https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85260
Bug ID: 85260
Summary: 8.0: python-2.7.14 miscompiled at -O3
Product: gcc
Version: 8.0.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: manuel.lauss at googlemail dot com
Target Milestone: ---
python-2.7.14 seems to be miscompiled at -O3, while -O2 is fine.
gcc-8 as of 20180405. gcc-7.3.1 -O3 is fine as well.
build # LD_LIBRARY_PATH=$PWD ./python
Segmentation fault (core dumped)
#0 0x00007f784416d43a in PyInstance_NewRaw (klass=klass@entry=0x7f78439209a8,
dict=0x7f7843d66910, dict@entry=0x0) at
/tmp-ram/portage/dev-lang/python-2.7.14-r1/work/Python-2.7.14/Objects/classobject.c:544
544 inst->in_dict = dict;
(gdb) list
539 return NULL;
540 }
541 inst->in_weakreflist = NULL;
542 Py_INCREF(klass);
543 inst->in_class = (PyClassObject *)klass;
544 inst->in_dict = dict;
545 _PyObject_GC_TRACK(inst);
546 return (PyObject *)inst;
547 }
Dump of assembler code for function PyInstance_NewRaw:
0x00007f784416d3d0 <+0>: push %rbp
0x00007f784416d3d1 <+1>: push %rbx
0x00007f784416d3d2 <+2>: sub $0x18,%rsp
0x00007f784416d3d6 <+6>: mov 0x149b9b(%rip),%rax #
0x7f78442b6f78
0x00007f784416d3dd <+13>: cmp %rax,0x8(%rdi)
0x00007f784416d3e1 <+17>: jne 0x7f784416d490 <PyInstance_NewRaw+192>
0x00007f784416d3e7 <+23>: mov %rdi,%rbx
0x00007f784416d3ea <+26>: mov %rsi,%rbp
0x00007f784416d3ed <+29>: test %rsi,%rsi
0x00007f784416d3f0 <+32>: je 0x7f784416d4b0 <PyInstance_NewRaw+224>
0x00007f784416d3f6 <+38>: mov 0x8(%rsi),%rax
0x00007f784416d3fa <+42>: testb $0x20,0xab(%rax)
0x00007f784416d401 <+49>: je 0x7f784416d4d0 <PyInstance_NewRaw+256>
0x00007f784416d407 <+55>: incq (%rsi)
0x00007f784416d40a <+58>: mov 0x1496cf(%rip),%rdi #
0x7f78442b6ae0
0x00007f784416d411 <+65>: callq 0x7f784414a390 <_PyObject_GC_New@plt>
0x00007f784416d416 <+70>: test %rax,%rax
0x00007f784416d419 <+73>: je 0x7f784416d4e8 <PyInstance_NewRaw+280>
0x00007f784416d41f <+79>: vmovq %rbx,%xmm1
0x00007f784416d424 <+84>: movq $0x0,0x20(%rax)
0x00007f784416d42c <+92>: vpinsrq $0x1,%rbp,%xmm1,%xmm0
0x00007f784416d432 <+98>: incq (%rbx)
0x00007f784416d435 <+101>: cmpq $0xfffffffffffffffe,-0x10(%rax)
=> 0x00007f784416d43a <+106>: vmovaps %xmm0,0x10(%rax)
0x00007f784416d43f <+111>: lea -0x20(%rax),%rbx
0x00007f784416d443 <+115>: jne 0x7f784416d478 <PyInstance_NewRaw+168>
0x00007f784416d445 <+117>: mov 0x149834(%rip),%rdx #
0x7f78442b6c80
0x00007f784416d44c <+124>: movq $0xfffffffffffffffd,-0x10(%rax)
0x00007f784416d454 <+132>: mov (%rdx),%rcx
0x00007f784416d457 <+135>: mov %rcx,-0x20(%rax)
0x00007f784416d45b <+139>: mov 0x8(%rcx),%rcx
0x00007f784416d45f <+143>: mov %rcx,-0x18(%rax)
0x00007f784416d463 <+147>: mov %rbx,(%rcx)
0x00007f784416d466 <+150>: mov (%rdx),%rdx
0x00007f784416d469 <+153>: mov %rbx,0x8(%rdx)
0x00007f784416d46d <+157>: add $0x18,%rsp
0x00007f784416d471 <+161>: pop %rbx
0x00007f784416d472 <+162>: pop %rbp
0x00007f784416d473 <+163>: retq
0x00007f784416d474 <+164>: nopl 0x0(%rax)
0x00007f784416d478 <+168>: lea 0xf4d1d(%rip),%rdi #
0x7f784426219c
0x00007f784416d47f <+175>: mov %rax,0x8(%rsp)
0x00007f784416d484 <+180>: callq 0x7f784414b980 <Py_FatalError@plt>
0x00007f784416d489 <+185>: mov 0x8(%rsp),%rax
0x00007f784416d48e <+190>: jmp 0x7f784416d445 <PyInstance_NewRaw+117>
0x00007f784416d490 <+192>: mov $0x209,%esi
0x00007f784416d495 <+197>: lea 0xf6184(%rip),%rdi #
0x7f7844263620
0x00007f784416d49c <+204>: callq 0x7f784414c090
<_PyErr_BadInternalCall@plt>
0x00007f784416d4a1 <+209>: add $0x18,%rsp
0x00007f784416d4a5 <+213>: xor %eax,%eax
0x00007f784416d4a7 <+215>: pop %rbx
0x00007f784416d4a8 <+216>: pop %rbp
0x00007f784416d4a9 <+217>: retq
0x00007f784416d4aa <+218>: nopw 0x0(%rax,%rax,1)
0x00007f784416d4b0 <+224>: callq 0x7f784414be40 <PyDict_New@plt>
0x00007f784416d4b5 <+229>: mov %rax,%rbp
[...]
configured with
CFLAGS="-O3 -march=haswell -mtune=haswell -pipe"
./configure --prefix=/usr --build=x86_64-pc-linux-gnu
--host=x86_64-pc-linux-gnu --mandir=/usr/share/man --infodir=/usr/share/info
--datadir=/usr/share --sysconfdir=/etc --localstatedir=/var/lib
--libdir=/usr/lib64 --with-fpectl --enable-shared --enable-ipv6 --with-threads
--enable-unicode=ucs4 --infodir=${prefix}/share/info
--mandir=${prefix}/share/man --with-computed-gotos --with-dbmliborder=gdbm
--with-libc= --enable-loadable-sqlite-extensions --with-system-expat
--with-system-ffi --without-ensurepip
Thanks,
Manuel
