Optimize precise mode integer ops (#907)

* improve precise integer operations: call into a wasm function to do the possibly-trapping div/rem, which handles the corner cases, instead of an ffi. also fix a bug in the existing parallel 64-bit code for this

* remove no longer needed wasm.js-post.js file (it moved into emscripten repo)

14 files changed, 323 insertions, 415 deletions

diff --git a/src/asm2wasm.h b/src/asm2wasm.h
index 32b6af5b0..c25855712 100644
--- a/src/asm2wasm.h
+++ b/src/asm2wasm.h
@@ -613,8 +613,63 @@ private:
     return ret;
   }
 
+  Expression* makePotentiallyTrappingI32Binary(BinaryOp op, Expression* left, Expression* right) {
+    if (imprecise) return builder.makeBinary(op, left, right);
+    // we are precise, and the wasm operation might trap if done over 0, so generate a safe call
+    auto *call = allocator.alloc<Call>();
+    switch (op) {
+      case BinaryOp::RemSInt32: call->target = I32S_REM; break;
+      case BinaryOp::RemUInt32: call->target = I32U_REM; break;
+      case BinaryOp::DivSInt32: call->target = I32S_DIV; break;
+      case BinaryOp::DivUInt32: call->target = I32U_DIV; break;
+      default: WASM_UNREACHABLE();
+    }
+    call->operands.push_back(left);
+    call->operands.push_back(right);
+    call->type = i32;
+    static std::set<Name> addedFunctions;
+    if (addedFunctions.count(call->target) == 0) {
+      Expression* result = builder.makeBinary(op,
+        builder.makeGetLocal(0, i32),
+        builder.makeGetLocal(1, i32)
+      );
+      if (op == DivSInt32) {
+        // guard against signed division overflow
+        result = builder.makeIf(
+          builder.makeBinary(AndInt32,
+            builder.makeBinary(EqInt32,
+              builder.makeGetLocal(0, i32),
+              builder.makeConst(Literal(std::numeric_limits<int32_t>::min()))
+            ),
+            builder.makeBinary(EqInt32,
+              builder.makeGetLocal(1, i32),
+              builder.makeConst(Literal(int32_t(-1)))
+            )
+          ),
+          builder.makeConst(Literal(int32_t(0))),
+          result
+        );
+      }
+      addedFunctions.insert(call->target);
+      auto func = new Function;
+      func->name = call->target;
+      func->params.push_back(i32);
+      func->params.push_back(i32);
+      func->result = i32;
+      func->body = builder.makeIf(
+        builder.makeUnary(EqZInt32,
+          builder.makeGetLocal(1, i32)
+        ),
+        builder.makeConst(Literal(int32_t(0))),
+        result
+      );
+      wasm.addFunction(func);
+    }
+    return call;
+  }
+
   // Some binary opts might trap, so emit them safely if we are precise
-  Expression* makeDangerousI64Binary(BinaryOp op, Expression* left, Expression* right) {
+  Expression* makePotentiallyTrappingI64Binary(BinaryOp op, Expression* left, Expression* right) {
     if (imprecise) return builder.makeBinary(op, left, right);
     // we are precise, and the wasm operation might trap if done over 0, so generate a safe call
     auto *call = allocator.alloc<Call>();
@@ -630,6 +685,27 @@ private:
     call->type = i64;
     static std::set<Name> addedFunctions;
     if (addedFunctions.count(call->target) == 0) {
+      Expression* result = builder.makeBinary(op,
+        builder.makeGetLocal(0, i64),
+        builder.makeGetLocal(1, i64)
+      );
+      if (op == DivSInt64) {
+        // guard against signed division overflow
+        result = builder.makeIf(
+          builder.makeBinary(AndInt32,
+            builder.makeBinary(EqInt64,
+              builder.makeGetLocal(0, i64),
+              builder.makeConst(Literal(std::numeric_limits<int64_t>::min()))
+            ),
+            builder.makeBinary(EqInt64,
+              builder.makeGetLocal(1, i64),
+              builder.makeConst(Literal(int64_t(-1)))
+            )
+          ),
+          builder.makeConst(Literal(int64_t(0))),
+          result
+        );
+      }
       addedFunctions.insert(call->target);
       auto func = new Function;
       func->name = call->target;
@@ -641,10 +717,7 @@ private:
           builder.makeGetLocal(1, i64)
         ),
         builder.makeConst(Literal(int64_t(0))),
-        builder.makeBinary(op,
-          builder.makeGetLocal(0, i64),
-          builder.makeGetLocal(1, i64)
-        )
+        result
       );
       wasm.addFunction(func);
     }
@@ -1511,29 +1584,7 @@ Function* Asm2WasmBuilder::processFunction(Ref ast) {
       } else if (!imprecise && (ret->op == BinaryOp::RemSInt32 || ret->op == BinaryOp::RemUInt32 ||
                                 ret->op == BinaryOp::DivSInt32 || ret->op == BinaryOp::DivUInt32)) {
         // we are precise, and the wasm operation might trap if done over 0, so generate a safe call
-        CallImport *call = allocator.alloc<CallImport>();
-        switch (ret->op) {
-          case BinaryOp::RemSInt32: call->target = I32S_REM; break;
-          case BinaryOp::RemUInt32: call->target = I32U_REM; break;
-          case BinaryOp::DivSInt32: call->target = I32S_DIV; break;
-          case BinaryOp::DivUInt32: call->target = I32U_DIV; break;
-          default: WASM_UNREACHABLE();
-        }
-        call->operands.push_back(ret->left);
