[PPC] FE support for generating VSX [negated] absolute value instructions

Includes new built-in, conversion of built-in to target-independent intrinsic
and update in the header file. Tests are also updated. There is a second part in
the backend for which I will post a separate code-review. BACKEND PART SHOULD BE
COMMITTED FIRST.

Phabricator: http://reviews.llvm.org/D17816
llvm-svn: 263051

2 files changed, 15 insertions, 3 deletions

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index fbba561f7cc..fc3d1266146 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -6992,6 +6992,16 @@ Value *CodeGenFunction::EmitPPCBuiltinExpr(unsigned BuiltinID,
     llvm::Function *F = CGM.getIntrinsic(ID, ResultType);
     return Builder.CreateCall(F, X);
   }
+
+  // Absolute value
+  case PPC::BI__builtin_vsx_xvabsdp:
+  case PPC::BI__builtin_vsx_xvabssp: {
+    llvm::Type *ResultType = ConvertType(E->getType());
+    Value *X = EmitScalarExpr(E->getArg(0));
+    llvm::Function *F = CGM.getIntrinsic(Intrinsic::fabs, ResultType);
+    return Builder.CreateCall(F, X);
+  }
+
   // FMA variations
   case PPC::BI__builtin_vsx_xvmaddadp:
   case PPC::BI__builtin_vsx_xvmaddasp:
diff --git a/clang/lib/Headers/altivec.h b/clang/lib/Headers/altivec.h
index 5973326fe4e..017f69678ec 100644
--- a/clang/lib/Headers/altivec.h
+++ b/clang/lib/Headers/altivec.h
@@ -124,16 +124,18 @@ vec_abs(vector signed long long __a) {
 #endif
 
 static vector float __ATTRS_o_ai vec_abs(vector float __a) {
+#ifdef __VSX__
+  return __builtin_vsx_xvabssp(__a);
+#else
   vector unsigned int __res =
       (vector unsigned int)__a & (vector unsigned int)(0x7FFFFFFF);
   return (vector float)__res;
+#endif
 }
 
 #if defined(__POWER8_VECTOR__) && defined(__powerpc64__)
 static vector double __ATTRS_o_ai vec_abs(vector double __a) {
-  vector unsigned long long __res = { 0x7FFFFFFFFFFFFFFF, 0x7FFFFFFFFFFFFFFF };
-  __res &= (vector unsigned int)__a;
-  return (vector double)__res;
+  return __builtin_vsx_xvabsdp(__a);
 }
 #endif