[WebAssembly] avoid to enable explicit disabled feature (#80094)

llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp

@@ -200,7 +200,8 @@ class CoalesceFeaturesAndStripAtomics final : public ModulePass {
   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 @@ class CoalesceFeaturesAndStripAtomics final : public ModulePass {
     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;
   }
 

llvm/test/CodeGen/WebAssembly/disable-feature.ll

@@ -0,0 +1,53 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mattr=-sign-ext,-bulk-memory | FileCheck %s
+
+target triple = "wasm32-unknown-unknown"
+
+define i8 @not_use_extend8_s(i8 %v, i8 %x) {
+; CHECK-LABEL: not_use_extend8_s:
+; CHECK:         .functype not_use_extend8_s (i32, i32) -> (i32)
+; CHECK-NEXT:  # %bb.0:
+; CHECK-NEXT:    local.get 0
+; CHECK-NEXT:    i32.const 24
+; CHECK-NEXT:    i32.shl
+; CHECK-NEXT:    i32.const 24
+; CHECK-NEXT:    i32.shr_s
+; CHECK-NEXT:    local.get 1
+; CHECK-NEXT:    i32.const 255
+; CHECK-NEXT:    i32.and
+; CHECK-NEXT:    i32.shr_s
+; CHECK-NEXT:    # fallthrough-return
+  %a = ashr i8 %v, %x
+  ret i8 %a
+}
+
+attributes #0 = { "target-features"="+bulk-memory," }
+
+declare void @llvm.memset.p0.i32(ptr, i8, i32, i1)
+
+define void @lower_bulk_memory(i8 %val) #0 {
+; CHECK-LABEL: lower_bulk_memory:
+; CHECK:         .functype lower_bulk_memory (i32) -> ()
+; CHECK-NEXT:    .local i32
+; CHECK-NEXT:  # %bb.0:
+; CHECK-NEXT:    global.get __stack_pointer
+; CHECK-NEXT:    i32.const 112
+; CHECK-NEXT:    i32.sub
+; CHECK-NEXT:    local.tee 1
+; CHECK-NEXT:    global.set __stack_pointer
+; CHECK-NEXT:    local.get 1
+; CHECK-NEXT:    i32.const 12
+; CHECK-NEXT:    i32.add
+; CHECK-NEXT:    local.get 0
+; CHECK-NEXT:    i32.const 100
+; CHECK-NEXT:    call memset
+; CHECK-NEXT:    drop
+; CHECK-NEXT:    local.get 1
+; CHECK-NEXT:    i32.const 112
+; CHECK-NEXT:    i32.add
+; CHECK-NEXT:    global.set __stack_pointer
+; CHECK-NEXT:    # fallthrough-return
+  %a = alloca [100 x i8]
+  call void @llvm.memset.p0.i32(ptr %a, i8 %val, i32 100, i1 false)
+  ret void
+}