-        call->operands.push_back(ret->right);
-        call->type = i32;
-        static std::set<Name> addedImport;
-        if (addedImport.count(call->target) == 0) {
-          addedImport.insert(call->target);
-          auto import = new Import;
-          import->name = call->target;
-          import->module = ASM2WASM;
-          import->base = call->target;
-          import->functionType = ensureFunctionType("iii", &wasm);
-          import->kind = ExternalKind::Function;
-          wasm.addImport(import);
-        }
-        return call;
+        return makePotentiallyTrappingI32Binary(ret->op, ret->left, ret->right);
       }
       return ret;
     } else if (what == SUB) {
@@ -1856,10 +1907,10 @@ Function* Asm2WasmBuilder::processFunction(Ref ast) {
                 if (name == I64_ADD) return builder.makeBinary(BinaryOp::AddInt64, left, right);
                 if (name == I64_SUB) return builder.makeBinary(BinaryOp::SubInt64, left, right);
                 if (name == I64_MUL) return builder.makeBinary(BinaryOp::MulInt64, left, right);
-                if (name == I64_UDIV) return makeDangerousI64Binary(BinaryOp::DivUInt64, left, right);
-                if (name == I64_SDIV) return makeDangerousI64Binary(BinaryOp::DivSInt64, left, right);
-                if (name == I64_UREM) return makeDangerousI64Binary(BinaryOp::RemUInt64, left, right);
-                if (name == I64_SREM) return makeDangerousI64Binary(BinaryOp::RemSInt64, left, right);
+                if (name == I64_UDIV) return makePotentiallyTrappingI64Binary(BinaryOp::DivUInt64, left, right);
+                if (name == I64_SDIV) return makePotentiallyTrappingI64Binary(BinaryOp::DivSInt64, left, right);
+                if (name == I64_UREM) return makePotentiallyTrappingI64Binary(BinaryOp::RemUInt64, left, right);
+                if (name == I64_SREM) return makePotentiallyTrappingI64Binary(BinaryOp::RemSInt64, left, right);
                 if (name == I64_AND) return builder.makeBinary(BinaryOp::AndInt64, left, right);
                 if (name == I64_OR) return builder.makeBinary(BinaryOp::OrInt64, left, right);
                 if (name == I64_XOR) return builder.makeBinary(BinaryOp::XorInt64, left, right);
diff --git a/src/js/wasm.js-post.js b/src/js/wasm.js-post.js
deleted file mode 100644
index e7a10f49a..000000000
--- a/src/js/wasm.js-post.js
+++ /dev/null
@@ -1,351 +0,0 @@
-/*
- * Copyright 2015 WebAssembly Community Group participants
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-function integrateWasmJS(Module) {
-  // wasm.js has several methods for creating the compiled code module here:
-  //  * 'native-wasm' : use native WebAssembly support in the browser
-  //  * 'interpret-s-expr': load s-expression code from a .wast and interpret
-  //  * 'interpret-binary': load binary wasm and interpret
-  //  * 'interpret-asm2wasm': load asm.js code, translate to wasm, and interpret
-  //  * 'asmjs': no wasm, just load the asm.js code and use that (good for testing)
-  // The method can be set at compile time (BINARYEN_METHOD), or runtime by setting Module['wasmJSMethod'].
-  // The method can be a comma-separated list, in which case, we will try the
-  // options one by one. Some of them can fail gracefully, and then we can try
-  // the next.
-
-  // inputs
-
-  var method = Module['wasmJSMethod'] || {{{ wasmJSMethod }}} || 'native-wasm'; // by default, use native support
-  Module['wasmJSMethod'] = method;
-
-  var wasmTextFile = Module['wasmTextFile'] || {{{ wasmTextFile }}};
-  var wasmBinaryFile = Module['wasmBinaryFile'] || {{{ wasmBinaryFile }}};
-  var asmjsCodeFile = Module['asmjsCodeFile'] || {{{ asmjsCodeFile }}};
-
-  // utilities
-
-  var wasmPageSize = 64*1024;
-
-  var asm2wasmImports = { // special asm2wasm imports
-    "f64-rem": function(x, y) {
-      return x % y;
-    },
-    "f64-to-int": function(x) {
-      return x | 0;
-    },
-    "i32s-div": function(x, y) {
-      return ((x | 0) / (y | 0)) | 0;
-    },
-    "i32u-div": function(x, y) {
-      return ((x >>> 0) / (y >>> 0)) >>> 0;
-    },
-    "i32s-rem": function(x, y) {
-      return ((x | 0) % (y | 0)) | 0;
-    },
-    "i32u-rem": function(x, y) {
-      return ((x >>> 0) % (y >>> 0)) >>> 0;
-    },
-    "debugger": function() {
-      debugger;
-    },
-  };
-
-  var info = {
-    'global': null,
-    'env': null,
-    'asm2wasm': asm2wasmImports,
-    'parent': Module // Module inside wasm-js.cpp refers to wasm-js.cpp; this allows access to the outside program.
-  };
-
-  var exports = null;
-
-  function lookupImport(mod, base) {
-    var lookup = info;
-    if (mod.indexOf('.') < 0) {
-      lookup = (lookup || {})[mod];
-    } else {
-      var parts = mod.split('.');
-      lookup = (lookup || {})[parts[0]];
-      lookup = (lookup || {})[parts[1]];
-    }
-    if (base) {
-      lookup = (lookup || {})[base];
-    }
-    if (lookup === undefined) {
-      abort('bad lookupImport to (' + mod + ').' + base);
-    }
-    return lookup;
-  }
-
-  function mergeMemory(newBuffer) {
-    // The wasm instance creates its memory. But static init code might have written to
-    // buffer already, including the mem init file, and we must copy it over in a proper merge.
