[PPC] add absolute difference altivec instructions and matching intrinsics

This patch corresponds to review https://reviews.llvm.org/D26072.
Committing on behalf of Sean Fertile.

llvm-svn: 285627
diff --git a/llvm/test/CodeGen/PowerPC/vec_absd.ll b/llvm/test/CodeGen/PowerPC/vec_absd.ll
new file mode 100644
index 0000000..37a3a5c
--- /dev/null
+++ b/llvm/test/CodeGen/PowerPC/vec_absd.ll
@@ -0,0 +1,40 @@
+; RUN: llc -verify-machineinstrs -mcpu=pwr9 -mtriple=powerpc64-unknown-linux-gnu  < %s | FileCheck %s
+; RUN: llc -verify-machineinstrs -mcpu=pwr9 -mtriple=powerpc64le-unknown-linux-gnu < %s | FileCheck %s
+
+; Check the vabsd* instructions that were added in PowerISA V3.0
+
+; Function Attrs: nounwind readnone
+declare <16 x i8> @llvm.ppc.altivec.vabsdub(<16 x i8>, <16 x i8>)
+
+; Function Attrs: nounwind readnone
+declare <8 x i16> @llvm.ppc.altivec.vabsduh(<8 x i16>, <8 x i16>)
+
+; Function Attrs: nounwind readnone
+declare <4 x i32> @llvm.ppc.altivec.vabsduw(<4 x i32>, <4 x i32>)
+
+define <16 x i8> @test_byte(<16 x i8> %a, <16 x i8> %b) {
+entry:
+  %res = tail call <16 x i8> @llvm.ppc.altivec.vabsdub(<16 x i8> %a, <16 x i8> %b)
+  ret <16 x i8> %res
+; CHECK-LABEL: @test_byte
+; CHECK: vabsdub 2, 2, 3
+; CHECK blr
+}
+
+define <8 x i16> @test_half(<8 x i16> %a, <8 x i16> %b) {
+entry:
+  %res = tail call <8 x i16> @llvm.ppc.altivec.vabsduh(<8 x i16> %a, <8 x i16> %b)
+  ret <8 x i16> %res
+; CHECK-LABEL: @test_half
+; CHECK: vabsduh 2, 2, 3
+; CHECK blr
+}
+
+define <4 x i32> @test_word(<4 x i32> %a, <4 x i32> %b) {
+entry:
+  %res = tail call <4 x i32> @llvm.ppc.altivec.vabsduw(<4 x i32> %a, <4 x i32> %b)
+  ret <4 x i32> %res
+; CHECK-LABEL: @test_word
+; CHECK: vabsduw 2, 2, 3
+; CHECK: blr
+}