+2008-06-04 Joseph Myers <joseph@codesourcery.com>
+ Maxim Kuvyrkov <maxim@codesourcery.com>
+
+ * config/m68k/m68k.opt (mxgot): New option.
+ * config/m68k/m68k.c (legitimize_pic_address): Handle -mxgot.
+ (m68k_output_addr_const_extra): New.
+ * config/m68k/m68k.h (OUTPUT_ADDR_CONST_EXTRA): New.
+ * config/m68k/m68k-protos.h (m68k_output_addr_const_extra): Declare.
+ * config/m68k/m68k.md (UNSPEC_GOTOFF): Define.
+ * doc/invoke.texi (M680x0 Options): Document -mxgot.
+
2008-06-04 Richard Guenther <rguenther@suse.de>
* tree-ssa-structalias.c (handle_ptr_arith): Correctly handle
extern int standard_68881_constant_p (rtx);
extern void print_operand_address (FILE *, rtx);
extern void print_operand (FILE *, rtx, int);
+extern bool m68k_output_addr_const_extra (FILE *, rtx);
extern void notice_update_cc (rtx, rtx);
extern bool m68k_legitimate_base_reg_p (rtx, bool);
extern bool m68k_legitimate_index_reg_p (rtx, bool);
{
gcc_assert (reg);
- pic_ref = gen_rtx_MEM (Pmode,
- gen_rtx_PLUS (Pmode,
- pic_offset_table_rtx, orig));
+ if (TARGET_COLDFIRE && TARGET_XGOT)
+ /* When compiling with -mxgot switch the code for the above
+ example will look like this:
+
+ movel a5, a0
+ addl _foo@GOT, a0
+ movel a0@, a0
+ movel #12345, a0@ */
+ {
+ rtx pic_offset;
+
+ /* Wrap ORIG in UNSPEC_GOTOFF to tip m68k_output_addr_const_extra
+ to put @GOT after reference. */
+ pic_offset = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, orig),
+ UNSPEC_GOTOFF);
+ pic_offset = gen_rtx_CONST (Pmode, pic_offset);
+ emit_move_insn (reg, pic_offset);
+ emit_insn (gen_addsi3 (reg, reg, pic_offset_table_rtx));
+ pic_ref = gen_rtx_MEM (Pmode, reg);
+ }
+ else
+ pic_ref = gen_rtx_MEM (Pmode,
+ gen_rtx_PLUS (Pmode,
+ pic_offset_table_rtx, orig));
crtl->uses_pic_offset_table = 1;
MEM_READONLY_P (pic_ref) = 1;
emit_move_insn (reg, pic_ref);
}
}
+/* m68k implementation of OUTPUT_ADDR_CONST_EXTRA. */
+
+bool
+m68k_output_addr_const_extra (FILE *file, rtx x)
+{
+ if (GET_CODE (x) != UNSPEC || XINT (x, 1) != UNSPEC_GOTOFF)
+ return false;
+
+ output_addr_const (file, XVECEXP (x, 0, 0));
+ /* ??? What is the non-MOTOROLA syntax? */
+ fputs ("@GOT", file);
+ return true;
+}
+
\f
/* A C compound statement to output to stdio stream STREAM the
assembler syntax for an instruction operand that is a memory
#define PRINT_OPERAND_ADDRESS(FILE, ADDR) print_operand_address (FILE, ADDR)
+#define OUTPUT_ADDR_CONST_EXTRA(FILE, X, FAIL) \
+do { \
+ if (! m68k_output_addr_const_extra (FILE, (X))) \
+ goto FAIL; \
+} while (0);
+
/* Values used in the MICROARCH argument to M68K_DEVICE. */
enum uarch_type
{
(UNSPEC_GOT 3)
(UNSPEC_IB 4)
(UNSPEC_TIE 5)
+ (UNSPEC_GOTOFF 6)
])
;; UNSPEC_VOLATILE usage:
mtune=
Target RejectNegative Joined
Tune for the specified target CPU or architecture
+
+mxgot
+Target Report Mask(XGOT)
+Support more than 8192 GOT entries on ColdFire
-mnobitfield -mrtd -mno-rtd -mdiv -mno-div -mshort @gol
-mno-short -mhard-float -m68881 -msoft-float -mpcrel @gol
-malign-int -mstrict-align -msep-data -mno-sep-data @gol
--mshared-library-id=n -mid-shared-library -mno-id-shared-library}
+-mshared-library-id=n -mid-shared-library -mno-id-shared-library @gol
+-mxgot -mno-xgot}
@emph{M68hc1x Options}
@gccoptlist{-m6811 -m6812 -m68hc11 -m68hc12 -m68hcs12 @gol
other values will force the allocation of that number to the current
library but is no more space or time efficient than omitting this option.
+@item -mxgot
+@itemx -mno-xgot
+@opindex mxgot
+@opindex mno-xgot
+When generating position-independent code for ColdFire, generate code
+that works if the GOT has more than 8192 entries. This code is
+larger and slower than code generated without this option. On M680x0
+processors, this option is not needed; @option{-fPIC} suffices.
+
+GCC normally uses a single instruction to load values from the GOT@.
+While this is relatively efficient, it only works if the GOT
+is smaller than about 64k. Anything larger causes the linker
+to report an error such as:
+
+@cindex relocation truncated to fit (ColdFire)
+@smallexample
+relocation truncated to fit: R_68K_GOT16O foobar
+@end smallexample
+
+If this happens, you should recompile your code with @option{-mxgot}.
+It should then work with very large GOTs. However, code generated with
+@option{-mxgot} is less efficient, since it takes 4 instructions to fetch
+the value of a global symbol.
+
+Note that some linkers, including newer versions of the GNU linker,
+can create multiple GOTs and sort GOT entries. If you have such a linker,
+you should only need to use @option{-mxgot} when compiling a single
+object file that accesses more than 8192 GOT entries. Very few do.
+
+These options have no effect unless GCC is generating
+position-independent code.
+
@end table
@node M68hc1x Options
+2008-06-04 Joseph Myers <joseph@codesourcery.com>
+ Maxim Kuvyrkov <maxim@codesourcery.com>
+
+ * gcc.target/m68k/xgot-1.c: New test.
+
2008-06-04 Richard Guenther <rguenther@suse.de>
* gcc.c-torture/execute/20080604-1.c: New testcase.
--- /dev/null
+/* { dg-do compile } */
+/* { dg-options "-fpic -mxgot" } */
+/* { dg-final { scan-assembler "foo@GOT,\%\[ad\]\[0-7\]" } } */
+
+extern int foo;
+
+int
+bar (void)
+{
+ return foo;
+}
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