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-rw-r--r--compiler/rustc_const_eval/src/interpret/intrinsics.rs46
-rw-r--r--compiler/rustc_const_eval/src/interpret/machine.rs8
-rw-r--r--library/core/src/intrinsics/mod.rs16
-rw-r--r--library/core/src/num/f128.rs3
-rw-r--r--library/core/src/num/f16.rs3
-rw-r--r--library/core/src/num/f32.rs3
-rw-r--r--library/core/src/num/f64.rs3
-rw-r--r--library/coretests/tests/floats/f128.rs18
-rw-r--r--library/coretests/tests/floats/f16.rs18
-rw-r--r--library/coretests/tests/floats/f32.rs21
-rw-r--r--library/coretests/tests/floats/f64.rs21
-rw-r--r--library/coretests/tests/floats/mod.rs39
-rw-r--r--library/coretests/tests/lib.rs1
-rw-r--r--library/std/src/lib.rs1
-rw-r--r--library/std/src/num/f32.rs3
-rw-r--r--library/std/src/num/f64.rs3
-rw-r--r--src/tools/miri/src/intrinsics/math.rs41
-rw-r--r--src/tools/miri/src/machine.rs5
18 files changed, 118 insertions, 135 deletions
diff --git a/compiler/rustc_const_eval/src/interpret/intrinsics.rs b/compiler/rustc_const_eval/src/interpret/intrinsics.rs
index 418dd658121..785978b4d71 100644
--- a/compiler/rustc_const_eval/src/interpret/intrinsics.rs
+++ b/compiler/rustc_const_eval/src/interpret/intrinsics.rs
@@ -636,6 +636,14 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                 dest,
                 rustc_apfloat::Round::NearestTiesToEven,
             )?,
+            sym::fmaf16 => self.fma_intrinsic::<Half>(args, dest)?,
+            sym::fmaf32 => self.fma_intrinsic::<Single>(args, dest)?,
+            sym::fmaf64 => self.fma_intrinsic::<Double>(args, dest)?,
+            sym::fmaf128 => self.fma_intrinsic::<Quad>(args, dest)?,
+            sym::fmuladdf16 => self.float_muladd_intrinsic::<Half>(args, dest)?,
+            sym::fmuladdf32 => self.float_muladd_intrinsic::<Single>(args, dest)?,
+            sym::fmuladdf64 => self.float_muladd_intrinsic::<Double>(args, dest)?,
+            sym::fmuladdf128 => self.float_muladd_intrinsic::<Quad>(args, dest)?,
 
             // Unsupported intrinsic: skip the return_to_block below.
             _ => return interp_ok(false),
@@ -1035,4 +1043,42 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         self.write_scalar(res, dest)?;
         interp_ok(())
     }
+
+    fn fma_intrinsic<F>(
+        &mut self,
+        args: &[OpTy<'tcx, M::Provenance>],
+        dest: &PlaceTy<'tcx, M::Provenance>,
+    ) -> InterpResult<'tcx, ()>
+    where
+        F: rustc_apfloat::Float + rustc_apfloat::FloatConvert<F> + Into<Scalar<M::Provenance>>,
+    {
+        let a: F = self.read_scalar(&args[0])?.to_float()?;
+        let b: F = self.read_scalar(&args[1])?.to_float()?;
+        let c: F = self.read_scalar(&args[2])?.to_float()?;
+
+        let res = a.mul_add(b, c).value;
+        let res = self.adjust_nan(res, &[a, b, c]);
+        self.write_scalar(res, dest)?;
+        interp_ok(())
+    }
+
+    fn float_muladd_intrinsic<F>(
+        &mut self,
+        args: &[OpTy<'tcx, M::Provenance>],
+        dest: &PlaceTy<'tcx, M::Provenance>,
+    ) -> InterpResult<'tcx, ()>
+    where
+        F: rustc_apfloat::Float + rustc_apfloat::FloatConvert<F> + Into<Scalar<M::Provenance>>,
+    {
+        let a: F = self.read_scalar(&args[0])?.to_float()?;
+        let b: F = self.read_scalar(&args[1])?.to_float()?;
+        let c: F = self.read_scalar(&args[2])?.to_float()?;
+
+        let fuse = M::float_fuse_mul_add(self);
+
+        let res = if fuse { a.mul_add(b, c).value } else { ((a * b).value + c).value };
+        let res = self.adjust_nan(res, &[a, b, c]);
+        self.write_scalar(res, dest)?;
+        interp_ok(())
+    }
 }
diff --git a/compiler/rustc_const_eval/src/interpret/machine.rs b/compiler/rustc_const_eval/src/interpret/machine.rs
index e22629993fb..1725635e0b4 100644
--- a/compiler/rustc_const_eval/src/interpret/machine.rs
+++ b/compiler/rustc_const_eval/src/interpret/machine.rs
@@ -289,6 +289,9 @@ pub trait Machine<'tcx>: Sized {
         a
     }
 
