[wasm-split] Configure split functions rather than kept functions (#6949)

The configuration for the module splitting utility previous took a set
of functions to keep in the primary module. Change it to take a list of
functions to split into the secondary module instead. This improves the
code quality in multi-split mode because it keeps stub functions
generated by previous splits from being moved into secondary modules
during later splits.

2 files changed, 58 insertions, 57 deletions

diff --git a/test/example/module-splitting.cpp b/test/example/module-splitting.cpp
index 81f095f48..b55beb1d3 100644
--- a/test/example/module-splitting.cpp
+++ b/test/example/module-splitting.cpp
@@ -28,14 +28,21 @@ void do_test(const std::set<Name>& keptFuncs, std::string&& module) {
   valid = validator.validate(*primary);
   assert(valid && "before invalid!");
 
+  std::set<Name> splitFuncs;
+  for (auto& func : primary->functions) {
+    splitFuncs.insert(func->name);
+  }
+
   std::cout << "Before:\n";
   std::cout << *primary.get();
 
   std::cout << "Keeping: ";
   if (keptFuncs.size()) {
     auto it = keptFuncs.begin();
+    splitFuncs.erase(*it);
     std::cout << *it++;
     while (it != keptFuncs.end()) {
+      splitFuncs.erase(*it);
       std::cout << ", " << *it++;
     }
   } else {
@@ -44,7 +51,7 @@ void do_test(const std::set<Name>& keptFuncs, std::string&& module) {
   std::cout << "\n";
 
   ModuleSplitting::Config config;
-  config.primaryFuncs = keptFuncs;
+  config.secondaryFuncs = std::move(splitFuncs);
   config.newExportPrefix = "%";
   auto secondary = splitFunctions(*primary, config).secondary;
 
@@ -443,7 +450,6 @@ void test_minimized_exports() {
   Module primary;
   primary.features = FeatureSet::All;
 
-  std::set<Name> keep;
   Expression* callBody = nullptr;
 
   Builder builder(primary);
@@ -453,7 +459,6 @@ void test_minimized_exports() {
     Name name = std::to_string(i);
     primary.addFunction(
       Builder::makeFunction(name, funcType, {}, builder.makeNop()));
-    keep.insert(name);
     callBody =
       builder.blockify(callBody, builder.makeCall(name, {}, Type::none));
 
@@ -470,7 +475,7 @@ void test_minimized_exports() {
   primary.addFunction(Builder::makeFunction("call", funcType, {}, callBody));
 
   ModuleSplitting::Config config;
-  config.primaryFuncs = std::move(keep);
+  config.secondaryFuncs = {"call"};
   config.newExportPrefix = "%";
   config.minimizeNewExportNames = true;
 
diff --git a/test/lit/wasm-split/multi-split.wast b/test/lit/wasm-split/multi-split.wast
index 9206e60ee..d7fb56c07 100644
--- a/test/lit/wasm-split/multi-split.wast
+++ b/test/lit/wasm-split/multi-split.wast
@@ -7,8 +7,10 @@
 ;; RUN: wasm-dis %t3.wasm | filecheck %s --check-prefix=CHECK-C
 
 (module
- (type $ret-i32 (func (result i32)))
  ;; PRIMARY:      (type $ret-i64 (func (result i64)))
+
+ ;; PRIMARY:      (type $ret-i32 (func (result i32)))
+ (type $ret-i32 (func (result i32)))
  (type $ret-i64 (func (result i64)))
  ;; PRIMARY:      (type $ret-f32 (func (result f32)))
  (type $ret-f32 (func (result f32)))
@@ -62,24 +64,24 @@
   )
   (i32.const 0)
  )
- ;; CHECK-B:      (type $0 (func (result i32)))
+ ;; CHECK-B:      (type $0 (func (result f32)))
 
- ;; CHECK-B:      (type $1 (func (result f32)))
+ ;; CHECK-B:      (type $1 (func (result i32)))
 
