[llvm] [X86][MC] Added support for -msse2avx option in llvm-mc (PR #96860)

[via llvm-commits]

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@@ -108,6 +109,10 @@ llvm::mc::RegisterMCTargetOptionsFlags::RegisterMCTargetOptionsFlags() {
       cl::desc("Emit internal instruction representation to assembly file"));
   MCBINDOPT(ShowMCInst);
 
+  static cl::opt<bool> SSE2AVX(
+      "msse2avx", cl::desc("Convert SSE Instructions to AVX Instructions"));
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JaydeepChauhan14 wrote:

So, we need to pass "-msse2avx" as clang/llvm-mc option, and use "x86-sse2avx" at backend...?
Something like,
```
  static cl::opt<bool> X86Sse2Avx(
      "msse2avx", cl::desc("Convert SSE Instructions to AVX Instructions"));
  MCBINDOPT(X86Sse2Avx);
```



https://github.com/llvm/llvm-project/pull/96860