[gcc r13-5300] tree-optimization/108482 - remove stray .LOOP_DIST_ALIAS calls

[Richard Biener <rguenth@gcc.gnu.org>]

https://gcc.gnu.org/g:ad4f8c4e375dd7603382ed3ff95bd184e1959918

commit r13-5300-gad4f8c4e375dd7603382ed3ff95bd184e1959918
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Jan 23 10:22:38 2023 +0100

    tree-optimization/108482 - remove stray .LOOP_DIST_ALIAS calls
    
    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).
    
            PR tree-optimization/108482
            * tree-vect-generic.cc (expand_vector_operations): Fold remaining
            .LOOP_DIST_ALIAS calls.
    
            * gcc.dg/torture/pr108482.c: New testcase.

Diff:
---
 gcc/testsuite/gcc.dg/torture/pr108482.c | 18 ++++++++++++++++++
 gcc/tree-vect-generic.cc                |  8 ++++++++
 2 files changed, 26 insertions(+)

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;
+	    }
 	}
     }