[clang] [clang][Interp] Implement IntegralAP::comp (PR #67954)

[Timm Baeder via cfe-commits]

https://github.com/tbaederr created https://github.com/llvm/llvm-project/pull/67954

None

>From fe7f8cddb7f4590f481fce3b99c7b56f8163d889 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Sun, 1 Oct 2023 19:57:03 +0200
Subject: [PATCH] [clang][Interp] Implement IntegralAP::comp

---
 clang/lib/AST/Interp/IntegralAP.h  | 1 -
 clang/test/AST/Interp/literals.cpp | 3 +++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/clang/lib/AST/Interp/IntegralAP.h b/clang/lib/AST/Interp/IntegralAP.h
index b2b367f30c238fe..b29aac2a73e3243 100644
--- a/clang/lib/AST/Interp/IntegralAP.h
+++ b/clang/lib/AST/Interp/IntegralAP.h
@@ -210,7 +210,6 @@ template <bool Signed> class IntegralAP final {
   }
 
   static bool comp(IntegralAP A, IntegralAP *R) {
-    assert(false);
     *R = IntegralAP(~A.V);
     return false;
   }
diff --git a/clang/test/AST/Interp/literals.cpp b/clang/test/AST/Interp/literals.cpp
index b57a0e64c5fac32..864c91dd0003b9e 100644
--- a/clang/test/AST/Interp/literals.cpp
+++ b/clang/test/AST/Interp/literals.cpp
@@ -87,6 +87,9 @@ constexpr int128_t Error = __LDBL_MAX__; // ref-warning {{implicit conversion of
                                          // expected-warning {{implicit conversion of out of range value}} \
                                          // expected-error {{must be initialized by a constant expression}} \
                                          // expected-note {{is outside the range of representable values of type}}
+
+  constexpr uint128_t UINT128_MAX = ~static_cast<uint128_t>(0);
+  static_assert(UINT128_MAX == static_cast<uint128_t>(-1), "");
 }
 #endif