LitIntType::Unsuffixed) | LitKind::Float(_, LitFloatType::Unsuffixed) => {},
             LitKind::Int(_, LitIntType::Signed(_) | LitIntType::Unsigned(_))
             | LitKind::Float(_, LitFloatType::Suffixed(_))
                 if cast_from.kind() == cast_to.kind() =>
@@ -63,26 +69,27 @@ pub(super) fn check<'tcx>(
                 if let Some(src) = snippet_opt(cx, cast_expr.span) {
                     if let Some(num_lit) = NumericLiteral::from_lit_kind(&src, &lit.node) {
                         lint_unnecessary_cast(cx, expr, num_lit.integer, cast_from, cast_to);
+                        return true;
                     }
                 }
             },
-            _ => {
-                if cast_from.kind() == cast_to.kind() && !in_external_macro(cx.sess(), expr.span) {
-                    span_lint_and_sugg(
-                        cx,
-                        UNNECESSARY_CAST,
-                        expr.span,
-                        &format!("casting to the same type is unnecessary (`{cast_from}` -> `{cast_to}`)"),
-                        "try",
-                        literal_str,
-                        Applicability::MachineApplicable,
-                    );
-                    return true;
-                }
-            },
+            _ => {},
         }
     }
 
+    if cast_from.kind() == cast_to.kind() && !in_external_macro(cx.sess(), expr.span) {
+        span_lint_and_sugg(
+            cx,
+            UNNECESSARY_CAST,
+            expr.span,
+            &format!("casting to the same type is unnecessary (`{cast_from}` -> `{cast_to}`)"),
+            "try",
+            cast_str,
+            Applicability::MachineApplicable,
+        );
+        return true;
+    }
+
     false
 }
 
diff --git a/tests/ui/floating_point_exp.fixed b/tests/ui/floating_point_exp.fixed
index c86a502d15f..b9e3d89c2b2 100644
--- a/tests/ui/floating_point_exp.fixed
+++ b/tests/ui/floating_point_exp.fixed
@@ -1,5 +1,6 @@
 // run-rustfix
 #![warn(clippy::imprecise_flops)]
+#![allow(clippy::unnecessary_cast)]
 
 fn main() {
     let x = 2f32;
diff --git a/tests/ui/floating_point_exp.rs b/tests/ui/floating_point_exp.rs
index e59589f912a..ef008dd9be0 100644
--- a/tests/ui/floating_point_exp.rs
+++ b/tests/ui/floating_point_exp.rs
@@ -1,5 +1,6 @@
 // run-rustfix
 #![warn(clippy::imprecise_flops)]
+#![allow(clippy::unnecessary_cast)]
 
 fn main() {
     let x = 2f32;
diff --git a/tests/ui/floating_point_exp.stderr b/tests/ui/floating_point_exp.stderr
index f84eede1987..b92fae56e42 100644
--- a/tests/ui/floating_point_exp.stderr
+++ b/tests/ui/floating_point_exp.stderr
@@ -1,5 +1,5 @@
 error: (e.pow(x) - 1) can be computed more accurately
-  --> $DIR/floating_point_exp.rs:6:13
+  --> $DIR/floating_point_exp.rs:7:13
    |
 LL |     let _ = x.exp() - 1.0;
    |             ^^^^^^^^^^^^^ help: consider using: `x.exp_m1()`
@@ -7,25 +7,25 @@ LL |     let _ = x.exp() - 1.0;
    = note: `-D clippy::imprecise-flops` implied by `-D warnings`
 
 error: (e.pow(x) - 1) can be computed more accurately
-  --> $DIR/floating_point_exp.rs:7:13
+  --> $DIR/floating_point_exp.rs:8:13
    |
 LL |     let _ = x.exp() - 1.0 + 2.0;
    |             ^^^^^^^^^^^^^ help: consider using: `x.exp_m1()`
 
 error: (e.pow(x) - 1) can be computed more accurately
-  --> $DIR/floating_point_exp.rs:8:13
+  --> $DIR/floating_point_exp.rs:9:13
    |
 LL |     let _ = (x as f32).exp() - 1.0 + 2.0;
    |             ^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(x as f32).exp_m1()`
 
 error: (e.pow(x) - 1) can be computed more accurately
-  --> $DIR/floating_point_exp.rs:14:13
+  --> $DIR/floating_point_exp.rs:15:13
    |
 LL |     let _ = x.exp() - 1.0;
    |             ^^^^^^^^^^^^^ help: consider using: `x.exp_m1()`
 