+    /// Determines whether the `fmuladd` intrinsics fuse the multiply-add or use separate operations.
+    fn float_fuse_mul_add(_ecx: &mut InterpCx<'tcx, Self>) -> bool;
+
     /// Called before a basic block terminator is executed.
     #[inline]
     fn before_terminator(_ecx: &mut InterpCx<'tcx, Self>) -> InterpResult<'tcx> {
@@ -673,6 +676,11 @@ pub macro compile_time_machine(<$tcx: lifetime>) {
     }
 
     #[inline(always)]
+    fn float_fuse_mul_add(_ecx: &mut InterpCx<$tcx, Self>) -> bool {
+        true
+    }
+
+    #[inline(always)]
     fn ub_checks(_ecx: &InterpCx<$tcx, Self>) -> InterpResult<$tcx, bool> {
         // We can't look at `tcx.sess` here as that can differ across crates, which can lead to
         // unsound differences in evaluating the same constant at different instantiation sites.
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)
     }
 
diff --git a/library/coretests/tests/floats/f128.rs b/library/coretests/tests/floats/f128.rs
index d31eba863f5..62278bf96c3 100644
--- a/library/coretests/tests/floats/f128.rs
+++ b/library/coretests/tests/floats/f128.rs
@@ -21,24 +21,6 @@ const TOL_PRECISE: f128 = 1e-28;
 // the intrinsics.
 
 #[test]
-#[cfg(not(miri))]
-#[cfg(target_has_reliable_f128_math)]
-fn test_mul_add() {
-    let nan: f128 = f128::NAN;
-    let inf: f128 = f128::INFINITY;
-    let neg_inf: f128 = f128::NEG_INFINITY;
-    assert_biteq!(12.3f128.mul_add(4.5, 6.7), 62.0500000000000000000000000000000037);
-    assert_biteq!((-12.3f128).mul_add(-4.5, -6.7), 48.6500000000000000000000000000000049);
-    assert_biteq!(0.0f128.mul_add(8.9, 1.2), 1.2);
-    assert_biteq!(3.4f128.mul_add(-0.0, 5.6), 5.6);
-    assert!(nan.mul_add(7.8, 9.0).is_nan());
-    assert_biteq!(inf.mul_add(7.8, 9.0), inf);
-    assert_biteq!(neg_inf.mul_add(7.8, 9.0), neg_inf);
-    assert_biteq!(8.9f128.mul_add(inf, 3.2), inf);
-    assert_biteq!((-3.2f128).mul_add(2.4, neg_inf), neg_inf);
-}
-
-#[test]
 #[cfg(any(miri, target_has_reliable_f128_math))]
 fn test_max_recip() {
     assert_approx_eq!(
diff --git a/library/coretests/tests/floats/f16.rs b/library/coretests/tests/floats/f16.rs
index 302fd0861d7..7ffafd467a5 100644
--- a/library/coretests/tests/floats/f16.rs
+++ b/library/coretests/tests/floats/f16.rs
@@ -23,24 +23,6 @@ const TOL_P4: f16 = 10.0;
 // the intrinsics.
 
