Add i64 high bits (tempRet0) helper funcs when legalizing JS interface (#1428)

* add tempRet0 helpers when necessary in legalize-js-interface

15 files changed, 208 insertions, 0 deletions

diff --git a/src/passes/LegalizeJSInterface.cpp b/src/passes/LegalizeJSInterface.cpp
index 7f6ee6b48..23a4868ac 100644
--- a/src/passes/LegalizeJSInterface.cpp
+++ b/src/passes/LegalizeJSInterface.cpp
@@ -35,6 +35,8 @@
 namespace wasm {
 
 Name TEMP_RET_0("tempRet0");
+Name GET_TEMP_RET_0("getTempRet0");
+Name SET_TEMP_RET_0("setTempRet0");
 
 struct LegalizeJSInterface : public Pass {
   void run(PassRunner* runner, Module* module) override {
@@ -99,12 +101,18 @@ struct LegalizeJSInterface : public Pass {
       passRunner.add<FixImports>(&illegalToLegal);
       passRunner.run();
     }
+
+    if (needTempRet0Helpers) {
+      addTempRet0Helpers(module);
+    }
   }
 
 private:
   // map of illegal to legal names for imports
   std::map<Name, Name> illegalToLegal;
 
+  bool needTempRet0Helpers = false;
+
   template<typename T>
   bool isIllegal(T* t) {
     for (auto param : t->params) {
@@ -233,6 +241,41 @@ private:
         LiteralUtils::makeZero(i32, *module),
         Builder::Mutable
       ));
+      needTempRet0Helpers = true;
+    }
+  }
+
+  void addTempRet0Helpers(Module* module) {
+    // We should also let JS access the tempRet0 global, which
+    // is necessary to send/receive 64-bit return values.
+    auto exportIt = [&](Function* func) {
+      auto* export_ = new Export;
+      export_->name = func->name;
+      export_->value = func->name;
+      export_->kind = ExternalKind::Function;
+      module->addExport(export_);
+    };
+    if (!module->getExportOrNull(GET_TEMP_RET_0)) {
+      Builder builder(*module);
+      auto* func = new Function();
+      func->name = GET_TEMP_RET_0;
+      func->result = i32;
+      func->body = builder.makeGetGlobal(TEMP_RET_0, i32);
+      module->addFunction(func);
+      exportIt(func);
+    }
+    if (!module->getExportOrNull(SET_TEMP_RET_0)) {
+      Builder builder(*module);
+      auto* func = new Function();
+      func->name = SET_TEMP_RET_0;
+      func->result = none;
+      func->params.push_back(i32);
+      func->body = builder.makeSetGlobal(
+        TEMP_RET_0,
+        builder.makeGetLocal(0, i32)
+      );
+      module->addFunction(func);
+      exportIt(func);
     }
   }
 };
diff --git a/test/passes/legalize-js-interface.txt b/test/passes/legalize-js-interface.txt
new file mode 100644
index 000000000..8f833de87
--- /dev/null
+++ b/test/passes/legalize-js-interface.txt
@@ -0,0 +1,37 @@
+(module
+ (type $0 (func (result i64)))
+ (global $tempRet0 (mut i32) (i32.const 0))
+ (export "func" (func $legalstub$func))
+ (export "getTempRet0" (func $getTempRet0))
+ (export "setTempRet0" (func $setTempRet0))
+ (func $func (; 0 ;) (type $0) (result i64)
+  (unreachable)
+ )
+ (func $legalstub$func (; 1 ;) (result i32)
+  (local $0 i64)
+  (set_local $0
+   (call $func)
+  )
+  (set_global $tempRet0
+   (i32.wrap/i64
+    (i64.shr_u
+     (get_local $0)
+     (i64.const 32)
+    )
+   )
+  )
+  (i32.wrap/i64
+   (get_local $0)
+  )
+ )
+ (func $getTempRet0 (; 2 ;) (result i32)
+  (get_global $tempRet0)
+ )
+ (func $setTempRet0 (; 3 ;) (param $0 i32)
+  (set_global $tempRet0
+   (get_local $0)
+  )
+ )
+)
+(module
+)
diff --git a/test/passes/legalize-js-interface.wast b/test/passes/legalize-js-interface.wast
new file mode 100644
index 000000000..bae2a8c75
--- /dev/null
+++ b/test/passes/legalize-js-interface.wast
@@ -0,0 +1,8 @@
+(module
+  (export "func" (func $func))
+  (func $func (result i64)
+    (unreachable)
+  )
+)
+(module)
+
diff --git a/test/threads.wasm-only.fromasm b/test/threads.wasm-only.fromasm
index 79ef9eb00..f633af016 100644
--- a/test/threads.wasm-only.fromasm
+++ b/test/threads.wasm-only.fromasm
@@ -4,6 +4,8 @@
  (global $tempRet0 (mut i32) (i32.const 0))
  (data (get_global $memoryBase) "threads.wasm-only.asm.js")
  (export "test64" (func $legalstub$test64))
+ (export "getTempRet0" (func $getTempRet0))
+ (export "setTempRet0" (func $setTempRet0))
  (func $test64 (; 0 ;) (result i64)
   (local $0 i64)
   (local $1 i64)
@@ -65,4 +67,12 @@
    (get_local $0)
   )
  )
+ (func $getTempRet0 (; 2 ;) (result i32)
+  (get_global $tempRet0)
+ )
+ (func $setTempRet0 (; 3 ;) (param $0 i32)
+  (set_global $tempRet0
+   (get_local $0)
+  )
+ )
 )
diff --git a/test/threads.wasm-only.fromasm.clamp b/test/threads.wasm-only.fromasm.clamp
index 79ef9eb00..f633af016 100644
--- a/test/threads.wasm-only.fromasm.clamp
+++ b/test/threads.wasm-only.fromasm.clamp
@@ -4,6 +4,8 @@
  (global $tempRet0 (mut i32) (i32.const 0))
  (data (get_global $memoryBase) "threads.wasm-only.asm.js")
  (export "test64" (func $legalstub$test64))
+ (export "getTempRet0" (func $getTempRet0))
+ (export "setTempRet0" (func $setTempRet0))
  (func $test64 (; 0 ;) (result i64)
   (local $0 i64)
   (local $1 i64)
@@ -65,4 +67,12 @@
    (get_local $0)
   )
  )
+ (func $getTempRet0 (; 2 ;) (result i32)
+  (get_global $tempRet0)
+ )
+ (func $setTempRet0 (; 3 ;) (param $0 i32)
+  (set_global $tempRet0
+   (get_local $0)
+  )
+ )
 )
diff --git a/test/threads.wasm-only.fromasm.clamp.no-opts b/test/threads.wasm-only.fromasm.clamp.no-opts
index 35b506e2b..971d690f4 100644
--- a/test/threads.wasm-only.fromasm.clamp.no-opts
+++ b/test/threads.wasm-only.fromasm.clamp.no-opts
@@ -7,6 +7,8 @@
  (global $STACKTOP (mut i32) (get_global $STACKTOP$asm2wasm$import))
  (global $tempRet0 (mut i32) (i32.const 0))
  (export "test64" (func $legalstub$test64))
+ (export "getTempRet0" (func $getTempRet0))
+ (export "setTempRet0" (func $setTempRet0))
  (func $test64 (; 0 ;) (result i64)
   (local $x i64)
   (local $y i64)
@@ -87,4 +89,12 @@
    (get_local $0)
   )
  )
+ (func $getTempRet0 (; 2 ;) (result i32)
+  (get_global $tempRet0)
+ )
+ (func $setTempRet0 (; 3 ;) (param $0 i32)
+  (set_global $tempRet0
+   (get_local $0)
+  )
+ )
 )
diff --git a/test/threads.wasm-only.fromasm.imprecise b/test/threads.wasm-only.fromasm.imprecise
index ccbb5870f..2c6fa3f18 100644
--- a/test/threads.wasm-only.fromasm.imprecise
+++ b/test/threads.wasm-only.fromasm.imprecise
@@ -2,6 +2,8 @@
  (import "env" "memory" (memory $0 (shared 256 256)))
  (global $tempRet0 (mut i32) (i32.const 0))
  (export "test64" (func $legalstub$test64))
