[WebAssembly] avoid to use explicit disabled feature

In `CoalesceFeaturesAndStripAtomics`, feature string is converted to FeatureBitset and back to feature string. It will lose information about explicit diasbled features.

1 files changed, 8 insertions, 2 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
index 2db1b64..0aadc6a 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
@@ -200,7 +200,8 @@ public:
   bool runOnModule(Module &M) override {
     FeatureBitset Features = coalesceFeatures(M);
 
-    std::string FeatureStr = getFeatureString(Features);
+    std::string FeatureStr =
+        getFeatureString(Features, WasmTM->getTargetFeatureString());
     WasmTM->setTargetFeatureString(FeatureStr);
     for (auto &F : M)
       replaceFeatures(F, FeatureStr);
@@ -238,12 +239,17 @@ private:
     return Features;
   }
 
-  std::string getFeatureString(const FeatureBitset &Features) {
+  static std::string getFeatureString(const FeatureBitset &Features,
+                                      StringRef TargetFS) {
     std::string Ret;
     for (const SubtargetFeatureKV &KV : WebAssemblyFeatureKV) {
       if (Features[KV.Value])
         Ret += (StringRef("+") + KV.Key + ",").str();
     }
+    SubtargetFeatures TF{TargetFS};
+    for (std::string const &F : TF.getFeatures())
+      if (!SubtargetFeatures::isEnabled(F))
+        Ret += F;
     return Ret;
   }