-    // TODO: avoid this copy, by avoiding such static init writes
-    // TODO: in shorter term, just copy up to the last static init write
-    var oldBuffer = Module['buffer'];
-    if (newBuffer.byteLength < oldBuffer.byteLength) {
-      Module['printErr']('the new buffer in mergeMemory is smaller than the previous one. in native wasm, we should grow memory here');
-    }
-    var oldView = new Int8Array(oldBuffer);
-    var newView = new Int8Array(newBuffer);
-
-    // If we have a mem init file, do not trample it
-    if (!memoryInitializer) {
-      oldView.set(newView.subarray(Module['STATIC_BASE'], Module['STATIC_BASE'] + Module['STATIC_BUMP']), Module['STATIC_BASE']);
-    }
-
-    newView.set(oldView);
-    updateGlobalBuffer(newBuffer);
-    updateGlobalBufferViews();
-  }
-
-  var WasmTypes = {
-    none: 0,
-    i32: 1,
-    i64: 2,
-    f32: 3,
-    f64: 4
-  };
-
-  function fixImports(imports) {
-    if (!{{{ WASM_BACKEND }}}) return imports;
-    var ret = {};
-    for (var i in imports) {
-      var fixed = i;
-      if (fixed[0] == '_') fixed = fixed.substr(1);
-      ret[fixed] = imports[i];
-    }
-    return ret;
-  }
-
-  function getBinary() {
-    var binary;
-    if (ENVIRONMENT_IS_WEB || ENVIRONMENT_IS_WORKER) {
-      binary = Module['wasmBinary'];
-      assert(binary, "on the web, we need the wasm binary to be preloaded and set on Module['wasmBinary']. emcc.py will do that for you when generating HTML (but not JS)");
-      binary = new Uint8Array(binary);
-    } else {
-      binary = Module['readBinary'](wasmBinaryFile);
-    }
-    return binary;
-  }
-
-  // do-method functions
-
-  function doJustAsm(global, env, providedBuffer) {
-    // if no Module.asm, or it's the method handler helper (see below), then apply
-    // the asmjs
-    if (typeof Module['asm'] !== 'function' || Module['asm'] === methodHandler) {
-      if (!Module['asmPreload']) {
-        // you can load the .asm.js file before this, to avoid this sync xhr and eval
-        eval(Module['read'](asmjsCodeFile)); // set Module.asm
-      } else {
-        Module['asm'] = Module['asmPreload'];
-      }
-    }
-    if (typeof Module['asm'] !== 'function') {
-      Module['printErr']('asm evalling did not set the module properly');
-      return false;
-    }
-    return Module['asm'](global, env, providedBuffer);
-  }
-
-  function doNativeWasm(global, env, providedBuffer) {
-    if (typeof WebAssembly !== 'object') {
-      Module['printErr']('no native wasm support detected');
-      return false;
-    }
-    // prepare memory import
-    if (!(Module['wasmMemory'] instanceof WebAssembly.Memory)) {
-      Module['printErr']('no native wasm Memory in use');
-      return false;
-    }
-    env['memory'] = Module['wasmMemory'];
-    // Load the wasm module and create an instance of using native support in the JS engine.
-    info['global'] = {
-      'NaN': NaN,
-      'Infinity': Infinity
-    };
-    info['global.Math'] = global.Math;
-    info['env'] = env;
-    var instance;
-    try {
-      instance = new WebAssembly.Instance(new WebAssembly.Module(getBinary()), info)
-    } catch (e) {
-      Module['printErr']('failed to compile wasm module: ' + e);
-      if (e.toString().indexOf('imported Memory with incompatible size') >= 0) {
-        Module['printErr']('Memory size incompatibility issues may be due to changing TOTAL_MEMORY at runtime to something too large. Use ALLOW_MEMORY_GROWTH to allow any size memory (and also make sure not to set TOTAL_MEMORY at runtime to something smaller than it was at compile time).');
-      }
-      return false;
-    }
-    exports = instance.exports;
-    if (exports.memory) mergeMemory(exports.memory);
-
-    Module["usingWasm"] = true;
-
-    return exports;
-  }
-
-  function doWasmPolyfill(global, env, providedBuffer, method) {
-    if (typeof WasmJS !== 'function') {
-      Module['printErr']('WasmJS not detected - polyfill not bundled?');
-      return false;
-    }
-
-    // Use wasm.js to polyfill and execute code in a wasm interpreter.
-    var wasmJS = WasmJS({});
-
-    // XXX don't be confused. Module here is in the outside program. wasmJS is the inner wasm-js.cpp.
-    wasmJS['outside'] = Module; // Inside wasm-js.cpp, Module['outside'] reaches the outside module.
-
-    // Information for the instance of the module.
-    wasmJS['info'] = info;
-
-    wasmJS['lookupImport'] = lookupImport;
-
-    assert(providedBuffer === Module['buffer']); // we should not even need to pass it as a 3rd arg for wasm, but that's the asm.js way.
