[Bug rtl-optimization/64286] Redundant extend removal ignores vector element type

[izamyatin at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64286

--- Comment #1 from Igor Zamyatin <izamyatin at gmail dot com> ---
Perhaps something like below to restrict ree for such cases?

diff --git a/gcc/ree.c b/gcc/ree.c
index 3376901..92370ea 100644
--- a/gcc/ree.c
+++ b/gcc/ree.c
@@ -1004,6 +1004,11 @@ add_removable_extension (const_rtx expr, rtx_insn *insn,
       struct df_link *defs, *def;
       ext_cand *cand;

+      if (!SCALAR_INT_MODE_P (GET_MODE (dest))
+      && (GET_MODE_UNIT_PRECISION (mode) !=
+          GET_MODE_UNIT_PRECISION (GET_MODE (XEXP (src, 0)))))
+    return;
+
       /* First, make sure we can get all the reaching definitions.  */
       defs = get_defs (insn, XEXP (src, 0), NULL);
       if (!defs)