[llvm] [RISCV][Peephole] Checking regclass compatibility in VMV (PR #138844)

[Luke Lau via llvm-commits]

================
@@ -89,3 +89,41 @@ body: |
     %passthru:vr = COPY $v8
     %x:vr = PseudoVADD_VV_MF4 %passthru, $noreg, $noreg, 4, 4 /* e16 */, 0 /* tu, mu */
     %y:vr = PseudoVMV_V_V_MF8 %passthru, %x, 4, 3 /* e8 */, 0 /* tu, mu */
+...
+---
+name:            diff_regclass
+body:             |
+  bb.0.entry:
+    liveins: $v8
+    ; CHECK-LABEL: name: diff_regclass
+    ; CHECK: liveins: $v8
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[PseudoVMV_V_I_MF2_:%[0-9]+]]:vr = PseudoVMV_V_I_MF2 $noreg, 0, -1, 5 /* e32 */, 0 /* tu, mu */
+    ; CHECK-NEXT: [[PseudoVMV_V_V_MF2_:%[0-9]+]]:vrnov0 = PseudoVMV_V_V_MF2 $noreg, [[PseudoVMV_V_I_MF2_]], 0, 5 /* e32 */, 0 /* tu, mu */
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:vmv0 = COPY $v8
+    ; CHECK-NEXT: [[PseudoVXOR_VV_MF2_MASK:%[0-9]+]]:vrnov0 = PseudoVXOR_VV_MF2_MASK [[PseudoVMV_V_V_MF2_]], [[PseudoVMV_V_I_MF2_]], [[PseudoVMV_V_I_MF2_]], [[COPY]], 0, 5 /* e32 */, 0 /* tu, mu */
+    %0:vr = PseudoVMV_V_I_MF2 $noreg, 0, -1, 5 /* e32 */, 0 /* tu, mu */
+    %1:vrnov0 = PseudoVMV_V_V_MF2 $noreg, %0, 0, 5 /* e32 */, 0 /* tu, mu */
+    %4:vmv0 = COPY $v8
+    %3:vrnov0 = PseudoVXOR_VV_MF2_MASK %1, %0, %0, %4, 0, 5 /* e32 */, 0 /* tu, mu */
----------------
lukel97 wrote:

Nit, but can we use a PseudoVADD_VV_M1_MASK to simplify the test case a bit?
```suggestion
    %4:vrnov0 = PseudoVADD_VV_M1_MASK %3, $noreg, $noreg, $noreg, 0, 5 /* e32 */, 0 /* tu, mu */
```

https://github.com/llvm/llvm-project/pull/138844