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Fix PR target/22260
- From: Eric Botcazou <ebotcazou at libertysurf dot fr>
- To: gcc-patches at gcc dot gnu dot org
- Cc: Mark Mitchell <mark at codesourcery dot com>
- Date: Fri, 1 Jul 2005 02:21:24 +0200
- Subject: Fix PR target/22260
This is an embarassing thinko in the new code to emit thunks without using
delay slots if -fno-delayed-branch, for example at -O0 (retrospectively, I
wonder whether adding this code was such a good idea), a regression present
in the 4.x compilers.
Loading the PIC register in the thunk clobbers %o7... but also the PIC
register itself that may have pointed to another GOT up to now.
Tested on sparc-sun-solaris2.8, applied to mainline and 4.0 branch as it's a
serious wrong code generation bug for C++.
2005-06-30 Eric Botcazou <ebotcazou@libertysurf.fr>
PR target/22260
* config/sparc/sparc.c (emit_and_preserve): Add 2nd register.
Preserve the 2nd register too, if present.
(sparc_output_mi_thunk) <PIC case>: Preserve the PIC register too.
Adjust call to emit_and_preserve.
--
Eric Botcazou
Index: config/sparc/sparc.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/sparc/sparc.c,v
retrieving revision 1.354.8.5
diff -u -p -r1.354.8.5 sparc.c
--- config/sparc/sparc.c 10 May 2005 16:02:49 -0000 1.354.8.5
+++ config/sparc/sparc.c 30 Jun 2005 23:39:33 -0000
@@ -8895,17 +8895,26 @@ sparc_rtx_costs (rtx x, int code, int ou
}
}
-/* Emit the sequence of insns SEQ while preserving the register REG. */
+/* Emit the sequence of insns SEQ while preserving the registers. */
static void
-emit_and_preserve (rtx seq, rtx reg)
+emit_and_preserve (rtx seq, rtx reg, rtx reg2)
{
+ /* STACK_BOUNDARY guarantees that this is a 2-word slot. */
rtx slot = gen_rtx_MEM (word_mode,
plus_constant (stack_pointer_rtx, SPARC_STACK_BIAS));
emit_insn (gen_stack_pointer_dec (GEN_INT (STACK_BOUNDARY/BITS_PER_UNIT)));
emit_insn (gen_rtx_SET (VOIDmode, slot, reg));
+ if (reg2)
+ emit_insn (gen_rtx_SET (VOIDmode,
+ adjust_address (slot, word_mode, UNITS_PER_WORD),
+ reg2));
emit_insn (seq);
+ if (reg2)
+ emit_insn (gen_rtx_SET (VOIDmode,
+ reg2,
+ adjust_address (slot, word_mode, UNITS_PER_WORD)));
emit_insn (gen_rtx_SET (VOIDmode, reg, slot));
emit_insn (gen_stack_pointer_inc (GEN_INT (STACK_BOUNDARY/BITS_PER_UNIT)));
}
@@ -9046,11 +9055,12 @@ sparc_output_mi_thunk (FILE *file, tree
{
/* The hoops we have to jump through in order to generate a sibcall
without using delay slots... */
- rtx spill_reg, seq, scratch = gen_rtx_REG (Pmode, 1);
+ rtx spill_reg, spill_reg2, seq, scratch = gen_rtx_REG (Pmode, 1);
if (flag_pic)
{
spill_reg = gen_rtx_REG (word_mode, 15); /* %o7 */
+ spill_reg2 = gen_rtx_REG (word_mode, PIC_OFFSET_TABLE_REGNUM);
start_sequence ();
/* Delay emitting the PIC helper function because it needs to
change the section and we are emitting assembly code. */
@@ -9058,7 +9068,7 @@ sparc_output_mi_thunk (FILE *file, tree
scratch = legitimize_pic_address (funexp, Pmode, scratch);
seq = get_insns ();
end_sequence ();
- emit_and_preserve (seq, spill_reg);
+ emit_and_preserve (seq, spill_reg, spill_reg2);
}
else if (TARGET_ARCH32)
{
@@ -9087,7 +9097,7 @@ sparc_output_mi_thunk (FILE *file, tree
sparc_emit_set_symbolic_const64 (scratch, funexp, spill_reg);
seq = get_insns ();
end_sequence ();
- emit_and_preserve (seq, spill_reg);
+ emit_and_preserve (seq, spill_reg, 0);
break;
default: