Re-reloop pass (#1009)

This adds a pass that converts to a CFG, runs the relooper, and re-generates wasm from that. This depends on flatten-control-flow being run before.

The main goal here is to help code generators other than asm2wasm (which already receives relooped code from fastcomp).

Author: kripken

CMakeLists.txt

@@ -168,6 +168,7 @@ ENDIF()
 # Static libraries
 ADD_SUBDIRECTORY(src/ast)
 ADD_SUBDIRECTORY(src/asmjs)
+ADD_SUBDIRECTORY(src/cfg)
 ADD_SUBDIRECTORY(src/emscripten-optimizer)
 ADD_SUBDIRECTORY(src/passes)
 ADD_SUBDIRECTORY(src/support)
@@ -178,14 +179,13 @@ ADD_SUBDIRECTORY(src/wasm)
 
 SET(binaryen_SOURCES
   src/binaryen-c.cpp
-  src/cfg/Relooper.cpp
 )
 IF(BUILD_STATIC_LIB)
   ADD_LIBRARY(binaryen STATIC ${binaryen_SOURCES})    
 ELSE()
   ADD_LIBRARY(binaryen SHARED ${binaryen_SOURCES})
 ENDIF()
-TARGET_LINK_LIBRARIES(binaryen ${all_passes} wasm asmjs ast support)
+TARGET_LINK_LIBRARIES(binaryen ${all_passes} wasm asmjs ast cfg support)
 INSTALL(TARGETS binaryen DESTINATION ${CMAKE_INSTALL_LIBDIR})
 
 INSTALL(FILES src/binaryen-c.h DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
@@ -198,7 +198,7 @@ SET(wasm-shell_SOURCES
 )
 ADD_EXECUTABLE(wasm-shell
                ${wasm-shell_SOURCES})
-TARGET_LINK_LIBRARIES(wasm-shell wasm asmjs emscripten-optimizer ${all_passes} ast support)
+TARGET_LINK_LIBRARIES(wasm-shell wasm asmjs emscripten-optimizer ${all_passes} ast cfg support)
 SET_PROPERTY(TARGET wasm-shell PROPERTY CXX_STANDARD 11)
 SET_PROPERTY(TARGET wasm-shell PROPERTY CXX_STANDARD_REQUIRED ON)
 INSTALL(TARGETS wasm-shell DESTINATION ${CMAKE_INSTALL_BINDIR})
@@ -208,7 +208,7 @@ SET(wasm-opt_SOURCES
 )
 ADD_EXECUTABLE(wasm-opt
                ${wasm-opt_SOURCES})
-TARGET_LINK_LIBRARIES(wasm-opt wasm asmjs emscripten-optimizer ${all_passes} ast support)
+TARGET_LINK_LIBRARIES(wasm-opt wasm asmjs emscripten-optimizer ${all_passes} ast cfg support)
 SET_PROPERTY(TARGET wasm-opt PROPERTY CXX_STANDARD 11)
 SET_PROPERTY(TARGET wasm-opt PROPERTY CXX_STANDARD_REQUIRED ON)
 INSTALL(TARGETS wasm-opt DESTINATION ${CMAKE_INSTALL_BINDIR})
@@ -218,7 +218,7 @@ SET(wasm-merge_SOURCES
 )
 ADD_EXECUTABLE(wasm-merge
                ${wasm-merge_SOURCES})
-TARGET_LINK_LIBRARIES(wasm-merge wasm asmjs emscripten-optimizer ${all_passes} ast support)
+TARGET_LINK_LIBRARIES(wasm-merge wasm asmjs emscripten-optimizer ${all_passes} ast cfg support)
 SET_PROPERTY(TARGET wasm-merge PROPERTY CXX_STANDARD 11)
 SET_PROPERTY(TARGET wasm-merge PROPERTY CXX_STANDARD_REQUIRED ON)
 INSTALL(TARGETS wasm-merge DESTINATION bin)
@@ -229,7 +229,7 @@ SET(asm2wasm_SOURCES
 )
 ADD_EXECUTABLE(asm2wasm
                ${asm2wasm_SOURCES})
-TARGET_LINK_LIBRARIES(asm2wasm emscripten-optimizer ${all_passes} wasm asmjs ast support)
+TARGET_LINK_LIBRARIES(asm2wasm emscripten-optimizer ${all_passes} wasm asmjs ast cfg support)
 SET_PROPERTY(TARGET asm2wasm PROPERTY CXX_STANDARD 11)
 SET_PROPERTY(TARGET asm2wasm PROPERTY CXX_STANDARD_REQUIRED ON)
 INSTALL(TARGETS asm2wasm DESTINATION ${CMAKE_INSTALL_BINDIR})
@@ -241,7 +241,7 @@ SET(s2wasm_SOURCES
 )
 ADD_EXECUTABLE(s2wasm
                ${s2wasm_SOURCES})
-TARGET_LINK_LIBRARIES(s2wasm passes wasm asmjs ast support)
+TARGET_LINK_LIBRARIES(s2wasm passes wasm asmjs ast cfg support)
 SET_PROPERTY(TARGET s2wasm PROPERTY CXX_STANDARD 11)
 SET_PROPERTY(TARGET s2wasm PROPERTY CXX_STANDARD_REQUIRED ON)
 INSTALL(TARGETS s2wasm DESTINATION ${CMAKE_INSTALL_BINDIR})
@@ -251,7 +251,7 @@ SET(wasm_as_SOURCES
 )
 ADD_EXECUTABLE(wasm-as
                ${wasm_as_SOURCES})
-TARGET_LINK_LIBRARIES(wasm-as wasm asmjs passes ast support)
+TARGET_LINK_LIBRARIES(wasm-as wasm asmjs passes ast cfg support)
 SET_PROPERTY(TARGET wasm-as PROPERTY CXX_STANDARD 11)
 SET_PROPERTY(TARGET wasm-as PROPERTY CXX_STANDARD_REQUIRED ON)
 INSTALL(TARGETS wasm-as DESTINATION ${CMAKE_INSTALL_BINDIR})
@@ -261,7 +261,7 @@ SET(wasm_dis_SOURCES
 )
 ADD_EXECUTABLE(wasm-dis
                ${wasm_dis_SOURCES})
-TARGET_LINK_LIBRARIES(wasm-dis passes wasm asmjs ast support)
+TARGET_LINK_LIBRARIES(wasm-dis passes wasm asmjs ast cfg support)
 SET_PROPERTY(TARGET wasm-dis PROPERTY CXX_STANDARD 11)
 SET_PROPERTY(TARGET wasm-dis PROPERTY CXX_STANDARD_REQUIRED ON)
 INSTALL(TARGETS wasm-dis DESTINATION ${CMAKE_INSTALL_BINDIR})
@@ -271,7 +271,7 @@ SET(wasm-ctor-eval_SOURCES
 )
 ADD_EXECUTABLE(wasm-ctor-eval
                ${wasm-ctor-eval_SOURCES})
-TARGET_LINK_LIBRARIES(wasm-ctor-eval wasm asmjs emscripten-optimizer ${all_passes} ast support)
+TARGET_LINK_LIBRARIES(wasm-ctor-eval wasm asmjs emscripten-optimizer ${all_passes} ast cfg support)
 SET_PROPERTY(TARGET wasm-ctor-eval PROPERTY CXX_STANDARD 11)
 SET_PROPERTY(TARGET wasm-ctor-eval PROPERTY CXX_STANDARD_REQUIRED ON)
 INSTALL(TARGETS wasm-ctor-eval DESTINATION bin)

