[clang-tools-extra] [compiler-rt] [flang] [clang] [llvm] [clang] Add support for new loop attribute [[clang::code_align()]] (PR #70762)

[Erich Keane via llvm-commits]

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@@ -322,6 +322,79 @@ static Attr *handleUnlikely(Sema &S, Stmt *St, const ParsedAttr &A,
   return ::new (S.Context) UnlikelyAttr(S.Context, A);
 }
 
+CodeAlignAttr *Sema::BuildCodeAlignAttr(const AttributeCommonInfo &CI,
+                                        Expr *E) {
+  if (!E->isValueDependent()) {
+    llvm::APSInt ArgVal;
+    ExprResult Res = VerifyIntegerConstantExpression(E, &ArgVal);
+    if (Res.isInvalid())
+      return nullptr;
+    E = Res.get();
+
+    // This attribute requires an integer argument which is a constant power of
+    // two between 1 and 4096 inclusive.
+    if (ArgVal < CodeAlignAttr::MinimumAlignment ||
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erichkeane wrote:

We can end up with an expression resulting in a negative that takes more than 64 bits (say, one that evaluates to an int128), so this has the same problem as the maximum case below.

https://github.com/llvm/llvm-project/pull/70762