[SPIRV]Fix translation of user functions into SPIR-V instructions

User may get their function a name the same as SPIR-V instruction.
In that case thier function call will be translated to SPIR-V instruction call.
The only functions that should be translated to SPIR-V instructions are SPIR-V built-ins and they should have __spirv prefix.
Add checking for __spirv prefix in demangler to filter SPIR-V built-ins from other function calls.

Author: MochalovaAn

llvm-spirv/lib/SPIRV/SPIRVUtil.cpp

@@ -438,16 +438,27 @@ std::string getPostfixForReturnType(const Type *PRetTy, bool IsSigned) {
          mapLLVMTypeToOCLType(PRetTy, IsSigned);
 }
 
+// Enqueue kernel, kernel query, pipe and address space cast built-ins
+// are not mangled.
+bool isNonMangledOCLBuiltin(StringRef Name) {
+  if (!Name.startswith("__"))
+    return false;
+
+  return isEnqueueKernelBI(Name) || isKernelQueryBI(Name) ||
+         isPipeOrAddressSpaceCastBI(Name.drop_front(2));
+}
+
 Op getSPIRVFuncOC(StringRef S, SmallVectorImpl<std::string> *Dec) {
   Op OC;
   SmallVector<StringRef, 2> Postfix;
   StringRef Name;
   if (!oclIsBuiltin(S, Name))
     Name = S;
   StringRef R(Name);
-  R = dePrefixSPIRVName(R, Postfix);
-  if (!getByName(R.str(), OC))
+  if ((!Name.startswith(kSPIRVName::Prefix) && !isNonMangledOCLBuiltin(S)) ||
+      !getByName(dePrefixSPIRVName(R, Postfix).str(), OC)) {
     return OpNop;
+  }
   if (Dec)
     for (auto &I : Postfix)
       Dec->push_back(I.str());
@@ -462,16 +473,6 @@ bool getSPIRVBuiltin(const std::string &OrigName, spv::BuiltIn &B) {
   return getByName(R.str(), B);
 }
 
-// Enqueue kernel, kernel query, pipe and address space cast built-ins
-// are not mangled.
-bool isNonMangledOCLBuiltin(StringRef Name) {
-  if (!Name.startswith("__"))
-    return false;
-
-  return isEnqueueKernelBI(Name) || isKernelQueryBI(Name) ||
-         isPipeOrAddressSpaceCastBI(Name.drop_front(2));
-}
-
 // Demangled name is a substring of the name. The DemangledName is updated only
 // if true is returned
 bool oclIsBuiltin(StringRef Name, StringRef &DemangledName, bool IsCpp) {
@@ -910,7 +911,7 @@ ConstantInt *mapSInt(Module *M, ConstantInt *I, std::function<int(int)> F) {
 bool isDecoratedSPIRVFunc(const Function *F, StringRef &UndecoratedName) {
   if (!F->hasName() || !F->getName().startswith(kSPIRVName::Prefix))
     return false;
-  UndecoratedName = undecorateSPIRVFunction(F->getName());
+  UndecoratedName = F->getName();
   return true;
 }
 

llvm-spirv/test/transcoding/BitReversePref.ll

@@ -0,0 +1,64 @@
+; RUN: llvm-as < %s -o %t.bc
+; RUN: llvm-spirv %t.bc -spirv-text -o - | FileCheck %s
+
+;CHECK:  Decorate [[#FUNC_NAME:]] LinkageAttributes "_Z10BitReversei"
+;CHECK-NOT: BitReverse
+;CHECK: FunctionCall [[#]] [[#]] [[#FUNC_NAME]]
+
+target datalayout = "e-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024-n8:16:32:64"
+target triple = "spir64-unknown-linux-sycldevice"
+
+%"class._ZTSZ4mainE3$_0.anon" = type { i8 }
+
+$_Z10BitReversei = comdat any
+
+; Function Attrs: norecurse
+define dso_local spir_kernel void @_ZTSZ4mainE15kernel_function() #0 !kernel_arg_addr_space !4 !kernel_arg_access_qual !4 !kernel_arg_type !4 !kernel_arg_base_type !4 !kernel_arg_type_qual !4 {
+entry:
+  %call = call spir_func i32 @_Z10BitReversei(i32 1)
+  ret void
+}
+
+; Function Attrs: argmemonly nounwind willreturn
+declare void @llvm.lifetime.start.p0i8(i64 immarg, i8* nocapture) #1
+
+; Function Attrs: argmemonly nounwind willreturn
+declare void @llvm.lifetime.end.p0i8(i64 immarg, i8* nocapture) #1
+
+; Function Attrs: inlinehint norecurse nounwind
+define linkonce_odr dso_local spir_func i32 @_Z10BitReversei(i32 %value) #3 comdat {
+entry:
+  %value.addr = alloca i32, align 4
+  %reversed = alloca i32, align 4
+  store i32 %value, i32* %value.addr, align 4, !tbaa !9
+  %0 = bitcast i32* %reversed to i8*
+  call void @llvm.lifetime.start.p0i8(i64 4, i8* %0) #4
+  store i32 0, i32* %reversed, align 4, !tbaa !9
+  %1 = load i32, i32* %reversed, align 4, !tbaa !9
+  %2 = bitcast i32* %reversed to i8*
+  call void @llvm.lifetime.end.p0i8(i64 4, i8* %2) #4
+  ret i32 %1
+}
+
+attributes #0 = { norecurse "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "sycl-module-id"="Test.cpp" "uniform-work-group-size"="true" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { argmemonly nounwind willreturn }
+attributes #2 = { inlinehint norecurse "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #3 = { inlinehint norecurse nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #4 = { nounwind }
+
+!llvm.module.flags = !{!0}
+!opencl.spir.version = !{!1}
+!spirv.Source = !{!2}
+!llvm.ident = !{!3}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{i32 1, i32 2}
+!2 = !{i32 4, i32 100000}
+!3 = !{!"clang version 11.0.0 (https://github.com/c199914007/llvm.git dc6656ef210464a1c4721eb793b6b6f78a9a2048)"}
+!4 = !{}
+!5 = !{!6, !6, i64 0}
+!6 = !{!"any pointer", !7, i64 0}
+!7 = !{!"omnipotent char", !8, i64 0}
+!8 = !{!"Simple C++ TBAA"}
+!9 = !{!10, !10, i64 0}
+!10 = !{!"int", !7, i64 0}