diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/passes/OptimizeInstructions.cpp | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/src/passes/OptimizeInstructions.cpp b/src/passes/OptimizeInstructions.cpp index ebe551d0c..f2ca4e0be 100644 --- a/src/passes/OptimizeInstructions.cpp +++ b/src/passes/OptimizeInstructions.cpp @@ -1853,10 +1853,6 @@ struct OptimizeInstructions return; } - // What the reference points to does not depend on the type, so casts may be - // removable. - skipCast(curr->value); - // Optimizating RefIs is not that obvious, since even if we know the result // evaluates to 0 or 1 then the replacement may not actually save code size, // since RefIsNull is a single byte (the others are 2), while adding a Const @@ -1874,6 +1870,21 @@ struct OptimizeInstructions replaceCurrent(builder.makeSequence( builder.makeDrop(curr->value), builder.makeConst(Literal::makeZero(Type::i32)))); + } else { + // What the reference points to does not depend on the type, so casts + // may be removable. Do this right before returning because removing a + // cast may remove info that we could have used to optimize. For + // example: + // + // (ref.is_func + // (ref.as_func + // (local.get $anyref))) + // + // The local has no useful type info. The cast forces it to be a + // function, so we can replace the ref.is with 1. But if we removed the + // ref.as first then we'd not have the type info we need to optimize + // that way. + skipCast(curr->value); } return; } @@ -1913,6 +1924,9 @@ struct OptimizeInstructions } } } + + // See above comment. + skipCast(curr->value); } void visitRefAs(RefAs* curr) { |