-
-    info.global = global;
-    info.env = env;
-
-    // polyfill interpreter expects an ArrayBuffer
-    assert(providedBuffer === Module['buffer']);
-    env['memory'] = providedBuffer;
-    assert(env['memory'] instanceof ArrayBuffer);
-
-    wasmJS['providedTotalMemory'] = Module['buffer'].byteLength;
-
-    // Prepare to generate wasm, using either asm2wasm or s-exprs
-    var code;
-    if (method === 'interpret-binary') {
-      code = getBinary();
-    } else {
-      code = Module['read'](method == 'interpret-asm2wasm' ? asmjsCodeFile : wasmTextFile);
-    }
-    var temp;
-    if (method == 'interpret-asm2wasm') {
-      temp = wasmJS['_malloc'](code.length + 1);
-      wasmJS['writeAsciiToMemory'](code, temp);
-      wasmJS['_load_asm2wasm'](temp);
-    } else if (method === 'interpret-s-expr') {
-      temp = wasmJS['_malloc'](code.length + 1);
-      wasmJS['writeAsciiToMemory'](code, temp);
-      wasmJS['_load_s_expr2wasm'](temp);
-    } else if (method === 'interpret-binary') {
-      temp = wasmJS['_malloc'](code.length);
-      wasmJS['HEAPU8'].set(code, temp);
-      wasmJS['_load_binary2wasm'](temp, code.length);
-    } else {
-      throw 'what? ' + method;
-    }
-    wasmJS['_free'](temp);
-
-    wasmJS['_instantiate'](temp);
-
-    if (Module['newBuffer']) {
-      mergeMemory(Module['newBuffer']);
-      Module['newBuffer'] = null;
-    }
-
-    exports = wasmJS['asmExports'];
-
-    return exports;
-  }
-
-  // We may have a preloaded value in Module.asm, save it
-  Module['asmPreload'] = Module['asm'];
-
-  // Memory growth integration code
-  Module['reallocBuffer'] = function(size) {
-    size = Math.ceil(size / wasmPageSize) * wasmPageSize; // round up to wasm page size
-    var old = Module['buffer'];
-    var result = exports['__growWasmMemory'](size / wasmPageSize); // tiny wasm method that just does grow_memory
-    if (Module["usingWasm"]) {
-      if (result !== (-1 | 0)) {
-        // success in native wasm memory growth, get the buffer from the memory
-        return Module['buffer'] = Module['wasmMemory'].buffer;
-      } else {
-        return null;
-      }
-    } else {
-      // in interpreter, we replace Module.buffer if we allocate
-      return Module['buffer'] !== old ? Module['buffer'] : null; // if it was reallocated, it changed
-    }
-  };
-
-  // Provide an "asm.js function" for the application, called to "link" the asm.js module. We instantiate
-  // the wasm module at that time, and it receives imports and provides exports and so forth, the app
-  // doesn't need to care that it is wasm or olyfilled wasm or asm.js.
-
-  Module['asm'] = function(global, env, providedBuffer) {
-    global = fixImports(global);
-    env = fixImports(env);
-
-    // import table
-    if (!env['table']) {
-      var TABLE_SIZE = Module['wasmTableSize'];
-      if (TABLE_SIZE === undefined) TABLE_SIZE = 1024; // works in binaryen interpreter at least
-      var MAX_TABLE_SIZE = Module['wasmMaxTableSize'];
-      if (typeof WebAssembly === 'object' && typeof WebAssembly.Table === 'function') {
-        if (MAX_TABLE_SIZE !== undefined) {
-          env['table'] = new WebAssembly.Table({ initial: TABLE_SIZE, maximum: MAX_TABLE_SIZE, element: 'anyfunc' });
-        } else {
-          env['table'] = new WebAssembly.Table({ initial: TABLE_SIZE, element: 'anyfunc' });
-        }
-      } else {
-        env['table'] = new Array(TABLE_SIZE); // works in binaryen interpreter at least
-      }
-      Module['wasmTable'] = env['table'];
-    }
-
-    if (!env['memoryBase']) {
-      env['memoryBase'] = Module['STATIC_BASE']; // tell the memory segments where to place themselves
-    }
-    if (!env['tableBase']) {
-      env['tableBase'] = 0; // table starts at 0 by default, in dynamic linking this will change
-    }
-    
-    // try the methods. each should return the exports if it succeeded
-
-    var exports;
-    var methods = method.split(',');
-
-    for (var i = 0; i < methods.length; i++) {
-      var curr = methods[i];
-
-      Module['printErr']('trying binaryen method: ' + curr);
-
-      if (curr === 'native-wasm') {
-        if (exports = doNativeWasm(global, env, providedBuffer)) break;
-      } else if (curr === 'asmjs') {
-        if (exports = doJustAsm(global, env, providedBuffer)) break;
-      } else if (curr === 'interpret-asm2wasm' || curr === 'interpret-s-expr' || curr === 'interpret-binary') {
-        if (exports = doWasmPolyfill(global, env, providedBuffer, curr)) break;
-      } else {
-        throw 'bad method: ' + curr;
