https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102566
--- Comment #11 from Thiago Macieira <thiago at kde dot org> ---
$ for ((i=0;i<32;++i)); do ~/dev/gcc/bin/gcc "-DCONSTANT=(1<<$i)" -S -o - -O2
/tmp/test.cpp | grep bts; done
lock btsl $0, (%rdi)
lock btsl $1, (%rdi)
lock btsl $2, (%rdi)
lock btsl $3, (%rdi)
lock btsl $4, (%rdi)
lock btsl $5, (%rdi)
lock btsl $6, (%rdi)
lock btsl $7, (%rdi)
lock btsl $8, (%rdi)
lock btsl $9, (%rdi)
lock btsl $10, (%rdi)
lock btsl $11, (%rdi)
lock btsl $12, (%rdi)
lock btsl $13, (%rdi)
lock btsl $14, (%rdi)
lock btsl $15, (%rdi)
lock btsl $16, (%rdi)
lock btsl $17, (%rdi)
lock btsl $18, (%rdi)
lock btsl $19, (%rdi)
lock btsl $20, (%rdi)
lock btsl $21, (%rdi)
lock btsl $22, (%rdi)
lock btsl $23, (%rdi)
lock btsl $24, (%rdi)
lock btsl $25, (%rdi)
lock btsl $26, (%rdi)
lock btsl $27, (%rdi)
lock btsl $28, (%rdi)
lock btsl $29, (%rdi)
lock btsl $30, (%rdi)
lock btsl $31, (%rdi)
And after changing to long:
$ for ((i=32;i<64;++i)); do ~/dev/gcc/bin/gcc "-DCONSTANT=(1L<<$i)" -S -o - -O2
/tmp/test.cpp | grep bts; done
lock btsq $32, (%rdi)
lock btsq $33, (%rdi)
lock btsq $34, (%rdi)
lock btsq $35, (%rdi)
lock btsq $36, (%rdi)
lock btsq $37, (%rdi)
lock btsq $38, (%rdi)
lock btsq $39, (%rdi)
lock btsq $40, (%rdi)
lock btsq $41, (%rdi)
lock btsq $42, (%rdi)
lock btsq $43, (%rdi)
lock btsq $44, (%rdi)
lock btsq $45, (%rdi)
lock btsq $46, (%rdi)
lock btsq $47, (%rdi)
lock btsq $48, (%rdi)
lock btsq $49, (%rdi)
lock btsq $50, (%rdi)
lock btsq $51, (%rdi)
lock btsq $52, (%rdi)
lock btsq $53, (%rdi)
lock btsq $54, (%rdi)
lock btsq $55, (%rdi)
lock btsq $56, (%rdi)
lock btsq $57, (%rdi)
lock btsq $58, (%rdi)
lock btsq $59, (%rdi)
lock btsq $60, (%rdi)
lock btsq $61, (%rdi)
lock btsq $62, (%rdi)
lock btsq $63, (%rdi)
But:
$ cat /tmp/test2.cpp
#include <atomic>
bool tbit(std::atomic<long> &i)
{
return i.fetch_or(1, std::memory_order_relaxed) & (~1);
}
$ ~/dev/gcc/bin/gcc -S -o - -O2 /tmp/test2.cpp
.file "test.cpp"
.text
/tmp/test.cpp: In function ‘bool tbit(std::atomic<long int>&)’:
/tmp/test.cpp:2:6: error: type mismatch in binary expression
2 | bool tbit(std::atomic<long> &i)
| ^~~~
long int
long unsigned int
__int_type
_9 = _6 & -2;
during GIMPLE pass: fab
/tmp/test.cpp:2:6: internal compiler error: verify_gimple failed
0x119fbba verify_gimple_in_cfg(function*, bool)
/home/tjmaciei/src/gcc/gcc/tree-cfg.c:5576
0x106ced7 execute_function_todo
/home/tjmaciei/src/gcc/gcc/passes.c:2042
0x106d8fb execute_todo
/home/tjmaciei/src/gcc/gcc/passes.c:2096
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
