[S390] convert/optimize csum_fold() to C
In the meantime gcc generates better code than the old inline
assemblies do. Original inline assembly results in:
lr %r1,%r2
sr %r3,%r3
lr %r2,%r1
srdl %r2,16
alr %r2,%r3
alr %r1,%r2
srl %r1,16
xilf %r1,65535
llghr %r2,%r1
br %r14
Out of the C code gcc generates this:
rll %r1,%r2,16
ar %r1,%r2
srl %r1,16
xilf %r1,65535
llghr %r2,%r1
br %r14
In addition we don't have any static register allocations anymore and
gcc is free to shuffle instructions around for better pipeline usage.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
1 file changed