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Marcelo Ricardo Leitner authored
Make it similar to time_before() macros: - easier to understand - make use of typecheck() to avoid working on unexpected variable types (made the issue on previous patch visible) - for _[lg]te versions, slighly faster, as the compiler used to generate a sequence of cmp/je/cmp/js instructions and now it's sub/test/jle (for _lte): Before, for sctp_outq_sack: if (primary->cacc.changeover_active) { 1f01: 80 b9 84 02 00 00 00 cmpb $0x0,0x284(%rcx) 1f08: 74 6e je 1f78 <sctp_outq_sack+0xe8> u8 clear_cycling = 0; if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) { 1f0a: 8b 81 80 02 00 00 mov 0x280(%rcx),%eax return ((s) - (t)) & TSN_SIGN_BIT; } static inline int TSN_lte(__u32 s, __u32 t) { return ((s) == (t)) || (((s) - (t)) & TSN_SIGN_BIT); 1f10: 8b 7d bc mov -0x44(%rbp),%edi 1f13: 39 c7 cmp %eax,%edi 1f15: 74 25 je 1f3c <sctp_outq_sack+0xac> 1f17: 39 f8 cmp %edi,%eax 1f19: 78 21 js 1f3c <sctp_outq_sack+0xac> primary->cacc.changeover_active = 0; After: if (primary->cacc.changeover_active) { 1ee7: 80 b9 84 02 00 00 00 cmpb $0x0,0x284(%rcx) 1eee: 74 73 je 1f63 <sctp_outq_sack+0xf3> u8 clear_cycling = 0; if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) { 1ef0: 8b 81 80 02 00 00 mov 0x280(%rcx),%eax 1ef6: 2b 45 b4 sub -0x4c(%rbp),%eax 1ef9: 85 c0 test %eax,%eax 1efb: 7e 26 jle 1f23 <sctp_outq_sack+0xb3> primary->cacc.changeover_active = 0; *_lt() generated pretty much the same code. Tested with gcc (GCC) 6.1.1 20160621. This patch also removes SSN_lte as it is not used and cleanups some comments. Signed-off-by:
Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
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