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

[Erich Keane via cfe-commits]

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@@ -322,6 +322,81 @@ 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 ||
+        (ArgVal < CodeAlignAttr::MaximumAlignment && !ArgVal.isPowerOf2())) {
+      Diag(CI.getLoc(), diag::err_attribute_power_of_two_in_range)
+          << CI << CodeAlignAttr::MinimumAlignment
+          << CodeAlignAttr::MaximumAlignment << ArgVal.getSExtValue();
+      return nullptr;
+    }
+
+    if (ArgVal > CodeAlignAttr::MaximumAlignment) {
+      if (ArgVal > std::numeric_limits<int32_t>::max() &&
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erichkeane wrote:

`https://llvm.org/doxygen/classllvm_1_1APInt.html#ae30d62aebec681aceb655de2489f12ba`

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