2024-07-22  Jakub Jelinek  <jakub@redhat.com>
	    Andrew Pinski  <quic_apinski@quicinc.com>

	PR tree-optimization/116034
	* tree-sra.c (maybe_rewrite_mem_ref_base): Only use IMAGPART_EXPR
	if MEM_REF offset is equal to element type size.

	* gcc.dg/pr116034.c: New test.

--- gcc/tree-ssa.c.jj	2024-03-11 11:00:46.768915988 +0100
+++ gcc/tree-ssa.c	2024-07-22 21:27:02.115530861 +0200
@@ -1506,7 +1506,10 @@ maybe_rewrite_mem_ref_base (tree *tp, bi
 	}
       else if (TREE_CODE (TREE_TYPE (sym)) == COMPLEX_TYPE
 	       && useless_type_conversion_p (TREE_TYPE (*tp),
-					     TREE_TYPE (TREE_TYPE (sym))))
+					     TREE_TYPE (TREE_TYPE (sym)))
+	       && (integer_zerop (TREE_OPERAND (*tp, 1))
+		   || tree_int_cst_equal (TREE_OPERAND (*tp, 1),
+					  TYPE_SIZE_UNIT (TREE_TYPE (*tp)))))
 	{
 	  *tp = build1 (integer_zerop (TREE_OPERAND (*tp, 1))
 			? REALPART_EXPR : IMAGPART_EXPR,
--- gcc/testsuite/gcc.dg/pr116034.c.jj	2024-07-22 21:39:50.050994243 +0200
+++ gcc/testsuite/gcc.dg/pr116034.c	2024-07-22 21:39:32.432213042 +0200
@@ -0,0 +1,21 @@
+/* PR tree-optimization/116034 */
+/* { dg-do run } */
+/* { dg-options "-O1 -fno-strict-aliasing" } */
+
+int g;
+
+static inline int
+foo (_Complex unsigned short c)
+{
+  __builtin_memmove (&g, 1 + (char *) &c, 2);
+  return g;
+}
+
+int
+main ()
+{
+  if (__SIZEOF_SHORT__ == 2
+      && __CHAR_BIT__ == 8
+      && foo (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ ? 0x0100 : 1) != 1)
+    __builtin_abort ();
+}