src/cfg/CMakeLists.txt

@@ -0,0 +1,4 @@
+SET(cfg_SOURCES
+  Relooper.cpp
+)
+ADD_LIBRARY(cfg STATIC ${cfg_SOURCES})

src/cfg/Relooper.cpp

@@ -57,6 +57,7 @@ static wasm::Expression* HandleFollowupMultiples(wasm::Expression* Ret, Shape* P
       int Id = iter.first;
       Shape* Body = iter.second;
       Curr->name = Builder.getBlockBreakName(Id);
+      Curr->finalize(); // it may now be reachable, via a break
       auto* Outer = Builder.makeBlock(Curr);
       Outer->list.push_back(Body->Render(Builder, InLoop));
       Outer->finalize(); // TODO: not really necessary

src/pass.h

@@ -152,11 +152,14 @@ class Pass {
   virtual void prepareToRun(PassRunner* runner, Module* module) {}
 
   // Implement this with code to run the pass on the whole module
-  virtual void run(PassRunner* runner, Module* module) = 0;
+  virtual void run(PassRunner* runner, Module* module) {
+    WASM_UNREACHABLE();
+  }
 
-  // Implement this with code to run the pass on a single function
+  // Implement this with code to run the pass on a single function, for
+  // a function-parallel pass
   virtual void runFunction(PassRunner* runner, Module* module, Function* function) {
-    WASM_UNREACHABLE(); // by default, passes cannot be run this way
+    WASM_UNREACHABLE();
   }
 
   // Function parallelism. By default, passes are not run in parallel, but you

src/passes/CMakeLists.txt

@@ -23,6 +23,7 @@ SET(passes_SOURCES
   Print.cpp
   PrintCallGraph.cpp
   RelooperJumpThreading.cpp
+  ReReloop.cpp
   RemoveImports.cpp
   RemoveMemory.cpp
   RemoveUnusedBrs.cpp