tree-optimization/112856 - fix LC SSA after loop header copying

When loop header copying unloops loops we have to possibly fixup
LC SSA.  I've take the opportunity to streamline the unloop_loops
API, removing the use of a ivcanon local global variable.

	PR tree-optimization/109689
	PR tree-optimization/112856
	* cfgloopmanip.h (unloop_loops): Adjust API.
	* tree-ssa-loop-ivcanon.cc (unloop_loops): Take edges_to_remove
	as parameter.
	(canonicalize_induction_variables): Adjust.
	(tree_unroll_loops_completely): Likewise.
	* tree-ssa-loop-ch.cc (ch_base::copy_headers): Rewrite into
	LC SSA if we unlooped some loops and we are in LC SSA.

	* gcc.dg/torture/pr109689.c: New testcase.
	* gcc.dg/torture/pr112856.c: Likewise.

gcc/cfgloopmanip.h

@@ -47,6 +47,7 @@ extern class loop *create_empty_loop_on_edge (edge, tree, tree, tree, tree,
 extern void unloop (class loop *, bool *, bitmap);
 extern void unloop_loops (vec<class loop *> &loops_to_unloop,
 			  vec<int> &loops_to_unloop_nunroll,
+			  vec<edge> &edges_to_remove,
 			  bitmap loop_closed_ssa_invalidated,
 			  bool *irred_invalidated);
 extern void copy_loop_info (class loop *loop, class loop *target);

gcc/testsuite/gcc.dg/torture/pr109689.c

@@ -0,0 +1,34 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-ftree-vectorize" } */
+
+int a, b, c, d, e;
+int main() {
+  char f;
+  while (a) {
+    int g, h = 3;
+    if (b)
+    i:
+      if (d)
+        goto j;
+  k:
+    if (a) {
+    j:
+      if (!g)
+        goto k;
+      if (e) {
+        while (e)
+          e = f;
+        h = 0;
+        goto i;
+      }
+      if (!h)
+        for (; g < 1; g++)
+          ;
+      g = ~((~c & h & c) ^ ~g);
+      if (!g)
+        for (; a < 1; a++)
+          f++;
+    }
+  }
+  return 0;
+}

gcc/testsuite/gcc.dg/torture/pr112856.c

@@ -0,0 +1,18 @@
+/* { dg-do compile } */
+
+double *SVD_A_0;
+int SVD_i, SVD_j, SVD_k, SVD_n;
+double SVD_f;
+void SVD() {
+  SVD_i = SVD_n - 1;
+  for (; SVD_i; SVD_i--) {
+    for (; SVD_j; SVD_j++) {
+      SVD_f = SVD_k = SVD_i;
+      for (; SVD_k < SVD_n; SVD_k++)
+        SVD_A_0[SVD_k] += SVD_f;
+    }
+    SVD_j = SVD_i;
+    for (; SVD_j < SVD_n; SVD_j++)
+      ;
+  }
+}

gcc/tree-ssa-loop-ch.cc

@@ -40,6 +40,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "gimple-range-path.h"
 #include "gimple-pretty-print.h"
 #include "cfganal.h"
+#include "tree-ssa-loop-manip.h"
 
 /* Return path query insteance for testing ranges of statements
    in headers of LOOP contained in basic block BB.
@@ -1149,7 +1150,13 @@ ch_base::copy_headers (function *fun)
   if (!loops_to_unloop.is_empty ())
     {
       bool irred_invalidated;
-      unloop_loops (loops_to_unloop, loops_to_unloop_nunroll, NULL, &irred_invalidated);
+      auto_bitmap lc_invalidated;
+      auto_vec<edge> edges_to_remove;
+      unloop_loops (loops_to_unloop, loops_to_unloop_nunroll, edges_to_remove,
+		    lc_invalidated, &irred_invalidated);
+      if (loops_state_satisfies_p (fun, LOOP_CLOSED_SSA)
+	  && !bitmap_empty_p (lc_invalidated))
+	rewrite_into_loop_closed_ssa (NULL, 0);
       changed = true;
     }
   free (bbs);

gcc/tree-ssa-loop-ivcanon.cc

@@ -667,6 +667,7 @@ static bitmap peeled_loops;
 void
 unloop_loops (vec<class loop *> &loops_to_unloop,
 	      vec<int> &loops_to_unloop_nunroll,
+	      vec<edge> &edges_to_remove,
 	      bitmap loop_closed_ssa_invalidated,
 	      bool *irred_invalidated)
 {
@@ -1361,7 +1362,7 @@ canonicalize_induction_variables (void)
     }
   gcc_assert (!need_ssa_update_p (cfun));
 
-  unloop_loops (loops_to_unloop, loops_to_unloop_nunroll,
+  unloop_loops (loops_to_unloop, loops_to_unloop_nunroll, edges_to_remove,
 		loop_closed_ssa_invalidated, &irred_invalidated);
   loops_to_unloop.release ();
   loops_to_unloop_nunroll.release ();
@@ -1511,9 +1512,8 @@ tree_unroll_loops_completely (bool may_increase_size, bool unroll_outer)
 	{
 	  unsigned i;
 
-	  unloop_loops (loops_to_unloop,
-			loops_to_unloop_nunroll,
-			loop_closed_ssa_invalidated,
+	  unloop_loops (loops_to_unloop, loops_to_unloop_nunroll,
+			edges_to_remove, loop_closed_ssa_invalidated,
 			&irred_invalidated);
 	  loops_to_unloop.release ();
 	  loops_to_unloop_nunroll.release ();