 error: (e.pow(x) - 1) can be computed more accurately
-  --> $DIR/floating_point_exp.rs:15:13
+  --> $DIR/floating_point_exp.rs:16:13
    |
 LL |     let _ = x.exp() - 1.0 + 2.0;
    |             ^^^^^^^^^^^^^ help: consider using: `x.exp_m1()`
diff --git a/tests/ui/floating_point_log.fixed b/tests/ui/floating_point_log.fixed
index 4def9300bb7..ee540646160 100644
--- a/tests/ui/floating_point_log.fixed
+++ b/tests/ui/floating_point_log.fixed
@@ -1,5 +1,5 @@
 // run-rustfix
-#![allow(dead_code, clippy::double_parens)]
+#![allow(dead_code, clippy::double_parens, clippy::unnecessary_cast)]
 #![warn(clippy::suboptimal_flops, clippy::imprecise_flops)]
 
 const TWO: f32 = 2.0;
diff --git a/tests/ui/floating_point_log.rs b/tests/ui/floating_point_log.rs
index 1e04caa7d2a..0590670a50b 100644
--- a/tests/ui/floating_point_log.rs
+++ b/tests/ui/floating_point_log.rs
@@ -1,5 +1,5 @@
 // run-rustfix
-#![allow(dead_code, clippy::double_parens)]
+#![allow(dead_code, clippy::double_parens, clippy::unnecessary_cast)]
 #![warn(clippy::suboptimal_flops, clippy::imprecise_flops)]
 
 const TWO: f32 = 2.0;
diff --git a/tests/ui/floating_point_logbase.fixed b/tests/ui/floating_point_logbase.fixed
index 936462f9406..7347bf72cbe 100644
--- a/tests/ui/floating_point_logbase.fixed
+++ b/tests/ui/floating_point_logbase.fixed
@@ -1,5 +1,6 @@
 // run-rustfix
 #![warn(clippy::suboptimal_flops)]
+#![allow(clippy::unnecessary_cast)]
 
 fn main() {
     let x = 3f32;
diff --git a/tests/ui/floating_point_logbase.rs b/tests/ui/floating_point_logbase.rs
index 0b56fa8fa41..ba5b8d40692 100644
--- a/tests/ui/floating_point_logbase.rs
+++ b/tests/ui/floating_point_logbase.rs
@@ -1,5 +1,6 @@
 // run-rustfix
 #![warn(clippy::suboptimal_flops)]
+#![allow(clippy::unnecessary_cast)]
 
 fn main() {
     let x = 3f32;
diff --git a/tests/ui/floating_point_logbase.stderr b/tests/ui/floating_point_logbase.stderr
index 384e3554cbb..9d736b5e1a2 100644
--- a/tests/ui/floating_point_logbase.stderr
+++ b/tests/ui/floating_point_logbase.stderr
@@ -1,5 +1,5 @@
 error: log base can be expressed more clearly
-  --> $DIR/floating_point_logbase.rs:7:13
+  --> $DIR/floating_point_logbase.rs:8:13
    |
 LL |     let _ = x.ln() / y.ln();
    |             ^^^^^^^^^^^^^^^ help: consider using: `x.log(y)`
@@ -7,25 +7,25 @@ LL |     let _ = x.ln() / y.ln();
    = note: `-D clippy::suboptimal-flops` implied by `-D warnings`
 
 error: log base can be expressed more clearly
-  --> $DIR/floating_point_logbase.rs:8:13
+  --> $DIR/floating_point_logbase.rs:9:13
    |
 LL |     let _ = (x as f32).ln() / y.ln();
    |             ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(x as f32).log(y)`
 
 error: log base can be expressed more clearly
-  --> $DIR/floating_point_logbase.rs:9:13
+  --> $DIR/floating_point_logbase.rs:10:13
    |
 LL |     let _ = x.log2() / y.log2();
    |             ^^^^^^^^^^^^^^^^^^^ help: consider using: `x.log(y)`
 
 error: log base can be expressed more clearly
-  --> $DIR/floating_point_logbase.rs:10:13
+  --> $DIR/floating_point_logbase.rs:11:13
    |
 LL |     let _ = x.log10() / y.log10();
    |             ^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.log(y)`
 
