[clang] [X86] Add MMX/SSE/AVX PHADD/SUB & HADDPS/D intrinsics to be used in constexpr (PR #156822)

[Simon Pilgrim via cfe-commits]

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@@ -3453,6 +3592,30 @@ bool InterpretBuiltin(InterpState &S, CodePtr OpPC, const CallExpr *Call,
   case Builtin::BI__builtin_elementwise_min:
     return interp__builtin_elementwise_maxmin(S, OpPC, Call, BuiltinID);
 
+  case clang::X86::BI__builtin_ia32_phaddw128:
+  case clang::X86::BI__builtin_ia32_phaddw256:
+  case clang::X86::BI__builtin_ia32_phaddd128:
+  case clang::X86::BI__builtin_ia32_phaddd256:
+  case clang::X86::BI__builtin_ia32_phaddsw128:
+  case clang::X86::BI__builtin_ia32_phaddsw256:
+  case clang::X86::BI__builtin_ia32_phsubw128:
+  case clang::X86::BI__builtin_ia32_phsubw256:
+  case clang::X86::BI__builtin_ia32_phsubd128:
+  case clang::X86::BI__builtin_ia32_phsubd256:
+  case clang::X86::BI__builtin_ia32_phsubsw128:
+  case clang::X86::BI__builtin_ia32_phsubsw256:
+    return interp_builtin_ia32ph_add_sub(S, OpPC, Frame, Call, BuiltinID);
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RKSimon wrote:

Can you use a callback like we do for interp__builtin_elementwise_int_binop to handle the add/addsat/sub/subsat cases? That should simplify interp_builtin_ia32ph_add_sub considerably.

https://github.com/llvm/llvm-project/pull/156822