-      }
-    }
-
-    if (!exports) throw 'no binaryen method succeeded. consider enabling more options, like interpreting, if you want that: https://github.com/kripken/emscripten/wiki/WebAssembly#binaryen-methods';
-
-    Module['printErr']('binaryen method succeeded.');
-
-    return exports;
-  };
-
-  var methodHandler = Module['asm']; // note our method handler, as we may modify Module['asm'] later
-}
-
diff --git a/test/debugInfo.fromasm b/test/debugInfo.fromasm
index f073f66a1..f19f244f5 100644
--- a/test/debugInfo.fromasm
+++ b/test/debugInfo.fromasm
@@ -1,7 +1,5 @@
 (module
-  (type $FUNCSIG$iii (func (param i32 i32) (result i32)))
   (type $FUNCSIG$vii (func (param i32 i32)))
-  (import "asm2wasm" "i32s-rem" (func $i32s-rem (param i32 i32) (result i32)))
   (import "env" "memory" (memory $0 256 256))
   (import "env" "table" (table 0 0 anyfunc))
   (import "env" "memoryBase" (global $memoryBase i32))
@@ -25,6 +23,16 @@
       (i32.const 1)
     )
   )
+  (func $i32s-rem (param $0 i32) (param $1 i32) (result i32)
+    (if i32
+      (get_local $1)
+      (i32.rem_s
+        (get_local $0)
+        (get_local $1)
+      )
+      (i32.const 0)
+    )
+  )
   (func $opts (param $0 i32) (param $1 i32) (result i32)
     ;; even-opted.cpp:2
     (set_local $1
diff --git a/test/debugInfo.fromasm.no-opts b/test/debugInfo.fromasm.no-opts
index 0e450a5ab..af52ca902 100644
--- a/test/debugInfo.fromasm.no-opts
+++ b/test/debugInfo.fromasm.no-opts
@@ -1,7 +1,5 @@
 (module
-  (type $FUNCSIG$iii (func (param i32 i32) (result i32)))
   (type $FUNCSIG$vii (func (param i32 i32)))
-  (import "asm2wasm" "i32s-rem" (func $i32s-rem (param i32 i32) (result i32)))
   (import "env" "memory" (memory $0 256 256))
   (import "env" "table" (table 0 0 anyfunc))
   (import "env" "memoryBase" (global $memoryBase i32))
@@ -45,6 +43,18 @@
       )
     )
   )
+  (func $i32s-rem (param $0 i32) (param $1 i32) (result i32)
+    (if i32
+      (i32.eqz
+        (get_local $1)
+      )
+      (i32.const 0)
+      (i32.rem_s
+        (get_local $0)
+        (get_local $1)
+      )
+    )
+  )
   (func $opts (param $x i32) (param $y i32) (result i32)
     ;; even-opted.cpp:1
     (set_local $x
diff --git a/test/emcc_O2_hello_world.fromasm b/test/emcc_O2_hello_world.fromasm
index 1cc6427ef..40f7d3585 100644
--- a/test/emcc_O2_hello_world.fromasm
+++ b/test/emcc_O2_hello_world.fromasm
@@ -1,9 +1,9 @@
 (module
   (type $FUNCSIG$iiii (func (param i32 i32 i32) (result i32)))
-  (type $FUNCSIG$iii (func (param i32 i32) (result i32)))
   (type $FUNCSIG$ii (func (param i32) (result i32)))
   (type $FUNCSIG$vi (func (param i32)))
   (type $FUNCSIG$i (func (result i32)))
+  (type $FUNCSIG$iii (func (param i32 i32) (result i32)))
   (type $FUNCSIG$v (func))
   (type $FUNCSIG$vii (func (param i32 i32)))
   (import "env" "STACKTOP" (global $STACKTOP$asm2wasm$import i32))
@@ -23,7 +23,6 @@
   (import "env" "___unlock" (func $___unlock (param i32)))
   (import "env" "___syscall140" (func $___syscall140 (param i32 i32) (result i32)))
   (import "env" "___syscall146" (func $___syscall146 (param i32 i32) (result i32)))
-  (import "asm2wasm" "i32u-div" (func $i32u-div (param i32 i32) (result i32)))
   (import "env" "memory" (memory $0 256 256))
   (import "env" "table" (table 18 18 anyfunc))
   (import "env" "memoryBase" (global $memoryBase i32))
@@ -9450,6 +9449,16 @@
       )
     )
   )
+  (func $i32u-div (param $0 i32) (param $1 i32) (result i32)
+    (if i32
+      (get_local $1)
+      (i32.div_u
+        (get_local $0)
+        (get_local $1)
+      )
+      (i32.const 0)
+    )
+  )
   (func $_fwrite (param $0 i32) (param $1 i32) (param $2 i32) (param $3 i32) (result i32)
     (local $4 i32)
     (local $5 i32)
diff --git a/test/emcc_O2_hello_world.fromasm.no-opts b/test/emcc_O2_hello_world.fromasm.no-opts
index 80801ea2d..e5c2052a6 100644
--- a/test/emcc_O2_hello_world.fromasm.no-opts
+++ b/test/emcc_O2_hello_world.fromasm.no-opts
@@ -1,9 +1,9 @@
 (module
   (type $FUNCSIG$iiii (func (param i32 i32 i32) (result i32)))
-  (type $FUNCSIG$iii (func (param i32 i32) (result i32)))
   (type $FUNCSIG$ii (func (param i32) (result i32)))
   (type $FUNCSIG$vi (func (param i32)))
   (type $FUNCSIG$i (func (result i32)))
+  (type $FUNCSIG$iii (func (param i32 i32) (result i32)))
   (type $FUNCSIG$v (func))
   (type $FUNCSIG$vii (func (param i32 i32)))
   (import "env" "STACKTOP" (global $STACKTOP$asm2wasm$import i32))
@@ -27,7 +27,6 @@
   (import "env" "___unlock" (func $___unlock (param i32)))
