[flang-commits] [clang] [flang] [lld] [llvm] AMDGPU: Introduce amdgpu triple arch (PR #206480)

[Robert Imschweiler via flang-commits]

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@@ -873,6 +879,24 @@ AMDGPUTargetMachine::AMDGPUTargetMachine(const Target &T, const Triple &TT,
       TLOF(createTLOF(getTargetTriple())) {
   initAsmInfo();
   if (TT.isAMDGCN()) {
+    // Triple is missing a representation for non-empty, but unrecognized
+    // subarches. Only permit no subarch for any subtarget if it was really
+    // empty.
+    bool IsUnknownSubArch =
+        TT.getSubArch() == Triple::NoSubArch && TT.getArchName().size() != 6;
+    if (IsUnknownSubArch)
+      reportFatalUsageError("unknown subarch " + TT.getArchName());
+
+    if (TT.getSubArch() != Triple::NoSubArch) {
+      AMDGPU::GPUKind Kind = AMDGPU::parseArchAMDGCN(CPU);
+      Triple::SubArchType GPUSubArch = AMDGPU::getSubArch(Kind);
+      if (Kind != AMDGPU::GK_NONE && GPUSubArch != TT.getSubArch() &&
+          TT.getSubArch() != AMDGPU::getMajorSubArch(GPUSubArch)) {
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ro-i wrote:

iiuc, this is not symmetric, in contrast to `isCPUValidForSubArch` / `isSubArchCompatible`?

https://github.com/llvm/llvm-project/pull/206480