[PATCH] D17313: [CUDA] Annotate all calls in CUDA device mode as convergent.

[Justin Lebar via cfe-commits]

jlebar updated this revision to Diff 48143.
jlebar added a comment.

Fix typo.


http://reviews.llvm.org/D17313

Files:
  lib/CodeGen/CGCall.cpp
  test/CodeGenCUDA/convergent.cu
  test/CodeGenCUDA/device-var-init.cu

Index: test/CodeGenCUDA/device-var-init.cu
===================================================================
--- test/CodeGenCUDA/device-var-init.cu
+++ test/CodeGenCUDA/device-var-init.cu
@@ -382,7 +382,7 @@
 // CHECK:   call void @_ZN4NETCC1IJEEEDpT_(%struct.NETC* %netc)
 // CHECK:   call void @_ZN7EC_I_ECC1Ev(%struct.EC_I_EC* %ec_i_ec)
 // CHECK:   call void @_ZN8EC_I_EC1C1Ev(%struct.EC_I_EC1* %ec_i_ec1)
-// CHECK:   call void @_ZN5T_V_TC1Ev(%struct.T_V_T* %t_v_t) #3
+// CHECK:   call void @_ZN5T_V_TC1Ev(%struct.T_V_T* %t_v_t)
 // CHECK:   call void @_ZN7T_B_NECC1Ev(%struct.T_B_NEC* %t_b_nec)
 // CHECK:   call void @_ZN7T_F_NECC1Ev(%struct.T_F_NEC* %t_f_nec)
 // CHECK:   call void @_ZN8T_FA_NECC1Ev(%struct.T_FA_NEC* %t_fa_nec)
Index: test/CodeGenCUDA/convergent.cu
===================================================================
--- test/CodeGenCUDA/convergent.cu
+++ test/CodeGenCUDA/convergent.cu
@@ -22,12 +22,16 @@
 // DEVICE-SAME: convergent
 // DEVICE-NEXT: define void @_Z3barv
 __host__ __device__ void baz();
-__host__ __device__ void bar() { baz(); }
+__host__ __device__ void bar() {
+  // DEVICE: call void @_Z3bazv() [[CALL_ATTR:#[0-9]+]]
+  baz();
+}
 
 // DEVICE: declare void @_Z3bazv() [[BAZ_ATTR:#[0-9]+]]
 // DEVICE: attributes [[BAZ_ATTR]] = {
 // DEVICE-SAME: convergent
 // DEVICE-SAME: }
+// DEVICE: attributes [[CALL_ATTR]] = { convergent }
 
 // HOST: declare void @_Z3bazv() [[BAZ_ATTR:#[0-9]+]]
 // HOST: attributes [[BAZ_ATTR]] = {
Index: lib/CodeGen/CGCall.cpp
===================================================================
--- lib/CodeGen/CGCall.cpp
+++ lib/CodeGen/CGCall.cpp
@@ -3139,7 +3139,13 @@
   if (CGM.getLangOpts().ObjCAutoRefCount)
     AddObjCARCExceptionMetadata(Inst);
 
-  return llvm::CallSite(Inst);
+  llvm::CallSite CS(Inst);
+  // All calls in CUDA device mode must conservatively be marked as convergent,
+  // preventing some optimizations.  The optimizer can remove this if it can
+  // prove the the callee is not convergent.
+  if (CGM.getLangOpts().CUDA && CGM.getLangOpts().CUDAIsDevice)
+    CS.setConvergent();
+  return CS;
 }
 
 /// \brief Store a non-aggregate value to an address to initialize it.  For
@@ -3539,6 +3545,14 @@
         Attrs.addAttribute(getLLVMContext(), llvm::AttributeSet::FunctionIndex,
                            llvm::Attribute::NoInline);
 
+  // All calls in CUDA device code are conservatively marked as convergent.  The
+  // optimizer is able to remove this attribute if it can prove that the callee
+  // is not convergent.
+  if (CGM.getLangOpts().CUDA && CGM.getLangOpts().CUDAIsDevice)
+    Attrs =
+        Attrs.addAttribute(getLLVMContext(), llvm::AttributeSet::FunctionIndex,
+                           llvm::Attribute::Convergent);
+
   CS.setAttributes(Attrs);
   CS.setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
 


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