1 files changed, 8 insertions, 100 deletions

diff --git a/src/wasm/wasm-binary.cpp b/src/wasm/wasm-binary.cpp
index 63adbb08f..b1fc03017 100644
--- a/src/wasm/wasm-binary.cpp
+++ b/src/wasm/wasm-binary.cpp
@@ -311,19 +311,16 @@ void WasmBinaryWriter::writeExports() {
   finishSection(start);
 }
 
-static bool isEmpty(Memory::Segment& segment) {
-  return segment.data.size() == 0;
-}
-
-static bool isConstantOffset(Memory::Segment& segment) {
-  return segment.offset && segment.offset->is<Const>();
-}
-
 void WasmBinaryWriter::writeDataSegments() {
   if (wasm->memory.segments.size() == 0) return;
-
-  Index emitted = 0;
-  auto emit = [&](Memory::Segment& segment) {
+  if (wasm->memory.segments.size() > WebLimitations::MaxDataSegments) {
+    std::cerr << "Some VMs may not accept this binary because it has a large "
+              << "number of data segments. Run the limit-segments pass to "
+              << "merge segments." << std::endl;
+  }
+  auto start = startSection(BinaryConsts::Section::Data);
+  o << U32LEB(wasm->memory.segments.size());
+  for (auto& segment : wasm->memory.segments) {
     uint32_t flags = 0;
     if (segment.isPassive) {
       flags |= BinaryConsts::IsPassive;
@@ -334,95 +331,6 @@ void WasmBinaryWriter::writeDataSegments() {
       o << int8_t(BinaryConsts::End);
     }
     writeInlineBuffer(&segment.data[0], segment.data.size());
-    emitted++;
-  };
-
-  Index numConstant = 0,
-        numDynamic = 0;
-  bool hasPassiveSegments = false;
-  for (auto& segment : wasm->memory.segments) {
-    if (!isEmpty(segment)) {
-      if (isConstantOffset(segment)) {
-        numConstant++;
-      } else {
-        numDynamic++;
-      }
-    }
-    hasPassiveSegments |= segment.isPassive;
-  }
-
-  if (hasPassiveSegments) {
-    if (wasm->memory.segments.size() > WebLimitations::MaxDataSegments) {
-      std::cerr << "too many data segments, wasm VMs may not accept this binary" << std::endl;
-    }
-    // TODO: merge segments in a pass that can fix up memory.init instructions
-    auto section = startSection(BinaryConsts::Section::Data);
-    o << U32LEB(wasm->memory.segments.size());
-    for (auto& segment : wasm->memory.segments) {
-      emit(segment);
-    }
-    finishSection(section);
-    return;
-  }
-  // check if we have too many dynamic data segments, which we can do nothing about
-  auto num = numConstant + numDynamic;
-  if (numDynamic + 1 >= WebLimitations::MaxDataSegments) {
-    std::cerr << "too many non-constant-offset data segments, wasm VMs may not accept this binary" << std::endl;
-  }
-  // we'll merge constant segments if we must
-  if (numConstant + numDynamic >= WebLimitations::MaxDataSegments) {
-    numConstant = WebLimitations::MaxDataSegments - numDynamic - 1;
-    num = numConstant + numDynamic;
-    assert(num == WebLimitations::MaxDataSegments - 1);
-  }
-  auto start = startSection(BinaryConsts::Section::Data);
-  o << U32LEB(num);
-  // first, emit all non-constant-offset segments; then emit the constants,
-  // which we may merge if forced to
-  auto& segments = wasm->memory.segments;
-  for (auto& segment : segments) {
-    if (isEmpty(segment)) continue;
-    if (isConstantOffset(segment)) continue;
-    emit(segment);
-  }
-  // from here on, we concern ourselves with non-empty constant-offset
-  // segments, the ones which we may need to merge
-  auto isRelevant = [](Memory::Segment& segment) {
-    return !isEmpty(segment) && isConstantOffset(segment);
-  };
-  for (Index i = 0; i < segments.size(); i++) {
-    auto& segment = segments[i];
-    if (!isRelevant(segment)) continue;
-    if (emitted + 2 < WebLimitations::MaxDataSegments) {
-      emit(segment);
-    } else {
-      // we can emit only one more segment! merge everything into one
-      // start the combined segment at the bottom of them all
-      auto start = segment.offset->cast<Const>()->value.getInteger();
-      for (Index j = i + 1; j < segments.size(); j++) {
-        auto& segment = segments[j];
-        if (!isRelevant(segment)) continue;
-        auto offset = segment.offset->cast<Const>()->value.getInteger();
-        start = std::min(start, offset);
-      }
-      // create the segment and add in all the data
-      Const c;
-      c.value = Literal(int32_t(start));
-      c.type = i32;
-      Memory::Segment combined(&c);
-      for (Index j = i; j < segments.size(); j++) {
-        auto& segment = segments[j];
-        if (!isRelevant(segment)) continue;
-        auto offset = segment.offset->cast<Const>()->value.getInteger();
-        auto needed = offset + segment.data.size() - start;
-        if (combined.data.size() < needed) {
-          combined.data.resize(needed);
-        }
-        std::copy(segment.data.begin(), segment.data.end(), combined.data.begin() + (offset - start));
-      }
-      emit(combined);
-      break;
-    }
   }
   finishSection(start);
 }