[PPC] Add vec_absd functions to altivec.h

[sfertile]

Summary

Adds three overloads of vec_absd to altivec .h, as well as matching PPC specific builtins:

vector unsigned char vec_absd (vector unsigned char, vector unsigned char);
vector unsigned int vec_absd (vector unsigned int, vector unsigned int);
vector unsigned short vec_absd (vector unsigned short, vector unsigned short);

[nemanjai]

This patch LGTM. I'll let @kbarton/@echristo have a look as well and have the final say.

[kbarton]

LGTM

[nemanjai]

Committed revision 285679.
Sean, please close this review pending no buildbot failures.

include/clang/Basic/BuiltinsPPC.def

 BUILTIN(__builtin_altivec_vctzd, "V2ULLiV2ULLi", "")
 
 // Vector population count built-ins
 BUILTIN(__builtin_altivec_vpopcntb, "V16UcV16Uc", "")
 BUILTIN(__builtin_altivec_vpopcnth, "V8UsV8Us", "")
 BUILTIN(__builtin_altivec_vpopcntw, "V4UiV4Ui", "")
 BUILTIN(__builtin_altivec_vpopcntd, "V2ULLiV2ULLi", "")
 
+// Absolute difference built-ins
+BUILTIN(__builtin_altivec_vabsdub, "V16UcV16UcV16Uc", "")
+BUILTIN(__builtin_altivec_vabsduh, "V8UsV8UsV8Us", "")
+BUILTIN(__builtin_altivec_vabsduw, "V4UiV4UiV4Ui", "")
+
 // VSX built-ins.
 
 BUILTIN(__builtin_vsx_lxvd2x, "V2divC*", "")
 BUILTIN(__builtin_vsx_lxvw4x, "V4iivC*", "")
 
 BUILTIN(__builtin_vsx_stxvd2x, "vV2div*", "")
 BUILTIN(__builtin_vsx_stxvw4x, "vV4iiv*", "")
 

lib/Headers/altivec.h

 }
 
 static __inline__ vector signed int __ATTRS_o_ai
 vec_abss(vector signed int __a) {
   return __builtin_altivec_vmaxsw(
       __a, __builtin_altivec_vsubsws((vector signed int)(0), __a));
 }
 
+/* vec_absd */
+#if defined(__POWER9_VECTOR__)
+
+static __inline__ vector unsigned char __ATTRS_o_ai
+vec_absd(vector unsigned char __a, vector unsigned char __b) {
+  return __builtin_altivec_vabsdub(__a, __b);
+}
+
+static __inline__ vector unsigned short __ATTRS_o_ai
+vec_absd(vector unsigned short __a, vector unsigned short __b) {
+  return __builtin_altivec_vabsduh(__a, __b);
+}
+
+static __inline__ vector unsigned int __ATTRS_o_ai
+vec_absd(vector unsigned int __a,  vector unsigned int __b) {
+  return __builtin_altivec_vabsduw(__a, __b);
+}
+
+#endif /* End __POWER9_VECTOR__ */
+
 /* vec_add */
 
 static __inline__ vector signed char __ATTRS_o_ai
 vec_add(vector signed char __a, vector signed char __b) {
   return __a + __b;
 }
 
 static __inline__ vector signed char __ATTRS_o_ai

test/CodeGen/builtins-ppc-p9vector.c

 }
 vector float test58(void) {
 // CHECK-BE: @llvm.ppc.vsx.xviexpsp(<4 x i32> %{{.+}}, <4 x i32>
 // CHECK-BE-NEXT: ret <4 x float>
 // CHECK: @llvm.ppc.vsx.xviexpsp(<4 x i32> %{{.+}}, <4 x i32>
 // CHECK-NEXT: ret <4 x float>
   return vec_insert_exp (vuia,vuib);
 }
+vector unsigned char test59(void) {
+// CHECK-BE: call <16 x i8> @llvm.ppc.altivec.vabsdub(<16 x i8> {{.+}}, <16 x i8> {{.+}})
+// CHECK: call <16 x i8> @llvm.ppc.altivec.vabsdub(<16 x i8> {{.+}}, <16 x i8> {{.+}})
+  return vec_absd(vuca, vucb);
+}
+vector unsigned short test60(void) {
+// CHECK-BE: call <8 x i16> @llvm.ppc.altivec.vabsduh(<8 x i16> {{.+}}, <8 x i16> {{.+}})
+// CHECK: call <8 x i16> @llvm.ppc.altivec.vabsduh(<8 x i16> {{.+}}, <8 x i16> {{.+}})
+  return vec_absd(vusa, vusb);
+}
+vector unsigned int test61(void) {
+// CHECK-BE: call <4 x i32> @llvm.ppc.altivec.vabsduw(<4 x i32> {{.+}}, <4 x i32> {{.+}})
+// CHECK: call <4 x i32> @llvm.ppc.altivec.vabsduw(<4 x i32> {{.+}}, <4 x i32> {{.+}})
+  return vec_absd(vuia, vuib);
+}