diff options
| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2022-02-11 09:51:32 +0100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2022-03-08 22:33:03 +1100 |
| commit | 0b0057cc4193c7cd9c0829a440e4901b29ce4ff8 (patch) | |
| tree | 284a6e964c2b9961fbdc1556dc877785770e48ba /lib/mpi/mpi-add.c | |
| parent | 6b3a3e12f8e6eea47428bb39aaf58832b50bb379 (diff) | |
powerpc/bitops: Force inlining of fls()
Building a kernel with CONFIG_CC_OPTIMISE_FOR_SIZE leads to
the following functions being copied several times in vmlinux:
31 times __ilog2_u32()
34 times fls()
Disassembly follows:
c00f476c <fls>:
c00f476c: 7c 63 00 34 cntlzw r3,r3
c00f4770: 20 63 00 20 subfic r3,r3,32
c00f4774: 4e 80 00 20 blr
c00f4778 <__ilog2_u32>:
c00f4778: 94 21 ff f0 stwu r1,-16(r1)
c00f477c: 7c 08 02 a6 mflr r0
c00f4780: 90 01 00 14 stw r0,20(r1)
c00f4784: 4b ff ff e9 bl c00f476c <fls>
c00f4788: 80 01 00 14 lwz r0,20(r1)
c00f478c: 38 63 ff ff addi r3,r3,-1
c00f4790: 7c 08 03 a6 mtlr r0
c00f4794: 38 21 00 10 addi r1,r1,16
c00f4798: 4e 80 00 20 blr
When forcing inlining of fls(), we get
c0008b80 <__ilog2_u32>:
c0008b80: 7c 63 00 34 cntlzw r3,r3
c0008b84: 20 63 00 1f subfic r3,r3,31
c0008b88: 4e 80 00 20 blr
vmlinux size gets reduced by 1 kbyte with that change.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/adc9c9d6378f6b5008246ca717993d7870188efb.1644569473.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'lib/mpi/mpi-add.c')
0 files changed, 0 insertions, 0 deletions