https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70750
David Abdurachmanov <david.abdurachmanov at gmail dot com> changed:
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--- Comment #1 from David Abdurachmanov <david.abdurachmanov at gmail dot com>
---
I have noticed this while comparing assembly generated by GCC 5.3.0 and GCC
6.0.1.
Examples (diff -u 5.3.0 6.0.1)
7 - ff 50 18 callq *0x18(%rax)
8 + 48 8b 40 18 mov 0x18(%rax),%rax
9 + ff d0 callq *%rax
41 - ff 50 08 callq *0x8(%rax)
42 - 4c 8b 7b f8 mov -0x8(%rbx),%r15
43 + 48 8b 40 08 mov 0x8(%rax),%rax
44 + ff d0 callq *%rax
45 + 49 8b 5f f8 mov -0x8(%r15),%rbx
49 - ff 50 08 callq *0x8(%rax)
50 + 48 8b 40 08 mov 0x8(%rax),%rax
51 + ff d0 callq *%rax
Seems that GCC 6.0.1 is no more combining mov + callq. I have not checked if it
was intentional change or not in GCC.
