Auto merge of #3214 - eduardosm:move-x86-code, r=RalfJung

Move some x86 intrinsics code to helper functions in `shims::x86`

To make them reusable for intrinsics of other x86 features.

Splitted from https://github.com/rust-lang/miri/pull/3192

3 files changed, 304 insertions, 265 deletions

diff --git a/src/tools/miri/src/shims/x86/mod.rs b/src/tools/miri/src/shims/x86/mod.rs
index 2ae269db412..d8c3b4826a9 100644
--- a/src/tools/miri/src/shims/x86/mod.rs
+++ b/src/tools/miri/src/shims/x86/mod.rs
@@ -1,3 +1,6 @@
+use rand::Rng as _;
+
+use rustc_apfloat::{ieee::Single, Float as _};
 use rustc_middle::{mir, ty};
 use rustc_span::Symbol;
 use rustc_target::abi::Size;
@@ -331,6 +334,210 @@ fn bin_op_simd_float_all<'tcx, F: rustc_apfloat::Float>(
     Ok(())
 }
 
+#[derive(Copy, Clone)]
+enum FloatUnaryOp {
+    /// sqrt(x)
+    ///
+    /// <https://www.felixcloutier.com/x86/sqrtss>
+    /// <https://www.felixcloutier.com/x86/sqrtps>
+    Sqrt,
+    /// Approximation of 1/x
+    ///
+    /// <https://www.felixcloutier.com/x86/rcpss>
+    /// <https://www.felixcloutier.com/x86/rcpps>
+    Rcp,
+    /// Approximation of 1/sqrt(x)
+    ///
+    /// <https://www.felixcloutier.com/x86/rsqrtss>
+    /// <https://www.felixcloutier.com/x86/rsqrtps>
+    Rsqrt,
+}
+
+/// Performs `which` scalar operation on `op` and returns the result.
+#[allow(clippy::arithmetic_side_effects)] // floating point operations without side effects
+fn unary_op_f32<'tcx>(
+    this: &mut crate::MiriInterpCx<'_, 'tcx>,
+    which: FloatUnaryOp,
+    op: &ImmTy<'tcx, Provenance>,
+) -> InterpResult<'tcx, Scalar<Provenance>> {
+    match which {
+        FloatUnaryOp::Sqrt => {
+            let op = op.to_scalar();
+            // FIXME using host floats
+            Ok(Scalar::from_u32(f32::from_bits(op.to_u32()?).sqrt().to_bits()))
+        }
+        FloatUnaryOp::Rcp => {
+            let op = op.to_scalar().to_f32()?;
+            let div = (Single::from_u128(1).value / op).value;
+            // Apply a relative error with a magnitude on the order of 2^-12 to simulate the
+            // inaccuracy of RCP.
+            let res = apply_random_float_error(this, div, -12);
+            Ok(Scalar::from_f32(res))
+        }
+        FloatUnaryOp::Rsqrt => {
+            let op = op.to_scalar().to_u32()?;
+            // FIXME using host floats
+            let sqrt = Single::from_bits(f32::from_bits(op).sqrt().to_bits().into());
+            let rsqrt = (Single::from_u128(1).value / sqrt).value;
+            // Apply a relative error with a magnitude on the order of 2^-12 to simulate the
+            // inaccuracy of RSQRT.
+            let res = apply_random_float_error(this, rsqrt, -12);
+            Ok(Scalar::from_f32(res))
+        }
+    }
+}
+
+/// Disturbes a floating-point result by a relative error on the order of (-2^scale, 2^scale).