+ (export "getTempRet0" (func $getTempRet0))
+ (export "setTempRet0" (func $setTempRet0))
  (func $test64 (; 0 ;) (result i64)
   (local $0 i64)
   (local $1 i64)
@@ -63,4 +65,12 @@
    (get_local $0)
   )
  )
+ (func $getTempRet0 (; 2 ;) (result i32)
+  (get_global $tempRet0)
+ )
+ (func $setTempRet0 (; 3 ;) (param $0 i32)
+  (set_global $tempRet0
+   (get_local $0)
+  )
+ )
 )
diff --git a/test/threads.wasm-only.fromasm.imprecise.no-opts b/test/threads.wasm-only.fromasm.imprecise.no-opts
index 35b506e2b..971d690f4 100644
--- a/test/threads.wasm-only.fromasm.imprecise.no-opts
+++ b/test/threads.wasm-only.fromasm.imprecise.no-opts
@@ -7,6 +7,8 @@
  (global $STACKTOP (mut i32) (get_global $STACKTOP$asm2wasm$import))
  (global $tempRet0 (mut i32) (i32.const 0))
  (export "test64" (func $legalstub$test64))
+ (export "getTempRet0" (func $getTempRet0))
+ (export "setTempRet0" (func $setTempRet0))
  (func $test64 (; 0 ;) (result i64)
   (local $x i64)
   (local $y i64)
@@ -87,4 +89,12 @@
    (get_local $0)
   )
  )
+ (func $getTempRet0 (; 2 ;) (result i32)
+  (get_global $tempRet0)
+ )
+ (func $setTempRet0 (; 3 ;) (param $0 i32)
+  (set_global $tempRet0
+   (get_local $0)
+  )
+ )
 )
diff --git a/test/threads.wasm-only.fromasm.no-opts b/test/threads.wasm-only.fromasm.no-opts
index 35b506e2b..971d690f4 100644
--- a/test/threads.wasm-only.fromasm.no-opts
+++ b/test/threads.wasm-only.fromasm.no-opts
@@ -7,6 +7,8 @@
  (global $STACKTOP (mut i32) (get_global $STACKTOP$asm2wasm$import))
  (global $tempRet0 (mut i32) (i32.const 0))
  (export "test64" (func $legalstub$test64))
+ (export "getTempRet0" (func $getTempRet0))
+ (export "setTempRet0" (func $setTempRet0))
  (func $test64 (; 0 ;) (result i64)
   (local $x i64)
   (local $y i64)
@@ -87,4 +89,12 @@
    (get_local $0)
   )
  )
+ (func $getTempRet0 (; 2 ;) (result i32)
+  (get_global $tempRet0)
+ )
+ (func $setTempRet0 (; 3 ;) (param $0 i32)
+  (set_global $tempRet0
+   (get_local $0)
+  )
+ )
 )
diff --git a/test/wasm-only.fromasm b/test/wasm-only.fromasm
index 46a388b48..596ab5eb6 100644
--- a/test/wasm-only.fromasm
+++ b/test/wasm-only.fromasm
@@ -17,6 +17,8 @@
  (export "illegalParam" (func $legalstub$illegalParam))
  (export "illegalResult" (func $legalstub$illegalResult))
  (export "keepAlive" (func $keepAlive))
+ (export "getTempRet0" (func $getTempRet0))
+ (export "setTempRet0" (func $setTempRet0))
  (func $loads (; 4 ;)
   (drop
    (i32.load8_s
@@ -1057,4 +1059,12 @@
    )
   )
  )
+ (func $getTempRet0 (; 29 ;) (result i32)
+  (get_global $tempRet0)
+ )
+ (func $setTempRet0 (; 30 ;) (param $0 i32)
+  (set_global $tempRet0
+   (get_local $0)
+  )
+ )
 )
diff --git a/test/wasm-only.fromasm.clamp b/test/wasm-only.fromasm.clamp
index 46a388b48..596ab5eb6 100644
--- a/test/wasm-only.fromasm.clamp
+++ b/test/wasm-only.fromasm.clamp
@@ -17,6 +17,8 @@
  (export "illegalParam" (func $legalstub$illegalParam))
  (export "illegalResult" (func $legalstub$illegalResult))
  (export "keepAlive" (func $keepAlive))
+ (export "getTempRet0" (func $getTempRet0))
+ (export "setTempRet0" (func $setTempRet0))
  (func $loads (; 4 ;)
   (drop
    (i32.load8_s
