backport: re PR rtl-optimization/68955 (wrong code at -O3 on x86-64-linux-gnu in...

	Backported from mainline
	2016-01-19  Jakub Jelinek  <jakub@redhat.com>

	PR rtl-optimization/68955
	PR rtl-optimization/64557
	* dse.c (record_store, check_mem_read_rtx): Don't call get_addr
	here.  Fix up formatting.
	* alias.c (get_addr): Handle VALUE +/- CONST_SCALAR_INT_P.

	* gcc.dg/torture/pr68955.c: New test.

From-SVN: r233331

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 39b4aa922abf0c5d67a634a885001c2fc066f140..90697adea800bccdbb42648fb74f545b113f7fa6 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,6 +1,14 @@
 2016-02-11  Jakub Jelinek  <jakub@redhat.com>
 
        Backported from mainline
+       2016-01-19  Jakub Jelinek  <jakub@redhat.com>
+
+       PR rtl-optimization/68955
+       PR rtl-optimization/64557
+       * dse.c (record_store, check_mem_read_rtx): Don't call get_addr
+       here.  Fix up formatting.
+       * alias.c (get_addr): Handle VALUE +/- CONST_SCALAR_INT_P.
+
        2016-01-11  Jakub Jelinek  <jakub@redhat.com>
 
        PR tree-optimization/69214

diff --git a/gcc/alias.c b/gcc/alias.c
index 9956306ae29479cec7c9aa04c054f6f661fcf578..a1e554058d770f79e60bfb541bfe3725ffcf844d 100644 (file)
--- a/gcc/alias.c
+++ b/gcc/alias.c
@@ -1882,8 +1882,8 @@ refs_newer_value_p (rtx expr, rtx v)
 }
 
 /* Convert the address X into something we can use.  This is done by returning
-   it unchanged unless it is a value; in the latter case we call cselib to get
-   a more useful rtx.  */
+   it unchanged unless it is a VALUE or VALUE +/- constant; for VALUE
+   we call cselib to get a more useful rtx.  */
 
 rtx
 get_addr (rtx x)
@@ -1892,7 +1892,23 @@ get_addr (rtx x)
   struct elt_loc_list *l;
 
   if (GET_CODE (x) != VALUE)
-    return x;
+    {
+      if ((GET_CODE (x) == PLUS || GET_CODE (x) == MINUS)
+         && GET_CODE (XEXP (x, 0)) == VALUE
+         && CONST_SCALAR_INT_P (XEXP (x, 1)))
+       {
+         rtx op0 = get_addr (XEXP (x, 0));
+         if (op0 != XEXP (x, 0))
+           {
+             if (GET_CODE (x) == PLUS
+                 && GET_CODE (XEXP (x, 1)) == CONST_INT)
+               return plus_constant (GET_MODE (x), op0, INTVAL (XEXP (x, 1)));
+             return simplify_gen_binary (GET_CODE (x), GET_MODE (x),
+                                         op0, XEXP (x, 1));
+           }
+       }
+      return x;
+    }
   v = CSELIB_VAL_PTR (x);
   if (v)
     {

diff --git a/gcc/dse.c b/gcc/dse.c
index 878fedcec3bbddd9def6ae95410e177041030c18..8ebf63f046e0164625ff73822cbe68b9f830e4be 100644 (file)
--- a/gcc/dse.c
+++ b/gcc/dse.c
@@ -1545,14 +1545,9 @@ record_store (rtx body, bb_info_t bb_info)
        mem_addr = base->val_rtx;
       else
        {
-         group_info_t group
-           = rtx_group_vec[group_id];
+         group_info_t group = rtx_group_vec[group_id];
          mem_addr = group->canon_base_addr;
        }
-      /* get_addr can only handle VALUE but cannot handle expr like:
-        VALUE + OFFSET, so call get_addr to get original addr for
-        mem_addr before plus_constant.  */
-      mem_addr = get_addr (mem_addr);
       if (offset)
        mem_addr = plus_constant (get_address_mode (mem), mem_addr, offset);
     }
@@ -2166,14 +2161,9 @@ check_mem_read_rtx (rtx *loc, void *data)
        mem_addr = base->val_rtx;
       else
        {
-         group_info_t group
-           = rtx_group_vec[group_id];
+         group_info_t group = rtx_group_vec[group_id];
          mem_addr = group->canon_base_addr;
        }
-      /* get_addr can only handle VALUE but cannot handle expr like:
-        VALUE + OFFSET, so call get_addr to get original addr for
-        mem_addr before plus_constant.  */
-      mem_addr = get_addr (mem_addr);
       if (offset)
        mem_addr = plus_constant (get_address_mode (mem), mem_addr, offset);
     }

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index c8a19a9fb6c3ed1421d1aa7118b52e4966091502..26d09551faea407b5ceb447d12dbe2e94cd6a359 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,6 +1,12 @@
 2016-02-11  Jakub Jelinek  <jakub@redhat.com>
 
        Backported from mainline
+       2016-01-19  Jakub Jelinek  <jakub@redhat.com>
+
+       PR rtl-optimization/68955
+       PR rtl-optimization/64557
+       * gcc.dg/torture/pr68955.c: New test.
+
        2016-01-11  Jakub Jelinek  <jakub@redhat.com>
 
        PR tree-optimization/69214

diff --git a/gcc/testsuite/gcc.dg/torture/pr68955.c b/gcc/testsuite/gcc.dg/torture/pr68955.c
new file mode 100644 (file)
index 0000000..e9da003
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr68955.c
@@ -0,0 +1,41 @@
+/* PR rtl-optimization/68955 */
+/* { dg-do run } */
+/* { dg-output "ONE1ONE" } */
+
+int a, b, c, d, g, m;
+int i[7][7][5] = { { { 5 } }, { { 5 } },
+                  { { 5 }, { 5 }, { 5 }, { 5 }, { 5 }, { -1 } } };
+static int j = 11;
+short e, f, h, k, l;
+
+static void
+foo ()
+{
+  for (; e < 5; e++)
+    for (h = 3; h; h--)
+      {
+       for (g = 1; g < 6; g++)
+         {
+           m = c == 0 ? b : b / c;
+           i[e][1][e] = i[1][1][1] | (m & l) && f;
+         }
+       for (k = 0; k < 6; k++)
+         {
+           for (d = 0; d < 6; d++)
+             i[1][e][h] = i[h][k][e] >= l;
+           i[e + 2][h + 3][e] = 6 & l;
+           i[2][1][2] = a;
+           for (; j < 5;)
+             for (;;)
+               ;
+         }
+      }
+}
+
+int
+main ()
+{
+  foo ();
+  __builtin_printf ("ONE%dONE\n", i[1][0][2]);
+  return 0;
+}