Filter out maxclusterrank for < SM_90

Author: jchlanda

llvm/lib/Target/NVPTX/NVPTXAsmPrinter.cpp

@@ -571,8 +571,12 @@ void NVPTXAsmPrinter::emitKernelFunctionDirectives(const Function &F,
   if (getMaxNReg(F, Maxnreg))
     O << ".maxnreg " << Maxnreg << "\n";
 
+  // .maxclusterrank directive requires SM_90 or higher, make sure that we
+  // filter it out for lower SM versions, as it causes a hard ptxas crash.
+  const NVPTXTargetMachine &NTM = static_cast<const NVPTXTargetMachine &>(TM);
+  const auto *STI = static_cast<const NVPTXSubtarget *>(NTM.getSubtargetImpl());
   unsigned Maxclusterrank = 0;
-  if (getMaxClusterRank(F, Maxclusterrank))
+  if (getMaxClusterRank(F, Maxclusterrank) && STI->getSmVersion() >= 90)
     O << ".maxclusterrank " << Maxclusterrank << "\n";
 }
 

llvm/test/CodeGen/NVPTX/maxclusterrank.ll

@@ -0,0 +1,26 @@
+; RUN: llc < %s -march=nvptx64 -mcpu=sm_90 | FileCheck %s --check-prefixes=CHECK,CHECK_SM_90
+; RUN: llc < %s -march=nvptx64 -mcpu=sm_80 | FileCheck %s --check-prefixes=CHECK,CHECK_SM_80
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v16:16:16-v32:32:32-v64:64:64-v128:128:128-n16:32:64"
+target triple = "nvptx64-unknown-unknown"
+
+; CHECK: .maxntid 128, 1, 1
+; CHECK: .minnctapersm 2
+; CHECK_SM_90: .maxclusterrank 8
+; CHECK_SM_80-NOT: .maxclusterrank 8
+
+; Make sure that for SM version prior to 90 `.maxclusterrank` directive is
+; sielently ignored.
+define dso_local void @_Z18TestMaxClusterRankv() {
+entry:
+  %a = alloca i32, align 4
+  store volatile i32 1, ptr %a, align 4
+  ret void
+}
+
+!nvvm.annotations = !{!0, !1, !2, !3}
+
+!0 = !{ptr @_Z18TestMaxClusterRankv, !"kernel", i32 1}
+!1 = !{ptr @_Z18TestMaxClusterRankv, !"maxntidx", i32 128}
+!2 = !{ptr @_Z18TestMaxClusterRankv, !"minctasm", i32 2}
+!3 = !{ptr @_Z18TestMaxClusterRankv, !"maxclusterrank", i32 8}