[Attributes] Add a method to check if an Attribute has AttrKind None. Use instead of hasAttribute(Attribute::None)

There's a special case in hasAttribute for None when pImpl is null. If pImpl is not null we dispatch to pImpl->hasAttribute which will always return false for Attribute::None.

So if we just want to check for None its sufficient to just check that pImpl is null. Which can even be done inline.

This patch adds a helper for that case which I hope will speed up our getSubtargetImpl implementations.

Differential Revision: https://reviews.llvm.org/D86744

1 files changed, 4 insertions, 6 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
index 7bf655c9..6e88530 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
@@ -160,12 +160,10 @@ WebAssemblyTargetMachine::getSubtargetImpl(const Function &F) const {
   Attribute CPUAttr = F.getFnAttribute("target-cpu");
   Attribute FSAttr = F.getFnAttribute("target-features");
 
-  std::string CPU = !CPUAttr.hasAttribute(Attribute::None)
-                        ? CPUAttr.getValueAsString().str()
-                        : TargetCPU;
-  std::string FS = !FSAttr.hasAttribute(Attribute::None)
-                       ? FSAttr.getValueAsString().str()
-                       : TargetFS;
+  std::string CPU =
+      CPUAttr.isValid() ? CPUAttr.getValueAsString().str() : TargetCPU;
+  std::string FS =
+      FSAttr.isValid() ? FSAttr.getValueAsString().str() : TargetFS;
 
   // This needs to be done before we create a new subtarget since any
   // creation will depend on the TM and the code generation flags on the