 #[test]
-#[cfg(not(miri))]
-#[cfg(target_has_reliable_f16_math)]
-fn test_mul_add() {
-    let nan: f16 = f16::NAN;
-    let inf: f16 = f16::INFINITY;
-    let neg_inf: f16 = f16::NEG_INFINITY;
-    assert_biteq!(12.3f16.mul_add(4.5, 6.7), 62.031);
-    assert_biteq!((-12.3f16).mul_add(-4.5, -6.7), 48.625);
-    assert_biteq!(0.0f16.mul_add(8.9, 1.2), 1.2);
-    assert_biteq!(3.4f16.mul_add(-0.0, 5.6), 5.6);
-    assert!(nan.mul_add(7.8, 9.0).is_nan());
-    assert_biteq!(inf.mul_add(7.8, 9.0), inf);
-    assert_biteq!(neg_inf.mul_add(7.8, 9.0), neg_inf);
-    assert_biteq!(8.9f16.mul_add(inf, 3.2), inf);
-    assert_biteq!((-3.2f16).mul_add(2.4, neg_inf), neg_inf);
-}
-
-#[test]
 #[cfg(any(miri, target_has_reliable_f16_math))]
 fn test_max_recip() {
     assert_approx_eq!(f16::MAX.recip(), 1.526624e-5f16, 1e-4);
diff --git a/library/coretests/tests/floats/f32.rs b/library/coretests/tests/floats/f32.rs
deleted file mode 100644
index a1fe8b07650..00000000000
--- a/library/coretests/tests/floats/f32.rs
+++ /dev/null
@@ -1,21 +0,0 @@
-use core::f32;
-
-use super::assert_biteq;
-
-// FIXME(#140515): mingw has an incorrect fma https://sourceforge.net/p/mingw-w64/bugs/848/
-#[cfg_attr(all(target_os = "windows", target_env = "gnu", not(target_abi = "llvm")), ignore)]
-#[test]
-fn test_mul_add() {
-    let nan: f32 = f32::NAN;
-    let inf: f32 = f32::INFINITY;
-    let neg_inf: f32 = f32::NEG_INFINITY;
-    assert_biteq!(f32::math::mul_add(12.3f32, 4.5, 6.7), 62.05);
-    assert_biteq!(f32::math::mul_add(-12.3f32, -4.5, -6.7), 48.65);
-    assert_biteq!(f32::math::mul_add(0.0f32, 8.9, 1.2), 1.2);
-    assert_biteq!(f32::math::mul_add(3.4f32, -0.0, 5.6), 5.6);
-    assert!(f32::math::mul_add(nan, 7.8, 9.0).is_nan());
-    assert_biteq!(f32::math::mul_add(inf, 7.8, 9.0), inf);
-    assert_biteq!(f32::math::mul_add(neg_inf, 7.8, 9.0), neg_inf);
-    assert_biteq!(f32::math::mul_add(8.9f32, inf, 3.2), inf);
-    assert_biteq!(f32::math::mul_add(-3.2f32, 2.4, neg_inf), neg_inf);
-}
diff --git a/library/coretests/tests/floats/f64.rs b/library/coretests/tests/floats/f64.rs
deleted file mode 100644
index 4c5a3d68d1f..00000000000
--- a/library/coretests/tests/floats/f64.rs
+++ /dev/null
@@ -1,21 +0,0 @@
-use core::f64;
-
-use super::assert_biteq;
-
-// FIXME(#140515): mingw has an incorrect fma https://sourceforge.net/p/mingw-w64/bugs/848/
-#[cfg_attr(all(target_os = "windows", target_env = "gnu", not(target_abi = "llvm")), ignore)]
-#[test]
-fn test_mul_add() {
-    let nan: f64 = f64::NAN;
-    let inf: f64 = f64::INFINITY;
-    let neg_inf: f64 = f64::NEG_INFINITY;
-    assert_biteq!(12.3f64.mul_add(4.5, 6.7), 62.050000000000004);
-    assert_biteq!((-12.3f64).mul_add(-4.5, -6.7), 48.650000000000006);
-    assert_biteq!(0.0f64.mul_add(8.9, 1.2), 1.2);
-    assert_biteq!(3.4f64.mul_add(-0.0, 5.6), 5.6);
-    assert!(nan.mul_add(7.8, 9.0).is_nan());
-    assert_biteq!(inf.mul_add(7.8, 9.0), inf);
-    assert_biteq!(neg_inf.mul_add(7.8, 9.0), neg_inf);
-    assert_biteq!(8.9f64.mul_add(inf, 3.2), inf);
-    assert_biteq!((-3.2f64).mul_add(2.4, neg_inf), neg_inf);
-}
diff --git a/library/coretests/tests/floats/mod.rs b/library/coretests/tests/floats/mod.rs
index d2b57223094..442f7e3ab65 100644
--- a/library/coretests/tests/floats/mod.rs
+++ b/library/coretests/tests/floats/mod.rs
@@ -34,6 +34,10 @@ trait TestableFloat: Sized {
     const RAW_12_DOT_5: Self;
     const RAW_1337: Self;
     const RAW_MINUS_14_DOT_25: Self;
+    /// The result of 12.3.mul_add(4.5, 6.7)
+    const MUL_ADD_RESULT: Self;
+    /// The result of (-12.3).mul_add(-4.5, -6.7)
+    const NEG_MUL_ADD_RESULT: Self;
 }
 
