https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110052
--- Comment #4 from Bernhard Reutner-Fischer <aldot at gcc dot gnu.org> ---
(In reply to Bernhard Reutner-Fischer from comment #3)
> Note that in this particular case myrealloc() is static, maybe i should have
> omitted the noipa attribute for it was only meant to simplify analysis and
> there is no such attribute in the original code.
> Furthermore, i would have hoped that given the placement of the definition
> of myrealloc() before the typedef foo_t, it should be unlikely that the
> usage of *foo would invalidate such an optimisation _in this particular
> case_. While the original code unfortunately does not mark *foo as restrict,
> adding restrict would hopefully make it clear that myrealloc() has no
> business in comparing foo's struct members, i'd hope?
>
> When i drop the noipa attribute in the v1 testcase to make it similar to the
> motivating case, i get:
Correction: When i replace noipa with noinline,noclone (and drop
-ffunction-sections -fdata-sections to improve readability), i get:
10: 0000000000000030 52 FUNC GLOBAL DEFAULT 1 bloat
10: 0000000000000030 21 FUNC GLOBAL DEFAULT 1 ok
0000000000000030 <bloat>:
30: 53 push %rbx
31: 48 89 fb mov %rdi,%rbx
34: 48 83 ec 10 sub $0x10,%rsp
38: 8b 47 14 mov 0x14(%rdi),%eax
3b: 48 83 7f 08 00 cmpq $0x0,0x8(%rdi)
40: 89 44 24 0c mov %eax,0xc(%rsp)
44: 75 11 jne 57 <bloat+0x27>
46: 48 8d 54 24 0c lea 0xc(%rsp),%rdx
4b: be 00 01 00 00 mov $0x100,%esi
50: 31 ff xor %edi,%edi
52: e8 a9 ff ff ff callq 0 <myrealloc>
57: 8b 44 24 0c mov 0xc(%rsp),%eax
5b: 89 43 14 mov %eax,0x14(%rbx)
5e: 48 83 c4 10 add $0x10,%rsp
62: 5b pop %rbx
63: c3 retq
0000000000000030 <ok>:
30: 48 83 7f 08 00 cmpq $0x0,0x8(%rdi)
35: 75 0d jne 44 <ok+0x14>
37: 48 8d 57 14 lea 0x14(%rdi),%rdx
3b: be 00 01 00 00 mov $0x100,%esi
40: 31 ff xor %edi,%edi
42: eb bc jmp 0 <myrealloc>
44: c3 retq
