[Bug target/36827] [4.3/4.4 Regression] newlib:libm/math/k_rem_pio2.c fails in reload

[joseph at codesourcery dot com]

------- Comment #5 from joseph at codesourcery dot com  2008-07-15 15:41 -------
Subject: Re:   New: newlib:libm/math/k_rem_pio2.c fails in reload

Please try this patch.  The m32c target seems to be generating its own 
invalid addresses and reloads for them, for reasons I don't quite 
understand, so something like this looks like it's needed to avoid reload 
generating further reloads in those cases.

Index: config/m32c/m32c.c
===================================================================
--- config/m32c/m32c.c  (revision 137836)
+++ config/m32c/m32c.c  (working copy)
@@ -1778,6 +1778,8 @@

 /* Addressing Modes */

+#define BIG_FB_ADJ 0
+
 /* Used by GO_IF_LEGITIMATE_ADDRESS.  The r8c/m32c family supports a
    wide range of non-orthogonal addressing modes, including the
    ability to double-indirect on *some* of them.  Not all insns
@@ -1895,6 +1897,17 @@
          return 0;
        }
     }
+  if (RTX_IS ("++rii"))
+    {
+      rtx reg = patternr[2];
+      HOST_WIDE_INT offs = INTVAL (patternr[3]);
+
+      /* Avoid reloads for addresses generated by
+        m32c_legitimize_reload_address being generated by
+        find_reloads_subreg_address.  */
+      if (REGNO (reg) == FB_REGNO && offs == -BIG_FB_ADJ)
+       return 1;
+    }
   return 0;
 }

@@ -1942,8 +1955,6 @@
    frame, so the third case seems best.  Note that we subtract the
    zero, but detect that in the addhi3 pattern.  */

-#define BIG_FB_ADJ 0
-
 /* Implements LEGITIMIZE_ADDRESS.  The only address we really have to
    worry about is frame base offsets, as $fb has a limited
    displacement range.  We deal with this by attempting to reload $fb


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36827