[clang] [llvm] [DirectX][DXIL] Set DXIL Version in DXIL target triple based on shader model version (PR #90809)

[Justin Bogner via cfe-commits]

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@@ -115,6 +115,30 @@ StringRef Triple::getArchName(ArchType Kind, SubArchType SubArch) {
     if (SubArch == AArch64SubArch_arm64e)
       return "arm64e";
     break;
+  case Triple::dxil:
+    switch (SubArch) {
+    case Triple::NoSubArch:
+    case Triple::DXILSubArch_v1_0:
+      return "dxilv1.0";
+    case Triple::DXILSubArch_v1_1:
+      return "dxilv1.1";
+    case Triple::DXILSubArch_v1_2:
+      return "dxilv1.2";
+    case Triple::DXILSubArch_v1_3:
+      return "dxilv1.3";
+    case Triple::DXILSubArch_v1_4:
+      return "dxilv1.4";
+    case Triple::DXILSubArch_v1_5:
+      return "dxilv1.5";
+    case Triple::DXILSubArch_v1_6:
+      return "dxilv1.6";
+    case Triple::DXILSubArch_v1_7:
+      return "dxilv1.7";
+    case Triple::DXILSubArch_v1_8:
+      return "dxilv1.8";
+    default:
+      return "";
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bogner wrote:

I would argue that returning an empty string here is just as inconsistent as erroring out/crashing. We should probably just do (2) even though it's obviously ridiculous, since for other architectures if you provide an invalid subarch they are indeed just as ridiculous.

If we want to shore this up so that invalid sub architectures do something more sensible we should do it for all targets and in a separate change.

https://github.com/llvm/llvm-project/pull/90809