[RISCV] Add test case for combining vrgather

[reames]

llvm/test/CodeGen/RISCV/rvv/combine-gather.ll

19

Please add a couple more tests where the result is not a concat. A few ideas:
0,1,2,3,0,1,2,3
0,1,2,3,11,10,9,8
0,1,2,3,12,13,14,15
0,1,2,3, 8,11,10,9

llvm/test/CodeGen/RISCV/rvv/combine-gather.ll

+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 2
+; RUN: llc -mtriple=riscv32 -mattr=+v < %s | FileCheck %s
+; RUN: llc -mtriple=riscv64 -mattr=+v < %s | FileCheck %s
+
+; FIXME: There should only be one vrgather here
+
+define <8 x i8> @gather_i8(<8 x i8> %v, <8 x i8> %w) {
+; CHECK-LABEL: gather_i8:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    vsetivli zero, 8, e8, mf2, ta, mu
+; CHECK-NEXT:    vid.v v11
+; CHECK-NEXT:    vrgather.vv v10, v8, v11
+; CHECK-NEXT:    li a0, 240
+; CHECK-NEXT:    vmv.s.x v0, a0
+; CHECK-NEXT:    vadd.vi v8, v11, -4
+; CHECK-NEXT:    vrgather.vv v10, v9, v8, v0.t
+; CHECK-NEXT:    vmv1r.v v8, v10
+; CHECK-NEXT:    ret
+  %res = shufflevector <8 x i8> %v, <8 x i8> %w, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 8, i32 9, i32 10, i32 11>
+  ret <8 x i8> %res
+}