Update src/test/assembly/x86_64-floating-point-clamp.rs

Simple Clamp Function

I thought this was more robust and easier to read. I also allowed this function to return early in order to skip the extra bound check (I'm sure the difference is negligible). I'm not sure if there was a reason for binding `self` to `x`; if so, please correct me.

Simple Clamp Function for f64

I thought this was more robust and easier to read. I also allowed this function to return early in order to skip the extra bound check (I'm sure the difference is negligible). I'm not sure if there was a reason for binding `self` to `x`; if so, please correct me.

Floating point clamp test

f32 clamp using mut self

f64 clamp using mut self

Update library/core/src/num/f32.rs

Update f64.rs

Update x86_64-floating-point-clamp.rs

Update src/test/assembly/x86_64-floating-point-clamp.rs

Update x86_64-floating-point-clamp.rs

Co-Authored-By: scottmcm <scottmcm@users.noreply.github.com>

diff --git a/library/core/src/num/f32.rs b/library/core/src/num/f32.rs
index 6548ad2e514fbacd9d2f25825c8c5726c7c3a0ff..f485e459121365129a5e00786179ac96d7831b0c 100644 (file)
--- a/library/core/src/num/f32.rs
+++ b/library/core/src/num/f32.rs
@@ -1282,15 +1282,14 @@ pub fn total_cmp(&self, other: &Self) -> crate::cmp::Ordering {
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[stable(feature = "clamp", since = "1.50.0")]
     #[inline]
-    pub fn clamp(self, min: f32, max: f32) -> f32 {
+    pub fn clamp(mut self, min: f32, max: f32) -> f32 {
         assert!(min <= max);
-        let mut x = self;
-        if x < min {
-            x = min;
+        if self < min {
+            self = min;
         }
-        if x > max {
-            x = max;
+        if self > max {
+            self = max;
         }
-        x
+        self
     }
 }

diff --git a/library/core/src/num/f64.rs b/library/core/src/num/f64.rs
index 75c92c2f8834a215fcbefa75c4d89f50e7fa79a6..3d385e3888a8b7c1c3fd54d53d5b24ff9b949eb1 100644 (file)
--- a/library/core/src/num/f64.rs
+++ b/library/core/src/num/f64.rs
@@ -1280,15 +1280,14 @@ pub fn total_cmp(&self, other: &Self) -> crate::cmp::Ordering {
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[stable(feature = "clamp", since = "1.50.0")]
     #[inline]
-    pub fn clamp(self, min: f64, max: f64) -> f64 {
+    pub fn clamp(mut self, min: f64, max: f64) -> f64 {
         assert!(min <= max);
-        let mut x = self;
-        if x < min {
-            x = min;
+        if self < min {
+            self = min;
         }
-        if x > max {
-            x = max;
+        if self > max {
+            self = max;
         }
-        x
+        self
     }
 }

diff --git a/src/test/assembly/x86_64-floating-point-clamp.rs b/src/test/assembly/x86_64-floating-point-clamp.rs
new file mode 100644 (file)
index 0000000..3388b0e
--- /dev/null
+++ b/src/test/assembly/x86_64-floating-point-clamp.rs
@@ -0,0 +1,25 @@
+// Floating-point clamp is designed to be implementable as max+min,
+// so check to make sure that's what it's actually emitting.
+
+// assembly-output: emit-asm
+// compile-flags: --crate-type=lib -O -C llvm-args=-x86-asm-syntax=intel
+// only-x86_64
+
+// CHECK-LABEL: clamp_demo:
+#[no_mangle]
+pub fn clamp_demo(a: f32, x: f32, y: f32) -> f32 {
+    // CHECK: maxss
+    // CHECK: minss
+    a.clamp(x, y)
+}
+
+// CHECK-LABEL: clamp12_demo:
+#[no_mangle]
+pub fn clamp12_demo(a: f32) -> f32 {
+    // CHECK-NEXT: movss   xmm1
+    // CHECK-NEXT: maxss   xmm1, xmm0
+    // CHECK-NEXT: movss   xmm0
+    // CHECK-NEXT: minss   xmm0, xmm1
+    // CHECK-NEXT: ret
+    a.clamp(1.0, 2.0)
+}