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| author | Quentin Carbonneaux <quentin@c9x.me> | 2022-12-13 10:50:27 +0100 |
|---|---|---|
| committer | Quentin Carbonneaux <quentin@c9x.me> | 2022-12-15 09:30:47 +0100 |
| commit | 99fea1e21174b18ccbd947787bea91140fd802e8 (patch) | |
| tree | 109fe6ff6dd10595ea1102fef23c55f58f3ba214 | |
| parent | 26c1c30b7d96d2170195970a8cdb3b024ba7421a (diff) | |
| download | roux-99fea1e21174b18ccbd947787bea91140fd802e8.tar.gz | |
bugfix in load elimination
When checking if two slices represent the same range of memory we must check that offsets match. The bug was revealed by a harec test.
| -rw-r--r-- | load.c | 2 | ||||
| -rw-r--r-- | test/load3.ssa | 50 |
2 files changed, 52 insertions, 0 deletions
diff --git a/load.c b/load.c index 551d02e..6f40cc7 100644 --- a/load.c +++ b/load.c @@ -248,6 +248,7 @@ def(Slice sl, bits msk, Blk *b, Ins *i, Loc *il) } else if (i->op == Oblit1) { assert(rtype(i->arg[0]) == RInt); sz = abs(rsval(i->arg[0])); + assert(i > b->ins); --i; assert(i->op == Oblit0); r1 = i->arg[1]; @@ -321,6 +322,7 @@ def(Slice sl, bits msk, Blk *b, Ins *i, Loc *il) for (ist=ilog; ist<&ilog[nlog]; ++ist) if (ist->isphi && ist->bid == b->id) if (req(ist->new.phi.m.ref, sl.ref)) + if (ist->new.phi.m.off == sl.off) if (ist->new.phi.m.sz == sl.sz) { r = ist->new.phi.p->to; if (msk != msks) diff --git a/test/load3.ssa b/test/load3.ssa new file mode 100644 index 0000000..73d60aa --- /dev/null +++ b/test/load3.ssa @@ -0,0 +1,50 @@ +# regression test for load() +# see comment below + +function w $rand() { +@start + ret 0 +} + +function w $chk(w %a, w %b) { +@start + %ok =w ceqw %a, 1 + %ok1 =w ceqw %b, 0 + %ok2 =w and %ok, %ok1 + %ret =w xor %ok2, 1 + ret %ret +} + +export +function w $main() { +@start + %s0 =l alloc4 8 + %s1 =l alloc4 8 + + storew 1, %s0 + %s04 =l add 4, %s0 + storew 0, %s04 + + %rnd =w call $rand() + jnz %rnd, @tt, @ff +@tt + jmp @blit +@ff + jmp @blit + +@blit + # we make sure def() checks + # offsets correctly when + # processing inserted phis; + # if not, %w1 will bogusly + # have the same value as %w0 + + blit %s0, %s1, 8 + + %w0 =w load %s1 + %s14 =l add 4, %s1 + %w1 =w load %s14 + + %ret =w call $chk(w %w0, w %w1) + ret %ret +} |