diff options
Diffstat (limited to 'src/asm2wasm.h')
| -rw-r--r-- | src/asm2wasm.h | 32 |
1 files changed, 31 insertions, 1 deletions
diff --git a/src/asm2wasm.h b/src/asm2wasm.h index 9abfe7432..153839065 100644 --- a/src/asm2wasm.h +++ b/src/asm2wasm.h @@ -2539,6 +2539,12 @@ Function* Asm2WasmBuilder::processFunction(Ref ast) { auto top = allocator.alloc<Block>(); if (canSwitch) { + + // we may need a break for the case where the condition doesn't match + // any of the cases. it should go to the default, if we have one, or + // outside if not + Break* breakWhenNotMatching = nullptr; + if (br->condition->type == i32) { Binary* offsetor = allocator.alloc<Binary>(); offsetor->op = BinaryOp::SubInt32; @@ -2554,7 +2560,28 @@ Function* Asm2WasmBuilder::processFunction(Ref ast) { offsetor->left = br->condition; offsetor->right = builder.makeConst(Literal(int64_t(min))); offsetor->type = i64; - br->condition = builder.makeUnary(UnaryOp::WrapInt64, offsetor); // TODO: check this fits in 32 bits + // the switch itself can be 32-bit, as the range is in a reasonable range. so after + // offsetting, we need to make sure there are no high bits, then we can just look + // at the lower 32 bits + auto temp = Builder::addVar(function, i64); + auto* block = builder.makeBlock(); + block->list.push_back(builder.makeSetLocal(temp, offsetor)); + // if high bits, we can break to the default (we'll fill in the name later) + breakWhenNotMatching = builder.makeBreak(Name(), nullptr, + builder.makeUnary( + UnaryOp::WrapInt64, + builder.makeBinary(BinaryOp::ShrUInt64, + builder.makeGetLocal(temp, i64), + builder.makeConst(Literal(int64_t(32))) + ) + ) + ); + block->list.push_back(breakWhenNotMatching); + block->list.push_back( + builder.makeGetLocal(temp, i64) + ); + block->finalize(); + br->condition = builder.makeUnary(UnaryOp::WrapInt64, block); } top->list.push_back(br); @@ -2595,6 +2622,9 @@ Function* Asm2WasmBuilder::processFunction(Ref ast) { if (br->default_.isNull()) { br->default_ = top->name; } + if (breakWhenNotMatching) { + breakWhenNotMatching->name = br->default_; + } for (size_t i = 0; i < br->targets.size(); i++) { if (br->targets[i].isNull()) br->targets[i] = br->default_; } |