Add support for Vector Sum Across Partial 1/2 Saturated on PowerPC

Author: lu-zero

src/etc/platform-intrinsics/powerpc.json

@@ -191,6 +191,13 @@
             "llvm": "vmsum{0.kind}hs",
             "ret": "i32",
             "args": ["0N", "0N", "0"]
+        },
+        {
+            "intrinsic": "sum2s",
+            "width": [128],
+            "llvm": "vsum2sws",
+            "ret": "s32",
+            "args": ["0", "0"]
         }
     ]
 }

src/librustc_platform_intrinsics/powerpc.rs

@@ -372,6 +372,11 @@ pub fn find(name: &str) -> Option<Intrinsic> {
             output: &::U32x4,
             definition: Named("llvm.ppc.altivec.vmsumuhs")
         },
+        "_vec_sum2s" => Intrinsic {
+            inputs: { static INPUTS: [&'static Type; 2] = [&::I32x4, &::I32x4]; &INPUTS },
+            output: &::I32x4,
+            definition: Named("llvm.ppc.altivec.vsum2sws")
+        },
         _ => return None,
     })
 }