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6c: extern registers must be considered used on return

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the peephole optimizer would remove stores to extern
register before a return statement as it would think
they are only set, but not used.
This commit is contained in:
cinap_lenrek 2021-11-17 01:23:57 +00:00
parent 3473fa237c
commit fc412aef3d
1 changed files with 2 additions and 0 deletions
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2
sys/src/cmd/6c/peep.c
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@ -890,6 +890,8 @@ copyu(Prog *p, Adr *v, Adr *s)
return 0;
case ARET: /* funny */
if(REGEXT && v->type <= REGEXT && v->type > exregoffset)
return 2;
if(v->type == REGRET || v->type == FREGRET)
return 2;
if(s != A)