Messages in this thread | | | From | David Laight <> | Subject | RE: x86/csum: Remove unnecessary odd handling | Date | Wed, 6 Sep 2023 14:38:49 +0000 |
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From: Noah Goldstein > Sent: 01 September 2023 23:21 ... > + return add32_with_carry(temp64 >> 32, temp64 & 0xffffffff);
The generic C alternative: return (temp64 + ror64(temp64, 32)) >> 32; is the same number of instructions but might get better scheduling.
The C version of csum_fold() from arc/include/asm/checksum.h is also better than the x86 asm version. (And also pretty much all the other architecture dependant copies.)
David
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