Clarify that both branches must have the same side effects

Author: Centri3

library/core/src/intrinsics.rs

@@ -2542,7 +2542,8 @@ extern "rust-intrinsic" {
     ///
     /// When calling this in a `const fn`, both paths must be semantically
     /// equivalent, that is, the result of the `true` branch and the `false`
-    /// branch return the same value *no matter what*.
+    /// branch must return the same value and have the same side-effects *no
+    /// matter what*.
     #[rustc_const_unstable(feature = "is_val_statically_known", issue = "none")]
     #[rustc_nounwind]
     #[cfg(not(bootstrap))]

src/tools/miri/src/shims/intrinsics/mod.rs

@@ -429,59 +429,4 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 
         Ok(())
     }
-<<<<<<< HEAD
-=======
-
-    fn float_to_int_unchecked<F>(
-        &self,
-        f: F,
-        dest_ty: Ty<'tcx>,
-    ) -> InterpResult<'tcx, Scalar<Provenance>>
-    where
-        F: Float + Into<Scalar<Provenance>>,
-    {
-        let this = self.eval_context_ref();
-
-        // Step 1: cut off the fractional part of `f`. The result of this is
-        // guaranteed to be precisely representable in IEEE floats.
-        let f = f.round_to_integral(Round::TowardZero).value;
-
-        // Step 2: Cast the truncated float to the target integer type and see if we lose any information in this step.
-        Ok(match dest_ty.kind() {
-            // Unsigned
-            ty::Uint(t) => {
-                let size = Integer::from_uint_ty(this, *t).size();
-                let res = f.to_u128(size.bits_usize());
-                if res.status.is_empty() {
-                    // No status flags means there was no further rounding or other loss of precision.
-                    Scalar::from_uint(res.value, size)
-                } else {
-                    // `f` was not representable in this integer type.
-                    throw_ub_format!(
-                        "`float_to_int_unchecked` intrinsic called on {f} which cannot be represented in target type `{dest_ty:?}`",
-                    );
-                }
-            }
-            // Signed
-            ty::Int(t) => {
-                let size = Integer::from_int_ty(this, *t).size();
-                let res = f.to_i128(size.bits_usize());
-                if res.status.is_empty() {
-                    // No status flags means there was no further rounding or other loss of precision.
-                    Scalar::from_int(res.value, size)
-                } else {
-                    // `f` was not representable in this integer type.
-                    throw_ub_format!(
-                        "`float_to_int_unchecked` intrinsic called on {f} which cannot be represented in target type `{dest_ty:?}`",
-                    );
-                }
-            }
-            // Nothing else
-            _ => span_bug!(
-                this.cur_span(),
-                "`float_to_int_unchecked` called with non-int output type {dest_ty:?}"
-            ),
-        })
-    }
->>>>>>> acbf90a9489 (Make MIRI choose the path randomly and rename the intrinsic)
 }