[clang] [Clang] Overflow Pattern Exclusions (PR #100272)

[Eli Friedman via cfe-commits]

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@@ -195,13 +196,23 @@ static bool CanElideOverflowCheck(const ASTContext &Ctx, const BinOpInfo &Op) {
   if (!Op.mayHaveIntegerOverflow())
     return true;
 
+  const UnaryOperator *UO = dyn_cast<UnaryOperator>(Op.E);
+
+  if (UO && UO->getOpcode() == UO_Minus && UO->isIntegerConstantExpr(Ctx) &&
+      Ctx.getLangOpts().isOverflowPatternExcluded(
+          LangOptions::OverflowPatternExclusionKind::NegUnsignedConst))
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efriedma-quic wrote:

Check isOverflowPatternExcluded() first, since it's cheaper to check.

https://github.com/llvm/llvm-project/pull/100272