From 2063b03d43303f7fd8612160027c405b9e284966 Mon Sep 17 00:00:00 2001
From: Artem Belevich <tra@google.com>
Date: Wed, 19 Aug 2015 20:48:20 +0000
Subject: [PATCH] [CUDA] Add appropriate host/device attribute to builtins.

Differential Revision: http://reviews.llvm.org/D12122

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@245496 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/clang/Basic/Builtins.h      |  5 +++++
 lib/Sema/SemaChecking.cpp           |  2 +-
 lib/Sema/SemaDecl.cpp               | 11 +++++++++
 test/SemaCUDA/builtins.cu           | 35 +++++++++++++++++++++++++++++
 test/SemaCUDA/implicit-intrinsic.cu |  6 ++---
 5 files changed, 55 insertions(+), 4 deletions(-)
 create mode 100644 test/SemaCUDA/builtins.cu

diff --git a/include/clang/Basic/Builtins.h b/include/clang/Basic/Builtins.h
index 554143d6be..87e2ac7079 100644
--- a/include/clang/Basic/Builtins.h
+++ b/include/clang/Basic/Builtins.h
@@ -81,6 +81,11 @@ public:
     return getRecord(ID).Type;
   }
 
+  /// \brief Return true if this function is a target-specific builtin
+  bool isTSBuiltin(unsigned ID) const {
+    return ID >= Builtin::FirstTSBuiltin;
+  }
+
   /// \brief Return true if this function has no side effects and doesn't
   /// read memory.
   bool isConst(unsigned ID) const {
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index a8a7009ccf..e2940c7f57 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -525,7 +525,7 @@ Sema::CheckBuiltinFunctionCall(FunctionDecl *FDecl, unsigned BuiltinID,
 
   // Since the target specific builtins for each arch overlap, only check those
   // of the arch we are compiling for.
-  if (BuiltinID >= Builtin::FirstTSBuiltin) {
+  if (Context.BuiltinInfo.isTSBuiltin(BuiltinID)) {
     switch (Context.getTargetInfo().getTriple().getArch()) {
       case llvm::Triple::arm:
       case llvm::Triple::armeb:
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index a8d1e1203e..d79d60c977 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -11187,6 +11187,17 @@ void Sema::AddKnownFunctionAttributes(FunctionDecl *FD) {
       FD->addAttr(NoThrowAttr::CreateImplicit(Context, FD->getLocation()));
     if (Context.BuiltinInfo.isConst(BuiltinID) && !FD->hasAttr<ConstAttr>())
       FD->addAttr(ConstAttr::CreateImplicit(Context, FD->getLocation()));
+    if (getLangOpts().CUDA && Context.BuiltinInfo.isTSBuiltin(BuiltinID) &&
+        !FD->hasAttr<CUDADeviceAttr>() && !FD->hasAttr<CUDAHostAttr>()) {
+      // Target-specific builtins are assumed to be intended for use
+      // in this particular CUDA compilation mode and should have
+      // appropriate attribute set so we can enforce CUDA function
+      // call restrictions.
+      if (getLangOpts().CUDAIsDevice)
+        FD->addAttr(CUDADeviceAttr::CreateImplicit(Context, FD->getLocation()));
+      else
+        FD->addAttr(CUDAHostAttr::CreateImplicit(Context, FD->getLocation()));
+    }
   }
 
   IdentifierInfo *Name = FD->getIdentifier();
diff --git a/test/SemaCUDA/builtins.cu b/test/SemaCUDA/builtins.cu
new file mode 100644
index 0000000000..80b9d69980
--- /dev/null
+++ b/test/SemaCUDA/builtins.cu
@@ -0,0 +1,35 @@
+// Tests that target-specific builtins have appropriate host/device
+// attributes and that CUDA call restrictions are enforced. Also
+// verify that non-target builtins can be used from both host and
+// device functions.
+//
+// REQUIRES: x86-registered-target
+// REQUIRES: nvptx-registered-target
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -fsyntax-only -verify %s
+// RUN: %clang_cc1 -triple nvptx64-unknown-cuda -fcuda-is-device \
+// RUN:   -fsyntax-only -verify %s
+
+
+#ifdef __CUDA_ARCH__
+// Device-side builtins are not allowed to be called from host functions.
+void hf() {
+  int x = __builtin_ptx_read_tid_x(); // expected-note  {{'__builtin_ptx_read_tid_x' declared here}}
+  // expected-error@-1 {{reference to __device__ function '__builtin_ptx_read_tid_x' in __host__ function}}
+  x = __builtin_abs(1);
+}
+__attribute__((device)) void df() {
+  int x = __builtin_ptx_read_tid_x();
+  x = __builtin_abs(1);
+}
+#else
+// Host-side builtins are not allowed to be called from device functions.
+__attribute__((device)) void df() {
+  int x = __builtin_ia32_rdtsc();   // expected-note {{'__builtin_ia32_rdtsc' declared here}}
+  // expected-error@-1 {{reference to __host__ function '__builtin_ia32_rdtsc' in __device__ function}}
+  x = __builtin_abs(1);
+}
+void hf() {
+  int x = __builtin_ia32_rdtsc();
+  x = __builtin_abs(1);
+}
+#endif
diff --git a/test/SemaCUDA/implicit-intrinsic.cu b/test/SemaCUDA/implicit-intrinsic.cu
index 3d24aa719e..7414a66b03 100644
--- a/test/SemaCUDA/implicit-intrinsic.cu
+++ b/test/SemaCUDA/implicit-intrinsic.cu
@@ -1,10 +1,10 @@
-// RUN: %clang_cc1 -std=gnu++11 -triple nvptx64-unknown-unknown -fsyntax-only -verify %s
+// RUN: %clang_cc1 -triple nvptx64-unknown-unknown -fcuda-is-device -fsyntax-only -verify %s
 
 #include "Inputs/cuda.h"
 
 // expected-no-diagnostics
 __device__ void __threadfence_system() {
-  // This shouldn't produce an error, since __nvvm_membar_sys is inferred to
-  // be __host__ __device__ and thus callable from device code.
+  // This shouldn't produce an error, since __nvvm_membar_sys should be
+  // __device__ and thus callable from device code.
   __nvvm_membar_sys();
 }
-- 
2.40.0