The only way for the do_operation object handler to be called for unary operations is when the zval is an object.
Therefore we know we have a zval of the correct type and there is no need to check for it.
We define module globals to be used with ZPP, which also avoids excessive initializing and clearing of variables,
something recommended by the GMP documentation.
We must use `mpz_fits_si_p()` instead of `mpz_fits_slong_p()` since the
latter is not suitable for LLP64 data models.
libgmp, however, does not define `mpz_fits_si_p()` (which is an mpir
addition), so we use `mpz_fits_slong_p()` there which should be fine.
Closes GH-16891.
even without sanitizers, it is reproducible but with the following
```
<?php
$g = gmp_init(256);
var_dump(gmp_pow($g, PHP_INT_MAX));
```
we get this
```
AddressSanitizer:DEADLYSIGNAL
=================================================================
==286922==ERROR: AddressSanitizer: FPE on unknown address 0x03e8000460ca (pc 0x7faf6c69de5c bp 0x400000000000004 sp 0x7ffe9843c740 T0)
#0 0x7faf6c69de5c in __pthread_kill_implementation nptl/pthread_kill.c:44
#1 0x7faf6c649c81 in __GI_raise ../sysdeps/posix/raise.c:26
#2 0x7faf6db9386c in __gmp_exception (/lib/x86_64-linux-gnu/libgmp.so.10+0xd86c) (BuildId: 1af68a49fe041a5bb48a2915c3d47541f713bb38)
#3 0x7faf6db938d3 in __gmp_overflow_in_mpz (/lib/x86_64-linux-gnu/libgmp.so.10+0xd8d3) (BuildId: 1af68a49fe041a5bb48a2915c3d47541f713bb38)
#4 0x7faf6dbac95c in __gmpz_realloc (/lib/x86_64-linux-gnu/libgmp.so.10+0x2695c) (BuildId: 1af68a49fe041a5bb48a2915c3d47541f713bb38)
#5 0x7faf6dba9038 in __gmpz_n_pow_ui (/lib/x86_64-linux-gnu/libgmp.so.10+0x23038) (BuildId: 1af68a49fe041a5bb48a2915c3d47541f713bb38)
#6 0x5565ae1ccd9f in zif_gmp_pow /home/dcarlier/Contribs/php-src/ext/gmp/gmp.c:1286
#7 0x5565aee96ea9 in ZEND_DO_ICALL_SPEC_RETVAL_USED_HANDLER /home/dcarlier/Contribs/php-src/Zend/zend_vm_execute.h:1312
#8 0x5565af144320 in execute_ex /home/dcarlier/Contribs/php-src/Zend/zend_vm_execute.h:56075
#9 0x5565af160f07 in zend_execute /home/dcarlier/Contribs/php-src/Zend/zend_vm_execute.h:60439
#10 0x5565aed6fafe in zend_execute_scripts /home/dcarlier/Contribs/php-src/Zend/zend.c:1842
#11 0x5565aeae70a8 in php_execute_script /home/dcarlier/Contribs/php-src/main/main.c:2578
#12 0x5565af532f4e in do_cli /home/dcarlier/Contribs/php-src/sapi/cli/php_cli.c:964
#13 0x5565af535877 in main /home/dcarlier/Contribs/php-src/sapi/cli/php_cli.c:1334
#14 0x7faf6c633d67 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
#15 0x7faf6c633e24 in __libc_start_main_impl ../csu/libc-start.c:360
#16 0x5565adc04040 in _start (/home/dcarlier/Contribs/php-src/sapi/cli/php+0x2604040) (BuildId: 949049955bdf8b7197390b1978a1dfc3ef6fdf38)
AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: FPE nptl/pthread_kill.c:44 in __pthread_kill_implementation
==286922==ABORTING
```
close GH-16384
We need not only to avoid the signed overflow while calculating
`bits_per_word` (reported issue), but also the unsigned overflow when
calculating `count`. While the former has a fixed threshold, the
latter does not, since it also depends on the size in base 2. Thus we
use a somewhat unconventional error message.
Closes GH-16418.
brainpower