[PATCH] tree-optimization/97173 - extend assert in vectorizable_live_operation

[Richard Biener]

The condition we're expecting to eventually run into isn't fully
captured by checking for CTORs, instead we can also run into the
CTOR element conversion.

Bootstrapped / tested on x86_64-unknown-linux-gnu, pushed.

2020-09-23  Richard Biener  <rguent...@suse.de>

        PR tree-optimization/97173
        * tree-vect-loop.c (vectorizable_live_operation): Extend
        assert to also conver element conversions.

        * gcc.dg/vect/pr97173.c: New testcase.
---
 gcc/testsuite/gcc.dg/vect/pr97173.c | 19 +++++++++++++++++++
 gcc/tree-vect-loop.c                |  6 ++++--
 2 files changed, 23 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/vect/pr97173.c

diff --git a/gcc/testsuite/gcc.dg/vect/pr97173.c 
b/gcc/testsuite/gcc.dg/vect/pr97173.c
new file mode 100644
index 00000000000..fd4a8893164
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr97173.c
@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+
+typedef struct {
+  char *track;
+  char *clocks;
+  char *fm;
+  char *weak;  
+} disk_t;
+
+disk_t disk_update_tlens_d;
+int disk_update_tlens_d_0;
+
+void disk_update_tlens() {
+  disk_update_tlens_d.track = disk_update_tlens_d.clocks =
+      disk_update_tlens_d.track + disk_update_tlens_d_0;
+  disk_update_tlens_d.fm = disk_update_tlens_d.clocks + disk_update_tlens_d_0;
+  disk_update_tlens_d.weak = disk_update_tlens_d.fm;
+  disk_update_tlens_d.track[2] = 5;
+}
diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index b1a6e1508c7..46d126c54ba 100644
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -8345,8 +8345,10 @@ vectorizable_live_operation (vec_info *vinfo,
            if (gimple_code (use_stmt) != GIMPLE_PHI
                && !vect_stmt_dominates_stmt_p (gsi_stmt (*gsi), use_stmt))
              {
-               gcc_assert (is_gimple_assign (use_stmt)
-                           && gimple_assign_rhs_code (use_stmt) == 
CONSTRUCTOR);
+               enum tree_code code = gimple_assign_rhs_code (use_stmt);
+               gcc_assert (code == CONSTRUCTOR
+                           || code == VIEW_CONVERT_EXPR
+                           || CONVERT_EXPR_CODE_P (code));
                if (dump_enabled_p ())
                  dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
                                   "Using original scalar computation for "
-- 
2.26.2