[PowerPC] Initial VSX intrinsic support, with min/max for vector double

Now that we have initial support for VSX, we can begin adding
intrinsics for programmer access to VSX instructions.  This patch
performs the necessary enablement in the front end, and tests it by
implementing intrinsics for minimum and maximum using the vector
double data type.

The main change in the front end is to no longer disallow "vector" and
"double" in the same declaration (lib/Sema/DeclSpec.cpp), but "vector"
and "long double" must still be disallowed.  The new intrinsics are
accessed via vec_max and vec_min with changes in
lib/Headers/altivec.h.  Note that for v4f32, we already access
corresponding VMX builtins, but with VSX enabled we should use the
forms that allow all 64 vector registers.

The new built-ins are defined in include/clang/Basic/BuiltinsPPC.def.

I've added a new test in test/CodeGen/builtins-ppc-vsx.c that is
similar to, but much smaller than, builtins-ppc-altivec.c.  This
allows us to test VSX IR generation without duplicating CHECK lines
for the existing bazillion Altivec tests.

Since vector double is now legal when VSX is available, I've modified
the error message, and changed where we test for it and for vector
long double, since the target machine isn't visible in the old place.
This serendipitously removed a not-pertinent warning about 'long'
being deprecated when used with 'vector', when "vector long double" is
encountered and we just want to issue an error.  The existing tests
test/Parser/altivec.c and test/Parser/cxx-altivec.cpp have been
updated accordingly, and I've added test/Parser/vsx.c to verify that
"vector double" is now legitimate with VSX enabled.

There is a companion patch for LLVM.

llvm-svn: 220989

3 files changed, 43 insertions, 6 deletions

diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index 4604b1cfa0f..587b13fe412 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -1136,7 +1136,9 @@ void PPCTargetInfo::getDefaultFeatures(llvm::StringMap<bool> &Features) const {
 }
 
 bool PPCTargetInfo::hasFeature(StringRef Feature) const {
-  return Feature == "powerpc";
+  return (Feature == "powerpc" ||
+	  (Feature == "vsx" && HasVSX) ||
+	  (Feature == "power8-vector" && HasP8Vector));
 }
 
   
diff --git a/clang/lib/Headers/altivec.h b/clang/lib/Headers/altivec.h
index 373eded482f..1ffefa85851 100644
--- a/clang/lib/Headers/altivec.h
+++ b/clang/lib/Headers/altivec.h
@@ -2667,8 +2667,20 @@ vec_max(vector unsigned int __a, vector bool int __b)
 static vector float __ATTRS_o_ai
 vec_max(vector float __a, vector float __b)
 {
+#ifdef __VSX__
+  return __builtin_vsx_xvmaxsp(__a, __b);
+#else
   return __builtin_altivec_vmaxfp(__a, __b);
+#endif
+}
+
+#ifdef __VSX__
+static vector double __ATTRS_o_ai
+vec_max(vector double __a, vector double __b)
+{
+  return __builtin_vsx_xvmaxdp(__a, __b);
 }
+#endif
 
 /* vec_vmaxsb */
 
@@ -2795,7 +2807,11 @@ vec_vmaxuw(vector unsigned int __a, vector bool int __b)
 static vector float __attribute__((__always_inline__))
 vec_vmaxfp(vector float __a, vector float __b)
 {
+#ifdef __VSX__
+  return __builtin_vsx_xvmaxsp(__a, __b);
+#else
   return __builtin_altivec_vmaxfp(__a, __b);
+#endif
 }
 
 /* vec_mergeh */
@@ -3299,8 +3315,20 @@ vec_min(vector unsigned int __a, vector bool int __b)
 static vector float __ATTRS_o_ai
 vec_min(vector float __a, vector float __b)
 {
+#ifdef __VSX__
+  return __builtin_vsx_xvminsp(__a, __b);
+#else
   return __builtin_altivec_vminfp(__a, __b);
+#endif
+}
+
+#ifdef __VSX__
+static vector double __ATTRS_o_ai
+vec_min(vector double __a, vector double __b)
+{
+  return __builtin_vsx_xvmindp(__a, __b);
 }
+#endif
 
 /* vec_vminsb */
 
@@ -3427,7 +3455,11 @@ vec_vminuw(vector unsigned int __a, vector bool int __b)
 static vector float __attribute__((__always_inline__))
 vec_vminfp(vector float __a, vector float __b)
 {
+#ifdef __VSX__
+  return __builtin_vsx_xvminsp(__a, __b);
+#else
   return __builtin_altivec_vminfp(__a, __b);
+#endif
 }
 
 /* vec_mladd */
diff --git a/clang/lib/Sema/DeclSpec.cpp b/clang/lib/Sema/DeclSpec.cpp
index bed94127b28..6e77d2769fa 100644
--- a/clang/lib/Sema/DeclSpec.cpp
+++ b/clang/lib/Sema/DeclSpec.cpp
@@ -18,6 +18,7 @@
 #include "clang/AST/NestedNameSpecifier.h"
 #include "clang/AST/TypeLoc.h"
 #include "clang/Basic/LangOptions.h"
+#include "clang/Basic/TargetInfo.h"
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Parse/ParseDiagnostic.h" // FIXME: remove this back-dependency!
 #include "clang/Sema/LocInfoType.h"
@@ -689,11 +690,6 @@ bool DeclSpec::SetTypeSpecType(TST T, SourceLocation Loc,
   }
   TypeSpecType = T;
   TypeSpecOwned = false;
-  if (TypeAltiVecVector && !TypeAltiVecBool && (TypeSpecType == TST_double)) {
-    PrevSpec = DeclSpec::getSpecifierName((TST) TypeSpecType, Policy);
-    DiagID = diag::err_invalid_vector_decl_spec;
-    return true;
-  }
   return false;
 }
 
@@ -987,6 +983,13 @@ void DeclSpec::Finish(DiagnosticsEngine &D, Preprocessor &PP, const PrintingPoli
       if ((TypeSpecType == TST_char) || (TypeSpecType == TST_int) ||
           (TypeSpecWidth != TSW_unspecified))
         TypeSpecSign = TSS_unsigned;
+    } else if (TypeSpecType == TST_double) {
+      // vector long double and vector long long double are never allowed.
+      // vector double is OK for Power7 and later.
+      if (TypeSpecWidth == TSW_long || TypeSpecWidth == TSW_longlong)
+        Diag(D, TSWLoc, diag::err_invalid_vector_long_double_decl_spec);
+      else if (!PP.getTargetInfo().hasFeature("vsx"))
+        Diag(D, TSTLoc, diag::err_invalid_vector_double_decl_spec);
     } else if (TypeSpecWidth == TSW_long) {
       Diag(D, TSWLoc, diag::warn_vector_long_decl_spec_combination)
         << getSpecifierName((TST)TypeSpecType, Policy);