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
