Skip to content

wasm-reduce: Improve tryToReduceCurrentToConst() #6193

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
kripken merged 2 commits into from
Jan 2, 2024
Merged

wasm-reduce: Improve tryToReduceCurrentToConst() #6193

Changes from 1 commit
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
0ddf1b6
work
kripken Dec 21, 2023
5066aaf
feedback: efficiency
kripken Dec 22, 2023
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
31 changes: 22 additions & 9 deletions src/tools/wasm-reduce.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,7 @@
#include "ir/iteration.h"
#include "ir/literal-utils.h"
#include "ir/properties.h"
#include "ir/utils.h"
#include "pass.h"
#include "support/colors.h"
#include "support/command-line.h"
Expand All @@ -42,6 +43,7 @@
#include "wasm-builder.h"
#include "wasm-io.h"
#include "wasm-validator.h"

#ifdef _WIN32
#ifndef NOMINMAX
#define NOMINMAX
Expand Down Expand Up @@ -71,6 +73,7 @@ std::string GetLastErrorStdStr() {
return std::string();
}
#endif

using namespace wasm;

// A timeout on every execution of the command.
Expand Down Expand Up @@ -1139,33 +1142,43 @@ struct Reducer
return false;
}

// try to replace a concrete value with a trivial constant
// Try to replace a concrete value with a trivial constant.
bool tryToReduceCurrentToConst() {
auto* curr = getCurrent();
if (curr->is<Const>()) {
return false;
}
// try to replace with a trivial value
if (curr->type.isNullable()) {

// References.
if (curr->type.isNullable() && !curr->is<RefNull>()) {
RefNull* n = builder->makeRefNull(curr->type.getHeapType());
return tryToReplaceCurrent(n);
}

// Tuples.
if (curr->type.isTuple() && curr->type.isDefaultable()) {
Expression* n =
builder->makeConstantExpression(Literal::makeZeros(curr->type));
if (ExpressionAnalyzer::equal(n, curr)) {
return false;
}
return tryToReplaceCurrent(n);
}

// Numbers. We try to replace them with a 0 or a 1.
if (!curr->type.isNumber()) {
return false;
}
// It's a number: try to replace it with a 0 or a 1 (trying more values
// could make sense too, but these handle most cases).
auto* c = builder->makeConst(Literal::makeZero(curr->type));
if (ExpressionAnalyzer::equal(c, curr)) {
Copy link
Member

@aheejin aheejin Dec 21, 2023

Choose a reason for hiding this comment

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

Can we use Literal::isZero or something for checking before making? (It doesn't seem to have Literal::isOne though.. Can we add it?)

Copy link
Member Author

@kripken kripken Dec 22, 2023 •
edited
Loading

Choose a reason for hiding this comment

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

Good idea, yeah, we can be a little more efficient here. I did that now.

Separately, not sure if it's worth adding Literal::isOne. It would save a little code but it is rare to check that I suspect...

Copy link
Member

@aheejin aheejin Dec 22, 2023

Choose a reason for hiding this comment

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

Sounds good

// It's already a zero.
return false;
}
if (tryToReplaceCurrent(c)) {
return true;
}
// It's not a zero. Try to make it a 1, if it isn't already.
c->value = Literal::makeOne(curr->type);
c->type = curr->type;
if (ExpressionAnalyzer::equal(c, curr)) {
return false;
}
return tryToReplaceCurrent(c);
}

Expand Down