[AMDGPU] Report error in clang if wave32 is requested where unsupported

clang/lib/Basic/Targets/AMDGPU.cpp

@@ -187,9 +187,15 @@ bool AMDGPUTargetInfo::initFeatureMap(
     return false;
 
   // TODO: Should move this logic into TargetParser
-  std::string ErrorMsg;
-  if (!insertWaveSizeFeature(CPU, getTriple(), Features, ErrorMsg)) {
-    Diags.Report(diag::err_invalid_feature_combination) << ErrorMsg;
+  auto HasError = insertWaveSizeFeature(CPU, getTriple(), Features);
+  switch (HasError.first) {
+  default:
+    break;
+  case llvm::AMDGPU::INVALID_FEATURE_COMBINATION:
+    Diags.Report(diag::err_invalid_feature_combination) << HasError.second;
+    return false;
+  case llvm::AMDGPU::UNSUPPORTED_TARGET_FEATURE:
+    Diags.Report(diag::err_opt_not_valid_on_target) << HasError.second;
     return false;
   }
 

clang/test/CodeGenOpenCL/amdgpu-features-illegal.cl

@@ -1,6 +1,8 @@
 // RUN: not %clang_cc1 -triple amdgcn -target-feature +wavefrontsize32 -target-feature +wavefrontsize64 -o /dev/null %s 2>&1 | FileCheck %s
 // RUN: not %clang_cc1 -triple amdgcn -target-cpu gfx1103 -target-feature +wavefrontsize32 -target-feature +wavefrontsize64 -o /dev/null %s 2>&1 | FileCheck %s
+// RUN: not %clang_cc1 -triple amdgcn -target-cpu gfx900 -target-feature +wavefrontsize32 -o /dev/null %s 2>&1 | FileCheck %s --check-prefix=GFX9
 
 // CHECK: error: invalid feature combination: 'wavefrontsize32' and 'wavefrontsize64' are mutually exclusive
+// GFX9: error: option 'wavefrontsize32' cannot be specified on this target
 
 kernel void test() {}

clang/test/SemaOpenCL/builtins-amdgcn-error-wave32.cl

@@ -12,8 +12,7 @@ void test_ballot_wave32(global uint* out, int a, int b) {
   *out = __builtin_amdgcn_ballot_w32(a == b);  // expected-error {{'__builtin_amdgcn_ballot_w32' needs target feature wavefrontsize32}}
 }
 
-// FIXME: Should error for subtargets that don't support wave32
-__attribute__((target("wavefrontsize32")))
+__attribute__((target("wavefrontsize32"))) // gfx9-error@*:* {{option 'wavefrontsize32' cannot be specified on this target}}
 void test_ballot_wave32_target_attr(global uint* out, int a, int b) {
   *out = __builtin_amdgcn_ballot_w32(a == b);
 }

llvm/include/llvm/TargetParser/TargetParser.h

@@ -157,6 +157,12 @@ enum ArchFeatureKind : uint32_t {
   FEATURE_WGP = 1 << 9,
 };
 
+enum FeatureError : uint32_t {
+  NO_ERROR = 0,
+  INVALID_FEATURE_COMBINATION,
+  UNSUPPORTED_TARGET_FEATURE
+};
+
 StringRef getArchFamilyNameAMDGCN(GPUKind AK);
 
 StringRef getArchNameAMDGCN(GPUKind AK);
@@ -177,8 +183,9 @@ void fillAMDGPUFeatureMap(StringRef GPU, const Triple &T,
                           StringMap<bool> &Features);
 
 /// Inserts wave size feature for given GPU into features map
-bool insertWaveSizeFeature(StringRef GPU, const Triple &T,
-                           StringMap<bool> &Features, std::string &ErrorMsg);
+std::pair<FeatureError, StringRef>
+insertWaveSizeFeature(StringRef GPU, const Triple &T,
+                      StringMap<bool> &Features);
 
 } // namespace AMDGPU
 } // namespace llvm

llvm/lib/TargetParser/TargetParser.cpp

@@ -616,18 +616,19 @@ static bool isWave32Capable(StringRef GPU, const Triple &T) {
   return IsWave32Capable;
 }
 
-bool AMDGPU::insertWaveSizeFeature(StringRef GPU, const Triple &T,
-                                   StringMap<bool> &Features,
-                                   std::string &ErrorMsg) {
+std::pair<FeatureError, StringRef>
+AMDGPU::insertWaveSizeFeature(StringRef GPU, const Triple &T,
+                              StringMap<bool> &Features) {
   bool IsWave32Capable = isWave32Capable(GPU, T);
   const bool IsNullGPU = GPU.empty();
-  // FIXME: Not diagnosing wavefrontsize32 on wave64 only targets.
-  const bool HaveWave32 =
-      (IsWave32Capable || IsNullGPU) && Features.count("wavefrontsize32");
+  const bool HaveWave32 = Features.count("wavefrontsize32");
   const bool HaveWave64 = Features.count("wavefrontsize64");
   if (HaveWave32 && HaveWave64) {
-    ErrorMsg = "'wavefrontsize32' and 'wavefrontsize64' are mutually exclusive";
-    return false;
+    return {AMDGPU::INVALID_FEATURE_COMBINATION,
+            "'wavefrontsize32' and 'wavefrontsize64' are mutually exclusive"};
+  }
+  if (HaveWave32 && !IsNullGPU && !IsWave32Capable) {
+    return {AMDGPU::UNSUPPORTED_TARGET_FEATURE, "wavefrontsize32"};
   }
   // Don't assume any wavesize with an unknown subtarget.
   if (!IsNullGPU) {
@@ -638,5 +639,5 @@ bool AMDGPU::insertWaveSizeFeature(StringRef GPU, const Triple &T,
       Features.insert(std::make_pair(DefaultWaveSizeFeature, true));
     }
   }
-  return true;
+  return {NO_ERROR, StringRef()};
 }