diff options
Diffstat (limited to 'src/ast')
| -rw-r--r-- | src/ast/effects.h | 16 | ||||
| -rw-r--r-- | src/ast/properties.h | 24 |
2 files changed, 29 insertions, 11 deletions
diff --git a/src/ast/effects.h b/src/ast/effects.h index a7a5d8fb2..6e4bb617e 100644 --- a/src/ast/effects.h +++ b/src/ast/effects.h @@ -39,7 +39,7 @@ struct EffectAnalyzer : public PostWalker<EffectAnalyzer> { if (breakNames.size() > 0) branches = true; } - bool branches = false; // branches out of this expression + bool branches = false; // branches out of this expression, returns, infinite loops, etc bool calls = false; std::set<Index> localsRead; std::set<Index> localsWritten; @@ -138,6 +138,18 @@ struct EffectAnalyzer : public PostWalker<EffectAnalyzer> { } void visitLoop(Loop* curr) { if (curr->name.is()) breakNames.erase(curr->name); // these were internal breaks + // if the loop is unreachable, then there is branching control flow: + // (1) if the body is unreachable because of a (return), uncaught (br) etc., then we + // already noted branching, so it is ok to mark it again (if we have *caught* + // (br)s, then they did not lead to the loop body being unreachable). + // (same logic applies to blocks) + // (2) if the loop is unreachable because it only has branches up to the loop + // top, but no way to get out, then it is an infinite loop, and we consider + // that a branching side effect (note how the same logic does not apply to + // blocks). + if (curr->type == unreachable) { + branches = true; + } } void visitCall(Call *curr) { calls = true; } @@ -182,6 +194,7 @@ struct EffectAnalyzer : public PostWalker<EffectAnalyzer> { case TruncUFloat64ToInt32: case TruncUFloat64ToInt64: { implicitTrap = true; + break; } default: {} } @@ -199,6 +212,7 @@ struct EffectAnalyzer : public PostWalker<EffectAnalyzer> { case RemSInt64: case RemUInt64: { implicitTrap = true; + break; } default: {} } diff --git a/src/ast/properties.h b/src/ast/properties.h index 9121deba5..097f7a8f0 100644 --- a/src/ast/properties.h +++ b/src/ast/properties.h @@ -60,11 +60,13 @@ struct Properties { if (auto* outer = curr->dynCast<Binary>()) { if (outer->op == ShrSInt32) { if (auto* outerConst = outer->right->dynCast<Const>()) { - if (auto* inner = outer->left->dynCast<Binary>()) { - if (inner->op == ShlInt32) { - if (auto* innerConst = inner->right->dynCast<Const>()) { - if (outerConst->value == innerConst->value) { - return inner->left; + if (outerConst->value.geti32() != 0) { + if (auto* inner = outer->left->dynCast<Binary>()) { + if (inner->op == ShlInt32) { + if (auto* innerConst = inner->right->dynCast<Const>()) { + if (outerConst->value == innerConst->value) { + return inner->left; + } } } } @@ -87,11 +89,13 @@ struct Properties { if (auto* outer = curr->dynCast<Binary>()) { if (outer->op == ShrSInt32) { if (auto* outerConst = outer->right->dynCast<Const>()) { - if (auto* inner = outer->left->dynCast<Binary>()) { - if (inner->op == ShlInt32) { - if (auto* innerConst = inner->right->dynCast<Const>()) { - if (outerConst->value.leU(innerConst->value).geti32()) { - return inner->left; + if (outerConst->value.geti32() != 0) { + if (auto* inner = outer->left->dynCast<Binary>()) { + if (inner->op == ShlInt32) { + if (auto* innerConst = inner->right->dynCast<Const>()) { + if (outerConst->value.leU(innerConst->value).geti32()) { + return inner->left; + } } } } |