@@ -1057,4 +1059,12 @@
    )
   )
  )
+ (func $getTempRet0 (; 29 ;) (result i32)
+  (get_global $tempRet0)
+ )
+ (func $setTempRet0 (; 30 ;) (param $0 i32)
+  (set_global $tempRet0
+   (get_local $0)
+  )
+ )
 )
diff --git a/test/wasm-only.fromasm.clamp.no-opts b/test/wasm-only.fromasm.clamp.no-opts
index 6e4a75bf2..680fe87ea 100644
--- a/test/wasm-only.fromasm.clamp.no-opts
+++ b/test/wasm-only.fromasm.clamp.no-opts
@@ -28,6 +28,8 @@
  (export "illegalParam" (func $legalstub$illegalParam))
  (export "illegalResult" (func $legalstub$illegalResult))
  (export "keepAlive" (func $keepAlive))
+ (export "getTempRet0" (func $getTempRet0))
+ (export "setTempRet0" (func $setTempRet0))
  (func $loads (; 9 ;)
   (local $i i32)
   (local $f f32)
@@ -1919,4 +1921,12 @@
    )
   )
  )
+ (func $getTempRet0 (; 45 ;) (result i32)
+  (get_global $tempRet0)
+ )
+ (func $setTempRet0 (; 46 ;) (param $0 i32)
+  (set_global $tempRet0
+   (get_local $0)
+  )
+ )
 )
diff --git a/test/wasm-only.fromasm.imprecise b/test/wasm-only.fromasm.imprecise
index 72e62809e..982600bef 100644
--- a/test/wasm-only.fromasm.imprecise
+++ b/test/wasm-only.fromasm.imprecise
@@ -15,6 +15,8 @@
  (export "illegalParam" (func $legalstub$illegalParam))
  (export "illegalResult" (func $legalstub$illegalResult))
  (export "keepAlive" (func $keepAlive))
+ (export "getTempRet0" (func $getTempRet0))
+ (export "setTempRet0" (func $setTempRet0))
  (func $stores (; 4 ;)
   (local $0 i32)
   (local $1 f64)
@@ -736,4 +738,12 @@
    )
   )
  )
+ (func $getTempRet0 (; 23 ;) (result i32)
+  (get_global $tempRet0)
+ )
+ (func $setTempRet0 (; 24 ;) (param $0 i32)
+  (set_global $tempRet0
+   (get_local $0)
+  )
+ )
 )
diff --git a/test/wasm-only.fromasm.imprecise.no-opts b/test/wasm-only.fromasm.imprecise.no-opts
index a414e6822..eaa5d7973 100644
--- a/test/wasm-only.fromasm.imprecise.no-opts
+++ b/test/wasm-only.fromasm.imprecise.no-opts
@@ -28,6 +28,8 @@
  (export "illegalParam" (func $legalstub$illegalParam))
  (export "illegalResult" (func $legalstub$illegalResult))
  (export "keepAlive" (func $keepAlive))
+ (export "getTempRet0" (func $getTempRet0))
+ (export "setTempRet0" (func $setTempRet0))
  (func $loads (; 9 ;)
   (local $i i32)
   (local $f f32)
@@ -1754,4 +1756,12 @@
    )
   )
  )
+ (func $getTempRet0 (; 37 ;) (result i32)
+  (get_global $tempRet0)
+ )
+ (func $setTempRet0 (; 38 ;) (param $0 i32)
+  (set_global $tempRet0
+   (get_local $0)
+  )
+ )
 )
diff --git a/test/wasm-only.fromasm.no-opts b/test/wasm-only.fromasm.no-opts
index 6e4a75bf2..680fe87ea 100644
--- a/test/wasm-only.fromasm.no-opts
+++ b/test/wasm-only.fromasm.no-opts
@@ -28,6 +28,8 @@
  (export "illegalParam" (func $legalstub$illegalParam))
  (export "illegalResult" (func $legalstub$illegalResult))
  (export "keepAlive" (func $keepAlive))
+ (export "getTempRet0" (func $getTempRet0))
+ (export "setTempRet0" (func $setTempRet0))
  (func $loads (; 9 ;)
   (local $i i32)
   (local $f f32)
@@ -1919,4 +1921,12 @@
    )
   )
  )
+ (func $getTempRet0 (; 45 ;) (result i32)
+  (get_global $tempRet0)
+ )
+ (func $setTempRet0 (; 46 ;) (param $0 i32)
+  (set_global $tempRet0
+   (get_local $0)
+  )
+ )
 )