Merge from rustc

Author: RalfJung

src/shims/intrinsics/mod.rs

@@ -60,7 +60,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         }
 
         // The rest jumps to `ret` immediately.
-        this.emulate_intrinsic_by_name(intrinsic_name, args, dest)?;
+        this.emulate_intrinsic_by_name(intrinsic_name, instance.args, args, dest)?;
 
         trace!("{:?}", this.dump_place(dest));
         this.go_to_block(ret);
@@ -71,6 +71,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
     fn emulate_intrinsic_by_name(
         &mut self,
         intrinsic_name: &str,
+        generic_args: ty::GenericArgsRef<'tcx>,
         args: &[OpTy<'tcx, Provenance>],
         dest: &PlaceTy<'tcx, Provenance>,
     ) -> InterpResult<'tcx> {
@@ -80,7 +81,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
             return this.emulate_atomic_intrinsic(name, args, dest);
         }
         if let Some(name) = intrinsic_name.strip_prefix("simd_") {
-            return this.emulate_simd_intrinsic(name, args, dest);
+            return this.emulate_simd_intrinsic(name, generic_args, args, dest);
         }
 
         match intrinsic_name {

src/shims/intrinsics/simd.rs

@@ -12,6 +12,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
     fn emulate_simd_intrinsic(
         &mut self,
         intrinsic_name: &str,
+        generic_args: ty::GenericArgsRef<'tcx>,
         args: &[OpTy<'tcx, Provenance>],
         dest: &PlaceTy<'tcx, Provenance>,
     ) -> InterpResult<'tcx> {
@@ -488,6 +489,38 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                     this.write_immediate(*val, &dest)?;
                 }
             }
+            "shuffle_generic" => {
+                let [left, right] = check_arg_count(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)?;
+
+                let index = generic_args[2].expect_const().eval(*this.tcx, this.param_env(), Some(this.tcx.span)).unwrap().unwrap_branch();
+                let index_len = index.len();
+
+                assert_eq!(left_len, right_len);
+                assert_eq!(index_len as u64, dest_len);
+
+                for i in 0..dest_len {
+                    let src_index: u64 = index[i as usize].unwrap_leaf()
+                        .try_to_u32().unwrap()
+                        .into();
+                    let dest = this.project_index(&dest, i)?;
+
+                    let val = if src_index < left_len {
+                        this.read_immediate(&this.project_index(&left, src_index)?)?
+                    } else if src_index < left_len.checked_add(right_len).unwrap() {
+                        let right_idx = src_index.checked_sub(left_len).unwrap();
+                        this.read_immediate(&this.project_index(&right, right_idx)?)?
+                    } else {
+                        span_bug!(
+                            this.cur_span(),
+                            "simd_shuffle index {src_index} is out of bounds for 2 vectors of size {left_len}",
+                        );
+                    };
+                    this.write_immediate(*val, &dest)?;
+                }
+            }
             "shuffle" => {
                 let [left, right, index] = check_arg_count(args)?;
                 let (left, left_len) = this.operand_to_simd(left)?;

tests/pass/portable-simd.rs

@@ -1,5 +1,6 @@
 //@compile-flags: -Zmiri-strict-provenance
-#![feature(portable_simd, platform_intrinsics)]
+#![feature(portable_simd, platform_intrinsics, adt_const_params, inline_const)]
+#![allow(incomplete_features)]
 use std::simd::*;
 
 extern "platform-intrinsic" {
@@ -390,6 +391,8 @@ fn simd_intrinsics() {
         fn simd_reduce_any<T>(x: T) -> bool;
         fn simd_reduce_all<T>(x: T) -> bool;
         fn simd_select<M, T>(m: M, yes: T, no: T) -> T;
+        fn simd_shuffle_generic<T, U, const IDX: &'static [u32]>(x: T, y: T) -> U;
+        fn simd_shuffle<T, IDX, U>(x: T, y: T, idx: IDX) -> U;
     }
     unsafe {
         // Make sure simd_eq returns all-1 for `true`
@@ -413,6 +416,22 @@ fn simd_intrinsics() {
             simd_select(i8x4::from_array([0, -1, -1, 0]), b, a),
             i32x4::from_array([10, 2, 10, 10])
         );
+        assert_eq!(
+            simd_shuffle_generic::<_, i32x4, {&[3, 1, 0, 2]}>(a, b),
+            a,
+        );
+        assert_eq!(
+            simd_shuffle::<_, _, i32x4>(a, b, const {[3, 1, 0, 2]}),
+            a,
+        );
+        assert_eq!(
+            simd_shuffle_generic::<_, i32x4, {&[7, 5, 4, 6]}>(a, b),
+            i32x4::from_array([4, 2, 1, 10]),
+        );
+        assert_eq!(
+            simd_shuffle::<_, _, i32x4>(a, b, const {[7, 5, 4, 6]}),
+            i32x4::from_array([4, 2, 1, 10]),
+        );
     }
 }