kernel_optimize_test/arch/mips/lib/Makefile
Ralf Baechle 1ee3630a3e MIPS: Use ARCH_USE_BUILTIN_BSWAP.
ARCH_USE_BUILTIN_BSWAP will use __builtin_bswap16(), __builtin_bswap32()
and __builtin_bswap64() where available.  This allows better instruction
scheduling.  On pre-R2 processors it will result in 32 bit and 64 bit
swapping being performed in a call to a __bswapsi2() rsp. __bswapdi2()
functions, so we add these, too.

For a 4.2 kernel with GCC 4.9 this yields the following kernel sizes:

   text    data     bss     dec     hex filename
3996071  155804   88992 4240867  40b5e3 vmlinux         ip22 baseline
3985687  159900   88992 4234579  409d53 vmlinux         ip22 + bswap patch
6913157  378552  251024 7542733  7317cd vmlinux         ip27 baseline
6878581  378552  251024 7508157  7290bd vmlinux         ip27 + bswap patch
5773777  268752  187424 6229953  5f0fc1 vmlinux         malta baseline
5773401  268752  187424 6229577  5f0e49 vmlinux         malta + bswap patch

Presumably the code size improvments yield better cache hit rate thus
better performance compensating for the extra function call but this
will still need to be benchmarked.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-10-26 09:49:43 +01:00

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569 B
Makefile

#
# Makefile for MIPS-specific library files..
#
lib-y += bitops.o csum_partial.o delay.o memcpy.o memset.o \
mips-atomic.o strlen_user.o strncpy_user.o \
strnlen_user.o uncached.o
obj-y += iomap.o
obj-$(CONFIG_PCI) += iomap-pci.o
lib-$(CONFIG_GENERIC_CSUM) := $(filter-out csum_partial.o, $(lib-y))
obj-$(CONFIG_CPU_GENERIC_DUMP_TLB) += dump_tlb.o
obj-$(CONFIG_CPU_R3000) += r3k_dump_tlb.o
obj-$(CONFIG_CPU_TX39XX) += r3k_dump_tlb.o
# libgcc-style stuff needed in the kernel
obj-y += ashldi3.o ashrdi3.o bswapsi.o bswapdi.o cmpdi2.o lshrdi3.o ucmpdi2.o