Patchwork wide-int branch

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Submitter Kenneth Zadeck
Date Aug. 25, 2013, 6:57 p.m.
Message ID <521A5384.2060505@naturalbridge.com>
Download mbox | patch
Permalink /patch/269720/
State New
Headers show

Comments

Kenneth Zadeck - Aug. 25, 2013, 6:57 p.m.
cleaned up code to get around tree-vrp issue.   added some code that 
richard is going to play with to see how hard it would be to clean up 
rtl constants.

kenny

Patch

Index: gcc/wide-int.cc
===================================================================
--- gcc/wide-int.cc	(revision 201968)
+++ gcc/wide-int.cc	(working copy)
@@ -171,6 +171,12 @@  wide_int_ro::from_rtx (const rtx_mode_t
     case CONST_INT:
       result.val[0] = INTVAL (x);
       result.len = 1;
+
+#if 0
+      if (prec != HOST_BITS_PER_WIDE_INT)
+	gcc_assert (result.val[0] == sext_hwi (result.val[0], prec));
+#endif
+
 #ifdef DEBUG_WIDE_INT
       debug_wh ("wide_int:: %s = from_rtx ("HOST_WIDE_INT_PRINT_HEX")\n",
 		result, INTVAL (x));
Index: gcc/wide-int.h
===================================================================
--- gcc/wide-int.h	(revision 201968)
+++ gcc/wide-int.h	(working copy)
@@ -1843,7 +1843,6 @@  wide_int_ro::zforce_to_size (unsigned in
 inline HOST_WIDE_INT
 wide_int_ro::sign_mask () const
 {
-  int i = len - 1;
   if (precision < HOST_BITS_PER_WIDE_INT)
     {
       /* We don't allow a int:0 inside a struct to get this far,
@@ -1853,14 +1852,13 @@  wide_int_ro::sign_mask () const
 	      >> (HOST_BITS_PER_WIDE_INT - 1));
     }
 
-  /* VRP appears to be badly broken and this is a very ugly fix.  */
-  if (i >= 0)
-    return val[i] >> (HOST_BITS_PER_WIDE_INT - 1);
-
-  gcc_unreachable ();
-#if 0
-  return val[len - 1] >> (HOST_BITS_PER_WIDE_INT - 1);
-#endif
+  /* TREE_VRP is not able to see that it is not possible for len to be
+     0.  So without this test, it warns about this which causes
+     bootstrap failures.  */
+  if (len < 1)
+    gcc_unreachable ();
+  else
+    return val[len - 1] >> (HOST_BITS_PER_WIDE_INT - 1);
 }
 
 /* Return THIS & C.  */