> > The test case listed in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=46164 > > shows the expected asm command "mov r1, r1" is not generated."r1" is defined > > as a volatile register, and there are three insns related to r1: > > > > (insn 98 97 40 3 (set (reg/v:SI 1 r1 [ b ]) (reg:SI 154 [ b ])) > > (insn 41 40 43 3 (set (reg/f:SI 148) (reg/v:SI 1 r1 [ b ])) > > (insn 43 41 45 3 (parallel [ > > (set (reg/v:SI 0 r0 [ ret ]) > > (asm_operands/v:SI ("mov %2, %2 mov %3, %3 mov %4, %4") > > ("=r") 0 [ > > (reg/v:SI 0 r0 [ a ]) > > (reg/v:SI 1 r1 [ b ]) > > (reg/v:SI 2 r2 [ c ]) > > (mem/c:QI (reg/f:SI 148) [0 MEM[(char *)&temp]+0 S1 > > A8]) > > 98+41 was not combined. Why? 41+43 was not combined. Why?
Actually, it looks like it first rejected 98+41, then combined 41+43 (and that is fine), and then it combined 98+43? Segher