+#[allow(clippy::arithmetic_side_effects)] // floating point arithmetic cannot panic
+fn apply_random_float_error<F: rustc_apfloat::Float>(
+    this: &mut crate::MiriInterpCx<'_, '_>,
+    val: F,
+    err_scale: i32,
+) -> F {
+    let rng = this.machine.rng.get_mut();
+    // generates rand(0, 2^64) * 2^(scale - 64) = rand(0, 1) * 2^scale
+    let err =
+        F::from_u128(rng.gen::<u64>().into()).value.scalbn(err_scale.checked_sub(64).unwrap());
+    // give it a random sign
+    let err = if rng.gen::<bool>() { -err } else { err };
+    // multiple the value with (1+err)
+    (val * (F::from_u128(1).value + err).value).value
+}
+
+/// Performs `which` operation on the first component of `op` and copies
+/// the other components. The result is stored in `dest`.
+fn unary_op_ss<'tcx>(
+    this: &mut crate::MiriInterpCx<'_, 'tcx>,
+    which: FloatUnaryOp,
+    op: &OpTy<'tcx, Provenance>,
+    dest: &PlaceTy<'tcx, Provenance>,
+) -> InterpResult<'tcx, ()> {
+    let (op, op_len) = this.operand_to_simd(op)?;
+    let (dest, dest_len) = this.place_to_simd(dest)?;
+
+    assert_eq!(dest_len, op_len);
+
+    let res0 = unary_op_f32(this, which, &this.read_immediate(&this.project_index(&op, 0)?)?)?;
+    this.write_scalar(res0, &this.project_index(&dest, 0)?)?;
+
+    for i in 1..dest_len {
+        this.copy_op(
+            &this.project_index(&op, i)?,
+            &this.project_index(&dest, i)?,
+            /*allow_transmute*/ false,
+        )?;
+    }
+
+    Ok(())
+}
+
+/// Performs `which` operation on each component of `op`, storing the
+/// result is stored in `dest`.
+fn unary_op_ps<'tcx>(
+    this: &mut crate::MiriInterpCx<'_, 'tcx>,
+    which: FloatUnaryOp,
+    op: &OpTy<'tcx, Provenance>,
+    dest: &PlaceTy<'tcx, Provenance>,
+) -> InterpResult<'tcx, ()> {
+    let (op, op_len) = this.operand_to_simd(op)?;
+    let (dest, dest_len) = this.place_to_simd(dest)?;
+
+    assert_eq!(dest_len, op_len);
+
+    for i in 0..dest_len {
+        let op = this.read_immediate(&this.project_index(&op, i)?)?;
+        let dest = this.project_index(&dest, i)?;
+
+        let res = unary_op_f32(this, which, &op)?;
+        this.write_scalar(res, &dest)?;
+    }
+
+    Ok(())
+}
+
+// Rounds the first element of `right` according to `rounding`
+// and copies the remaining elements from `left`.
+fn round_first<'tcx, F: rustc_apfloat::Float>(
+    this: &mut crate::MiriInterpCx<'_, 'tcx>,
+    left: &OpTy<'tcx, Provenance>,
+    right: &OpTy<'tcx, Provenance>,
+    rounding: &OpTy<'tcx, Provenance>,
+    dest: &PlaceTy<'tcx, Provenance>,
+) -> InterpResult<'tcx, ()> {
+    let (left, left_len) = this.operand_to_simd(left)?;
+    let (right, right_len) = this.operand_to_simd(right)?;
+    let (dest, dest_len) = this.place_to_simd(dest)?;
+
+    assert_eq!(dest_len, left_len);
