https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113907
--- Comment #16 from Sam James <sjames at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #14
> So it certainly doesn't surprise me some length < 8 check is optimized away
> given the above range info. The question is if it is correct and what
> values the length actually get at runtime if you e.g. compile with -O0.
(gdb) b uprv_copyArray16
Breakpoint 1 at 0xf770e71b: file udataswp.cpp, line 147.
(gdb) b uprv_copyArray64
Breakpoint 2 at 0xf770e7ba: file udataswp.cpp, line 164.
(gdb) r
Breakpoint 1, uprv_copyArray16 (ds=0x5655e4f0, inData=0xf32a4010, length=2,
outData=0xf7f24094, pErrorCode=0xffffc47c) at udataswp.cpp:147
147 if(pErrorCode==nullptr || U_FAILURE(*pErrorCode)) {
(gdb) c
Continuing.
Breakpoint 1, uprv_copyArray16 (ds=0x5655e4f0, inData=0xf32a4014, length=4,
outData=0xf7f24098, pErrorCode=0xffffc47c) at udataswp.cpp:147
147 if(pErrorCode==nullptr || U_FAILURE(*pErrorCode)) {
(gdb) c
Continuing.
[Inferior 1 (process 2861598) exited normally]
(gdb)
Oops.