   (import "env" "___syscall140" (func $___syscall140 (param i32 i32) (result i32)))
   (import "env" "___syscall146" (func $___syscall146 (param i32 i32) (result i32)))
-  (import "asm2wasm" "i32u-div" (func $i32u-div (param i32 i32) (result i32)))
   (import "env" "memory" (memory $0 256 256))
   (import "env" "table" (table 18 18 anyfunc))
   (import "env" "memoryBase" (global $memoryBase i32))
@@ -11347,6 +11346,18 @@
       (get_local $i4)
     )
   )
+  (func $i32u-div (param $0 i32) (param $1 i32) (result i32)
+    (if i32
+      (i32.eqz
+        (get_local $1)
+      )
+      (i32.const 0)
+      (i32.div_u
+        (get_local $0)
+        (get_local $1)
+      )
+    )
+  )
   (func $_fwrite (param $i1 i32) (param $i2 i32) (param $i3 i32) (param $i4 i32) (result i32)
     (local $i5 i32)
     (local $i6 i32)
diff --git a/test/emcc_hello_world.fromasm b/test/emcc_hello_world.fromasm
index 7dbe75147..87cf3f385 100644
--- a/test/emcc_hello_world.fromasm
+++ b/test/emcc_hello_world.fromasm
@@ -1,11 +1,11 @@
 (module
   (type $FUNCSIG$iiii (func (param i32 i32 i32) (result i32)))
   (type $FUNCSIG$id (func (param f64) (result i32)))
-  (type $FUNCSIG$iii (func (param i32 i32) (result i32)))
   (type $FUNCSIG$ii (func (param i32) (result i32)))
   (type $FUNCSIG$vi (func (param i32)))
   (type $FUNCSIG$v (func))
   (type $FUNCSIG$i (func (result i32)))
+  (type $FUNCSIG$iii (func (param i32 i32) (result i32)))
   (type $FUNCSIG$vii (func (param i32 i32)))
   (import "env" "STACKTOP" (global $STACKTOP$asm2wasm$import i32))
   (import "env" "STACK_MAX" (global $STACK_MAX$asm2wasm$import i32))
@@ -29,10 +29,6 @@
   (import "env" "_sysconf" (func $_sysconf (param i32) (result i32)))
   (import "env" "___syscall146" (func $___syscall146 (param i32 i32) (result i32)))
   (import "asm2wasm" "f64-to-int" (func $f64-to-int (param f64) (result i32)))
-  (import "asm2wasm" "i32s-div" (func $i32s-div (param i32 i32) (result i32)))
-  (import "asm2wasm" "i32s-rem" (func $i32s-rem (param i32 i32) (result i32)))
-  (import "asm2wasm" "i32u-rem" (func $i32u-rem (param i32 i32) (result i32)))
-  (import "asm2wasm" "i32u-div" (func $i32u-div (param i32 i32) (result i32)))
   (import "env" "memory" (memory $0 256 256))
   (import "env" "table" (table 18 18 anyfunc))
   (import "env" "memoryBase" (global $memoryBase i32))
@@ -2234,6 +2230,59 @@
       )
     )
   )
+  (func $i32s-div (param $0 i32) (param $1 i32) (result i32)
+    (if i32
+      (get_local $1)
+      (if i32
+        (i32.and
+          (i32.eq
+            (get_local $0)
+            (i32.const -2147483648)
+          )
+          (i32.eq
+            (get_local $1)
+            (i32.const -1)
+          )
+        )
+        (i32.const 0)
+        (i32.div_s
+          (get_local $0)
+          (get_local $1)
+        )
+      )
+      (i32.const 0)
+    )
+  )
+  (func $i32s-rem (param $0 i32) (param $1 i32) (result i32)
+    (if i32
+      (get_local $1)
+      (i32.rem_s
+        (get_local $0)
+        (get_local $1)
+      )
+      (i32.const 0)
+    )
+  )
+  (func $i32u-rem (param $0 i32) (param $1 i32) (result i32)
+    (if i32
+      (get_local $1)
+      (i32.rem_u
+        (get_local $0)
+        (get_local $1)
+      )
+      (i32.const 0)
+    )
+  )
+  (func $i32u-div (param $0 i32) (param $1 i32) (result i32)
+    (if i32
+      (get_local $1)
+      (i32.div_u
+        (get_local $0)
+        (get_local $1)
+      )
+      (i32.const 0)
+    )
+  )
   (func $_printf_core (param $0 i32) (param $1 i32) (param $2 i32) (param $3 i32) (param $4 i32) (result i32)
     (local $5 i32)
     (local $6 i32)
diff --git a/test/emcc_hello_world.fromasm.no-opts b/test/emcc_hello_world.fromasm.no-opts
index 10cae59e8..1b51d826c 100644
--- a/test/emcc_hello_world.fromasm.no-opts
+++ b/test/emcc_hello_world.fromasm.no-opts
@@ -1,11 +1,11 @@
 (module
   (type $FUNCSIG$iiii (func (param i32 i32 i32) (result i32)))
   (type $FUNCSIG$id (func (param f64) (result i32)))
-  (type $FUNCSIG$iii (func (param i32 i32) (result i32)))
   (type $FUNCSIG$ii (func (param i32) (result i32)))
   (type $FUNCSIG$vi (func (param i32)))
   (type $FUNCSIG$v (func))
   (type $FUNCSIG$i (func (result i32)))
+  (type $FUNCSIG$iii (func (param i32 i32) (result i32)))
   (type $FUNCSIG$vii (func (param i32 i32)))
   (import "env" "STACKTOP" (global $STACKTOP$asm2wasm$import i32))
   (import "env" "STACK_MAX" (global $STACK_MAX$asm2wasm$import i32))
@@ -33,10 +33,6 @@
   (import "env" "_sysconf" (func $_sysconf (param i32) (result i32)))
