[llvm] [SPIRV] Use StringRef instead of std::string (NFC) (PR #138408)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-spir-v

Author: Kazu Hirata (kazutakahirata)

<details>
<summary>Changes</summary>

We can use StringRef for PassPrefix because it is used only with
StringRef::starts_with.


---
Full diff: https://github.com/llvm/llvm-project/pull/138408.diff


1 Files Affected:

- (modified) llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp (+3-3) 


``````````diff
diff --git a/llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp b/llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp
index 78c0d252cb834..c516be0297e66 100644
--- a/llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp
@@ -184,11 +184,11 @@ namespace SPIRV {
 /// Parses the name part of the demangled builtin call.
 std::string lookupBuiltinNameHelper(StringRef DemangledCall,
                                     FPDecorationId *DecorationId) {
-  const static std::string PassPrefix = "(anonymous namespace)::";
+  StringRef PassPrefix = "(anonymous namespace)::";
   std::string BuiltinName;
   // Itanium Demangler result may have "(anonymous namespace)::" prefix
-  if (DemangledCall.starts_with(PassPrefix.c_str()))
-    BuiltinName = DemangledCall.substr(PassPrefix.length());
+  if (DemangledCall.starts_with(PassPrefix))
+    BuiltinName = DemangledCall.substr(PassPrefix.size());
   else
     BuiltinName = DemangledCall;
   // Extract the builtin function name and types of arguments from the call

``````````

</details>


https://github.com/llvm/llvm-project/pull/138408