Support complex target features combinations

This patch is mainly doing two things:

1. Adding support for parentheses, making the combination of target features
   more diverse;
2. Making the priority of ’,‘ is higher than that of '|' by default. So I need
   to make some change with PTX Builtin function.

Differential Revision: https://reviews.llvm.org/D89184

Author: MoringLiu

clang/include/clang/Basic/BuiltinsNVPTX.def

@@ -43,7 +43,7 @@
 #define PTX60 "ptx60|" PTX61
 
 #pragma push_macro("AND")
-#define AND(a, b) a "," b
+#define AND(a, b) "(" a "),(" b ")"
 
 // Special Registers
 

clang/lib/CodeGen/CodeGenFunction.cpp

@@ -2307,34 +2307,6 @@ void CGBuilderInserter::InsertHelper(
     CGF->InsertHelper(I, Name, BB, InsertPt);
 }
 
-static bool hasRequiredFeatures(const SmallVectorImpl<StringRef> &ReqFeatures,
-                                CodeGenModule &CGM, const FunctionDecl *FD,
-                                std::string &FirstMissing) {
-  // If there aren't any required features listed then go ahead and return.
-  if (ReqFeatures.empty())
-    return false;
-
-  // Now build up the set of caller features and verify that all the required
-  // features are there.
-  llvm::StringMap<bool> CallerFeatureMap;
-  CGM.getContext().getFunctionFeatureMap(CallerFeatureMap, FD);
-
-  // If we have at least one of the features in the feature list return
-  // true, otherwise return false.
-  return std::all_of(
-      ReqFeatures.begin(), ReqFeatures.end(), [&](StringRef Feature) {
-        SmallVector<StringRef, 1> OrFeatures;
-        Feature.split(OrFeatures, '|');
-        return llvm::any_of(OrFeatures, [&](StringRef Feature) {
-          if (!CallerFeatureMap.lookup(Feature)) {
-            FirstMissing = Feature.str();
-            return false;
-          }
-          return true;
-        });
-      });
-}
-
 // Emits an error if we don't have a valid set of target features for the
 // called function.
 void CodeGenFunction::checkTargetFeatures(const CallExpr *E,
@@ -2361,19 +2333,20 @@ void CodeGenFunction::checkTargetFeatures(SourceLocation Loc,
   // listed cpu and any listed features.
   unsigned BuiltinID = TargetDecl->getBuiltinID();
   std::string MissingFeature;
+  llvm::StringMap<bool> CallerFeatureMap;
+  CGM.getContext().getFunctionFeatureMap(CallerFeatureMap, FD);
   if (BuiltinID) {
-    SmallVector<StringRef, 1> ReqFeatures;
-    const char *FeatureList =
-        CGM.getContext().BuiltinInfo.getRequiredFeatures(BuiltinID);
+    StringRef FeatureList(
+        CGM.getContext().BuiltinInfo.getRequiredFeatures(BuiltinID));
     // Return if the builtin doesn't have any required features.
-    if (!FeatureList || StringRef(FeatureList) == "")
+    if (FeatureList.empty())
       return;
-    StringRef(FeatureList).split(ReqFeatures, ',');
-    if (!hasRequiredFeatures(ReqFeatures, CGM, FD, MissingFeature))
+    assert(FeatureList.find(' ') == StringRef::npos &&
+           "Space in feature list");
+    TargetFeatures TF(CallerFeatureMap);
+    if (!TF.hasRequiredFeatures(FeatureList))
       CGM.getDiags().Report(Loc, diag::err_builtin_needs_feature)
-          << TargetDecl->getDeclName()
-          << CGM.getContext().BuiltinInfo.getRequiredFeatures(BuiltinID);
-
+          << TargetDecl->getDeclName() << FeatureList;
   } else if (!TargetDecl->isMultiVersion() &&
              TargetDecl->hasAttr<TargetAttr>()) {
     // Get the required features for the callee.
@@ -2396,7 +2369,13 @@ void CodeGenFunction::checkTargetFeatures(SourceLocation Loc,
       if (F.getValue())
         ReqFeatures.push_back(F.getKey());
     }
-    if (!hasRequiredFeatures(ReqFeatures, CGM, FD, MissingFeature))
+    if (!llvm::all_of(ReqFeatures, [&](StringRef Feature) {
+      if (!CallerFeatureMap.lookup(Feature)) {
+        MissingFeature = Feature.str();
+        return false;
+      }
+      return true;
+    }))
       CGM.getDiags().Report(Loc, diag::err_function_needs_feature)
           << FD->getDeclName() << TargetDecl->getDeclName() << MissingFeature;
   }

