[PATCH] Fix tree-loop-distribution.c ICE with -ftrapv (PR tree-optimization/89278)

[Jakub Jelinek]

Hi!

The following testcase ICEs, because we try to gimplify a complex expression
that with -ftrapv wants to emit multiple bbs.  Fixed by using
rewrite_to_non_trapping_overflow.  Bootstrapped/regtested on x86_64-linux
and i686-linux, ok for trunk and 8.3?

2019-02-14  Richard Biener  <rguent...@suse.de>
            Jakub Jelinek  <ja...@redhat.com>

        PR tree-optimization/89278
        * tree-loop-distribution.c: Include tree-eh.h.
        (generate_memset_builtin, generate_memcpy_builtin): Call
        rewrite_to_non_trapping_overflow on builtin->size before passing it
        to force_gimple_operand_gsi.

        * gcc.dg/pr89278.c: New test.

--- gcc/tree-loop-distribution.c.jj     2019-01-10 11:43:02.255576992 +0100
+++ gcc/tree-loop-distribution.c        2019-02-14 12:17:24.403403131 +0100
@@ -114,6 +114,7 @@ along with GCC; see the file COPYING3.
 #include "tree-scalar-evolution.h"
 #include "params.h"
 #include "tree-vectorizer.h"
+#include "tree-eh.h"
 
 
 #define MAX_DATAREFS_NUM \
@@ -996,7 +997,7 @@ generate_memset_builtin (struct loop *lo
   /* The new statements will be placed before LOOP.  */
   gsi = gsi_last_bb (loop_preheader_edge (loop)->src);
 
-  nb_bytes = builtin->size;
+  nb_bytes = rewrite_to_non_trapping_overflow (builtin->size);
   nb_bytes = force_gimple_operand_gsi (&gsi, nb_bytes, true, NULL_TREE,
                                       false, GSI_CONTINUE_LINKING);
   mem = builtin->dst_base;
@@ -1048,7 +1049,7 @@ generate_memcpy_builtin (struct loop *lo
   /* The new statements will be placed before LOOP.  */
   gsi = gsi_last_bb (loop_preheader_edge (loop)->src);
 
-  nb_bytes = builtin->size;
+  nb_bytes = rewrite_to_non_trapping_overflow (builtin->size);
   nb_bytes = force_gimple_operand_gsi (&gsi, nb_bytes, true, NULL_TREE,
                                       false, GSI_CONTINUE_LINKING);
   dest = builtin->dst_base;
--- gcc/testsuite/gcc.dg/pr89278.c.jj   2019-02-14 12:18:38.778173413 +0100
+++ gcc/testsuite/gcc.dg/pr89278.c      2019-02-14 12:18:19.065499344 +0100
@@ -0,0 +1,23 @@
+/* PR tree-optimization/89278 */
+/* { dg-do compile } */
+/* { dg-options "-O1 -ftrapv -ftree-loop-distribute-patterns --param 
max-loop-header-insns=2" } */
+
+void
+foo (int *w, int x, int y, int z)
+{
+  while (x < y + z)
+    {
+      w[x] = 0;
+      ++x;
+    }
+}
+
+void
+bar (int *__restrict u, int *__restrict w, int x, int y, int z)
+{
+  while (x < y + z)
+    {
+      w[x] = u[x];
+      ++x;
+    }
+}

        Jakub