[Power10] Implement custom codegen for the vec_replace_elt and vec_replace_unaligned builtins.

This patch implements custom codegen for the vec_replace_elt and
vec_replace_unaligned builtins.

These builtins map to the @llvm.ppc.altivec.vinsw and @llvm.ppc.altivec.vinsd
intrinsics depending on the arguments. The main motivation for doing custom
codegen for these intrinsics is because there are float and double versions of
the builtin. Normally, the converting the float to an integer would be done via
fptoui in the IR. This is incorrect as fptoui truncates the value and we must
ensure the value is not truncated. Therefore, we provide custom codegen to utilize
bitcast instead as bitcasts do not truncate.

Differential Revision: https://reviews.llvm.org/D83500

1 files changed, 19 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index f2b70be..eeb3222 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -2570,6 +2570,17 @@ static bool isValidBPFPreserveFieldInfoArg(Expr *Arg) {
           dyn_cast<ArraySubscriptExpr>(Arg->IgnoreParens()));
 }
 
+static bool isEltOfVectorTy(ASTContext &Context, CallExpr *Call, Sema &S,
+                            QualType VectorTy, QualType EltTy) {
+  QualType VectorEltTy = VectorTy->castAs<VectorType>()->getElementType();
+  if (!Context.hasSameType(VectorEltTy, EltTy)) {
+    S.Diag(Call->getBeginLoc(), diag::err_typecheck_call_different_arg_types)
+        << Call->getSourceRange() << VectorEltTy << EltTy;
+    return false;
+  }
+  return true;
+}
+
 static bool isValidBPFPreserveTypeInfoArg(Expr *Arg) {
   QualType ArgType = Arg->getType();
   if (ArgType->getAsPlaceholderType())
@@ -3222,6 +3233,14 @@ bool Sema::CheckPPCBuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
     return SemaVSXCheck(TheCall);
   case PPC::BI__builtin_altivec_vgnb:
      return SemaBuiltinConstantArgRange(TheCall, 1, 2, 7);
+  case PPC::BI__builtin_altivec_vec_replace_elt:
+  case PPC::BI__builtin_altivec_vec_replace_unaligned: {
+    QualType VecTy = TheCall->getArg(0)->getType();
+    QualType EltTy = TheCall->getArg(1)->getType();
+    unsigned Width = Context.getIntWidth(EltTy);
+    return SemaBuiltinConstantArgRange(TheCall, 2, 0, Width == 32 ? 12 : 8) ||
+           !isEltOfVectorTy(Context, TheCall, *this, VecTy, EltTy);
+  }
   case PPC::BI__builtin_vsx_xxeval:
      return SemaBuiltinConstantArgRange(TheCall, 3, 0, 255);
   case PPC::BI__builtin_altivec_vsldbi: