[RISCV][VLOPT] Add vfirst and vcpop to getOperandInfo (#122295)

Author: michaelmaitland

llvm/lib/Target/RISCV/RISCVVLOptimizer.cpp

@@ -488,6 +488,10 @@ getOperandLog2EEW(const MachineOperand &MO, const MachineRegisterInfo *MRI) {
   case RISCV::VFCVT_F_X_V:
   // Vector Floating-Point Merge Instruction
   case RISCV::VFMERGE_VFM:
+  // Vector count population in mask vcpop.m
+  // vfirst find-first-set mask bit
+  case RISCV::VCPOP_M:
+  case RISCV::VFIRST_M:
     return MILog2SEW;
 
   // Vector Widening Integer Add/Subtract

llvm/test/CodeGen/RISCV/rvv/vl-opt-op-info.mir

@@ -1438,3 +1438,63 @@ body: |
     %x:vr = nofpexcept PseudoVFCVT_X_F_V_M1 $noreg, $noreg, 0, -1, 5 /* e32 */, 0
     %y:vr = PseudoVFREDMAX_VS_MF2_E32 $noreg, %x, %x, 1, 5 /* e32 */, 0
 ...
+---
+name: vfirst_v
+body: |
+  bb.0:
+    ; CHECK-LABEL: name: vfirst_v
+    ; CHECK: %x:vr = PseudoVMAND_MM_B8 $noreg, $noreg, 1, 0 /* e8 */
+    ; CHECK-NEXT: %y:gpr = PseudoVFIRST_M_B8 %x, 1, 0 /* e8 */
+    %x:vr = PseudoVMAND_MM_B8 $noreg, $noreg, -1, 0
+    %y:gpr = PseudoVFIRST_M_B8 %x, 1, 0
+...
+---
+name: vfirst_v_incompatible_eew
+body: |
+  bb.0:
+    ; CHECK-LABEL: name: vfirst_v_incompatible_eew
+    ; CHECK: %x:vr = PseudoVADD_VV_M1 $noreg, $noreg, $noreg, -1, 3 /* e8 */, 0 /* tu, mu */
+    ; CHECK-NEXT: %y:gpr = PseudoVFIRST_M_B8 %x, 1, 0 /* e8 */
+    %x:vr = PseudoVADD_VV_M1 $noreg, $noreg, $noreg, -1, 3 /* e8 */, 0
+    %y:gpr = PseudoVFIRST_M_B8 %x, 1, 0
+...
+---
+name: vfirst_v_incompatible_emul
+body: |
+  bb.0:
+    ; CHECK-LABEL: name: vfirst_v_incompatible_emul
+    ; CHECK: %x:vr = PseudoVMAND_MM_B8 $noreg, $noreg, -1, 0 /* e8 */
+    ; CHECK-NEXT: %y:gpr = PseudoVFIRST_M_B16 %x, 1, 0 /* e8 */
+    %x:vr = PseudoVMAND_MM_B8 $noreg, $noreg, -1, 0
+    %y:gpr = PseudoVFIRST_M_B16 %x, 1, 0
+...
+---
+name: vcpop_v
+body: |
+  bb.0:
+    ; CHECK-LABEL: name: vcpop_v
+    ; CHECK: %x:vr = PseudoVMAND_MM_B8 $noreg, $noreg, 1, 0 /* e8 */
+    ; CHECK-NEXT: %y:gpr = PseudoVCPOP_M_B8 %x, 1, 0 /* e8 */
+    %x:vr = PseudoVMAND_MM_B8 $noreg, $noreg, -1, 0
+    %y:gpr = PseudoVCPOP_M_B8 %x, 1, 0
+...
+---
+name: vcopop_v_incompatible_eew
+body: |
+  bb.0:
+    ; CHECK-LABEL: name: vcopop_v_incompatible_eew
+    ; CHECK: %x:vr = PseudoVADD_VV_M1 $noreg, $noreg, $noreg, -1, 3 /* e8 */, 0 /* tu, mu */
+    ; CHECK-NEXT: %y:gpr = PseudoVCPOP_M_B8 %x, 1, 0 /* e8 */
+    %x:vr = PseudoVADD_VV_M1 $noreg, $noreg, $noreg, -1, 3 /* e8 */, 0
+    %y:gpr = PseudoVCPOP_M_B8 %x, 1, 0
+...
+---
+name: vcpop_v_incompaitble_emul
+body: |
+  bb.0:
+    ; CHECK-LABEL: name: vcpop_v_incompaitble_emul
+    ; CHECK: %x:vr = PseudoVMAND_MM_B8 $noreg, $noreg, -1, 0 /* e8 */
+    ; CHECK-NEXT: %y:gpr = PseudoVCPOP_M_B16 %x, 1, 0 /* e8 */
+    %x:vr = PseudoVMAND_MM_B8 $noreg, $noreg, -1, 0
+    %y:gpr = PseudoVCPOP_M_B16 %x, 1, 0
+...