For now, module relocation functions are implemented as an array
of handlers of type reloc_handler_t.
Convert that array into a single switch-case function to:
- remove unused arguments;
- change the return type of simple handlers to void;
- remove the array and don't use any data at all;
- avoid using indirect calls;
- allow the compiler to inline and greatly optimize
the relocation function[s].
The result on MIPS32 R2 with GCC 10.2 -O2 is:
scripts/bloat-o-meter -c arch/mips/kernel/__module.o arch/mips/kernel/module.o
add/remove: 1/11 grow/shrink: 1/0 up/down: 876/-1436 (-560)
Function old new delta
apply_relocate 456 1148 +692
apply_r_mips_pc - 184 +184
apply_r_mips_none 8 - -8
apply_r_mips_32 16 - -16
apply_r_mips_64 76 - -76
apply_r_mips_highest 88 - -88
apply_r_mips_higher 108 - -108
apply_r_mips_26 132 - -132
apply_r_mips_pc26 160 - -160
apply_r_mips_pc21 160 - -160
apply_r_mips_pc16 160 - -160
apply_r_mips_hi16 172 - -172
apply_r_mips_lo16 356 - -356
Total: Before=2608, After=2048, chg -21.47%
add/remove: 0/0 grow/shrink: 0/0 up/down: 0/0 (0)
Data old new delta
Total: Before=12, After=12, chg +0.00%
add/remove: 0/1 grow/shrink: 0/0 up/down: 0/-248 (-248)
RO Data old new delta
reloc_handlers 248 - -248
Total: Before=248, After=0, chg -100.00%
All functions were collapsed into a single one that is called
directly by $(srctree)/kernel/module.c.
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
049a68efbf