diff options
Diffstat (limited to 'fold.c')
| -rw-r--r-- | fold.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/fold.c b/fold.c index f992b3a..3ff0bc7 100644 --- a/fold.c +++ b/fold.c @@ -1,8 +1,8 @@ #include "all.h" enum { - Bot = -2, /* lattice bottom */ - Top = -1, /* lattice top */ + Bot = -1, /* lattice bottom */ + Top = 0, /* lattice top (matches UNDEF) */ }; typedef struct Edge Edge; @@ -126,7 +126,6 @@ visitjmp(Blk *b, int n, Fn *fn) switch (b->jmp.type) { case Jjnz: l = latval(b->jmp.arg); - assert(l != Top && "ssa invariant broken"); if (l == Bot) { edge[n][1].work = flowrk; edge[n][0].work = &edge[n][1]; @@ -174,7 +173,6 @@ renref(Ref *r) if (rtype(*r) == RTmp) if ((l=val[r->val]) != Bot) { - assert(l != Top && "ssa invariant broken"); *r = CON(l); return 1; } @@ -294,9 +292,13 @@ fold(Fn *fn) for (i=b->ins; i<&b->ins[b->nins]; i++) if (renref(&i->to)) *i = (Ins){.op = Onop}; - else + else { for (n=0; n<2; n++) renref(&i->arg[n]); + if (isstore(i->op)) + if (req(i->arg[0], UNDEF)) + *i = (Ins){.op = Onop}; + } renref(&b->jmp.arg); if (b->jmp.type == Jjnz && rtype(b->jmp.arg) == RCon) { if (iscon(&fn->con[b->jmp.arg.val], 0, 0)) { |