Support the assume_aligned function attribute
In addition to __builtin_assume_aligned, GCC also supports an assume_aligned
attribute which specifies the alignment (and optional offset) of a function's
return value. Here we implement support for the assume_aligned attribute by making
use of the @llvm.assume intrinsic.
llvm-svn: 218500
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 62a3e11..9d194a3 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -129,6 +129,29 @@
}
}
+static void instantiateDependentAssumeAlignedAttr(
+ Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
+ const AssumeAlignedAttr *Aligned, Decl *New) {
+ // The alignment expression is a constant expression.
+ EnterExpressionEvaluationContext Unevaluated(S, Sema::ConstantEvaluated);
+
+ Expr *E, *OE = nullptr;
+ ExprResult Result = S.SubstExpr(Aligned->getAlignment(), TemplateArgs);
+ if (Result.isInvalid())
+ return;
+ E = Result.getAs<Expr>();
+
+ if (Aligned->getOffset()) {
+ Result = S.SubstExpr(Aligned->getOffset(), TemplateArgs);
+ if (Result.isInvalid())
+ return;
+ OE = Result.getAs<Expr>();
+ }
+
+ S.AddAssumeAlignedAttr(Aligned->getLocation(), New, E, OE,
+ Aligned->getSpellingListIndex());
+}
+
static void instantiateDependentEnableIfAttr(
Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
const EnableIfAttr *A, const Decl *Tmpl, Decl *New) {
@@ -176,6 +199,12 @@
continue;
}
+ const AssumeAlignedAttr *AssumeAligned = dyn_cast<AssumeAlignedAttr>(TmplAttr);
+ if (AssumeAligned) {
+ instantiateDependentAssumeAlignedAttr(*this, TemplateArgs, AssumeAligned, New);
+ continue;
+ }
+
const EnableIfAttr *EnableIf = dyn_cast<EnableIfAttr>(TmplAttr);
if (EnableIf && EnableIf->getCond()->isValueDependent()) {
instantiateDependentEnableIfAttr(*this, TemplateArgs, EnableIf, Tmpl,