-fsanitize=function,MicrosoftMangle: Switch to xxh3_64bits

Following recent changes switching from xxh64 to xxh32 for better
hashing performance (e.g., D154813). These particular instances likely
have negligible time, but this change moves us toward removing xxHash64.

The type hash for -fsanitize=function will change, following a recent
change D148785 (not in any release yet) to the type hash scheme, though
sanitizers don't sign up for cross-version compatibility anyway.

The MicrosoftMangle instance is for internal symbols that need no
compatibility guarantee, as emphasized by the comment.

Author: MaskRay

clang/lib/AST/MicrosoftMangle.cpp

@@ -485,7 +485,7 @@ MicrosoftMangleContextImpl::MicrosoftMangleContextImpl(ASTContext &Context,
   SourceManager &SM = Context.getSourceManager();
   if (const FileEntry *FE = SM.getFileEntryForID(SM.getMainFileID())) {
     // Truncate the hash so we get 8 characters of hexadecimal.
-    uint32_t TruncatedHash = uint32_t(xxHash64(FE->getName()));
+    uint32_t TruncatedHash = uint32_t(xxh3_64bits(FE->getName()));
     AnonymousNamespaceHash = llvm::utohexstr(TruncatedHash);
   } else {
     // If we don't have a path to the main file, we'll just use 0.

clang/lib/CodeGen/CodeGenFunction.cpp

@@ -577,8 +577,8 @@ CodeGenFunction::getUBSanFunctionTypeHash(QualType Ty) const {
   std::string Mangled;
   llvm::raw_string_ostream Out(Mangled);
   CGM.getCXXABI().getMangleContext().mangleTypeName(Ty, Out, false);
-  return llvm::ConstantInt::get(CGM.Int32Ty,
-                                static_cast<uint32_t>(llvm::xxHash64(Mangled)));
+  return llvm::ConstantInt::get(
+      CGM.Int32Ty, static_cast<uint32_t>(llvm::xxh3_64bits(Mangled)));
 }
 
 void CodeGenFunction::EmitKernelMetadata(const FunctionDecl *FD,

clang/test/CodeGen/ubsan-function.cpp

@@ -17,7 +17,7 @@ void fun() {}
 // CHECK: [[LABEL1]]:
 // CHECK: getelementptr <{ i32, i32 }>, ptr {{.*}}, i32 -1, i32 1, !nosanitize
 // CHECK: load i32, ptr {{.*}}, align {{.*}}, !nosanitize
-// CHECK: icmp eq i32 {{.*}}, -1522505972, !nosanitize
+// CHECK: icmp eq i32 {{.*}}, 905068220, !nosanitize
 // CHECK: br i1 {{.*}}, label %[[LABEL3:.*]], label %[[LABEL2:[^,]*]], {{.*}}!nosanitize
 // CHECK: [[LABEL2]]:
 // 64:    call void @__ubsan_handle_function_type_mismatch_abort(ptr @[[#]], i64 %[[#]]) #[[#]], !nosanitize
@@ -32,4 +32,4 @@ void fun() {}
 // CHECK-NEXT:   ret void
 void caller(void (*f)()) { f(); }
 
-// CHECK: ![[FUNCSAN]] = !{i32 -1056584962, i32 -1522505972}
+// CHECK: ![[FUNCSAN]] = !{i32 -1056584962, i32 905068220}

clang/test/CodeGenCXX/catch-undef-behavior.cpp

@@ -405,7 +405,7 @@ void indirect_function_call(void (*p)(int)) {
   // CalleeTypeHash check
   // CHECK: [[CalleeTypeHashPtr:%.+]] = getelementptr <{ i32, i32 }>, ptr [[PTR]], i32 -1, i32 1
   // CHECK-NEXT: [[CalleeTypeHash:%.+]] = load i32, ptr [[CalleeTypeHashPtr]]
-  // CHECK-NEXT: [[CalleeTypeHashMatch:%.+]] = icmp eq i32 [[CalleeTypeHash]], 27004076
+  // CHECK-NEXT: [[CalleeTypeHashMatch:%.+]] = icmp eq i32 [[CalleeTypeHash]], -1988405058
   // CHECK-NEXT: br i1 [[CalleeTypeHashMatch]]
 
   p(42);
@@ -740,4 +740,4 @@ void ThisAlign::this_align_lambda_2() {
 
 // CHECK: attributes [[NR_NUW]] = { noreturn nounwind }
 
-// CHECK-FUNCSAN: ![[FUNCSAN]] = !{i32 -1056584962, i32 -1302768377}
+// CHECK-FUNCSAN: ![[FUNCSAN]] = !{i32 -1056584962, i32 -1000226989}