  ;; CHECK-B:      (type $2 (func (result i64)))
 
- ;; CHECK-B:      (import "" "table_3" (table $timport$0 2 funcref))
-
- ;; CHECK-B:      (import "" "table" (table $timport$1 1 funcref))
+ ;; CHECK-B:      (import "" "table_4" (table $timport$0 1 funcref))
 
  ;; CHECK-B:      (import "" "b" (func $C (result f32)))
 
- ;; CHECK-B:      (elem $0 (table $timport$0) (i32.const 0) func $B $1)
+ ;; CHECK-B:      (import "" "c" (func $fimport$1 (result i32)))
+
+ ;; CHECK-B:      (elem $0 (i32.const 0) $B)
 
  ;; CHECK-B:      (func $B (result i64)
  ;; CHECK-B-NEXT:  (drop
- ;; CHECK-B-NEXT:   (call_ref $0
- ;; CHECK-B-NEXT:    (ref.func $1)
+ ;; CHECK-B-NEXT:   (call_ref $1
+ ;; CHECK-B-NEXT:    (ref.func $fimport$1)
  ;; CHECK-B-NEXT:   )
  ;; CHECK-B-NEXT:  )
  ;; CHECK-B-NEXT:  (drop
@@ -88,7 +90,7 @@
  ;; CHECK-B-NEXT:   )
  ;; CHECK-B-NEXT:  )
  ;; CHECK-B-NEXT:  (drop
- ;; CHECK-B-NEXT:   (call_ref $1
+ ;; CHECK-B-NEXT:   (call_ref $0
  ;; CHECK-B-NEXT:    (ref.func $C)
  ;; CHECK-B-NEXT:   )
  ;; CHECK-B-NEXT:  )
@@ -112,33 +114,29 @@
   )
   (i64.const 0)
  )
- ;; CHECK-C:      (type $0 (func (result i64)))
+ ;; CHECK-C:      (type $0 (func (result i32)))
 
- ;; CHECK-C:      (type $1 (func (result i32)))
+ ;; CHECK-C:      (type $1 (func (result i64)))
 
  ;; CHECK-C:      (type $2 (func (result f32)))
 
- ;; CHECK-C:      (import "" "table_4" (table $timport$0 2 funcref))
+ ;; CHECK-C:      (import "" "table_6" (table $timport$0 1 funcref))
 
- ;; CHECK-C:      (import "" "table_3" (table $timport$1 2 funcref))
+ ;; CHECK-C:      (import "" "c" (func $fimport$0 (result i32)))
 
- ;; CHECK-C:      (elem $0 (table $timport$0) (i32.const 0) func $0 $C)
+ ;; CHECK-C:      (import "" "d" (func $fimport$1 (result i64)))
 
- ;; CHECK-C:      (func $0 (result i64)
- ;; CHECK-C-NEXT:  (call_indirect (type $0)
- ;; CHECK-C-NEXT:   (i32.const 0)
- ;; CHECK-C-NEXT:  )
- ;; CHECK-C-NEXT: )
+ ;; CHECK-C:      (elem $0 (i32.const 0) $C)
 
  ;; CHECK-C:      (func $C (result f32)
  ;; CHECK-C-NEXT:  (drop
- ;; CHECK-C-NEXT:   (call_ref $1
- ;; CHECK-C-NEXT:    (ref.func $3)
+ ;; CHECK-C-NEXT:   (call_ref $0
+ ;; CHECK-C-NEXT:    (ref.func $fimport$0)
  ;; CHECK-C-NEXT:   )
  ;; CHECK-C-NEXT:  )
  ;; CHECK-C-NEXT:  (drop
- ;; CHECK-C-NEXT:   (call_ref $0
- ;; CHECK-C-NEXT:    (ref.func $2)
+ ;; CHECK-C-NEXT:   (call_ref $1
+ ;; CHECK-C-NEXT:    (ref.func $fimport$1)
  ;; CHECK-C-NEXT:   )
  ;; CHECK-C-NEXT:  )
  ;; CHECK-C-NEXT:  (drop
@@ -169,52 +167,50 @@
 )
 ;; PRIMARY:      (table $0 1 funcref)
 
