http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51244
--- Comment #33 from Kazumoto Kojima <kkojima at gcc dot gnu.org> 2012-03-15
07:52:21 UTC ---
(In reply to comment #31)
> Created attachment 26859 [details]
> testresult on sh4-unknown-linux-gnu [trunk revision 185088].
FYI, looking into the libstdc++ failures for sh4-unknown-linux-gnu,
it seems that the call insn was swapped before prologue frame insns
and then it makes unwinder confused. -fno-delayed-branch also stops
that swapping for these failing cases. The patch below works for me.
* config/sh/sh.c (sh_expand_prologue): Emit blockage at the end
of prologue for unwinder and profiler.
--- ORIG/trunk/gcc/config/sh/sh.c 2012-03-06 10:28:32.000000000 +0900
+++ trunk/gcc/config/sh/sh.c 2012-03-14 20:22:15.000000000 +0900
@@ -7234,6 +7234,13 @@ sh_expand_prologue (void)
emit_insn (gen_shcompact_incoming_args ());
}
+ /* If we are profiling, make sure no instructions are scheduled before
+ the call to mcount. Similarly if some call instructions are swapped
+ before frame related insns, it'll make unwinder confused because
+ currently SH has no unwind info for function epilogues. */
+ if (crtl->profile || flag_exceptions || flag_unwind_tables)
+ emit_insn (gen_blockage ());
+
if (flag_stack_usage_info)
current_function_static_stack_size = stack_usage;
}
