[clang] [X86][ByteCode] Allow PSHUFB intrinsics to be used in constexpr #156612 (PR #163148)

[via cfe-commits]

================
@@ -11619,6 +11619,44 @@ static bool evalPackBuiltin(const CallExpr *E, EvalInfo &Info, APValue &Result,
   return true;
 }
 
+static bool evalPshufbBuiltin(EvalInfo &Info, const CallExpr *Call,
----------------
shashank1545 wrote:

I initially explored evalPshufBuiltin, but since the function handles the control as a scalar and applies different shuffle logic, integrating the pshufb seemed to require heavy conditional branching which i thought might complicate readability. However, this is my first LLVM contribution and i completely understand if i am missing some broader context. I am happy to rework this or refactor both implementations together if that would be a good long term solution. 

https://github.com/llvm/llvm-project/pull/163148