Improve address offset range computation

From-SVN: r163081

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 9c838ba4ad2da272ac90670f523dedec738921ce..5773fc3c7f93e1341c06110f7dee30791160f913 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2010-08-10  Xinliang David Li  <davidxl@google.com>
+
+       * tree-ssa-loop-ivopts.c (get_address_cost): Properly
+       compute max/min offset in address.
+
 2010-08-10  Vladimir Makarov  <vmakarov@redhat.com>
 
        * ira-live.c: Include sbitmap.h.

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 3f38faf0fbd4e9e44f8495ddbeec70ff8c925e10..38f0ee015e3aefd3783f3c54f07120bb194de994 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2010-08-10  xinliang David Li  <davidxl@google.com>
+       * gcc.dg/tree-ssa/loop-19.c: Add option
+       -fno-prefetch-loop-array
+
 2010-08-10  Bernd Schmidt  <bernds@codesourcery.com>
 
        PR middle-end/45182

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loop-19.c b/gcc/testsuite/gcc.dg/tree-ssa/loop-19.c
index 9ec893298a10bd0eea44b8bab2c617d6b7880fa6..4dfd2277dbc5145cce463b5488aec9adde8edcf0 100644 (file)
--- a/gcc/testsuite/gcc.dg/tree-ssa/loop-19.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/loop-19.c
@@ -6,7 +6,7 @@
 
 /* { dg-do compile { target { i?86-*-* || { x86_64-*-* || powerpc_hard_double } } } } */
 /* { dg-require-effective-target nonpic } */
-/* { dg-options "-O3 -fdump-tree-optimized" } */
+/* { dg-options "-O3 -fno-prefetch-loop-arrays -fdump-tree-optimized" } */
 
 # define N      2000000
 static double   a[N],c[N];

diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c
index 1d65b4aadfa08e85ce5ad08a1378928d068e3e08..c940d413de8c254a0be1a96848646adb10b011a7 100644 (file)
--- a/gcc/tree-ssa-loop-ivopts.c
+++ b/gcc/tree-ssa-loop-ivopts.c
@@ -3241,9 +3241,8 @@ get_address_cost (bool symbol_present, bool var_present,
   if (!data)
     {
       HOST_WIDE_INT i;
-      HOST_WIDE_INT start = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
-      HOST_WIDE_INT rat, off;
-      int old_cse_not_expected;
+      HOST_WIDE_INT rat, off = 0;
+      int old_cse_not_expected, width;
       unsigned sym_p, var_p, off_p, rat_p, add_c;
       rtx seq, addr, base;
       rtx reg0, reg1;
@@ -3252,33 +3251,40 @@ get_address_cost (bool symbol_present, bool var_present,
 
       reg1 = gen_raw_REG (address_mode, LAST_VIRTUAL_REGISTER + 1);
 
+      width = GET_MODE_BITSIZE (address_mode) - 1;
+      if (width > (HOST_BITS_PER_WIDE_INT - 1))
+       width = HOST_BITS_PER_WIDE_INT - 1;
       addr = gen_rtx_fmt_ee (PLUS, address_mode, reg1, NULL_RTX);
-      for (i = start; i <= 1 << 20; i <<= 1)
+
+      for (i = width; i >= 0; i--)
        {
-         XEXP (addr, 1) = gen_int_mode (i, address_mode);
-         if (!memory_address_addr_space_p (mem_mode, addr, as))
+         off = -((HOST_WIDE_INT) 1 << i);
+         XEXP (addr, 1) = gen_int_mode (off, address_mode);
+         if (memory_address_addr_space_p (mem_mode, addr, as))
            break;
        }
-      data->max_offset = i == start ? 0 : i >> 1;
-      off = data->max_offset;
+      data->min_offset = (i == -1? 0 : off);
 
-      for (i = start; i <= 1 << 20; i <<= 1)
+      for (i = width; i >= 0; i--)
        {
-         XEXP (addr, 1) = gen_int_mode (-i, address_mode);
-         if (!memory_address_addr_space_p (mem_mode, addr, as))
+         off = ((HOST_WIDE_INT) 1 << i) - 1;
+         XEXP (addr, 1) = gen_int_mode (off, address_mode);
+         if (memory_address_addr_space_p (mem_mode, addr, as))
            break;
        }
-      data->min_offset = i == start ? 0 : -(i >> 1);
+      if (i == -1)
+        off = 0;
+      data->max_offset = off;
 
       if (dump_file && (dump_flags & TDF_DETAILS))
        {
          fprintf (dump_file, "get_address_cost:\n");
-         fprintf (dump_file, "  min offset %s %d\n",
+         fprintf (dump_file, "  min offset %s " HOST_WIDE_INT_PRINT_DEC "\n",
                   GET_MODE_NAME (mem_mode),
-                  (int) data->min_offset);
-         fprintf (dump_file, "  max offset %s %d\n",
+                  data->min_offset);
+         fprintf (dump_file, "  max offset %s " HOST_WIDE_INT_PRINT_DEC "\n",
                   GET_MODE_NAME (mem_mode),
-                  (int) data->max_offset);
+                  data->max_offset);
        }
 
       rat = 1;