diff options
| -rw-r--r-- | fold.c | 23 |
1 files changed, 15 insertions, 8 deletions
diff --git a/fold.c b/fold.c index 58a7c4f..3f72155 100644 --- a/fold.c +++ b/fold.c @@ -19,14 +19,14 @@ static Use **usewrk; static uint nuse; static int -czero(Con *c, int w) +iscon(Con *c, int w, uint64_t k) { if (c->type != CBits) return 0; if (w) - return c->bits.i == 0; + return (uint64_t)c->bits.i == k; else - return (uint32_t)c->bits.i == 0; + return (uint32_t)c->bits.i == (uint32_t)k; } static int @@ -132,7 +132,7 @@ visitjmp(Blk *b, int n, Fn *fn) edge[n][0].work = &edge[n][1]; flowrk = &edge[n][0]; } - else if (czero(&fn->con[l], 0)) { + else if (iscon(&fn->con[l], 0, 0)) { assert(edge[n][0].dead); edge[n][1].work = flowrk; flowrk = &edge[n][1]; @@ -297,7 +297,7 @@ fold(Fn *fn) renref(&i->arg[n]); renref(&b->jmp.arg); if (b->jmp.type == Jjnz && rtype(b->jmp.arg) == RCon) { - if (czero(&fn->con[b->jmp.arg.val], 0)) { + if (iscon(&fn->con[b->jmp.arg.val], 0, 0)) { edgedel(b, &b->s1); b->s1 = b->s2; b->s2 = 0; @@ -365,6 +365,16 @@ foldint(Con *res, int op, int w, Con *cl, Con *cr) } else if (cl->type == CAddr || cr->type == CAddr) return 1; + if (op == Odiv || op == Orem || op == Oudiv || op == Ourem) { + if (iscon(cr, w, 0)) + return 1; + if (op == Odiv || op == Orem) { + x = w ? INT64_MIN : INT32_MIN; + if (iscon(cr, w, -1)) + if (iscon(cl, w, x)) + return 1; + } + } switch (op) { case Oadd: x = l.u + r.u; break; case Osub: x = l.u - r.u; break; @@ -508,9 +518,6 @@ opfold(int op, int cls, Con *cl, Con *cr, Fn *fn) Ref r; Con c; - if ((op == Odiv || op == Oudiv - || op == Orem || op == Ourem) && czero(cr, KWIDE(cls))) - return Bot; if (cls == Kw || cls == Kl) { if (foldint(&c, op, cls == Kl, cl, cr)) return Bot; |