+    assert_eq!(dest_len, right_len);
+
+    let rounding = rounding_from_imm(this.read_scalar(rounding)?.to_i32()?)?;
+
+    let op0: F = this.read_scalar(&this.project_index(&right, 0)?)?.to_float()?;
+    let res = op0.round_to_integral(rounding).value;
+    this.write_scalar(
+        Scalar::from_uint(res.to_bits(), Size::from_bits(F::BITS)),
+        &this.project_index(&dest, 0)?,
+    )?;
+
+    for i in 1..dest_len {
+        this.copy_op(
+            &this.project_index(&left, i)?,
+            &this.project_index(&dest, i)?,
+            /*allow_transmute*/ false,
+        )?;
+    }
+
+    Ok(())
+}
+
+// Rounds all elements of `op` according to `rounding`.
+fn round_all<'tcx, F: rustc_apfloat::Float>(
+    this: &mut crate::MiriInterpCx<'_, 'tcx>,
+    op: &OpTy<'tcx, Provenance>,
+    rounding: &OpTy<'tcx, Provenance>,
+    dest: &PlaceTy<'tcx, Provenance>,
+) -> InterpResult<'tcx, ()> {
+    let (op, op_len) = this.operand_to_simd(op)?;
+    let (dest, dest_len) = this.place_to_simd(dest)?;
+
+    assert_eq!(dest_len, op_len);
+
+    let rounding = rounding_from_imm(this.read_scalar(rounding)?.to_i32()?)?;
+
+    for i in 0..dest_len {
+        let op: F = this.read_scalar(&this.project_index(&op, i)?)?.to_float()?;
+        let res = op.round_to_integral(rounding).value;
+        this.write_scalar(
+            Scalar::from_uint(res.to_bits(), Size::from_bits(F::BITS)),
+            &this.project_index(&dest, i)?,
+        )?;
+    }
+
+    Ok(())
+}
+
+/// Gets equivalent `rustc_apfloat::Round` from rounding mode immediate of
+/// `round.{ss,sd,ps,pd}` intrinsics.
+fn rounding_from_imm<'tcx>(rounding: i32) -> InterpResult<'tcx, rustc_apfloat::Round> {
+    // The fourth bit of `rounding` only affects the SSE status
+    // register, which cannot be accessed from Miri (or from Rust,
+    // for that matter), so we can ignore it.
+    match rounding & !0b1000 {
+        // When the third bit is 0, the rounding mode is determined by the
+        // first two bits.
+        0b000 => Ok(rustc_apfloat::Round::NearestTiesToEven),
+        0b001 => Ok(rustc_apfloat::Round::TowardNegative),
+        0b010 => Ok(rustc_apfloat::Round::TowardPositive),
+        0b011 => Ok(rustc_apfloat::Round::TowardZero),
+        // When the third bit is 1, the rounding mode is determined by the
+        // SSE status register. Since we do not support modifying it from
+        // Miri (or Rust), we assume it to be at its default mode (round-to-nearest).
+        0b100..=0b111 => Ok(rustc_apfloat::Round::NearestTiesToEven),
+        rounding => throw_unsup_format!("unsupported rounding mode 0x{rounding:02x}"),
+    }
+}
+
 /// Converts each element of `op` from floating point to signed integer.
 ///
 /// When the input value is NaN or out of range, fall back to minimum value.
@@ -408,3 +615,81 @@ fn horizontal_bin_op<'tcx>(
 
