[PATCH] tree-optimization/108482 - remove stray .LOOP_DIST_ALIAS calls

[Richard Biener via Gcc-patches]

The following deals with .LOOP_DIST_ALIAS surviving vectorization
because any of the loops involved were elided between loop distribution
and vectorization.  As opposed to .LOOP_VECTORIZED which exists only
between if-conversion and vectorization with no intermediate passes
this is more difficult to deal with in advance and thus cleaning
up after vectorization looks better.  There's the unconditional
vector lowering pass which looks like a good place for this (for
SIMD uid we have pass_simduid_cleanup).

Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.

OK?

Thanks,
Richard.

        PR tree-optimization/108482
        * tree-vect-generic.cc (expand_vector_operations): Fold remaining
        .LOOP_DIST_ALIAS calls.

        * gcc.dg/torture/pr108482.c: New testcase.
---
 gcc/testsuite/gcc.dg/torture/pr108482.c | 18 ++++++++++++++++++
 gcc/tree-vect-generic.cc                |  8 ++++++++
 2 files changed, 26 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/torture/pr108482.c

diff --git a/gcc/testsuite/gcc.dg/torture/pr108482.c 
b/gcc/testsuite/gcc.dg/torture/pr108482.c
new file mode 100644
index 00000000000..8dc1169a9c5
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr108482.c
@@ -0,0 +1,18 @@
+/* { dg-do compile } */
+
+int g_30, g_261, g_263, func_1___trans_tmp_17;
+int **g_120;
+int *g_530;
+void func_1() {
+  int *l_29 = &g_30;
+  *l_29 = 1;
+  g_263 = 0;
+  for (; g_263 <= 1; g_263 += 1) {
+    g_530 = 0;
+    if (*l_29) {
+      char *l_1694 = (char *)&g_261;
+      *l_1694 &= **g_120;
+    } else
+      *l_29 ^= func_1___trans_tmp_17;
+  }
+}
diff --git a/gcc/tree-vect-generic.cc b/gcc/tree-vect-generic.cc
index 2e2d7567293..166a248f4b9 100644
--- a/gcc/tree-vect-generic.cc
+++ b/gcc/tree-vect-generic.cc
@@ -2398,6 +2398,14 @@ expand_vector_operations (void)
          if (maybe_clean_eh_stmt (gsi_stmt (gsi))
              && gimple_purge_dead_eh_edges (bb))
            cfg_changed = true;
+         /* If a .LOOP_DIST_ALIAS call prevailed loops got elided
+            before vectorization got a chance to get at them.  Simply
+            fold as if loop distribution wasn't performed.  */
+         if (gimple_call_internal_p (gsi_stmt (gsi), IFN_LOOP_DIST_ALIAS))
+           {
+             fold_loop_internal_call (gsi_stmt (gsi), boolean_false_node);
+             cfg_changed = true;
+           }
        }
     }
 
-- 
2.35.3