[PowerPC][Altivec] Fix constant argument for vec_dss

Summary:
This is similar to vec_ct* in https://reviews.llvm.org/rL304205.

The argument must be a constant, otherwise instruction selection
will fail. always_inline is not enough for isel to always fold
everything away at -O0.

The fix is to turn the function into macros in altivec.h.

Fixes https://bugs.llvm.org/show_bug.cgi?id=43072

Reviewers: nemanjai, hfinkel, #powerpc, wuzish

Reviewed By: #powerpc, wuzish

Subscribers: wuzish, kbarton, MaskRay, shchenz, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D66699

llvm-svn: 370902

2 files changed, 3 insertions, 3 deletions

diff --git a/clang/lib/Headers/altivec.h b/clang/lib/Headers/altivec.h
index 4008440b2bc..a7f480e45d8 100644
--- a/clang/lib/Headers/altivec.h
+++ b/clang/lib/Headers/altivec.h
@@ -3286,9 +3286,7 @@ static __inline__ vector double __ATTRS_o_ai vec_div(vector double __a,
 
 /* vec_dss */
 
-static __inline__ void __attribute__((__always_inline__)) vec_dss(int __a) {
-  __builtin_altivec_dss(__a);
-}
+#define vec_dss __builtin_altivec_dss
 
 /* vec_dssall */
 
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index f6a705a70ac..bb06517ad51 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -3220,6 +3220,8 @@ bool Sema::CheckPPCBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
   case PPC::BI__builtin_altivec_crypto_vshasigmad:
     return SemaBuiltinConstantArgRange(TheCall, 1, 0, 1) ||
            SemaBuiltinConstantArgRange(TheCall, 2, 0, 15);
+  case PPC::BI__builtin_altivec_dss:
+    return SemaBuiltinConstantArgRange(TheCall, 0, 0, 3);
   case PPC::BI__builtin_tbegin:
   case PPC::BI__builtin_tend: i = 0; l = 0; u = 1; break;
   case PPC::BI__builtin_tsr: i = 0; l = 0; u = 7; break;