[Bug ipa/68331] [meta-bug] fipa-pta issues

["david.abdurachmanov at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68331

--- Comment #11 from David Abdurachmanov <david.abdurachmanov at gmail dot com> ---
"Good" code, annotated by me. Now notice from my previous message that the fix
for this PR, caused

49 89 1c 24             mov    %rbx,(%r12)

to be removed. We lost one instruction which stored the address of allocated
objected via "pointer".

00000000000187b0 <std::_MakeUniq<edm::ParameterDescription<int>
>::__single_object std::make_unique<edm::ParameterDescription<int>, char const
(&) [16], int const&, bool&>(char const (&) [16], int const&, bool&) [clone
.isra.142]>:
   187b0:       41 56                   push   %r14
   187b2:       41 55                   push   %r13
   187b4:       49 89 f6                mov    %rsi,%r14
   187b7:       41 54                   push   %r12
   187b9:       55                      push   %rbp
   187ba:       49 89 fc                mov    %rdi,%r12
   187bd:       53                      push   %rbx

// Allocate 40 bytes on the heap

   187be:       bf 28 00 00 00          mov    $0x28,%edi
   187c3:       49 89 d5                mov    %rdx,%r13
   187c6:       0f b6 e9                movzbl %cl,%ebp
   187c9:       e8 62 e5 ff ff          callq  16d30 <operator new(unsigned
long)@plt>

// Store returned pointer in RBX

   187ce:       48 89 c3                mov    %rax,%rbx
   187d1:       e8 da f8 ff ff          callq  180b0 <edm::ParameterTypes
edm::ParameterTypeToEnum::toEnum<int>()@plt>
   187d6:       41 b8 01 00 00 00       mov    $0x1,%r8d
   187dc:       89 e9                   mov    %ebp,%ecx
   187de:       89 c2                   mov    %eax,%edx
   187e0:       4c 89 f6                mov    %r14,%rsi

// Call the ctor, pass pointer (this) from RBX

   187e3:       48 89 df                mov    %rbx,%rdi
   187e6:       e8 75 e8 ff ff          callq  17060
<edm::ParameterDescriptionBase::ParameterDescriptionBase(char const*,
edm::ParameterTypes, bool, bool)@plt>
   187eb:       48 8b 05 a6 36 03 00    mov    0x336a6(%rip),%rax        #
4be98 <_DYNAMIC+0x430>

// Store RBX to memory pointed by R12

   187f2:       49 89 1c 24             mov    %rbx,(%r12)
   187f6:       48 83 c0 10             add    $0x10,%rax
   187fa:       48 89 03                mov    %rax,(%rbx)
   187fd:       41 8b 45 00             mov    0x0(%r13),%eax
   18801:       89 43 20                mov    %eax,0x20(%rbx)

// Put address in R12 into return register

   18804:       4c 89 e0                mov    %r12,%rax
   18807:       5b                      pop    %rbx
   18808:       5d                      pop    %rbp
   18809:       41 5c                   pop    %r12
   1880b:       41 5d                   pop    %r13
   1880d:       41 5e                   pop    %r14
   1880f:       c3                      retq
   18810:       48 89 c5                mov    %rax,%rbp
   18813:       48 89 df                mov    %rbx,%rdi
   18816:       be 28 00 00 00          mov    $0x28,%esi
   1881b:       e8 50 e4 ff ff          callq  16c70 <operator delete(void*,
unsigned long)@plt>
   18820:       48 89 ef                mov    %rbp,%rdi
   18823:       e8 48 ef ff ff          callq  17770 <_Unwind_Resume@plt>
   18828:       0f 1f 84 00 00 00 00    nopl   0x0(%rax,%rax,1)
   1882f:       00