[clang] [X86][clang-cl] Add CL option /vlen (PR #166375)

[Phoebe Wang via cfe-commits]

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@@ -133,6 +133,24 @@
 // tune: "-target-cpu" "sandybridge"
 // tune-SAME: "-tune-cpu" "haswell"
 
+// RUN: %clang_cl -m64 -arch:AVX512 -vlen=512 --target=x86_64-pc-windows -### -- 2>&1 %s | FileCheck -check-prefix=vlen512 %s
+// vlen512: "-mprefer-vector-width=512"
+
+// RUN: %clang_cl -m64 -arch:AVX512 -vlen=256 --target=x86_64-pc-windows -### -- 2>&1 %s | FileCheck -check-prefix=vlen256 %s
+// vlen256: "-mprefer-vector-width=256"
+
+// RUN: %clang_cl -m64 -arch:AVX512 -vlen=512 -vlen --target=x86_64-pc-windows -### -- 2>&1 %s | FileCheck -check-prefix=noprefer %s
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phoebewang wrote:

Done.

https://github.com/llvm/llvm-project/pull/166375