 error: log base can be expressed more clearly
-  --> $DIR/floating_point_logbase.rs:11:13
+  --> $DIR/floating_point_logbase.rs:12:13
    |
 LL |     let _ = x.log(5f32) / y.log(5f32);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.log(y)`
diff --git a/tests/ui/floating_point_powf.fixed b/tests/ui/floating_point_powf.fixed
index e7ef45634df..f7f93de2957 100644
--- a/tests/ui/floating_point_powf.fixed
+++ b/tests/ui/floating_point_powf.fixed
@@ -1,5 +1,6 @@
 // run-rustfix
 #![warn(clippy::suboptimal_flops, clippy::imprecise_flops)]
+#![allow(clippy::unnecessary_cast)]
 
 fn main() {
     let x = 3f32;
diff --git a/tests/ui/floating_point_powf.rs b/tests/ui/floating_point_powf.rs
index d749aa2d48a..499fc0e15e4 100644
--- a/tests/ui/floating_point_powf.rs
+++ b/tests/ui/floating_point_powf.rs
@@ -1,5 +1,6 @@
 // run-rustfix
 #![warn(clippy::suboptimal_flops, clippy::imprecise_flops)]
+#![allow(clippy::unnecessary_cast)]
 
 fn main() {
     let x = 3f32;
diff --git a/tests/ui/floating_point_powf.stderr b/tests/ui/floating_point_powf.stderr
index e9693de8fc9..7c9d50db2f7 100644
--- a/tests/ui/floating_point_powf.stderr
+++ b/tests/ui/floating_point_powf.stderr
@@ -1,5 +1,5 @@
 error: exponent for bases 2 and e can be computed more accurately
-  --> $DIR/floating_point_powf.rs:6:13
+  --> $DIR/floating_point_powf.rs:7:13
    |
 LL |     let _ = 2f32.powf(x);
    |             ^^^^^^^^^^^^ help: consider using: `x.exp2()`
@@ -7,43 +7,43 @@ LL |     let _ = 2f32.powf(x);
    = note: `-D clippy::suboptimal-flops` implied by `-D warnings`
 
 error: exponent for bases 2 and e can be computed more accurately
-  --> $DIR/floating_point_powf.rs:7:13
+  --> $DIR/floating_point_powf.rs:8:13
    |
 LL |     let _ = 2f32.powf(3.1);
    |             ^^^^^^^^^^^^^^ help: consider using: `3.1f32.exp2()`
 
 error: exponent for bases 2 and e can be computed more accurately
-  --> $DIR/floating_point_powf.rs:8:13
+  --> $DIR/floating_point_powf.rs:9:13
    |
 LL |     let _ = 2f32.powf(-3.1);
    |             ^^^^^^^^^^^^^^^ help: consider using: `(-3.1f32).exp2()`
 
 error: exponent for bases 2 and e can be computed more accurately
-  --> $DIR/floating_point_powf.rs:9:13
+  --> $DIR/floating_point_powf.rs:10:13
    |
 LL |     let _ = std::f32::consts::E.powf(x);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.exp()`
 
 error: exponent for bases 2 and e can be computed more accurately
-  --> $DIR/floating_point_powf.rs:10:13
+  --> $DIR/floating_point_powf.rs:11:13
    |
 LL |     let _ = std::f32::consts::E.powf(3.1);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `3.1f32.exp()`
 
 error: exponent for bases 2 and e can be computed more accurately
-  --> $DIR/floating_point_powf.rs:11:13
+  --> $DIR/floating_point_powf.rs:12:13
    |
 LL |     let _ = std::f32::consts::E.powf(-3.1);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(-3.1f32).exp()`
 
 error: square-root of a number can be computed more efficiently and accurately
-  --> $DIR/floating_point_powf.rs:12:13
+  --> $DIR/floating_point_powf.rs:13:13
    |
 LL |     let _ = x.powf(1.0 / 2.0);
    |             ^^^^^^^^^^^^^^^^^ help: consider using: `x.sqrt()`
 
 error: cube-root of a number can be computed more accurately
-  --> $DIR/floating_point_powf.rs:13:13
+  --> $DIR/floating_point_powf.rs:14:13
    |
 LL |     let _ = x.powf(1.0 / 3.0);
    |             ^^^^^^^^^^^^^^^^^ help: consider using: `x.cbrt()`
@@ -51,139 +51,139 @@ LL |     let _ = x.powf(1.0 / 3.0);
    = note: `-D clippy::imprecise-flops` implied by `-D warnings`
 
 error: cube-root of a number can be computed more accurately
-  --> $DIR/floating_point_powf.rs:14:13
+  --> $DIR/floating_point_powf.rs:15:13
    |
 LL |     let _ = (x as f32).powf(1.0 / 3.0);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(x as f32).cbrt()`
 
