https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80759
--- Comment #49 from ro at CeBiTec dot Uni-Bielefeld.DE <ro at CeBiTec dot
Uni-Bielefeld.DE> ---
> --- Comment #47 from Daniel Santos <daniel.santos at pobox dot com> ---
[...]
> I'm sorry for the delay again. I've been having some health problems
> infringing upon my hacking time.
No worries at all: don't even think about this stuff before you're well again!
> I wanted to study the use of __USER_LABEL_PREFIX__ to make sure I understand
> the implications. I'm not completely clear on rather or not this is
> automatically applied when a back end uses gen_rtx_SYMBOL_REF (or some such),
> but guess is that it is. It is also plausible to omit Darwin support for now,
That's my understanding as well.
> as I've learned that 64-bit Wine isn't yet working for Darwin either. If
> there
> are further problems, then that might be the smartest way to go since I don't
> have access to such a machine witch which I can test, experiment, debug, etc.
> But if this does the trick, then all the better.
We're getting considerably closer with this latest patch. I'll describe
the current issues below; maybe some of them are issues even beyond Darwin.
> I changed the C() macro to ASMNAME() just because I prefer helpful names and I
> decided to yank out all of the FUNC_BEGIN/FUNC_END macros from ms-sysv.c and
> just use #if directives directly in the string definition. There's no sense
> in
> maintaining a separate set of asm support macros dealing in strings when
> there's only one use site.
Fine with me. The new names are certainly more expressive, while I'd
just ripped the definitions out of libffi to see if I could something
working that way at all.
> I also noticed a possible "gotcha" with the #if __x86_64__ and __SSE2__ -- not
> that I would expect necessarily expect it to happen.
I'm not sure this is even possible...
> In hopes of making your review easier, below is a delta between this new (v6)
> patch set and your last posted patches.
The new patch works fine for me on both x86_64-pc-linux-gnu (as
expected) and i386-pc-solaris2.12.
On x86_64-apple-darwin11.4.2, there are a couple of isues, some of which
I'd already resolved before you posted the revised patch.
* Initially all tests SEGVed like this (e.g. with -p0 and compiled with -O2):
Program received signal SIGSEGV, Segmentation fault.
0x000000010004664d in regs_to_mem ()
1: x/i $pc
=> 0x10004664d <regs_to_mem>: movaps %xmm6,(%rax)
(gdb) where
#0 0x000000010004664d in regs_to_mem ()
#1 0x00000001000465df in do_test_body ()
#2 0x000000010002f227 in do_tests_0000 ()
#3 0x00000001000468e3 in main ()
Here, %rax is 0x0.
This happens because some setup happens between do_test_body0 and
do_test_body, and do_test_aligned jumps directly to do_test_body:
.globl _do_test_body0
.no_dead_strip _do_test_body0
_do_test_body0:
movq _test_data@GOTPCREL(%rip), %rax
.globl _do_test_body
_do_test_body:
# Save registers.
lea (%rax), %rax
call _regs_to_mem
By that jump, you bypass the setup of %rax and make the test FAIL. I
managed to avoid this by changing the jmp to do_test_body0 instead.
This gets me past this failure, and works on Linux/x86_64, too.
However, this makes the tests FAIL on Solaris/x86, supposedly due to
the -fomit-frame-pointer/-fno-omit-frame-pointer difference (though I
haven't looked more closely).
* With the do_test_body0 jump, I hit the next issue on Darwin with -O0:
the test SEGVs here:
Program received signal SIGSEGV, Segmentation fault.
