AMDGPU: Consider nobuiltin when querying defined libfuncs

[Pierre-vh]

llvm/lib/Target/AMDGPU/AMDGPULibFunc.cpp

960

nit: can you add a small not explaining why it's important to respect this attr?
e.g. what happens if we don't respect it? what does this fix?

Note can be here or in the test, doesn't matter, it's just to preserve some context surrounding this change.

[arsenm]

llvm/lib/Target/AMDGPU/AMDGPULibFunc.cpp

960

I think the correct place is the LangRef, where this is already semi-documented

[arsenm]

58fd1de09f637e2c6e7003eefb46e28ef361c9e0

llvm/lib/Target/AMDGPU/AMDGPULibFunc.cpp

bool AMDGPULibFunc::isCompatibleSignature(const FunctionType *FuncTy) const {
   // TODO: Validate types make sense
   return !FuncTy->isVarArg() && FuncTy->getNumParams() == getNumArgs();
 }
 
 Function *AMDGPULibFunc::getFunction(Module *M, const AMDGPULibFunc &fInfo) {
   std::string FuncName = fInfo.mangle();
   Function *F = dyn_cast_or_null<Function>(
     M->getValueSymbolTable().lookup(FuncName));
+  if (!F || F->isDeclaration())
+    return nullptr;
 
-  // check formal with actual types conformance
-  if (F && !F->isDeclaration() &&
-      fInfo.isCompatibleSignature(F->getFunctionType()))
-    return F;
+  if (F->hasFnAttribute(Attribute::NoBuiltin))
+    return nullptr;
 
+  if (!fInfo.isCompatibleSignature(F->getFunctionType()))
     return nullptr;
+
+  return F;
 }
 
 FunctionCallee AMDGPULibFunc::getOrInsertFunction(Module *M,
                                                   const AMDGPULibFunc &fInfo) {
   std::string const FuncName = fInfo.mangle();
   Function *F = dyn_cast_or_null<Function>(
     M->getValueSymbolTable().lookup(FuncName));
 
-  // check formal with actual types conformance
-  if (F && !F->isDeclaration() &&
+  if (F) {
+    if (F->hasFnAttribute(Attribute::NoBuiltin))
+      return nullptr;
+    if (!F->isDeclaration() &&
         fInfo.isCompatibleSignature(F->getFunctionType()))
       return F;
+  }
 
   FunctionType *FuncTy = fInfo.getFunctionType(*M);
 
   bool hasPtr = false;
   for (FunctionType::param_iterator
          PI = FuncTy->param_begin(),
          PE = FuncTy->param_end();
        PI != PE; ++PI) {

llvm/test/CodeGen/AMDGPU/simplify-libcall-nobuiltin-def.ll

+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2
+; RUN: opt -S -mtriple=amdgcn-- -passes=amdgpu-usenative -amdgpu-use-native=all < %s | FileCheck %s
+
+; Verify nobuiltin is respected on a defined function. native_cos is
+; marked nobuiltin, but native_sin is not.
+
+define float @_Z10native_sinf(float %x) {
+; CHECK-LABEL: define float @_Z10native_sinf
+; CHECK-SAME: (float [[X:%.*]]) {
+; CHECK-NEXT:    [[RESULT:%.*]] = call float asm "
+; CHECK-NEXT:    ret float [[RESULT]]
+;
+  %result = call float asm "; $0 = native_sin($1)", "=v,v"(float %x)
+  ret float %result
+}
+
+define float @_Z10native_cosf(float %x) nobuiltin {
+; CHECK-LABEL: define float @_Z10native_cosf
+; CHECK-SAME: (float [[X:%.*]]) #[[ATTR0:[0-9]+]] {
+; CHECK-NEXT:    [[RESULT:%.*]] = call float asm "
+; CHECK-NEXT:    ret float [[RESULT]]
+;
+  %result = call float asm "; $0 = native_cos($1)", "=v,v"(float %x)
+  ret float %result
+}
+
+define float @_Z3sinf(float %x) {
+; CHECK-LABEL: define float @_Z3sinf
+; CHECK-SAME: (float [[X:%.*]]) {
+; CHECK-NEXT:    [[RESULT:%.*]] = call float asm "
+; CHECK-NEXT:    ret float [[RESULT]]
+;
+  %result = call float asm "; $0 = sin($1)", "=v,v"(float %x)
+  ret float %result
+}
+
+define float @_Z3cosf(float %x) {
+; CHECK-LABEL: define float @_Z3cosf
+; CHECK-SAME: (float [[X:%.*]]) {
+; CHECK-NEXT:    [[RESULT:%.*]] = call float asm "
+; CHECK-NEXT:    ret float [[RESULT]]
+;
+  %result = call float asm "; $0 = cos($1)", "=v,v"(float %x)
+  ret float %result
+}
+
+define float @call_cos(float %x) {
+; CHECK-LABEL: define float @call_cos
+; CHECK-SAME: (float [[X:%.*]]) {
+; CHECK-NEXT:    [[RESULT:%.*]] = call float @_Z3cosf(float [[X]])
+; CHECK-NEXT:    ret float [[RESULT]]
+;
+  %result = call float @_Z3cosf(float %x)
+  ret float %result
+}
+
+define float @call_sin(float %x) {
+; CHECK-LABEL: define float @call_sin
+; CHECK-SAME: (float [[X:%.*]]) {
+; CHECK-NEXT:    [[RESULT:%.*]] = call float @_Z10native_sinf(float [[X]])
+; CHECK-NEXT:    ret float [[RESULT]]
+;
+  %result = call float @_Z3sinf(float %x)
+  ret float %result
+}