Handle same-section relocations where the destination is at an address >=

0x00400000.

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 2b7a433..d259c7c 100644 (file)
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,8 @@
+2000-03-17  Nick Clifton  <nickc@cygnus.com>
+
+       * config/tc-arm.c (md_apply_fix3): Handle same-section relocations
+       that have a destingation >= 0x400000.
+
 Thu Mar 16 23:45:16 2000  J"orn Rennecke <amylaar@cygnus.co.uk>
 
        * config/tc-sh.c (md_begin): When encountering insn that are

diff --git a/gas/config/tc-arm.c b/gas/config/tc-arm.c
index f8f43be..55cca9d 100644 (file)
--- a/gas/config/tc-arm.c
+++ b/gas/config/tc-arm.c
@@ -5560,13 +5560,63 @@ md_apply_fix3 (fixP, val, seg)
     case BFD_RELOC_ARM_PCREL_BRANCH:
       newval = md_chars_to_number (buf, INSN_SIZE);
 
+      /* Sign-extend a 24-bit number.  */
+#define SEXT24(x)      ((((x) & 0xffffff) ^ (~ 0x7fffff)) + 0x800000)
+
 #ifdef OBJ_ELF
       if (! target_oabi)
-        value = fixP->fx_offset;
+       value = fixP->fx_offset;
 #endif
-      value  = (value >> 2) & 0x00ffffff;
-      value  = (value + (newval & 0x00ffffff)) & 0x00ffffff;
-      newval = value | (newval & 0xff000000);
+
+      /* We are going to store value (shifted right by two) in the
+        instruction, in a 24 bit, signed field.  Thus we need to check
+        that none of the top 8 bits of the shifted value (top 7 bits of
+         the unshifted, unsigned value) are set, or that they are all set.  */
+      if ((value & 0xfe000000UL) != 0
+         && ((value & 0xfe000000UL) != 0xfe000000UL))
+       {
+#ifdef OBJ_ELF
+         /* Normally we would be stuck at this point, since we cannot store
+            the absolute address that is the destination of the branch in the
+            24 bits of the branch instruction.  If however, we happen to know
+            that the destination of the branch is in the same section as the
+            branch instruciton itself, then we can compute the relocation for
+            ourselves and not have to bother the linker with it.
+            
+            FIXME: The tests for OBJ_ELF and ! target_oabi are only here
+            because I have not worked out how to do this for OBJ_COFF or
+            target_oabi.  */
+         if (! target_oabi
+             && fixP->fx_addsy != NULL
+             && S_IS_DEFINED (fixP->fx_addsy)
+             && S_GET_SEGMENT (fixP->fx_addsy) == seg)
+           {
+             /* Get pc relative value to go into the branch.  */
+             value = * val;
+
+             /* Permit a backward branch provided that enough bits are set.
+                Allow a forwards branch, provided that enough bits are clear.  */
+             if ((value & 0xfe000000UL) == 0xfe000000UL
+                 || (value & 0xfe000000UL) == 0)
+               fixP->fx_done = 1;
+           }
+         
+         if (! fixP->fx_done)
+#endif
+           as_bad_where (fixP->fx_file, fixP->fx_line,
+                         _("gas can't handle same-section branch dest >= 0x04000000"));
+       }
+
+      value >>= 2;
+      value += SEXT24 (newval);
+      
+      if ((value & 0xff000000UL) != 0
+         && (fixP->fx_done == 0
+             || ((value & 0xff000000UL) != 0xff000000UL)))
+       as_bad_where (fixP->fx_file, fixP->fx_line,
+                     _("out of range branch"));
+      
+      newval = (value & 0x00ffffff) | (newval & 0xff000000);
       md_number_to_chars (buf, newval, INSN_SIZE);
       break;