Re-block SRoA on SIMD types

Fixes 144621

2 files changed, 50 insertions, 0 deletions

diff --git a/tests/mir-opt/sroa/simd_sroa.foo.ScalarReplacementOfAggregates.diff b/tests/mir-opt/sroa/simd_sroa.foo.ScalarReplacementOfAggregates.diff
new file mode 100644
index 00000000000..74403247108
--- /dev/null
+++ b/tests/mir-opt/sroa/simd_sroa.foo.ScalarReplacementOfAggregates.diff
@@ -0,0 +1,32 @@
+- // MIR for `foo` before ScalarReplacementOfAggregates
++ // MIR for `foo` after ScalarReplacementOfAggregates
+  
+  fn foo(_1: &[Simd<u8, 16>], _2: Simd<u8, 16>) -> () {
+      debug simds => _1;
+      debug _unused => _2;
+      let mut _0: ();
+      let _3: std::simd::Simd<u8, 16>;
+      let _4: usize;
+      let mut _5: usize;
+      let mut _6: bool;
+      scope 1 {
+          debug a => _3;
+      }
+  
+      bb0: {
+          StorageLive(_3);
+          StorageLive(_4);
+          _4 = const 0_usize;
+          _5 = PtrMetadata(copy _1);
+          _6 = Lt(copy _4, copy _5);
+          assert(move _6, "index out of bounds: the length is {} but the index is {}", move _5, copy _4) -> [success: bb1, unwind continue];
+      }
+  
+      bb1: {
+          _3 = copy (*_1)[_4];
+          StorageDead(_4);
+          StorageDead(_3);
+          return;
+      }
+  }
+  
diff --git a/tests/mir-opt/sroa/simd_sroa.rs b/tests/mir-opt/sroa/simd_sroa.rs
new file mode 100644
index 00000000000..1ae84d3f975
--- /dev/null
+++ b/tests/mir-opt/sroa/simd_sroa.rs
@@ -0,0 +1,18 @@
+//@ needs-unwind
+#![feature(portable_simd)]
+
+// SRoA expands things even if they're unused
+// <https://github.com/rust-lang/rust/issues/144621>
+
+use std::simd::Simd;
+
+// EMIT_MIR simd_sroa.foo.ScalarReplacementOfAggregates.diff
+pub(crate) fn foo(simds: &[Simd<u8, 16>], _unused: Simd<u8, 16>) {
+    // CHECK-LABEL: fn foo
+    // CHECK-NOT: [u8; 16]
+    // CHECK: let [[SIMD:_.+]]: std::simd::Simd<u8, 16>;
+    // CHECK-NOT: [u8; 16]
+    // CHECK: [[SIMD]] = copy (*_1)[0 of 1];
+    // CHECK-NOT: [u8; 16]
+    let a = simds[0];
+}