     Ok(())
 }
+
+/// Conditionally multiplies the packed floating-point elements in
+/// `left` and `right` using the high 4 bits in `imm`, sums the calculated
+/// products (up to 4), and conditionally stores the sum in `dest` using
+/// the low 4 bits of `imm`.
+fn conditional_dot_product<'tcx>(
+    this: &mut crate::MiriInterpCx<'_, 'tcx>,
+    left: &OpTy<'tcx, Provenance>,
+    right: &OpTy<'tcx, Provenance>,
+    imm: &OpTy<'tcx, Provenance>,
+    dest: &PlaceTy<'tcx, Provenance>,
+) -> InterpResult<'tcx, ()> {
+    let (left, left_len) = this.operand_to_simd(left)?;
+    let (right, right_len) = this.operand_to_simd(right)?;
+    let (dest, dest_len) = this.place_to_simd(dest)?;
+
+    assert_eq!(left_len, right_len);
+    assert!(dest_len <= 4);
+
+    let imm = this.read_scalar(imm)?.to_u8()?;
+
+    let element_layout = left.layout.field(this, 0);
+
+    // Calculate dot product
+    // Elements are floating point numbers, but we can use `from_int`
+    // because the representation of 0.0 is all zero bits.
+    let mut sum = ImmTy::from_int(0u8, element_layout);
+    for i in 0..left_len {
+        if imm & (1 << i.checked_add(4).unwrap()) != 0 {
+            let left = this.read_immediate(&this.project_index(&left, i)?)?;
+            let right = this.read_immediate(&this.project_index(&right, i)?)?;
+
+            let mul = this.wrapping_binary_op(mir::BinOp::Mul, &left, &right)?;
+            sum = this.wrapping_binary_op(mir::BinOp::Add, &sum, &mul)?;
+        }
+    }
+
+    // Write to destination (conditioned to imm)
+    for i in 0..dest_len {
+        let dest = this.project_index(&dest, i)?;
+
+        if imm & (1 << i) != 0 {
+            this.write_immediate(*sum, &dest)?;
+        } else {
+            this.write_scalar(Scalar::from_int(0u8, element_layout.size), &dest)?;
+        }
+    }
+
+    Ok(())
+}
+
+/// Folds SIMD vectors `lhs` and `rhs` into a value of type `T` using `f`.
+fn bin_op_folded<'tcx, T>(
+    this: &crate::MiriInterpCx<'_, 'tcx>,
+    lhs: &OpTy<'tcx, Provenance>,
+    rhs: &OpTy<'tcx, Provenance>,
+    init: T,
+    mut f: impl FnMut(T, ImmTy<'tcx, Provenance>, ImmTy<'tcx, Provenance>) -> InterpResult<'tcx, T>,
+) -> InterpResult<'tcx, T> {
+    assert_eq!(lhs.layout, rhs.layout);
+
+    let (lhs, lhs_len) = this.operand_to_simd(lhs)?;
+    let (rhs, rhs_len) = this.operand_to_simd(rhs)?;
+
+    assert_eq!(lhs_len, rhs_len);
+
+    let mut acc = init;
+    for i in 0..lhs_len {
+        let lhs = this.project_index(&lhs, i)?;
+        let rhs = this.project_index(&rhs, i)?;
+
+        let lhs = this.read_immediate(&lhs)?;
+        let rhs = this.read_immediate(&rhs)?;
+        acc = f(acc, lhs, rhs)?;
+    }
+
+    Ok(acc)
+}
diff --git a/src/tools/miri/src/shims/x86/sse.rs b/src/tools/miri/src/shims/x86/sse.rs
index 6e06f62b34c..1e9afc1e9e0 100644
--- a/src/tools/miri/src/shims/x86/sse.rs
+++ b/src/tools/miri/src/shims/x86/sse.rs
@@ -1,11 +1,12 @@
-use rustc_apfloat::{ieee::Single, Float as _};
+use rustc_apfloat::ieee::Single;
 use rustc_middle::mir;
 use rustc_span::Symbol;
 use rustc_target::spec::abi::Abi;
 
