Skip to content

[ARITH] RewriteSimplifier: improved cmp simplification #2851

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
tqchen merged 1 commit into from
Mar 23, 2019
Merged

[ARITH] RewriteSimplifier: improved cmp simplification #2851

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
20 changes: 13 additions & 7 deletions src/arithmetic/rewrite_simplify.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -96,6 +96,8 @@ class RewriteSimplifier::Impl : public IRMutator {
kEQ,
kGT,
kLT,
kGE,
kLE,
kNE
};
// reference to the main analyzer
Expand Down Expand Up @@ -140,6 +142,12 @@ class RewriteSimplifier::Impl : public IRMutator {
if (dbound->max_value < val) {
return kLT;
}
if (dbound->min_value >= val) {

@kazum kazum Mar 22, 2019

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

dbound->min_value == val looks a bit cleaner? We don't reach here when dbound->min_value > val.

@sgrechanik-h sgrechanik-h Mar 22, 2019

Copy link
Copy Markdown
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Good point, I didn't notice that. However I would leave it the way it is, because it feels more straightforward, and also it is more consistent with the case of symbolic bounds.

return kGE;
}
if (dbound->max_value <= val) {
return kLE;
}
return kUnknown;
}

Expand Down Expand Up @@ -994,12 +1002,10 @@ Mutate_(const EQ* op, const Expr& self) {

if (IsIndexType(op->a.type())) {
CompareResult result = TryCompare(op->a - op->b, 0);
if (result != kUnknown) {
if (result == kEQ) {
return make_const(op->type, true);
} else {
return make_const(op->type, false);
}
if (result == kEQ) {
return make_const(op->type, true);
} else if (result == kNE || result == kGT || result == kLT) {
return make_const(op->type, false);
}
TVM_TRY_REWRITE(x - c1 == 0, x == c1);
TVM_TRY_REWRITE(c1 - x == 0, x == c1);
Expand Down Expand Up @@ -1055,7 +1061,7 @@ Mutate_(const LT* op, const Expr& self) {
if (result == kLT) {
return make_const(op->type, true);
}
if (result == kEQ || result == kGT) {
if (result == kEQ || result == kGT || result == kGE) {
return make_const(op->type, false);
}

Expand Down
15 changes: 15 additions & 0 deletions tests/python/unittest/test_arith_rewrite_simplify.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -450,6 +450,21 @@ def test_cmp_simplify():
ck.verify(tvm.max(8, x) > 10, tvm.expr.LT(10, x))
ck.verify(x + 1 < tvm.max(8, x), x < 7)

ck.analyzer.update(x, tvm.arith.ConstIntBound(0, 10), override=True)
ck.analyzer.update(y, tvm.arith.ConstIntBound(-10, 0), override=True)
ck.analyzer.update(z, tvm.arith.ConstIntBound(-5, 5), override=True)

ck.verify(x < 11, tvm.const(1, "bool"))
ck.verify(x <= 10, tvm.const(1, "bool"))
ck.verify(z <= 5, tvm.const(1, "bool"))
ck.verify(x + y <= 10, tvm.const(1, "bool"))
ck.verify(x + y >= -10, tvm.const(1, "bool"))
ck.verify(z - 5 <= y + 10, tvm.const(1, "bool"))
ck.verify(tvm.all(x > -1, z <= x + 5), tvm.const(1, "bool"))
ck.verify(x*y <= 0, tvm.const(1, "bool"))
ck.verify((x + 1)*(y - 1) < 0, tvm.const(1, "bool"))
ck.verify(y*y >= 0, tvm.const(1, "bool"))


def test_logical_simplify():
ck = RewriteChecker()
Expand Down