[clang] [llvm] [DirectX] Set DXIL Version using shader model version in compilation target profile (PR #89823)

[Justin Bogner via llvm-commits]

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@@ -98,9 +103,47 @@ std::optional<std::string> tryParseProfile(StringRef Profile) {
   else if (llvm::getAsUnsignedInteger(Parts[2], 0, Minor))
     return std::nullopt;
 
-  // dxil-unknown-shadermodel-hull
+  // Determine DXIL version number using the minor version number of Shader
+  // Model version specified in target profile. Prior to decoupling DXIL version
+  // numbering from that of Shader Model DXIL version 1.Y corresponds to SM 6.Y.
+  // E.g., dxilv1.Y-unknown-shadermodelX.Y-hull
   llvm::Triple T;
-  T.setArch(Triple::ArchType::dxil);
+  Triple::SubArchType SubArch = llvm::Triple::NoSubArch;
+  switch (Minor) {
+  case 0:
+    SubArch = llvm::Triple::DXILSubArch_v1_0;
+    break;
+  case 1:
+    SubArch = llvm::Triple::DXILSubArch_v1_1;
+    break;
+  case 2:
+    SubArch = llvm::Triple::DXILSubArch_v1_2;
+    break;
+  case 3:
+    SubArch = llvm::Triple::DXILSubArch_v1_3;
+    break;
+  case 4:
+    SubArch = llvm::Triple::DXILSubArch_v1_4;
+    break;
+  case 5:
+    SubArch = llvm::Triple::DXILSubArch_v1_5;
+    break;
+  case 6:
+    SubArch = llvm::Triple::DXILSubArch_v1_6;
+    break;
+  case 7:
+    SubArch = llvm::Triple::DXILSubArch_v1_7;
+    break;
+  case 8:
+  case OfflineLibMinor:
+    // Always consider minor version x as the latest supported minor version
+    SubArch = llvm::Triple::DXILSubArch_v1_8;
----------------
bogner wrote:

It might make updates here less error prone if we added `DXILSubArch_v1_x = DXILSubArch_v1_8` or `LastDXILSubArch = DXILSubArch_v1_8` to the enum in Triple.h, depending on which of those makes more logical sense.

https://github.com/llvm/llvm-project/pull/89823