Bug #10080
Updated by normalperson (Eric Wong) almost 10 years ago
Since GCC 4.8.3, some static inline functions (such as rb_call0) are not
inlined in the generated machine code. This happens in both x86-64 and ppc64
platforms and it can be verified by using the following commands:
~~~
(in ppc64)
objdump -dS ruby | grep bl.*rb_call0
155838: c1 f8 ff 4b bl 1550f8 <rb_call0+0x8>
1558a4: 55 f8 ff 4b bl 1550f8 <rb_call0+0x8>
1559e4: 15 f7 ff 4b bl 1550f8 <rb_call0+0x8>
158b88: 71 c5 ff 4b bl 1550f8 <rb_call0+0x8>
15bf40: b9 91 ff 4b bl 1550f8 <rb_call0+0x8>
15c0f8: 01 90 ff 4b bl 1550f8 <rb_call0+0x8>
15c490: 69 8c ff 4b bl 1550f8 <rb_call0+0x8>
15c4cc: 2d 8c ff 4b bl 1550f8 <rb_call0+0x8>
15c8bc: 3d 88 ff 4b bl 1550f8 <rb_call0+0x8>
15cc94: 65 84 ff 4b bl 1550f8 <rb_call0+0x8>
15d344: b5 7d ff 4b bl 1550f8 <rb_call0+0x8>
15d3c4: 35 7d ff 4b bl 1550f8 <rb_call0+0x8>
(in x86-64)
objdump -dS ruby | grep call\.*rb_call0
126280: e8 cb f9 ff ff callq 125c50 <rb_call0>
126347: e8 04 f9 ff ff callq 125c50 <rb_call0>
1264cc: e8 7f f7 ff ff callq 125c50 <rb_call0>
128a9e: e8 ad d1 ff ff callq 125c50 <rb_call0>
12ade9: e8 62 ae ff ff callq 125c50 <rb_call0>
12af6a: e8 e1 ac ff ff callq 125c50 <rb_call0>
12b2e6: e8 65 a9 ff ff callq 125c50 <rb_call0>
12b5d7: e8 74 a6 ff ff callq 125c50 <rb_call0>
12b899: e8 b2 a3 ff ff callq 125c50 <rb_call0>
12bccd: e8 7e 9f ff ff callq 125c50 <rb_call0>
12bdf0: e8 5b 9e ff ff callq 125c50 <rb_call0>
~~~
This behaviour can be fixed if every inlined function were marked with the always_inline attribute when compiling with GCC.