 impl TestableFloat for f16 {
@@ -58,6 +62,8 @@ impl TestableFloat for f16 {
     const RAW_12_DOT_5: Self = Self::from_bits(0x4a40);
     const RAW_1337: Self = Self::from_bits(0x6539);
     const RAW_MINUS_14_DOT_25: Self = Self::from_bits(0xcb20);
+    const MUL_ADD_RESULT: Self = 62.031;
+    const NEG_MUL_ADD_RESULT: Self = 48.625;
 }
 
 impl TestableFloat for f32 {
@@ -84,6 +90,8 @@ impl TestableFloat for f32 {
     const RAW_12_DOT_5: Self = Self::from_bits(0x41480000);
     const RAW_1337: Self = Self::from_bits(0x44a72000);
     const RAW_MINUS_14_DOT_25: Self = Self::from_bits(0xc1640000);
+    const MUL_ADD_RESULT: Self = 62.05;
+    const NEG_MUL_ADD_RESULT: Self = 48.65;
 }
 
 impl TestableFloat for f64 {
@@ -106,6 +114,8 @@ impl TestableFloat for f64 {
     const RAW_12_DOT_5: Self = Self::from_bits(0x4029000000000000);
     const RAW_1337: Self = Self::from_bits(0x4094e40000000000);
     const RAW_MINUS_14_DOT_25: Self = Self::from_bits(0xc02c800000000000);
+    const MUL_ADD_RESULT: Self = 62.050000000000004;
+    const NEG_MUL_ADD_RESULT: Self = 48.650000000000006;
 }
 
 impl TestableFloat for f128 {
@@ -128,6 +138,8 @@ impl TestableFloat for f128 {
     const RAW_12_DOT_5: Self = Self::from_bits(0x40029000000000000000000000000000);
     const RAW_1337: Self = Self::from_bits(0x40094e40000000000000000000000000);
     const RAW_MINUS_14_DOT_25: Self = Self::from_bits(0xc002c800000000000000000000000000);
+    const MUL_ADD_RESULT: Self = 62.0500000000000000000000000000000037;
+    const NEG_MUL_ADD_RESULT: Self = 48.6500000000000000000000000000000049;
 }
 