clang/lib/CodeGen/CodeGenFunction.h

@@ -4688,6 +4688,77 @@ class CodeGenFunction : public CodeGenTypeCache {
   llvm::Value *FormResolverCondition(const MultiVersionResolverOption &RO);
 };
 
+/// TargetFeatures - This class is used to check whether the builtin function
+/// has the required tagert specific features. It is able to support the
+/// combination of ','(and), '|'(or), and '()'. By default, the priority of
+/// ',' is higher than that of '|' .
+/// E.g:
+/// A,B|C means the builtin function requires both A and B, or C.
+/// If we want the builtin function requires both A and B, or both A and C,
+/// there are two ways: A,B|A,C or A,(B|C).
+/// The FeaturesList should not contain spaces, and brackets must appear in
+/// pairs.
+class TargetFeatures {
+  struct FeatureListStatus {
+    bool HasFeatures;
+    StringRef CurFeaturesList;
+  };
+
+  const llvm::StringMap<bool> &CallerFeatureMap;
+
+  FeatureListStatus getAndFeatures(StringRef FeatureList) {
+    int InParentheses = 0;
+    bool HasFeatures = true;
+    size_t SubexpressionStart = 0;
+    for (size_t i = 0, e = FeatureList.size(); i < e; ++i) {
+      char CurrentToken = FeatureList[i];
+      switch (CurrentToken) {
+      default:
+        break;
+      case '(':
+        if (InParentheses == 0)
+          SubexpressionStart = i + 1;
+        ++InParentheses;
+        break;
+      case ')':
+        --InParentheses;
+        assert(InParentheses >= 0 && "Parentheses are not in pair");
+        LLVM_FALLTHROUGH;
+      case '|':
+      case ',':
+        if (InParentheses == 0) {
+          if (HasFeatures && i != SubexpressionStart) {
+            StringRef F = FeatureList.slice(SubexpressionStart, i);
+            HasFeatures = CurrentToken == ')' ? hasRequiredFeatures(F)
+                                              : CallerFeatureMap.lookup(F);
+          }
+          SubexpressionStart = i + 1;
+          if (CurrentToken == '|') {
+            return {HasFeatures, FeatureList.substr(SubexpressionStart)};
+          }
+        }
+        break;
+      }
+    }
+    assert(InParentheses == 0 && "Parentheses are not in pair");
+    if (HasFeatures && SubexpressionStart != FeatureList.size())
+      HasFeatures =
+          CallerFeatureMap.lookup(FeatureList.substr(SubexpressionStart));
+    return {HasFeatures, StringRef()};
+  }
+
+public:
+  bool hasRequiredFeatures(StringRef FeatureList) {
+    FeatureListStatus FS = {false, FeatureList};
+    while (!FS.HasFeatures && !FS.CurFeaturesList.empty())
+      FS = getAndFeatures(FS.CurFeaturesList);
+    return FS.HasFeatures;
+  }
+
+  TargetFeatures(const llvm::StringMap<bool> &CallerFeatureMap)
+      : CallerFeatureMap(CallerFeatureMap) {}
+};
+
 inline DominatingLLVMValue::saved_type
 DominatingLLVMValue::save(CodeGenFunction &CGF, llvm::Value *value) {
   if (!needsSaving(value)) return saved_type(value, false);