-use rand::Rng as _;
-
-use super::{bin_op_simd_float_all, bin_op_simd_float_first, FloatBinOp};
+use super::{
+    bin_op_simd_float_all, bin_op_simd_float_first, unary_op_ps, unary_op_ss, FloatBinOp,
+    FloatUnaryOp,
+};
 use crate::*;
 use shims::foreign_items::EmulateForeignItemResult;
 
@@ -219,124 +220,3 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
         Ok(EmulateForeignItemResult::NeedsJumping)
     }
 }
-
-#[derive(Copy, Clone)]
-enum FloatUnaryOp {
-    /// sqrt(x)
-    ///
-    /// <https://www.felixcloutier.com/x86/sqrtss>
-    /// <https://www.felixcloutier.com/x86/sqrtps>
-    Sqrt,
-    /// Approximation of 1/x
-    ///
-    /// <https://www.felixcloutier.com/x86/rcpss>
-    /// <https://www.felixcloutier.com/x86/rcpps>
-    Rcp,
-    /// Approximation of 1/sqrt(x)
-    ///
-    /// <https://www.felixcloutier.com/x86/rsqrtss>
-    /// <https://www.felixcloutier.com/x86/rsqrtps>
-    Rsqrt,
-}
-
-/// Performs `which` scalar operation on `op` and returns the result.
-#[allow(clippy::arithmetic_side_effects)] // floating point operations without side effects
-fn unary_op_f32<'tcx>(
-    this: &mut crate::MiriInterpCx<'_, 'tcx>,
-    which: FloatUnaryOp,
-    op: &ImmTy<'tcx, Provenance>,
-) -> InterpResult<'tcx, Scalar<Provenance>> {
-    match which {
-        FloatUnaryOp::Sqrt => {
-            let op = op.to_scalar();
-            // FIXME using host floats
-            Ok(Scalar::from_u32(f32::from_bits(op.to_u32()?).sqrt().to_bits()))
-        }
-        FloatUnaryOp::Rcp => {
-            let op = op.to_scalar().to_f32()?;
-            let div = (Single::from_u128(1).value / op).value;
-            // Apply a relative error with a magnitude on the order of 2^-12 to simulate the
-            // inaccuracy of RCP.
-            let res = apply_random_float_error(this, div, -12);
-            Ok(Scalar::from_f32(res))
-        }
-        FloatUnaryOp::Rsqrt => {
-            let op = op.to_scalar().to_u32()?;
-            // FIXME using host floats
-            let sqrt = Single::from_bits(f32::from_bits(op).sqrt().to_bits().into());
-            let rsqrt = (Single::from_u128(1).value / sqrt).value;
-            // Apply a relative error with a magnitude on the order of 2^-12 to simulate the
-            // inaccuracy of RSQRT.
-            let res = apply_random_float_error(this, rsqrt, -12);
-            Ok(Scalar::from_f32(res))
-        }
-    }
-}
-
-/// Disturbes a floating-point result by a relative error on the order of (-2^scale, 2^scale).
-#[allow(clippy::arithmetic_side_effects)] // floating point arithmetic cannot panic
-fn apply_random_float_error<F: rustc_apfloat::Float>(
-    this: &mut crate::MiriInterpCx<'_, '_>,
-    val: F,
-    err_scale: i32,
-) -> F {
-    let rng = this.machine.rng.get_mut();
-    // generates rand(0, 2^64) * 2^(scale - 64) = rand(0, 1) * 2^scale
-    let err =
-        F::from_u128(rng.gen::<u64>().into()).value.scalbn(err_scale.checked_sub(64).unwrap());
-    // give it a random sign
-    let err = if rng.gen::<bool>() { -err } else { err };
-    // multiple the value with (1+err)
-    (val * (F::from_u128(1).value + err).value).value
-}
-
-/// Performs `which` operation on the first component of `op` and copies
-/// the other components. The result is stored in `dest`.
-fn unary_op_ss<'tcx>(
-    this: &mut crate::MiriInterpCx<'_, 'tcx>,
-    which: FloatUnaryOp,
-    op: &OpTy<'tcx, Provenance>,
-    dest: &PlaceTy<'tcx, Provenance>,
-) -> InterpResult<'tcx, ()> {
-    let (op, op_len) = this.operand_to_simd(op)?;
-    let (dest, dest_len) = this.place_to_simd(dest)?;
-
-    assert_eq!(dest_len, op_len);
-
-    let res0 = unary_op_f32(this, which, &this.read_immediate(&this.project_index(&op, 0)?)?)?;
-    this.write_scalar(res0, &this.project_index(&dest, 0)?)?;
-
-    for i in 1..dest_len {
-        this.copy_op(
-            &this.project_index(&op, i)?,
-            &this.project_index(&dest, i)?,
-            /*allow_transmute*/ false,
-        )?;
-    }
-
-    Ok(())
-}
-
-/// Performs `which` operation on each component of `op`, storing the
-/// result is stored in `dest`.
-fn unary_op_ps<'tcx>(
-    this: &mut crate::MiriInterpCx<'_, 'tcx>,
-    which: FloatUnaryOp,
-    op: &OpTy<'tcx, Provenance>,
-    dest: &PlaceTy<'tcx, Provenance>,
-) -> InterpResult<'tcx, ()> {
-    let (op, op_len) = this.operand_to_simd(op)?;
-    let (dest, dest_len) = this.place_to_simd(dest)?;
-
-    assert_eq!(dest_len, op_len);
-
-    for i in 0..dest_len {
-        let op = this.read_immediate(&this.project_index(&op, i)?)?;
-        let dest = this.project_index(&dest, i)?;
-
-        let res = unary_op_f32(this, which, &op)?;
-        this.write_scalar(res, &dest)?;
-    }
-
-    Ok(())
-}
diff --git a/src/tools/miri/src/shims/x86/sse41.rs b/src/tools/miri/src/shims/x86/sse41.rs
index b3d1056ab06..08e3404a224 100644
--- a/src/tools/miri/src/shims/x86/sse41.rs
+++ b/src/tools/miri/src/shims/x86/sse41.rs
@@ -1,8 +1,7 @@
-use rustc_middle::mir;
 use rustc_span::Symbol;
-use rustc_target::abi::Size;
 use rustc_target::spec::abi::Abi;
 