 /// Determine the tolerance for values of the argument type.
@@ -359,8 +371,6 @@ macro_rules! float_test {
 
 mod f128;
 mod f16;
-mod f32;
-mod f64;
 
 float_test! {
     name: num,
@@ -1541,3 +1551,28 @@ float_test! {
         assert_biteq!(Float::from_bits(masked_nan2), Float::from_bits(masked_nan2));
     }
 }
+
+float_test! {
+    name: mul_add,
+    attrs: {
+        f16: #[cfg(any(miri, target_has_reliable_f16))],
+        // FIXME(#140515): mingw has an incorrect fma https://sourceforge.net/p/mingw-w64/bugs/848/
+        f32: #[cfg_attr(all(target_os = "windows", target_env = "gnu", not(target_abi = "llvm")), ignore)],
+        f64: #[cfg_attr(all(target_os = "windows", target_env = "gnu", not(target_abi = "llvm")), ignore)],
+        f128: #[cfg(any(miri, target_has_reliable_f128))],
+    },
+    test<Float> {
+        let nan: Float = Float::NAN;
+        let inf: Float = Float::INFINITY;
+        let neg_inf: Float = Float::NEG_INFINITY;
+        assert_biteq!(flt(12.3).mul_add(4.5, 6.7), Float::MUL_ADD_RESULT);
+        assert_biteq!((flt(-12.3)).mul_add(-4.5, -6.7), Float::NEG_MUL_ADD_RESULT);
+        assert_biteq!(flt(0.0).mul_add(8.9, 1.2), 1.2);
+        assert_biteq!(flt(3.4).mul_add(-0.0, 5.6), 5.6);
+        assert!(nan.mul_add(7.8, 9.0).is_nan());
+        assert_biteq!(inf.mul_add(7.8, 9.0), inf);
+        assert_biteq!(neg_inf.mul_add(7.8, 9.0), neg_inf);
+        assert_biteq!(flt(8.9).mul_add(inf, 3.2), inf);
+        assert_biteq!((flt(-3.2)).mul_add(2.4, neg_inf), neg_inf);
+    }
+}
diff --git a/library/coretests/tests/lib.rs b/library/coretests/tests/lib.rs
index 5c519f3a499..a80d7f8b44d 100644
--- a/library/coretests/tests/lib.rs
+++ b/library/coretests/tests/lib.rs
@@ -20,6 +20,7 @@
 #![feature(const_convert)]
 #![feature(const_destruct)]
 #![feature(const_eval_select)]
+#![feature(const_mul_add)]
 #![feature(const_ops)]
 #![feature(const_option_ops)]
 #![feature(const_ref_cell)]
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index 45abd6bca8a..233e41aa345 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -332,6 +332,7 @@
 #![feature(char_internals)]
 #![feature(clone_to_uninit)]
 #![feature(const_convert)]
+#![feature(const_mul_add)]
 #![feature(core_intrinsics)]
 #![feature(core_io_borrowed_buf)]
 #![feature(drop_guard)]
diff --git a/library/std/src/num/f32.rs b/library/std/src/num/f32.rs
index ac1d889cc37..e7810e77e76 100644
--- a/library/std/src/num/f32.rs
+++ b/library/std/src/num/f32.rs
@@ -217,7 +217,8 @@ impl f32 {
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
-    pub fn mul_add(self, a: f32, b: f32) -> f32 {
+    #[rustc_const_unstable(feature = "const_mul_add", issue = "146724")]
+    pub const fn mul_add(self, a: f32, b: f32) -> f32 {
         core::f32::math::mul_add(self, a, b)
     }
 
diff --git a/library/std/src/num/f64.rs b/library/std/src/num/f64.rs
index 55c8593a0c0..cbebbfb1be1 100644
--- a/library/std/src/num/f64.rs
+++ b/library/std/src/num/f64.rs
@@ -217,7 +217,8 @@ impl f64 {
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
-    pub fn mul_add(self, a: f64, b: f64) -> f64 {
+    #[rustc_const_unstable(feature = "const_mul_add", issue = "146724")]
+    pub const fn mul_add(self, a: f64, b: f64) -> f64 {
         core::f64::math::mul_add(self, a, b)
     }
 