   (import "env" "___syscall146" (func $___syscall146 (param i32 i32) (result i32)))
   (import "asm2wasm" "f64-to-int" (func $f64-to-int (param f64) (result i32)))
-  (import "asm2wasm" "i32s-div" (func $i32s-div (param i32 i32) (result i32)))
-  (import "asm2wasm" "i32s-rem" (func $i32s-rem (param i32 i32) (result i32)))
-  (import "asm2wasm" "i32u-rem" (func $i32u-rem (param i32 i32) (result i32)))
-  (import "asm2wasm" "i32u-div" (func $i32u-div (param i32 i32) (result i32)))
   (import "env" "memory" (memory $0 256 256))
   (import "env" "table" (table 18 18 anyfunc))
   (import "env" "memoryBase" (global $memoryBase i32))
@@ -4638,6 +4634,67 @@
     )
     (return)
   )
+  (func $i32s-div (param $0 i32) (param $1 i32) (result i32)
+    (if i32
+      (i32.eqz
+        (get_local $1)
+      )
+      (i32.const 0)
+      (if i32
+        (i32.and
+          (i32.eq
+            (get_local $0)
+            (i32.const -2147483648)
+          )
+          (i32.eq
+            (get_local $1)
+            (i32.const -1)
+          )
+        )
+        (i32.const 0)
+        (i32.div_s
+          (get_local $0)
+          (get_local $1)
+        )
+      )
+    )
+  )
+  (func $i32s-rem (param $0 i32) (param $1 i32) (result i32)
+    (if i32
+      (i32.eqz
+        (get_local $1)
+      )
+      (i32.const 0)
+      (i32.rem_s
+        (get_local $0)
+        (get_local $1)
+      )
+    )
+  )
+  (func $i32u-rem (param $0 i32) (param $1 i32) (result i32)
+    (if i32
+      (i32.eqz
+        (get_local $1)
+      )
+      (i32.const 0)
+      (i32.rem_u
+        (get_local $0)
+        (get_local $1)
+      )
+    )
+  )
+  (func $i32u-div (param $0 i32) (param $1 i32) (result i32)
+    (if i32
+      (i32.eqz
+        (get_local $1)
+      )
+      (i32.const 0)
+      (i32.div_u
+        (get_local $0)
+        (get_local $1)
+      )
+    )
+  )
   (func $_printf_core (param $$f i32) (param $$fmt i32) (param $$ap i32) (param $$nl_arg i32) (param $$nl_type i32) (result i32)
     (local $$$ i32)
     (local $$$$i i32)
diff --git a/test/memorygrowth.fromasm b/test/memorygrowth.fromasm
index e33525578..b06a13f64 100644
--- a/test/memorygrowth.fromasm
+++ b/test/memorygrowth.fromasm
@@ -1,10 +1,10 @@
 (module
   (type $FUNCSIG$iiii (func (param i32 i32 i32) (result i32)))
-  (type $FUNCSIG$iii (func (param i32 i32) (result i32)))
   (type $FUNCSIG$ii (func (param i32) (result i32)))
   (type $FUNCSIG$vi (func (param i32)))
   (type $FUNCSIG$v (func))
   (type $FUNCSIG$vii (func (param i32 i32)))
+  (type $FUNCSIG$iii (func (param i32 i32) (result i32)))
   (import "env" "STACKTOP" (global $r$asm2wasm$import i32))
   (import "env" "STACK_MAX" (global $s$asm2wasm$import i32))
   (import "env" "abort" (func $ja (param i32)))
@@ -19,7 +19,6 @@
   (import "env" "___syscall54" (func $wa (param i32 i32) (result i32)))
   (import "env" "___unlock" (func $xa (param i32)))
   (import "env" "___syscall146" (func $ya (param i32 i32) (result i32)))
-  (import "asm2wasm" "i32u-div" (func $i32u-div (param i32 i32) (result i32)))
   (import "env" "memory" (memory $0 256))
   (import "env" "table" (table 8 8 anyfunc))
   (import "env" "memoryBase" (global $memoryBase i32))
@@ -9442,6 +9441,16 @@
       )
     )
   )
+  (func $i32u-div (param $0 i32) (param $1 i32) (result i32)
+    (if i32
+      (get_local $1)
+      (i32.div_u
+        (get_local $0)
+        (get_local $1)
+      )
+      (i32.const 0)
+    )
+  )
   (func $bb (param $0 i32) (param $1 i32) (param $2 i32) (param $3 i32) (result i32)
     (local $4 i32)
     (local $5 i32)
diff --git a/test/memorygrowth.fromasm.no-opts b/test/memorygrowth.fromasm.no-opts
index a27f419ae..c9569d0bd 100644
--- a/test/memorygrowth.fromasm.no-opts
+++ b/test/memorygrowth.fromasm.no-opts
@@ -1,10 +1,10 @@
 (module
   (type $FUNCSIG$iiii (func (param i32 i32 i32) (result i32)))
-  (type $FUNCSIG$iii (func (param i32 i32) (result i32)))
   (type $FUNCSIG$ii (func (param i32) (result i32)))
   (type $FUNCSIG$vi (func (param i32)))
   (type $FUNCSIG$v (func))
   (type $FUNCSIG$vii (func (param i32 i32)))
+  (type $FUNCSIG$iii (func (param i32 i32) (result i32)))
   (import "env" "STACKTOP" (global $r$asm2wasm$import i32))
   (import "env" "STACK_MAX" (global $s$asm2wasm$import i32))
   (import "env" "tempDoublePtr" (global $t$asm2wasm$import i32))
@@ -23,7 +23,6 @@
   (import "env" "___syscall54" (func $wa (param i32 i32) (result i32)))
   (import "env" "___unlock" (func $xa (param i32)))
   (import "env" "___syscall146" (func $ya (param i32 i32) (result i32)))