 error: exponentiation with integer powers can be computed more efficiently
-  --> $DIR/floating_point_powf.rs:15:13
+  --> $DIR/floating_point_powf.rs:16:13
    |
 LL |     let _ = x.powf(3.0);
    |             ^^^^^^^^^^^ help: consider using: `x.powi(3)`
 
 error: exponentiation with integer powers can be computed more efficiently
-  --> $DIR/floating_point_powf.rs:16:13
+  --> $DIR/floating_point_powf.rs:17:13
    |
 LL |     let _ = x.powf(-2.0);
    |             ^^^^^^^^^^^^ help: consider using: `x.powi(-2)`
 
 error: exponentiation with integer powers can be computed more efficiently
-  --> $DIR/floating_point_powf.rs:17:13
+  --> $DIR/floating_point_powf.rs:18:13
    |
 LL |     let _ = x.powf(16_777_215.0);
    |             ^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.powi(16_777_215)`
 
 error: exponentiation with integer powers can be computed more efficiently
-  --> $DIR/floating_point_powf.rs:18:13
+  --> $DIR/floating_point_powf.rs:19:13
    |
 LL |     let _ = x.powf(-16_777_215.0);
    |             ^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.powi(-16_777_215)`
 
 error: exponentiation with integer powers can be computed more efficiently
-  --> $DIR/floating_point_powf.rs:19:13
+  --> $DIR/floating_point_powf.rs:20:13
    |
 LL |     let _ = (x as f32).powf(-16_777_215.0);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(x as f32).powi(-16_777_215)`
 
 error: exponentiation with integer powers can be computed more efficiently
-  --> $DIR/floating_point_powf.rs:20:13
+  --> $DIR/floating_point_powf.rs:21:13
    |
 LL |     let _ = (x as f32).powf(3.0);
    |             ^^^^^^^^^^^^^^^^^^^^ help: consider using: `(x as f32).powi(3)`
 
 error: cube-root of a number can be computed more accurately
-  --> $DIR/floating_point_powf.rs:21:13
+  --> $DIR/floating_point_powf.rs:22:13
    |
 LL |     let _ = (1.5_f32 + 1.0).powf(1.0 / 3.0);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(1.5_f32 + 1.0).cbrt()`
 
 error: cube-root of a number can be computed more accurately
-  --> $DIR/floating_point_powf.rs:22:13
+  --> $DIR/floating_point_powf.rs:23:13
    |
 LL |     let _ = 1.5_f64.powf(1.0 / 3.0);
    |             ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `1.5_f64.cbrt()`
 
 error: square-root of a number can be computed more efficiently and accurately
-  --> $DIR/floating_point_powf.rs:23:13
+  --> $DIR/floating_point_powf.rs:24:13
    |
 LL |     let _ = 1.5_f64.powf(1.0 / 2.0);
    |             ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `1.5_f64.sqrt()`
 
 error: exponentiation with integer powers can be computed more efficiently
-  --> $DIR/floating_point_powf.rs:24:13
+  --> $DIR/floating_point_powf.rs:25:13
    |
 LL |     let _ = 1.5_f64.powf(3.0);
    |             ^^^^^^^^^^^^^^^^^ help: consider using: `1.5_f64.powi(3)`
 
 error: exponent for bases 2 and e can be computed more accurately
-  --> $DIR/floating_point_powf.rs:33:13
+  --> $DIR/floating_point_powf.rs:34:13
    |
 LL |     let _ = 2f64.powf(x);
    |             ^^^^^^^^^^^^ help: consider using: `x.exp2()`
 
 error: exponent for bases 2 and e can be computed more accurately
-  --> $DIR/floating_point_powf.rs:34:13
+  --> $DIR/floating_point_powf.rs:35:13
    |
 LL |     let _ = 2f64.powf(3.1);
    |             ^^^^^^^^^^^^^^ help: consider using: `3.1f64.exp2()`
 
 error: exponent for bases 2 and e can be computed more accurately
-  --> $DIR/floating_point_powf.rs:35:13
+  --> $DIR/floating_point_powf.rs:36:13
    |
 LL |     let _ = 2f64.powf(-3.1);
    |             ^^^^^^^^^^^^^^^ help: consider using: `(-3.1f64).exp2()`
 
 error: exponent for bases 2 and e can be computed more accurately
-  --> $DIR/floating_point_powf.rs:36:13
+  --> $DIR/floating_point_powf.rs:37:13
    |
 LL |     let _ = std::f64::consts::E.powf(x);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.exp()`
 