diff --git a/src/tools/miri/src/intrinsics/math.rs b/src/tools/miri/src/intrinsics/math.rs
index b9c99f28594..0cc4342f0d5 100644
--- a/src/tools/miri/src/intrinsics/math.rs
+++ b/src/tools/miri/src/intrinsics/math.rs
@@ -1,4 +1,3 @@
-use rand::Rng;
 use rustc_apfloat::{self, Float, FloatConvert, Round};
 use rustc_middle::mir;
 use rustc_middle::ty::{self, FloatTy};
@@ -39,46 +38,6 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
             "sqrtf64" => sqrt::<rustc_apfloat::ieee::Double>(this, args, dest)?,
             "sqrtf128" => sqrt::<rustc_apfloat::ieee::Quad>(this, args, dest)?,
 
-            "fmaf32" => {
-                let [a, b, c] = check_intrinsic_arg_count(args)?;
-                let a = this.read_scalar(a)?.to_f32()?;
-                let b = this.read_scalar(b)?.to_f32()?;
-                let c = this.read_scalar(c)?.to_f32()?;
-                let res = a.mul_add(b, c).value;
-                let res = this.adjust_nan(res, &[a, b, c]);
-                this.write_scalar(res, dest)?;
-            }
-            "fmaf64" => {
-                let [a, b, c] = check_intrinsic_arg_count(args)?;
-                let a = this.read_scalar(a)?.to_f64()?;
-                let b = this.read_scalar(b)?.to_f64()?;
-                let c = this.read_scalar(c)?.to_f64()?;
-                let res = a.mul_add(b, c).value;
-                let res = this.adjust_nan(res, &[a, b, c]);
-                this.write_scalar(res, dest)?;
-            }
-
-            "fmuladdf32" => {
-                let [a, b, c] = check_intrinsic_arg_count(args)?;
-                let a = this.read_scalar(a)?.to_f32()?;
-                let b = this.read_scalar(b)?.to_f32()?;
-                let c = this.read_scalar(c)?.to_f32()?;
-                let fuse: bool = this.machine.float_nondet && this.machine.rng.get_mut().random();
-                let res = if fuse { a.mul_add(b, c).value } else { ((a * b).value + c).value };
-                let res = this.adjust_nan(res, &[a, b, c]);
-                this.write_scalar(res, dest)?;
-            }
-            "fmuladdf64" => {
-                let [a, b, c] = check_intrinsic_arg_count(args)?;
-                let a = this.read_scalar(a)?.to_f64()?;
-                let b = this.read_scalar(b)?.to_f64()?;
-                let c = this.read_scalar(c)?.to_f64()?;
-                let fuse: bool = this.machine.float_nondet && this.machine.rng.get_mut().random();
-                let res = if fuse { a.mul_add(b, c).value } else { ((a * b).value + c).value };
-                let res = this.adjust_nan(res, &[a, b, c]);
-                this.write_scalar(res, dest)?;
-            }
-
             #[rustfmt::skip]
             | "fadd_fast"
             | "fsub_fast"
diff --git a/src/tools/miri/src/machine.rs b/src/tools/miri/src/machine.rs
index 04c8bee72c0..d307636e782 100644
--- a/src/tools/miri/src/machine.rs
+++ b/src/tools/miri/src/machine.rs
@@ -1294,6 +1294,11 @@ impl<'tcx> Machine<'tcx> for MiriMachine<'tcx> {
     }
 
     #[inline(always)]
+    fn float_fuse_mul_add(ecx: &mut InterpCx<'tcx, Self>) -> bool {
+        ecx.machine.float_nondet && ecx.machine.rng.get_mut().random()
+    }
+
+    #[inline(always)]
     fn ub_checks(ecx: &InterpCx<'tcx, Self>) -> InterpResult<'tcx, bool> {
         interp_ok(ecx.tcx.sess.ub_checks())
     }
generated by cgit-pink 1.4.1-3-g733a5 (git 2.37.1) at 2025-10-26 17:33:45 +0000