0x0000000100031c4e in do_test_body0 ()
at
/vol/gcc/src/hg/trunk/solaris/gcc/testsuite/gcc.target/x86_64/abi/ms-sysv/ms-sysv.c:163
163 __asm__ ("\n"
1: x/i $pc
=> 0x100031c4e <do_test_body0+21>: mov %rax,0x2a8(%rdi)
(gdb) where
(gdb) p/x $rdi
$1 = 0x5dc3340b214ef45c
which is no wonder since %rdi got clobbered just before. Here's the
assembler output:
.globl _do_test_body0
.no_dead_strip _do_test_body0
_do_test_body0:
pushq %rbp
movq %rsp, %rbp
movq _test_data@GOTPCREL(%rip), %rax
movq _test_data@GOTPCREL(%rip), %rdx
movq _test_data@GOTPCREL(%rip), %rcx
movq _test_data@GOTPCREL(%rip), %rsi
movq _test_data@GOTPCREL(%rip), %rdi
.globl _do_test_body
_do_test_body:
# Save registers.
lea (%rax), %rax
call _regs_to_mem
# Load registers with random data.
lea 224(%rdx), %rax
call _mem_to_regs
# Save original return address.
pop %rax
movq %rax, 680(%rdi)
# Call the test function
call *672(%rsi)
# Restore the original return address.
movq 680(%rdi), %rcx
push %rcx
By clobbering %rdi (and %rsi), you cause the SEGV above. To work
around this, I've wrapped the save/restore of those regs in !__APPLE__
which gets me a bit further.
* Now I hit another SEGV here:
Program received signal SIGSEGV, Segmentation fault.
0x0000000100001922 in msabi_00_0 ()
at
/var/gcc/regression/trunk/10.7-gcc/build/gcc/testsuite/gcc/ms-sysv/ms-sysv-generated.h:16
16 {
1: x/i $pc
=> 0x100001922 <msabi_00_0+13>: movaps %xmm6,(%rsp)
(gdb) where
#0 0x0000000100001922 in msabi_00_0 ()
at
/var/gcc/regression/trunk/10.7-gcc/build/gcc/testsuite/gcc/ms-sysv/ms-sysv-generated.h:16
#1 0x0000000100031c77 in do_test_body0 ()
at
/vol/gcc/src/hg/trunk/solaris/gcc/testsuite/gcc.target/x86_64/abi/ms-sysv/ms-sysv.c:163
Cannot access memory at address 0x6fdc16ba5f5f46bc
At this point I gave up for now...
Here's the snippet I've been using to get that far:
diff --git a/gcc/testsuite/gcc.target/x86_64/abi/ms-sysv/do-test.S
b/gcc/testsuite/gcc.target/x86_64/abi/ms-sysv/do-test.S
--- a/gcc/testsuite/gcc.target/x86_64/abi/ms-sysv/do-test.S
+++ b/gcc/testsuite/gcc.target/x86_64/abi/ms-sysv/do-test.S
@@ -69,8 +69,10 @@ FUNC_BEGIN(regs_to_mem)
MOVAPS %xmm13, 0x70(%rax)
MOVAPS %xmm14, 0x80(%rax)
MOVAPS %xmm15, 0x90(%rax)
+#ifndef __APPLE__
mov %rsi, 0xa0(%rax)
mov %rdi, 0xa8(%rax)
+#endif
mov %rbx, 0xb0(%rax)
mov %rbp, 0xb8(%rax)
mov %r12, 0xc0(%rax)
@@ -91,8 +93,10 @@ FUNC_BEGIN(mem_to_regs)
MOVAPS 0x70(%rax),%xmm13
MOVAPS 0x80(%rax),%xmm14
MOVAPS 0x90(%rax),%xmm15
+#ifndef __APPLE__
mov 0xa0(%rax),%rsi
mov 0xa8(%rax),%rdi
+#endif
mov 0xb0(%rax),%rbx
mov 0xb8(%rax),%rbp
mov 0xc0(%rax),%r12
@@ -121,7 +125,11 @@ FUNC_BEGIN(do_test_aligned)
int $3 # Stack not aligned
L0:
popf
+#ifdef __APPLE__
+ jmp ASMNAME(do_test_body0)
+#else
jmp ASMNAME(do_test_body)
+#endif
FUNC_END(do_test_aligned)
FUNC_END(do_test_unaligned)
Rainer