 error: exponent for bases 2 and e can be computed more accurately
-  --> $DIR/floating_point_powf.rs:37:13
+  --> $DIR/floating_point_powf.rs:38:13
    |
 LL |     let _ = std::f64::consts::E.powf(3.1);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `3.1f64.exp()`
 
 error: exponent for bases 2 and e can be computed more accurately
-  --> $DIR/floating_point_powf.rs:38:13
+  --> $DIR/floating_point_powf.rs:39:13
    |
 LL |     let _ = std::f64::consts::E.powf(-3.1);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(-3.1f64).exp()`
 
 error: square-root of a number can be computed more efficiently and accurately
-  --> $DIR/floating_point_powf.rs:39:13
+  --> $DIR/floating_point_powf.rs:40:13
    |
 LL |     let _ = x.powf(1.0 / 2.0);
    |             ^^^^^^^^^^^^^^^^^ help: consider using: `x.sqrt()`
 
 error: cube-root of a number can be computed more accurately
-  --> $DIR/floating_point_powf.rs:40:13
+  --> $DIR/floating_point_powf.rs:41:13
    |
 LL |     let _ = x.powf(1.0 / 3.0);
    |             ^^^^^^^^^^^^^^^^^ help: consider using: `x.cbrt()`
 
 error: exponentiation with integer powers can be computed more efficiently
-  --> $DIR/floating_point_powf.rs:41:13
+  --> $DIR/floating_point_powf.rs:42:13
    |
 LL |     let _ = x.powf(3.0);
    |             ^^^^^^^^^^^ help: consider using: `x.powi(3)`
 
 error: exponentiation with integer powers can be computed more efficiently
-  --> $DIR/floating_point_powf.rs:42:13
+  --> $DIR/floating_point_powf.rs:43:13
    |
 LL |     let _ = x.powf(-2.0);
    |             ^^^^^^^^^^^^ help: consider using: `x.powi(-2)`
 
 error: exponentiation with integer powers can be computed more efficiently
-  --> $DIR/floating_point_powf.rs:43:13
+  --> $DIR/floating_point_powf.rs:44:13
    |
 LL |     let _ = x.powf(-2_147_483_648.0);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.powi(-2_147_483_648)`
 
 error: exponentiation with integer powers can be computed more efficiently
-  --> $DIR/floating_point_powf.rs:44:13
+  --> $DIR/floating_point_powf.rs:45:13
    |
 LL |     let _ = x.powf(2_147_483_647.0);
    |             ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `x.powi(2_147_483_647)`
diff --git a/tests/ui/floating_point_powi.fixed b/tests/ui/floating_point_powi.fixed
index 5758db7c6c8..68c81316930 100644
--- a/tests/ui/floating_point_powi.fixed
+++ b/tests/ui/floating_point_powi.fixed
@@ -1,5 +1,6 @@
 // run-rustfix
 #![warn(clippy::suboptimal_flops)]
+#![allow(clippy::unnecessary_cast)]
 
 fn main() {
     let one = 1;
diff --git a/tests/ui/floating_point_powi.rs b/tests/ui/floating_point_powi.rs
index 5926bf1b000..96101a487ee 100644
--- a/tests/ui/floating_point_powi.rs
+++ b/tests/ui/floating_point_powi.rs
@@ -1,5 +1,6 @@
 // run-rustfix
 #![warn(clippy::suboptimal_flops)]
+#![allow(clippy::unnecessary_cast)]
 
 fn main() {
     let one = 1;
diff --git a/tests/ui/floating_point_powi.stderr b/tests/ui/floating_point_powi.stderr
index a3c74544212..a651954a5f8 100644
--- a/tests/ui/floating_point_powi.stderr
+++ b/tests/ui/floating_point_powi.stderr
@@ -1,5 +1,5 @@
 error: multiply and add expressions can be calculated more efficiently and accurately
-  --> $DIR/floating_point_powi.rs:9:13
+  --> $DIR/floating_point_powi.rs:10:13
    |
 LL |     let _ = x.powi(2) + y;
    |             ^^^^^^^^^^^^^ help: consider using: `x.mul_add(x, y)`
@@ -7,25 +7,25 @@ LL |     let _ = x.powi(2) + y;
    = note: `-D clippy::suboptimal-flops` implied by `-D warnings`
 
