[PATCH, PR middle-end/66134] Fix coalescing for bounds used in abnormal phi

[Ilya Enkovich]

Hi,

This patch fixes misuse of abnormal bounds copy to avoid coalescing issue.   
Bootstrapped and regtested for x86_64-unknown-linux-gnu.  Applied to trunk.  Is 
it OK for gcc-5?

Thanks,
Ilya
--
gcc/

2015-05-15  Ilya Enkovich  <enkovich....@gmail.com>

        PR middle-end/66134
        * tree-chkp.c (chkp_get_orginal_bounds_for_abnormal_copy): New.
        (chkp_maybe_copy_and_register_bounds): Don't copy abnormal copy.

gcc/testsuite/

2015-05-15  Ilya Enkovich  <enkovich....@gmail.com>

        PR middle-end/66134
        * gcc.target/i386/mpx/pr66134.c: New test.


diff --git a/gcc/testsuite/gcc.target/i386/mpx/pr66134.c 
b/gcc/testsuite/gcc.target/i386/mpx/pr66134.c
new file mode 100755
index 0000000..3889674
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/mpx/pr66134.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fcheck-pointer-bounds -mmpx -fno-tree-ccp" } */
+
+extern int vfork (void) __attribute__ ((__nothrow__ , __leaf__));
+void test1 (void);
+void test2 (void);
+void test3 (int *);
+
+void test (int *p)
+{
+ test1 ();
+ p++;
+ test2 ();
+ p++;
+ vfork ();
+ test3 (p);
+}
diff --git a/gcc/tree-chkp.c b/gcc/tree-chkp.c
index 288470b..17a52bc 100644
--- a/gcc/tree-chkp.c
+++ b/gcc/tree-chkp.c
@@ -1097,7 +1097,20 @@ chkp_get_bounds_var (tree ptr_var)
   return bnd_var;
 }
 
+/* If BND is an abnormal bounds copy, return a copied value.
+   Otherwise return BND.  */
+static tree
+chkp_get_orginal_bounds_for_abnormal_copy (tree bnd)
+{
+  if (bitmap_bit_p (chkp_abnormal_copies, SSA_NAME_VERSION (bnd)))
+    {
+      gimple bnd_def = SSA_NAME_DEF_STMT (bnd);
+      gcc_checking_assert (gimple_code (bnd_def) == GIMPLE_ASSIGN);
+      bnd = gimple_assign_rhs1 (bnd_def);
+    }
 
+  return bnd;
+}
 
 /* Register bounds BND for object PTR in global bounds table.
    A copy of bounds may be created for abnormal ssa names.
@@ -1141,11 +1154,7 @@ chkp_maybe_copy_and_register_bounds (tree ptr, tree bnd)
       /* For abnormal copies we may just find original
         bounds and use them.  */
       if (!abnormal_ptr && !SSA_NAME_IS_DEFAULT_DEF (bnd))
-       {
-         gimple bnd_def = SSA_NAME_DEF_STMT (bnd);
-         gcc_checking_assert (gimple_code (bnd_def) == GIMPLE_ASSIGN);
-         bnd = gimple_assign_rhs1 (bnd_def);
-       }
+       bnd = chkp_get_orginal_bounds_for_abnormal_copy (bnd);
       /* For undefined values we usually use none bounds
         value but in case of abnormal edge it may cause
         coalescing failures.  Use default definition of
@@ -1177,6 +1186,7 @@ chkp_maybe_copy_and_register_bounds (tree ptr, tree bnd)
            copy = make_temp_ssa_name (pointer_bounds_type_node,
                                       gimple_build_nop (),
                                       CHKP_BOUND_TMP_NAME);
+         bnd = chkp_get_orginal_bounds_for_abnormal_copy (bnd);
          assign = gimple_build_assign (copy, bnd);
 
          if (dump_file && (dump_flags & TDF_DETAILS))