[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);
+
+  case clang::X86::BI__builtin_ia32_haddpd:
+  case clang::X86::BI__builtin_ia32_haddpd256:
+  case clang::X86::BI__builtin_ia32_haddps:
+  case clang::X86::BI__builtin_ia32_haddps256:
+  case clang::X86::BI__builtin_ia32_hsubpd:
+  case clang::X86::BI__builtin_ia32_hsubpd256:
+  case clang::X86::BI__builtin_ia32_hsubps:
+  case clang::X86::BI__builtin_ia32_hsubps256:
+    return interp_builtin_floatph_add_sub(S, OpPC, Frame, Call, BuiltinID);
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RKSimon wrote:

Same - can we use a callback? Ideally we'd merge interp_builtin_ia32ph_add_sub and interp_builtin_floatph_add_sub into a single function with callbacks that works with the APValue ops, but not sure if this would work?

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