 error: multiply and add expressions can be calculated more efficiently and accurately
-  --> $DIR/floating_point_powi.rs:10:13
+  --> $DIR/floating_point_powi.rs:11:13
    |
 LL |     let _ = x + y.powi(2);
    |             ^^^^^^^^^^^^^ help: consider using: `y.mul_add(y, x)`
 
 error: multiply and add expressions can be calculated more efficiently and accurately
-  --> $DIR/floating_point_powi.rs:11:13
+  --> $DIR/floating_point_powi.rs:12:13
    |
 LL |     let _ = x + (y as f32).powi(2);
    |             ^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(y as f32).mul_add(y as f32, x)`
 
 error: multiply and add expressions can be calculated more efficiently and accurately
-  --> $DIR/floating_point_powi.rs:12:13
+  --> $DIR/floating_point_powi.rs:13:13
    |
 LL |     let _ = (x.powi(2) + y).sqrt();
    |             ^^^^^^^^^^^^^^^ help: consider using: `x.mul_add(x, y)`
 
 error: multiply and add expressions can be calculated more efficiently and accurately
-  --> $DIR/floating_point_powi.rs:13:13
+  --> $DIR/floating_point_powi.rs:14:13
    |
 LL |     let _ = (x + y.powi(2)).sqrt();
    |             ^^^^^^^^^^^^^^^ help: consider using: `y.mul_add(y, x)`
diff --git a/tests/ui/manual_bits.fixed b/tests/ui/manual_bits.fixed
index 386360dbdcd..e7f8cd878ca 100644
--- a/tests/ui/manual_bits.fixed
+++ b/tests/ui/manual_bits.fixed
@@ -6,7 +6,8 @@
     clippy::useless_conversion,
     path_statements,
     unused_must_use,
-    clippy::unnecessary_operation
+    clippy::unnecessary_operation,
+    clippy::unnecessary_cast
 )]
 
 use std::mem::{size_of, size_of_val};
diff --git a/tests/ui/manual_bits.rs b/tests/ui/manual_bits.rs
index 62638f047eb..7b1d1549528 100644
--- a/tests/ui/manual_bits.rs
+++ b/tests/ui/manual_bits.rs
@@ -6,7 +6,8 @@
     clippy::useless_conversion,
     path_statements,
     unused_must_use,
-    clippy::unnecessary_operation
+    clippy::unnecessary_operation,
+    clippy::unnecessary_cast
 )]
 
