[PowerPC] Add VSX builtins for vec_div

This patch adds builtin support for xvdivdp and xvdivsp, along with a
test case.  Straightforward stuff.

There's a companion patch for Clang.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221983 91177308-0d34-0410-b5e6-96231b3b80d8

test/CodeGen/PowerPC/vsx-div.ll

@@ -0,0 +1,29 @@
+; RUN: llc -mcpu=pwr7 -mattr=+vsx -O1 -mtriple=powerpc64-unknown-linux-gnu < %s | FileCheck %s
+
+@vf = global <4 x float> <float -1.500000e+00, float 2.500000e+00, float -3.500000e+00, float 4.500000e+00>, align 16
+@vd = global <2 x double> <double 3.500000e+00, double -7.500000e+00>, align 16
+@vf_res = common global <4 x float> zeroinitializer, align 16
+@vd_res = common global <2 x double> zeroinitializer, align 16
+
+define void @test1() {
+entry:
+  %0 = load <4 x float>* @vf, align 16
+  %1 = tail call <4 x float> @llvm.ppc.vsx.xvdivsp(<4 x float> %0, <4 x float> %0)
+  store <4 x float> %1, <4 x float>* @vf_res, align 16
+  ret void
+}
+; CHECK-LABEL: @test1
+; CHECK: xvdivsp
+
+define void @test2() {
+entry:
+  %0 = load <2 x double>* @vd, align 16
+  %1 = tail call <2 x double> @llvm.ppc.vsx.xvdivdp(<2 x double> %0, <2 x double> %0)
+  store <2 x double> %1, <2 x double>* @vd_res, align 16
+  ret void
+}
+; CHECK-LABEL: @test2
+; CHECK: xvdivdp
+
+declare <2 x double> @llvm.ppc.vsx.xvdivdp(<2 x double>, <2 x double>)
+declare <4 x float> @llvm.ppc.vsx.xvdivsp(<4 x float>, <4 x float>)