-;; PRIMARY:      (table $1 2 funcref)
+;; PRIMARY:      (table $1 1 funcref)
 
-;; PRIMARY:      (table $2 2 funcref)
+;; PRIMARY:      (table $2 1 funcref)
 
 ;; PRIMARY:      (elem $0 (table $0) (i32.const 0) funcref (item (ref.null nofunc)))
 
-;; PRIMARY:      (elem $1 (table $1) (i32.const 0) funcref (item (ref.null nofunc)) (item (ref.null nofunc)))
+;; PRIMARY:      (elem $1 (table $1) (i32.const 0) funcref (item (ref.null nofunc)))
 
-;; PRIMARY:      (elem $2 (table $2) (i32.const 0) funcref (item (ref.null nofunc)) (item (ref.null nofunc)))
+;; PRIMARY:      (elem $2 (table $2) (i32.const 0) funcref (item (ref.null nofunc)))
 
-;; PRIMARY:      (export "a" (func $0))
+;; PRIMARY:      (export "a" (func $1))
 
-;; PRIMARY:      (export "b" (func $1))
+;; PRIMARY:      (export "b" (func $3))
 
 ;; PRIMARY:      (export "table" (table $0))
 
-;; PRIMARY:      (export "table_3" (table $1))
+;; PRIMARY:      (export "c" (func $0))
+
+;; PRIMARY:      (export "table_4" (table $1))
+
+;; PRIMARY:      (export "d" (func $2))
+
+;; PRIMARY:      (export "table_6" (table $2))
+
+;; PRIMARY:      (func $0 (result i32)
+;; PRIMARY-NEXT:  (call_indirect (type $ret-i32)
+;; PRIMARY-NEXT:   (i32.const 0)
+;; PRIMARY-NEXT:  )
+;; PRIMARY-NEXT: )
 
-;; PRIMARY:      (export "table_4" (table $2))
+;; PRIMARY:      (func $1 (result i64)
+;; PRIMARY-NEXT:  (call_indirect (type $ret-i64)
+;; PRIMARY-NEXT:   (i32.const 0)
+;; PRIMARY-NEXT:  )
+;; PRIMARY-NEXT: )
 
-;; PRIMARY:      (func $0 (result i64)
+;; PRIMARY:      (func $2 (result i64)
 ;; PRIMARY-NEXT:  (call_indirect (type $ret-i64)
 ;; PRIMARY-NEXT:   (i32.const 0)
 ;; PRIMARY-NEXT:  )
 ;; PRIMARY-NEXT: )
 
-;; PRIMARY:      (func $1 (result f32)
+;; PRIMARY:      (func $3 (result f32)
 ;; PRIMARY-NEXT:  (call_indirect (type $ret-f32)
-;; PRIMARY-NEXT:   (i32.const 1)
+;; PRIMARY-NEXT:   (i32.const 0)
 ;; PRIMARY-NEXT:  )
 ;; PRIMARY-NEXT: )
-
-;; CHECK-B:      (func $1 (result i32)
-;; CHECK-B-NEXT:  (call_indirect (type $0)
-;; CHECK-B-NEXT:   (i32.const 0)
-;; CHECK-B-NEXT:  )
-;; CHECK-B-NEXT: )
-
-;; CHECK-C:      (func $2 (result i64)
-;; CHECK-C-NEXT:  (call_indirect (type $0)
-;; CHECK-C-NEXT:   (i32.const 0)
-;; CHECK-C-NEXT:  )
-;; CHECK-C-NEXT: )
-
-;; CHECK-C:      (func $3 (result i32)
-;; CHECK-C-NEXT:  (call_indirect (type $1)
-;; CHECK-C-NEXT:   (i32.const 1)
-;; CHECK-C-NEXT:  )
-;; CHECK-C-NEXT: )