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| author | Quentin Carbonneaux <quentin@c9x.me> | 2021-07-28 01:15:51 +0200 |
|---|---|---|
| committer | Quentin Carbonneaux <quentin@c9x.me> | 2021-07-28 01:57:05 +0200 |
| commit | b543ffed71497fb079bfdca53934870a1189c325 (patch) | |
| tree | 6443ecd62d9fd42ed6203529bd15316ff2082a6c /amd64 | |
| parent | 5a4369dd279b1ee50779ae4ab16daaa035eeeb69 (diff) | |
| download | roux-b543ffed71497fb079bfdca53934870a1189c325.tar.gz | |
handle fast locals in amd64 shifts (afl)
Reported by Alessandro Mantovani. Although unlikely in real programs it was found that using the address of a fast local in amd64 shifts triggers assertion failures. We now err when the shift count is given by an address; but we allow shifting an address.
Diffstat (limited to 'amd64')
| -rw-r--r-- | amd64/isel.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/amd64/isel.c b/amd64/isel.c index 31199da..e8a78f3 100644 --- a/amd64/isel.c +++ b/amd64/isel.c @@ -244,13 +244,18 @@ sel(Ins i, ANum *an, Fn *fn) case Osar: case Oshr: case Oshl: - if (rtype(i.arg[1]) == RCon) - goto Emit; r0 = i.arg[1]; + if (rtype(r0) == RCon) + goto Emit; + if (fn->tmp[r0.val].slot != -1) + err("unlikely argument %%%s in %s", + fn->tmp[r0.val].name, optab[i.op].name); i.arg[1] = TMP(RCX); emit(Ocopy, Kw, R, TMP(RCX), R); emiti(i); + i1 = curi; emit(Ocopy, Kw, TMP(RCX), r0, R); + fixarg(&i1->arg[0], argcls(&i, 0), i1, fn); break; case Onop: break; @@ -336,7 +341,7 @@ Emit: die("unknown instruction %s", optab[i.op].name); } - while (i0 > curi && --i0) { + while (i0>curi && --i0) { assert(rslot(i0->arg[0], fn) == -1); assert(rslot(i0->arg[1], fn) == -1); } |