[gcc r12-7372] tree-optimization/104676 - free nb_iterations after loop distribution

[gcc r12-7372] tree-optimization/104676 - free nb_iterations after loop distribution

[Richard Biener]

https://gcc.gnu.org/g:a4066d3a5097333f17c0d7be1630a98f3a5b1c1d

commit r12-7372-ga4066d3a5097333f17c0d7be1630a98f3a5b1c1d
Author: Richard Biener <rguenther@suse.de>
Date:   Thu Feb 24 14:34:52 2022 +0100

    tree-optimization/104676 - free nb_iterations after loop distribution
    
    Loop distribution can release SSA names used in nb_iterations, make
    sure to release those.
    
    2022-02-24  Richard Biener  <rguenther@suse.de>
    
            PR tree-optimization/104676
            * tree-loop-distribution.cc (loop_distribution::execute):
            Do a full scev_reset.
    
            * gcc.dg/torture/pr104676.c: New testcase.

Diff:
---
 gcc/testsuite/gcc.dg/torture/pr104676.c | 35 +++++++++++++++++++++++++++++++++
 gcc/tree-loop-distribution.cc           |  2 +-
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/gcc/testsuite/gcc.dg/torture/pr104676.c b/gcc/testsuite/gcc.dg/torture/pr104676.c
new file mode 100644
index 00000000000..50845bb9e15
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr104676.c
@@ -0,0 +1,35 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-ftree-loop-distribution -ftree-parallelize-loops=2" } */
+
+struct S {
+  int f;
+};
+
+int n;
+
+int
+foo (struct S *s)
+{
+  int arr[3];
+  int v = 0;
+
+  for (n = 0; n < 2; ++n)
+    {
+      int i;
+
+      for (i = 0; i < 2; ++i)
+        {
+          int j;
+
+          for (j = 0; j < s->f; ++j)
+            ++v;
+        }
+
+      if (v)
+        arr[0] = 0;
+
+      arr[n + 1] = 0;
+    }
+
+  return arr[0];
+}
diff --git a/gcc/tree-loop-distribution.cc b/gcc/tree-loop-distribution.cc
index c7b42857263..8ee40d88816 100644
--- a/gcc/tree-loop-distribution.cc
+++ b/gcc/tree-loop-distribution.cc
@@ -3853,7 +3853,7 @@ loop_distribution::execute (function *fun)
 
       /* Cached scalar evolutions now may refer to wrong or non-existing
 	 loops.  */
-      scev_reset_htab ();
+      scev_reset ();
       mark_virtual_operands_for_renaming (fun);
       rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
     }