[gcc r11-11266] d: Fix gdc -O2 -mavx generates misaligned vmovdqa instruction [PR114171]

[Iain Buclaw]

https://gcc.gnu.org/g:3e60064a03a1a6d38ceb5ca4eb7e1f4d30a8aed1

commit r11-11266-g3e60064a03a1a6d38ceb5ca4eb7e1f4d30a8aed1
Author: Iain Buclaw <ibuclaw@gdcproject.org>
Date:   Sun Mar 3 02:26:37 2024 +0100

    d: Fix gdc -O2 -mavx generates misaligned vmovdqa instruction [PR114171]
    
            PR d/114171
    
    gcc/d/ChangeLog:
    
            * d-codegen.cc (lower_struct_comparison): Keep alignment of original
            type in reinterpret cast for comparison.
    
    gcc/testsuite/ChangeLog:
    
            * gdc.dg/torture/pr114171.d: New test.
    
    (cherry picked from commit 623f52775e677bb3d6e9e7ef97196741dd904b1e)

Diff:
---
 gcc/d/d-codegen.cc                      |  1 +
 gcc/testsuite/gdc.dg/torture/pr114171.d | 29 +++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/gcc/d/d-codegen.cc b/gcc/d/d-codegen.cc
index e51e686e3c0..e917a606642 100644
--- a/gcc/d/d-codegen.cc
+++ b/gcc/d/d-codegen.cc
@@ -993,6 +993,7 @@ lower_struct_comparison (tree_code code, StructDeclaration *sd,
 	      if (tmode == NULL_TREE)
 		tmode = make_unsigned_type (GET_MODE_BITSIZE (mode.require ()));
 
+	      tmode = build_aligned_type (tmode, TYPE_ALIGN (stype));
 	      t1ref = build_vconvert (tmode, t1ref);
 	      t2ref = build_vconvert (tmode, t2ref);
 
diff --git a/gcc/testsuite/gdc.dg/torture/pr114171.d b/gcc/testsuite/gdc.dg/torture/pr114171.d
new file mode 100644
index 00000000000..0f9ffcab916
--- /dev/null
+++ b/gcc/testsuite/gdc.dg/torture/pr114171.d
@@ -0,0 +1,29 @@
+// { dg-do run }
+// { dg-additional-options "-mavx" { target avx_runtime } }
+// { dg-skip-if "needs gcc/config.d" { ! d_runtime } }
+import gcc.builtins;
+
+struct S1
+{
+    string label;
+}
+
+struct S2
+{
+    ulong pad;
+    S1 label;
+}
+
+pragma(inline, false)
+auto newitem()
+{
+    void *p = __builtin_malloc(S2.sizeof);
+    __builtin_memset(p, 0, S2.sizeof);
+    return cast(S2*) p;
+}
+
+int main()
+{
+    auto bn = newitem();
+    return bn.label is S1.init ? 0 : 1;
+}