+use super::{bin_op_folded, conditional_dot_product, round_all, round_first};
 use crate::*;
 use shims::foreign_items::EmulateForeignItemResult;
 
@@ -104,41 +103,7 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
                 let [left, right, imm] =
                     this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
 
-                let (left, left_len) = this.operand_to_simd(left)?;
-                let (right, right_len) = this.operand_to_simd(right)?;
-                let (dest, dest_len) = this.place_to_simd(dest)?;
-
-                assert_eq!(left_len, right_len);
-                assert!(dest_len <= 4);
-
-                let imm = this.read_scalar(imm)?.to_u8()?;
-
-                let element_layout = left.layout.field(this, 0);
-
-                // Calculate dot product
-                // Elements are floating point numbers, but we can use `from_int`
-                // because the representation of 0.0 is all zero bits.
-                let mut sum = ImmTy::from_int(0u8, element_layout);
-                for i in 0..left_len {
-                    if imm & (1 << i.checked_add(4).unwrap()) != 0 {
-                        let left = this.read_immediate(&this.project_index(&left, i)?)?;
-                        let right = this.read_immediate(&this.project_index(&right, i)?)?;
-
-                        let mul = this.wrapping_binary_op(mir::BinOp::Mul, &left, &right)?;
-                        sum = this.wrapping_binary_op(mir::BinOp::Add, &sum, &mul)?;
-                    }
-                }
-
-                // Write to destination (conditioned to imm)
-                for i in 0..dest_len {
-                    let dest = this.project_index(&dest, i)?;
-
-                    if imm & (1 << i) != 0 {
-                        this.write_immediate(*sum, &dest)?;
-                    } else {
-                        this.write_scalar(Scalar::from_int(0u8, element_layout.size), &dest)?;
-                    }
-                }
+                conditional_dot_product(this, left, right, imm, dest)?;
             }
             // Used to implement the _mm_floor_ss, _mm_ceil_ss and _mm_round_ss
             // functions. Rounds the first element of `right` according to `rounding`
@@ -257,112 +222,21 @@ pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>:
             "ptestz" | "ptestc" | "ptestnzc" => {
                 let [op, mask] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
 
