Rollup merge of #157768 - davidtwco:scalable-vector-transparent-wrapper, r=lqd

codegen_ssa: peel trans. wrappers on scalable vecs

Transparent wrappers around scalable vectors like `MaybeUninit<svuint32_t>` need alloca of scalable vector types, which requires peeling off transparent wrappers so the correct code path is used.

Author: JonathanBrouwer

compiler/rustc_codegen_ssa/src/mir/place.rs

@@ -111,7 +111,7 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
         bx: &mut Bx,
         layout: TyAndLayout<'tcx>,
     ) -> Self {
-        if layout.deref().is_scalable_vector() {
+        if layout.peel_transparent_wrappers(bx).deref().is_scalable_vector() {
             Self::alloca_scalable(bx, layout)
         } else {
             Self::alloca_size(bx, layout.size, layout)
@@ -157,7 +157,11 @@ impl<'a, 'tcx, V: CodegenObject> PlaceRef<'tcx, V> {
         bx: &mut Bx,
         layout: TyAndLayout<'tcx>,
     ) -> Self {
-        PlaceValue::new_sized(bx.alloca_with_ty(layout), layout.align.abi).with_type(layout)
+        PlaceValue::new_sized(
+            bx.alloca_with_ty(layout.peel_transparent_wrappers(bx)),
+            layout.align.abi,
+        )
+        .with_type(layout)
     }
 }
 

tests/ui/scalable-vectors/transparent-wrappers.rs

@@ -0,0 +1,50 @@
+//@ only-aarch64
+//@ build-pass
+//@ compile-flags: --emit=obj -Ctarget-feature=+sve
+//@ edition:2021
+#![feature(simd_ffi)]
+#![feature(stdarch_aarch64_sve)]
+
+use std::arch::aarch64::*;
+
+// Tests that scalable vectors in transparent wrapper types compile correctly (that is, that
+// alloca we generate in LLVM IR are for scalable vector types and not arrays, because rustc
+// looks through the transparent wrapper).
+
+static I16_147: [i16; 147] = [
+    0x0, 0x400, 0x37ff, 0x3800, 0x3801, 0x3bff, 0x3c00, 0x3c01, 0x3e00, 0x4900, 0x7bff, 0x7c00,
+    0x7f23, 0x7e00, 0x7d23, 0x7c01, 0x12, 0x3ff, 0x1, -0x8000, -0x7c00, -0x4801, -0x4800, -0x47ff,
+    -0x4401, -0x4400, -0x43ff, -0x4200, -0x3700, -0x401, -0x400, -0xdd, -0x200, -0x2dd, -0x3ff,
+    -0x7fee, -0x7c01, -0x7fff, -0x400, -0x4000, 0x5140, 0x5800, 0x63d2, 0x5630, 0x3560, -0x6e6f,
+    0x4178, 0x6212, 0x67d0, 0x3312, 0x4cef, 0x4973, 0x3ecc, 0x5166, 0x4d80, 0x6248, 0x46fd, 0x39c4,
+    0x39c5, 0x4866, 0x6050, 0x498e, 0x4a0f, 0x3555, -0x400, -0x4000, -0x6e6f, 0x5140, 0x5800,
+    -0x7fff, -0x7c01, 0x63d2, 0x5630, 0x3560, 0x4178, 0x7d23, 0x7c01, 0x12, -0x4800, 0x3ff, 0x1,
+    0x7e00, 0x7f23, -0x8000, -0x7c00, -0x4801, -0x47ff, 0x3312, 0x4cef, 0x4973, 0x39c4, 0x3ecc,
+    0x5166, 0x67d0, 0x6212, 0x4d80, 0x6248, 0x46fd, 0x39c5, -0x43ff, -0x4200, -0x3700, -0x3ff,
+    -0x401, -0x400, -0x4400, -0x4401, -0xdd, -0x200, -0x2dd, -0x7fee, 0x37ff, 0x3800, 0x3801,
+    0x7bff, 0x3bff, 0x3c00, 0x400, 0x0, 0x3c01, 0x3e00, 0x4900, 0x7c00, 0x498e, 0x4a0f, 0x6050,
+    0x4866, 0x3555, 0x0, 0x400, 0x37ff, 0x3800, 0x3801, 0x3bff, 0x3c00, 0x3c01, 0x3e00, 0x4900,
+    0x7bff, 0x7c00, 0x7f23, 0x7e00, 0x7d23, 0x7c01, 0x12, 0x3ff, 0x1,
+];
+
+#[allow(improper_ctypes)]
+unsafe extern "C" {
+    fn svcreate2_s16_wrapper(__dst: *mut svint16x2_t, x0: *const svint16_t, x1: *const svint16_t);
+}
+
+fn main() {
+    unsafe {
+        let __pred = svptrue_b16();
+        let x0_val = svld1_s16(__pred, I16_147.as_ptr().add(0) as _);
+
+        let mut __c_return_value = std::mem::MaybeUninit::uninit();
+        svcreate2_s16_wrapper(__c_return_value.as_mut_ptr(), &raw const x0_val, &raw const x0_val);
+        let __c_return_value = __c_return_value.assume_init();
+
+        let eq = svcmpeq_s16(
+            __pred,
+            svget2_s16::<0>(__c_return_value),
+            svget2_s16::<0>(__c_return_value),
+        );
+    }
+}