diff options
Diffstat (limited to 'src/passes/RemoveUnusedBrs.cpp')
| -rw-r--r-- | src/passes/RemoveUnusedBrs.cpp | 39 |
1 files changed, 24 insertions, 15 deletions
diff --git a/src/passes/RemoveUnusedBrs.cpp b/src/passes/RemoveUnusedBrs.cpp index 786fcaf67..2d944d212 100644 --- a/src/passes/RemoveUnusedBrs.cpp +++ b/src/passes/RemoveUnusedBrs.cpp @@ -35,7 +35,8 @@ namespace wasm { // not have side effects (as they would run unconditionally) static bool canTurnIfIntoBrIf(Expression* ifCondition, Expression* brValue, - PassOptions& options) { + PassOptions& options, + FeatureSet features) { // if the if isn't even reached, this is all dead code anyhow if (ifCondition->type == Type::unreachable) { return false; @@ -43,11 +44,11 @@ static bool canTurnIfIntoBrIf(Expression* ifCondition, if (!brValue) { return true; } - EffectAnalyzer value(options, brValue); + EffectAnalyzer value(options, features, brValue); if (value.hasSideEffects()) { return false; } - return !EffectAnalyzer(options, ifCondition).invalidates(value); + return !EffectAnalyzer(options, features, ifCondition).invalidates(value); } // Check if it is not worth it to run code unconditionally. This @@ -302,11 +303,13 @@ struct RemoveUnusedBrs : public WalkerPass<PostWalker<RemoveUnusedBrs>> { } void visitIf(If* curr) { + FeatureSet features = getModule()->features; if (!curr->ifFalse) { // if without an else. try to reduce // if (condition) br => br_if (condition) if (Break* br = curr->ifTrue->dynCast<Break>()) { - if (canTurnIfIntoBrIf(curr->condition, br->value, getPassOptions())) { + if (canTurnIfIntoBrIf( + curr->condition, br->value, getPassOptions(), features)) { if (!br->condition) { br->condition = curr->condition; } else { @@ -327,7 +330,7 @@ struct RemoveUnusedBrs : public WalkerPass<PostWalker<RemoveUnusedBrs>> { } // Of course we can't do this if the br's condition has side // effects, as we would then execute those unconditionally. - if (EffectAnalyzer(getPassOptions(), br->condition) + if (EffectAnalyzer(getPassOptions(), features, br->condition) .hasSideEffects()) { return; } @@ -521,7 +524,8 @@ struct RemoveUnusedBrs : public WalkerPass<PostWalker<RemoveUnusedBrs>> { return false; } // if there is control flow, we must stop looking - if (EffectAnalyzer(getPassOptions(), curr).branches) { + if (EffectAnalyzer(getPassOptions(), getModule()->features, curr) + .transfersControlFlow()) { return false; } if (i == 0) { @@ -744,6 +748,7 @@ struct RemoveUnusedBrs : public WalkerPass<PostWalker<RemoveUnusedBrs>> { // the if is dead // * note that we do this at the end, because un-conditionalizing can // interfere with optimizeLoop()ing. + FeatureSet features = getModule()->features; auto& list = curr->list; for (Index i = 0; i < list.size(); i++) { auto* iff = list[i]->dynCast<If>(); @@ -755,7 +760,7 @@ struct RemoveUnusedBrs : public WalkerPass<PostWalker<RemoveUnusedBrs>> { auto* ifTrueBreak = iff->ifTrue->dynCast<Break>(); if (ifTrueBreak && !ifTrueBreak->condition && canTurnIfIntoBrIf( - iff->condition, ifTrueBreak->value, passOptions)) { + iff->condition, ifTrueBreak->value, passOptions, features)) { // we are an if-else where the ifTrue is a break without a // condition, so we can do this ifTrueBreak->condition = iff->condition; @@ -768,7 +773,7 @@ struct RemoveUnusedBrs : public WalkerPass<PostWalker<RemoveUnusedBrs>> { auto* ifFalseBreak = iff->ifFalse->dynCast<Break>(); if (ifFalseBreak && !ifFalseBreak->condition && canTurnIfIntoBrIf( - iff->condition, ifFalseBreak->value, passOptions)) { + iff->condition, ifFalseBreak->value, passOptions, features)) { ifFalseBreak->condition = Builder(*getModule()).makeUnary(EqZInt32, iff->condition); ifFalseBreak->finalize(); @@ -797,7 +802,7 @@ struct RemoveUnusedBrs : public WalkerPass<PostWalker<RemoveUnusedBrs>> { if (shrink && br2->type != Type::unreachable) { // Join adjacent br_ifs to the same target, making one br_if // with a "selectified" condition that executes both. - if (!EffectAnalyzer(passOptions, br2->condition) + if (!EffectAnalyzer(passOptions, features, br2->condition) .hasSideEffects()) { // it's ok to execute them both, do it Builder builder(*getModule()); @@ -888,8 +893,10 @@ struct RemoveUnusedBrs : public WalkerPass<PostWalker<RemoveUnusedBrs>> { // If the items we move around have side effects, we can't do // this. // TODO: we could use a select, in some cases..? - if (!EffectAnalyzer(passOptions, br->value).hasSideEffects() && - !EffectAnalyzer(passOptions, br->condition) + FeatureSet features = getModule()->features; + if (!EffectAnalyzer(passOptions, features, br->value) + .hasSideEffects() && + !EffectAnalyzer(passOptions, features, br->condition) .hasSideEffects()) { ExpressionManipulator::nop(list[0]); Builder builder(*getModule()); @@ -923,11 +930,12 @@ struct RemoveUnusedBrs : public WalkerPass<PostWalker<RemoveUnusedBrs>> { return nullptr; } // Check if side effects allow this. - EffectAnalyzer condition(passOptions, iff->condition); + FeatureSet features = getModule()->features; + EffectAnalyzer condition(passOptions, features, iff->condition); if (!condition.hasSideEffects()) { - EffectAnalyzer ifTrue(passOptions, iff->ifTrue); + EffectAnalyzer ifTrue(passOptions, features, iff->ifTrue); if (!ifTrue.hasSideEffects()) { - EffectAnalyzer ifFalse(passOptions, iff->ifFalse); + EffectAnalyzer ifFalse(passOptions, features, iff->ifFalse); if (!ifFalse.hasSideEffects()) { return Builder(*getModule()) .makeSelect(iff->condition, iff->ifTrue, iff->ifFalse); @@ -1184,7 +1192,8 @@ struct RemoveUnusedBrs : public WalkerPass<PostWalker<RemoveUnusedBrs>> { } // if the condition has side effects, we can't replace many // appearances of it with a single one - if (EffectAnalyzer(passOptions, conditionValue).hasSideEffects()) { + if (EffectAnalyzer(passOptions, getModule()->features, conditionValue) + .hasSideEffects()) { start++; continue; } |