-  (import "asm2wasm" "i32u-div" (func $i32u-div (param i32 i32) (result i32)))
   (import "env" "memory" (memory $0 256))
   (import "env" "table" (table 8 8 anyfunc))
   (import "env" "memoryBase" (global $memoryBase i32))
@@ -11306,6 +11305,18 @@
       (get_local $d)
     )
   )
+  (func $i32u-div (param $0 i32) (param $1 i32) (result i32)
+    (if i32
+      (i32.eqz
+        (get_local $1)
+      )
+      (i32.const 0)
+      (i32.div_u
+        (get_local $0)
+        (get_local $1)
+      )
+    )
+  )
   (func $bb (param $a i32) (param $b i32) (param $c i32) (param $d i32) (result i32)
     (local $e i32)
     (local $f i32)
diff --git a/test/unit.fromasm b/test/unit.fromasm
index 4f7b2c6a9..bbce09412 100644
--- a/test/unit.fromasm
+++ b/test/unit.fromasm
@@ -1,7 +1,6 @@
 (module
   (type $FUNCSIG$id (func (param f64) (result i32)))
   (type $FUNCSIG$ddd (func (param f64 f64) (result f64)))
-  (type $FUNCSIG$iii (func (param i32 i32) (result i32)))
   (type $FUNCSIG$vf (func (param f32)))
   (type $FUNCSIG$vi (func (param i32)))
   (type $FUNCSIG$v (func))
@@ -17,7 +16,6 @@
   (import "env" "return_int" (func $return_int (result i32)))
   (import "asm2wasm" "f64-to-int" (func $f64-to-int (param f64) (result i32)))
   (import "asm2wasm" "f64-rem" (func $f64-rem (param f64 f64) (result f64)))
-  (import "asm2wasm" "i32u-div" (func $i32u-div (param i32 i32) (result i32)))
   (import "env" "memory" (memory $0 256 256))
   (import "env" "table" (table 24 24 anyfunc))
   (import "env" "memoryBase" (global $memoryBase i32))
@@ -252,6 +250,16 @@
       (f64.const 1.2)
     )
   )
+  (func $i32u-div (param $0 i32) (param $1 i32) (result i32)
+    (if i32
+      (get_local $1)
+      (i32.div_u
+        (get_local $0)
+        (get_local $1)
+      )
+      (i32.const 0)
+    )
+  )
   (func $big_uint_div_u (result i32)
     (call $i32u-div
       (i32.const -1)
diff --git a/test/unit.fromasm.no-opts b/test/unit.fromasm.no-opts
index 29fede80c..d18dfd77e 100644
--- a/test/unit.fromasm.no-opts
+++ b/test/unit.fromasm.no-opts
@@ -1,7 +1,6 @@
 (module
   (type $FUNCSIG$id (func (param f64) (result i32)))
   (type $FUNCSIG$ddd (func (param f64 f64) (result f64)))
-  (type $FUNCSIG$iii (func (param i32 i32) (result i32)))
   (type $FUNCSIG$vf (func (param f32)))
   (type $FUNCSIG$vi (func (param i32)))
   (type $FUNCSIG$v (func))
@@ -21,7 +20,6 @@
   (import "env" "return_int" (func $return_int (result i32)))
   (import "asm2wasm" "f64-to-int" (func $f64-to-int (param f64) (result i32)))
   (import "asm2wasm" "f64-rem" (func $f64-rem (param f64 f64) (result f64)))
-  (import "asm2wasm" "i32u-div" (func $i32u-div (param i32 i32) (result i32)))
   (import "env" "memory" (memory $0 256 256))
   (import "env" "table" (table 24 24 anyfunc))
   (import "env" "memoryBase" (global $memoryBase i32))
@@ -379,6 +377,18 @@
       )
     )
   )
+  (func $i32u-div (param $0 i32) (param $1 i32) (result i32)
+    (if i32
+      (i32.eqz
+        (get_local $1)
+      )
+      (i32.const 0)
+      (i32.div_u
+        (get_local $0)
+        (get_local $1)
+      )
+    )
+  )
   (func $big_uint_div_u (result i32)
     (local $x i32)
     (set_local $x
diff --git a/test/wasm-only.fromasm b/test/wasm-only.fromasm
index 1a50a4385..dbb67e746 100644
--- a/test/wasm-only.fromasm
+++ b/test/wasm-only.fromasm
@@ -148,9 +148,22 @@
         (get_local $1)
       )
       (i64.const 0)
-      (i64.div_s
-        (get_local $0)
-        (get_local $1)
+      (if i64
+        (i32.and
+          (i64.eq
+            (get_local $0)
+            (i64.const -9223372036854775808)
+          )
+          (i64.eq
+            (get_local $1)
+            (i64.const -1)
+          )
+        )
+        (i64.const 0)
+        (i64.div_s
+          (get_local $0)
+          (get_local $1)
+        )
       )
     )
   )
diff --git a/test/wasm-only.fromasm.no-opts b/test/wasm-only.fromasm.no-opts
index eae9c4597..ae1fa211b 100644
--- a/test/wasm-only.fromasm.no-opts
+++ b/test/wasm-only.fromasm.no-opts
@@ -296,9 +296,22 @@
         (get_local $1)
       )
       (i64.const 0)
-      (i64.div_s
-        (get_local $0)
-        (get_local $1)
+      (if i64
+        (i32.and
+          (i64.eq
+            (get_local $0)
+            (i64.const -9223372036854775808)
+          )
+          (i64.eq
+            (get_local $1)
+            (i64.const -1)
+          )
+        )
+        (i64.const 0)
+        (i64.div_s
+          (get_local $0)
+          (get_local $1)
+        )
       )
     )
   )