 use std::mem::{size_of, size_of_val};
diff --git a/tests/ui/manual_bits.stderr b/tests/ui/manual_bits.stderr
index 69c591a203d..652fafbc41d 100644
--- a/tests/ui/manual_bits.stderr
+++ b/tests/ui/manual_bits.stderr
@@ -1,5 +1,5 @@
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:15:5
+  --> $DIR/manual_bits.rs:16:5
    |
 LL |     size_of::<i8>() * 8;
    |     ^^^^^^^^^^^^^^^^^^^ help: consider using: `i8::BITS as usize`
@@ -7,169 +7,169 @@ LL |     size_of::<i8>() * 8;
    = note: `-D clippy::manual-bits` implied by `-D warnings`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:16:5
+  --> $DIR/manual_bits.rs:17:5
    |
 LL |     size_of::<i16>() * 8;
    |     ^^^^^^^^^^^^^^^^^^^^ help: consider using: `i16::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:17:5
+  --> $DIR/manual_bits.rs:18:5
    |
 LL |     size_of::<i32>() * 8;
    |     ^^^^^^^^^^^^^^^^^^^^ help: consider using: `i32::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:18:5
+  --> $DIR/manual_bits.rs:19:5
    |
 LL |     size_of::<i64>() * 8;
    |     ^^^^^^^^^^^^^^^^^^^^ help: consider using: `i64::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:19:5
+  --> $DIR/manual_bits.rs:20:5
    |
 LL |     size_of::<i128>() * 8;
    |     ^^^^^^^^^^^^^^^^^^^^^ help: consider using: `i128::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:20:5
+  --> $DIR/manual_bits.rs:21:5
    |
 LL |     size_of::<isize>() * 8;
    |     ^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `isize::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:22:5
+  --> $DIR/manual_bits.rs:23:5
    |
 LL |     size_of::<u8>() * 8;
    |     ^^^^^^^^^^^^^^^^^^^ help: consider using: `u8::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:23:5
+  --> $DIR/manual_bits.rs:24:5
    |
 LL |     size_of::<u16>() * 8;
    |     ^^^^^^^^^^^^^^^^^^^^ help: consider using: `u16::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:24:5
+  --> $DIR/manual_bits.rs:25:5
    |
 LL |     size_of::<u32>() * 8;
    |     ^^^^^^^^^^^^^^^^^^^^ help: consider using: `u32::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:25:5
+  --> $DIR/manual_bits.rs:26:5
    |
 LL |     size_of::<u64>() * 8;
    |     ^^^^^^^^^^^^^^^^^^^^ help: consider using: `u64::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:26:5
+  --> $DIR/manual_bits.rs:27:5
    |
 LL |     size_of::<u128>() * 8;
    |     ^^^^^^^^^^^^^^^^^^^^^ help: consider using: `u128::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:27:5
+  --> $DIR/manual_bits.rs:28:5
    |
 LL |     size_of::<usize>() * 8;
    |     ^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `usize::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:29:5
+  --> $DIR/manual_bits.rs:30:5
    |
 LL |     8 * size_of::<i8>();
    |     ^^^^^^^^^^^^^^^^^^^ help: consider using: `i8::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:30:5
+  --> $DIR/manual_bits.rs:31:5
    |
 LL |     8 * size_of::<i16>();
    |     ^^^^^^^^^^^^^^^^^^^^ help: consider using: `i16::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:31:5
+  --> $DIR/manual_bits.rs:32:5
    |
 LL |     8 * size_of::<i32>();
    |     ^^^^^^^^^^^^^^^^^^^^ help: consider using: `i32::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:32:5
+  --> $DIR/manual_bits.rs:33:5
    |
 LL |     8 * size_of::<i64>();
    |     ^^^^^^^^^^^^^^^^^^^^ help: consider using: `i64::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:33:5
+  --> $DIR/manual_bits.rs:34:5
    |
 LL |     8 * size_of::<i128>();
    |     ^^^^^^^^^^^^^^^^^^^^^ help: consider using: `i128::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:34:5
+  --> $DIR/manual_bits.rs:35:5
    |
 LL |     8 * size_of::<isize>();
    |     ^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `isize::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:36:5
+  --> $DIR/manual_bits.rs:37:5
    |
 LL |     8 * size_of::<u8>();
    |     ^^^^^^^^^^^^^^^^^^^ help: consider using: `u8::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:37:5
+  --> $DIR/manual_bits.rs:38:5
    |
 LL |     8 * size_of::<u16>();
    |     ^^^^^^^^^^^^^^^^^^^^ help: consider using: `u16::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:38:5
+  --> $DIR/manual_bits.rs:39:5
    |
 LL |     8 * size_of::<u32>();
    |     ^^^^^^^^^^^^^^^^^^^^ help: consider using: `u32::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:39:5
+  --> $DIR/manual_bits.rs:40:5
    |
 LL |     8 * size_of::<u64>();
    |     ^^^^^^^^^^^^^^^^^^^^ help: consider using: `u64::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:40:5
+  --> $DIR/manual_bits.rs:41:5
    |
 LL |     8 * size_of::<u128>();
    |     ^^^^^^^^^^^^^^^^^^^^^ help: consider using: `u128::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:41:5
+  --> $DIR/manual_bits.rs:42:5
    |
 LL |     8 * size_of::<usize>();
    |     ^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `usize::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:51:5
+  --> $DIR/manual_bits.rs:52:5
    |
 LL |     size_of::<Word>() * 8;
    |     ^^^^^^^^^^^^^^^^^^^^^ help: consider using: `Word::BITS as usize`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:55:18
+  --> $DIR/manual_bits.rs:56:18
    |
 LL |     let _: u32 = (size_of::<u128>() * 8) as u32;
    |                  ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `u128::BITS`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:56:18
+  --> $DIR/manual_bits.rs:57:18
    |
 LL |     let _: u32 = (size_of::<u128>() * 8).try_into().unwrap();
    |                  ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `u128::BITS`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:57:13
+  --> $DIR/manual_bits.rs:58:13
    |
 LL |     let _ = (size_of::<u128>() * 8).pow(5);
    |             ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(u128::BITS as usize)`
 