-                let (op, op_len) = this.operand_to_simd(op)?;
-                let (mask, mask_len) = this.operand_to_simd(mask)?;
-
-                assert_eq!(op_len, mask_len);
-
-                let f = match unprefixed_name {
-                    "ptestz" => |op, mask| op & mask == 0,
-                    "ptestc" => |op, mask| op & mask == mask,
-                    "ptestnzc" => |op, mask| op & mask != 0 && op & mask != mask,
-                    _ => unreachable!(),
-                };
-
-                let mut all_zero = true;
-                for i in 0..op_len {
-                    let op = this.read_scalar(&this.project_index(&op, i)?)?.to_u64()?;
-                    let mask = this.read_scalar(&this.project_index(&mask, i)?)?.to_u64()?;
-                    all_zero &= f(op, mask);
-                }
-
-                this.write_scalar(Scalar::from_i32(all_zero.into()), dest)?;
+                let res = bin_op_folded(this, op, mask, true, |acc, op, mask| {
+                    let op = op.to_scalar().to_uint(op.layout.size)?;
+                    let mask = mask.to_scalar().to_uint(mask.layout.size)?;
+                    Ok(match unprefixed_name {
+                        "ptestz" => acc && (op & mask) == 0,
+                        "ptestc" => acc && (op & mask) == mask,
+                        "ptestnzc" => acc && (op & mask) != 0 && (op & mask) != mask,
+                        _ => unreachable!(),
+                    })
+                })?;
+
+                this.write_scalar(Scalar::from_i32(res.into()), dest)?;
             }
             _ => return Ok(EmulateForeignItemResult::NotSupported),
         }
         Ok(EmulateForeignItemResult::NeedsJumping)
     }
 }
-
-// Rounds the first element of `right` according to `rounding`
-// and copies the remaining elements from `left`.
-fn round_first<'tcx, F: rustc_apfloat::Float>(
-    this: &mut crate::MiriInterpCx<'_, 'tcx>,
-    left: &OpTy<'tcx, Provenance>,
-    right: &OpTy<'tcx, Provenance>,
-    rounding: &OpTy<'tcx, Provenance>,
-    dest: &PlaceTy<'tcx, Provenance>,
-) -> InterpResult<'tcx, ()> {
-    let (left, left_len) = this.operand_to_simd(left)?;
-    let (right, right_len) = this.operand_to_simd(right)?;
-    let (dest, dest_len) = this.place_to_simd(dest)?;
-
-    assert_eq!(dest_len, left_len);
-    assert_eq!(dest_len, right_len);
-
-    let rounding = rounding_from_imm(this.read_scalar(rounding)?.to_i32()?)?;
-
-    let op0: F = this.read_scalar(&this.project_index(&right, 0)?)?.to_float()?;
-    let res = op0.round_to_integral(rounding).value;
-    this.write_scalar(
-        Scalar::from_uint(res.to_bits(), Size::from_bits(F::BITS)),
-        &this.project_index(&dest, 0)?,
-    )?;
-
-    for i in 1..dest_len {
-        this.copy_op(
-            &this.project_index(&left, i)?,
-            &this.project_index(&dest, i)?,
-            /*allow_transmute*/ false,
-        )?;
-    }
-
-    Ok(())
-}
-
-// Rounds all elements of `op` according to `rounding`.
-fn round_all<'tcx, F: rustc_apfloat::Float>(
-    this: &mut crate::MiriInterpCx<'_, 'tcx>,
-    op: &OpTy<'tcx, Provenance>,
-    rounding: &OpTy<'tcx, Provenance>,
-    dest: &PlaceTy<'tcx, Provenance>,
-) -> InterpResult<'tcx, ()> {
-    let (op, op_len) = this.operand_to_simd(op)?;
-    let (dest, dest_len) = this.place_to_simd(dest)?;
-
-    assert_eq!(dest_len, op_len);
-
-    let rounding = rounding_from_imm(this.read_scalar(rounding)?.to_i32()?)?;
-
-    for i in 0..dest_len {
-        let op: F = this.read_scalar(&this.project_index(&op, i)?)?.to_float()?;
-        let res = op.round_to_integral(rounding).value;
-        this.write_scalar(
-            Scalar::from_uint(res.to_bits(), Size::from_bits(F::BITS)),
-            &this.project_index(&dest, i)?,
-        )?;
-    }
-
-    Ok(())
-}
-
-/// Gets equivalent `rustc_apfloat::Round` from rounding mode immediate of
-/// `round.{ss,sd,ps,pd}` intrinsics.
-fn rounding_from_imm<'tcx>(rounding: i32) -> InterpResult<'tcx, rustc_apfloat::Round> {
-    // The fourth bit of `rounding` only affects the SSE status
-    // register, which cannot be accessed from Miri (or from Rust,
-    // for that matter), so we can ignore it.
-    match rounding & !0b1000 {
-        // When the third bit is 0, the rounding mode is determined by the
-        // first two bits.
-        0b000 => Ok(rustc_apfloat::Round::NearestTiesToEven),
-        0b001 => Ok(rustc_apfloat::Round::TowardNegative),
-        0b010 => Ok(rustc_apfloat::Round::TowardPositive),
-        0b011 => Ok(rustc_apfloat::Round::TowardZero),
-        // When the third bit is 1, the rounding mode is determined by the
-        // SSE status register. Since we do not support modifying it from
-        // Miri (or Rust), we assume it to be at its default mode (round-to-nearest).
-        0b100..=0b111 => Ok(rustc_apfloat::Round::NearestTiesToEven),
-        rounding => throw_unsup_format!("unsupported rounding mode 0x{rounding:02x}"),
-    }
-}