5 files changed, 16 insertions, 12 deletions
diff --git a/library/core/src/intrinsics/mod.rs b/library/core/src/intrinsics/mod.rs
index eaf2738d8b7..cef700be9ea 100644
--- a/library/core/src/intrinsics/mod.rs
+++ b/library/core/src/intrinsics/mod.rs
@@ -1312,28 +1312,28 @@ pub fn log2f128(x: f128) -> f128;
 /// [`f16::mul_add`](../../std/primitive.f16.html#method.mul_add)
 #[rustc_intrinsic]
 #[rustc_nounwind]
-pub fn fmaf16(a: f16, b: f16, c: f16) -> f16;
+pub const fn fmaf16(a: f16, b: f16, c: f16) -> f16;
 /// Returns `a * b + c` for `f32` values.
 ///
 /// The stabilized version of this intrinsic is
 /// [`f32::mul_add`](../../std/primitive.f32.html#method.mul_add)
 #[rustc_intrinsic]
 #[rustc_nounwind]
-pub fn fmaf32(a: f32, b: f32, c: f32) -> f32;
+pub const fn fmaf32(a: f32, b: f32, c: f32) -> f32;
 /// Returns `a * b + c` for `f64` values.
 ///
 /// The stabilized version of this intrinsic is
 /// [`f64::mul_add`](../../std/primitive.f64.html#method.mul_add)
 #[rustc_intrinsic]
 #[rustc_nounwind]
-pub fn fmaf64(a: f64, b: f64, c: f64) -> f64;
+pub const fn fmaf64(a: f64, b: f64, c: f64) -> f64;
 /// Returns `a * b + c` for `f128` values.
 ///
 /// The stabilized version of this intrinsic is
 /// [`f128::mul_add`](../../std/primitive.f128.html#method.mul_add)
 #[rustc_intrinsic]
 #[rustc_nounwind]
-pub fn fmaf128(a: f128, b: f128, c: f128) -> f128;
+pub const fn fmaf128(a: f128, b: f128, c: f128) -> f128;
 
 /// Returns `a * b + c` for `f16` values, non-deterministically executing
 /// either a fused multiply-add or two operations with rounding of the
@@ -1347,7 +1347,7 @@ pub fn fmaf128(a: f128, b: f128, c: f128) -> f128;
 /// example.
 #[rustc_intrinsic]
 #[rustc_nounwind]
-pub fn fmuladdf16(a: f16, b: f16, c: f16) -> f16;
+pub const fn fmuladdf16(a: f16, b: f16, c: f16) -> f16;
 /// Returns `a * b + c` for `f32` values, non-deterministically executing
 /// either a fused multiply-add or two operations with rounding of the
 /// intermediate result.
@@ -1360,7 +1360,7 @@ pub fn fmuladdf16(a: f16, b: f16, c: f16) -> f16;
 /// example.
 #[rustc_intrinsic]
 #[rustc_nounwind]
-pub fn fmuladdf32(a: f32, b: f32, c: f32) -> f32;
+pub const fn fmuladdf32(a: f32, b: f32, c: f32) -> f32;
 /// Returns `a * b + c` for `f64` values, non-deterministically executing
 /// either a fused multiply-add or two operations with rounding of the
 /// intermediate result.
@@ -1373,7 +1373,7 @@ pub fn fmuladdf32(a: f32, b: f32, c: f32) -> f32;
 /// example.
 #[rustc_intrinsic]
 #[rustc_nounwind]
-pub fn fmuladdf64(a: f64, b: f64, c: f64) -> f64;
+pub const fn fmuladdf64(a: f64, b: f64, c: f64) -> f64;
 /// Returns `a * b + c` for `f128` values, non-deterministically executing
 /// either a fused multiply-add or two operations with rounding of the
 /// intermediate result.
@@ -1386,7 +1386,7 @@ pub fn fmuladdf64(a: f64, b: f64, c: f64) -> f64;
 /// example.
 #[rustc_intrinsic]
 #[rustc_nounwind]
-pub fn fmuladdf128(a: f128, b: f128, c: f128) -> f128;
+pub const fn fmuladdf128(a: f128, b: f128, c: f128) -> f128;
 
 /// Returns the largest integer less than or equal to an `f16`.
 ///
diff --git a/library/core/src/num/f128.rs b/library/core/src/num/f128.rs
index 3b03cde0372..73ca3fbb142 100644
--- a/library/core/src/num/f128.rs
+++ b/library/core/src/num/f128.rs
@@ -1659,7 +1659,8 @@ impl f128 {
     #[doc(alias = "fmaf128", alias = "fusedMultiplyAdd")]
     #[unstable(feature = "f128", issue = "116909")]
     #[must_use = "method returns a new number and does not mutate the original value"]
-    pub fn mul_add(self, a: f128, b: f128) -> f128 {
+    #[rustc_const_unstable(feature = "const_mul_add", issue = "146724")]
+    pub const fn mul_add(self, a: f128, b: f128) -> f128 {
         intrinsics::fmaf128(self, a, b)
     }
 
diff --git a/library/core/src/num/f16.rs b/library/core/src/num/f16.rs
index a027d63005b..a9dbade0e65 100644
--- a/library/core/src/num/f16.rs
+++ b/library/core/src/num/f16.rs
@@ -1634,7 +1634,8 @@ impl f16 {
     #[unstable(feature = "f16", issue = "116909")]
     #[doc(alias = "fmaf16", alias = "fusedMultiplyAdd")]
     #[must_use = "method returns a new number and does not mutate the original value"]
-    pub fn mul_add(self, a: f16, b: f16) -> f16 {
+    #[rustc_const_unstable(feature = "const_mul_add", issue = "146724")]
+    pub const fn mul_add(self, a: f16, b: f16) -> f16 {
         intrinsics::fmaf16(self, a, b)
     }
 
diff --git a/library/core/src/num/f32.rs b/library/core/src/num/f32.rs
index bfc091c54b2..53474cd3e90 100644
--- a/library/core/src/num/f32.rs
+++ b/library/core/src/num/f32.rs
@@ -1798,7 +1798,8 @@ pub mod math {
     #[doc(alias = "fmaf", alias = "fusedMultiplyAdd")]
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[unstable(feature = "core_float_math", issue = "137578")]
-    pub fn mul_add(x: f32, y: f32, z: f32) -> f32 {
+    #[rustc_const_unstable(feature = "const_mul_add", issue = "146724")]
+    pub const fn mul_add(x: f32, y: f32, z: f32) -> f32 {
         intrinsics::fmaf32(x, y, z)
     }
 
diff --git a/library/core/src/num/f64.rs b/library/core/src/num/f64.rs
index 21cd77d8014..78113a60bbc 100644
--- a/library/core/src/num/f64.rs
+++ b/library/core/src/num/f64.rs
@@ -1796,7 +1796,8 @@ pub mod math {
     #[doc(alias = "fma", alias = "fusedMultiplyAdd")]
     #[unstable(feature = "core_float_math", issue = "137578")]
     #[must_use = "method returns a new number and does not mutate the original value"]
-    pub fn mul_add(x: f64, a: f64, b: f64) -> f64 {
+    #[rustc_const_unstable(feature = "const_mul_add", issue = "146724")]
+    pub const fn mul_add(x: f64, a: f64, b: f64) -> f64 {
         intrinsics::fmaf64(x, a, b)
     }