 error: usage of `mem::size_of::<T>()` to obtain the size of `T` in bits
-  --> $DIR/manual_bits.rs:58:14
+  --> $DIR/manual_bits.rs:59:14
    |
 LL |     let _ = &(size_of::<u128>() * 8);
    |              ^^^^^^^^^^^^^^^^^^^^^^^ help: consider using: `(u128::BITS as usize)`
diff --git a/tests/ui/ptr_offset_with_cast.fixed b/tests/ui/ptr_offset_with_cast.fixed
index 718e391e8bf..c57e2990fb9 100644
--- a/tests/ui/ptr_offset_with_cast.fixed
+++ b/tests/ui/ptr_offset_with_cast.fixed
@@ -1,4 +1,5 @@
 // run-rustfix
+#![allow(clippy::unnecessary_cast)]
 
 fn main() {
     let vec = vec![b'a', b'b', b'c'];
diff --git a/tests/ui/ptr_offset_with_cast.rs b/tests/ui/ptr_offset_with_cast.rs
index f613742c741..3de7997acdd 100644
--- a/tests/ui/ptr_offset_with_cast.rs
+++ b/tests/ui/ptr_offset_with_cast.rs
@@ -1,4 +1,5 @@
 // run-rustfix
+#![allow(clippy::unnecessary_cast)]
 
 fn main() {
     let vec = vec![b'a', b'b', b'c'];
diff --git a/tests/ui/ptr_offset_with_cast.stderr b/tests/ui/ptr_offset_with_cast.stderr
index fd45224ca06..3ba40593d64 100644
--- a/tests/ui/ptr_offset_with_cast.stderr
+++ b/tests/ui/ptr_offset_with_cast.stderr
@@ -1,5 +1,5 @@
 error: use of `offset` with a `usize` casted to an `isize`
-  --> $DIR/ptr_offset_with_cast.rs:12:17
+  --> $DIR/ptr_offset_with_cast.rs:13:17
    |
 LL |         let _ = ptr.offset(offset_usize as isize);
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `ptr.add(offset_usize)`
@@ -7,7 +7,7 @@ LL |         let _ = ptr.offset(offset_usize as isize);
    = note: `-D clippy::ptr-offset-with-cast` implied by `-D warnings`
 
 error: use of `wrapping_offset` with a `usize` casted to an `isize`
-  --> $DIR/ptr_offset_with_cast.rs:16:17
+  --> $DIR/ptr_offset_with_cast.rs:17:17
    |
 LL |         let _ = ptr.wrapping_offset(offset_usize as isize);
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `ptr.wrapping_add(offset_usize)`
diff --git a/tests/ui/unnecessary_cast.fixed b/tests/ui/unnecessary_cast.fixed
index 70ec3e94380..94dc9642726 100644
--- a/tests/ui/unnecessary_cast.fixed
+++ b/tests/ui/unnecessary_cast.fixed
@@ -103,4 +103,12 @@ mod fixable {
         #[allow(clippy::precedence)]
         let _: f64 = -8.0_f64.exp(); // should suggest `-8.0_f64.exp()` here not to change code behavior
     }
+
+    fn issue_9562_non_literal() {
+        fn foo() -> f32 {
+            0.
+        }
+
+        let _num = foo();
+    }
 }
diff --git a/tests/ui/unnecessary_cast.rs b/tests/ui/unnecessary_cast.rs
index 36c1a87fab6..e5150256f69 100644
--- a/tests/ui/unnecessary_cast.rs
+++ b/tests/ui/unnecessary_cast.rs
@@ -103,4 +103,12 @@ mod fixable {
         #[allow(clippy::precedence)]
         let _: f64 = -(8.0 as f64).exp(); // should suggest `-8.0_f64.exp()` here not to change code behavior
     }
+
+    fn issue_9562_non_literal() {
+        fn foo() -> f32 {
+            0.
+        }
+
+        let _num = foo() as f32;
+    }
 }
diff --git a/tests/ui/unnecessary_cast.stderr b/tests/ui/unnecessary_cast.stderr
index a52b92c339c..e5c3dd5e53f 100644
--- a/tests/ui/unnecessary_cast.stderr
+++ b/tests/ui/unnecessary_cast.stderr
@@ -174,5 +174,11 @@ error: casting float literal to `f64` is unnecessary
 LL |         let _: f64 = -(8.0 as f64).exp(); // should suggest `-8.0_f64.exp()` here not to change code behavior
    |                       ^^^^^^^^^^^^ help: try: `8.0_f64`
 
-error: aborting due to 29 previous errors
+error: casting to the same type is unnecessary (`f32` -> `f32`)
+  --> $DIR/unnecessary_cast.rs:112:20
+   |
+LL |         let _num = foo() as f32;
+   |                    ^^^^^^^^^^^^ help: try: `foo()`
+
+error: aborting due to 30 previous errors