[llvm] [NVPTX] Add ELF flags for Nvidia cubin files (PR #75624)

[Fangrui Song via llvm-commits]

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@@ -846,6 +846,49 @@ enum {
 #include "ELFRelocs/AMDGPU.def"
 };
 
+// NVPTX specific e_flags.
+enum : unsigned {
+  // Processor selection mask for EF_CUDA_SM* values.
+  EF_CUDA_SM = 0xff,
+
+  // SM based processor values.
+  EF_CUDA_SM20 = 0x14,
+  EF_CUDA_SM21 = 0x15,
+  EF_CUDA_SM30 = 0x1e,
+  EF_CUDA_SM32 = 0x20,
+  EF_CUDA_SM35 = 0x23,
+  EF_CUDA_SM37 = 0x25,
+  EF_CUDA_SM50 = 0x32,
+  EF_CUDA_SM52 = 0x34,
+  EF_CUDA_SM53 = 0x35,
+  EF_CUDA_SM60 = 0x3c,
+  EF_CUDA_SM61 = 0x3d,
+  EF_CUDA_SM62 = 0x3e,
+  EF_CUDA_SM70 = 0x46,
+  EF_CUDA_SM72 = 0x48,
+  EF_CUDA_SM75 = 0x4b,
+  EF_CUDA_SM80 = 0x50,
+  EF_CUDA_SM86 = 0x56,
+  EF_CUDA_SM87 = 0x57,
+  EF_CUDA_SM89 = 0x59,
+  // The sm_90a variant uses the same machine flag.
+  EF_CUDA_SM90 = 0x5a,
+
+  // Unified texture binding is enabled.
+  EF_CUDA_TEXMODE_UNIFIED = 0x100,
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MaskRay wrote:

Is there a specification for these values? Or are they derived from `.headerflags` output?

https://github.com/llvm/llvm-project/pull/75624