[RISCV][VLOPT] Fix passthru check in getOperandInfo (llvm#112244)

If a pseudo has a passthru, I believe the first source operand will have
operand no 2, not 1.

Author: lukel97

llvm/lib/Target/RISCV/RISCVTargetMachine.cpp

@@ -128,6 +128,7 @@ extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeRISCVTarget() {
   initializeRISCVPreRAExpandPseudoPass(*PR);
   initializeRISCVExpandPseudoPass(*PR);
   initializeRISCVVectorPeepholePass(*PR);
+  initializeRISCVVLOptimizerPass(*PR);
   initializeRISCVInsertVSETVLIPass(*PR);
   initializeRISCVInsertReadWriteCSRPass(*PR);
   initializeRISCVInsertWriteVXRMPass(*PR);

llvm/lib/Target/RISCV/RISCVVLOptimizer.cpp

@@ -431,7 +431,7 @@ static OperandInfo getOperandInfo(const MachineInstr &MI,
   case RISCV::VWMACCSU_VV:
   case RISCV::VWMACCSU_VX:
   case RISCV::VWMACCUS_VX: {
-    bool IsOp1 = HasPassthru ? MO.getOperandNo() == 1 : MO.getOperandNo() == 2;
+    bool IsOp1 = HasPassthru ? MO.getOperandNo() == 2 : MO.getOperandNo() == 1;
     bool TwoTimes = IsMODef || IsOp1;
     unsigned Log2EEW = TwoTimes ? MILog2SEW + 1 : MILog2SEW;
     RISCVII::VLMUL EMUL =
@@ -467,7 +467,7 @@ static OperandInfo getOperandInfo(const MachineInstr &MI,
   case RISCV::VNCLIP_WI:
   case RISCV::VNCLIP_WV:
   case RISCV::VNCLIP_WX: {
-    bool IsOp1 = HasPassthru ? MO.getOperandNo() == 1 : MO.getOperandNo() == 2;
+    bool IsOp1 = HasPassthru ? MO.getOperandNo() == 2 : MO.getOperandNo() == 1;
     bool TwoTimes = IsOp1;
     unsigned Log2EEW = TwoTimes ? MILog2SEW + 1 : MILog2SEW;
     RISCVII::VLMUL EMUL =

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

@@ -40,13 +40,20 @@ declare <vscale x 2 x i16> @llvm.riscv.vnsrl.nxv2i16.nxv2i32.nxv2i16(
   iXLen);
 
 define <vscale x 2 x i16> @intrinsic_vnsrl_wv_nxv2i16_nxv2i32_nxv2i16(<vscale x 2 x i16> %a, <vscale x 2 x i16> %b, iXLen %2, <vscale x 2 x i32> %3, <vscale x 2 x i32> %4, <vscale x 2 x i16> %z) nounwind {
-; CHECK-LABEL: intrinsic_vnsrl_wv_nxv2i16_nxv2i32_nxv2i16:
-; CHECK:       # %bb.0: # %entry
-; CHECK-NEXT:    vsetvli a1, zero, e16, mf2, ta, ma
-; CHECK-NEXT:    vwadd.vv v10, v8, v9
-; CHECK-NEXT:    vsetvli zero, a0, e16, mf2, ta, ma
-; CHECK-NEXT:    vnsrl.wv v8, v10, v12
-; CHECK-NEXT:    ret
+; NOVLOPT-LABEL: intrinsic_vnsrl_wv_nxv2i16_nxv2i32_nxv2i16:
+; NOVLOPT:       # %bb.0: # %entry
+; NOVLOPT-NEXT:    vsetvli a1, zero, e16, mf2, ta, ma
+; NOVLOPT-NEXT:    vwadd.vv v10, v8, v9
+; NOVLOPT-NEXT:    vsetvli zero, a0, e16, mf2, ta, ma
+; NOVLOPT-NEXT:    vnsrl.wv v8, v10, v12
+; NOVLOPT-NEXT:    ret
+;
+; VLOPT-LABEL: intrinsic_vnsrl_wv_nxv2i16_nxv2i32_nxv2i16:
+; VLOPT:       # %bb.0: # %entry
+; VLOPT-NEXT:    vsetvli zero, a0, e16, mf2, ta, ma
+; VLOPT-NEXT:    vwadd.vv v10, v8, v9
+; VLOPT-NEXT:    vnsrl.wv v8, v10, v12
+; VLOPT-NEXT:    ret
 entry:
   %c = sext <vscale x 2 x i16> %a to <vscale x 2 x i32>
   %d = sext <vscale x 2 x i16> %b to <vscale x 2 x i32>
@@ -67,14 +74,22 @@ declare <vscale x 2 x i16> @llvm.riscv.vnclip.nxv2i16.nxv2i32.nxv2i16(
   iXLen, iXLen);
 
 define <vscale x 2 x i16> @vnclip(<vscale x 2 x i16> %a, <vscale x 2 x i16> %b, iXLen %2, <vscale x 2 x i32> %3, <vscale x 2 x i32> %4, <vscale x 2 x i16> %z) nounwind {
-; CHECK-LABEL: vnclip:
-; CHECK:       # %bb.0: # %entry
-; CHECK-NEXT:    vsetvli a1, zero, e16, mf2, ta, ma
-; CHECK-NEXT:    vwadd.vv v10, v8, v9
-; CHECK-NEXT:    csrwi vxrm, 0
-; CHECK-NEXT:    vsetvli zero, a0, e16, mf2, ta, ma
-; CHECK-NEXT:    vnclip.wv v8, v10, v12
-; CHECK-NEXT:    ret
+; NOVLOPT-LABEL: vnclip:
+; NOVLOPT:       # %bb.0: # %entry
+; NOVLOPT-NEXT:    vsetvli a1, zero, e16, mf2, ta, ma
+; NOVLOPT-NEXT:    vwadd.vv v10, v8, v9
+; NOVLOPT-NEXT:    csrwi vxrm, 0
+; NOVLOPT-NEXT:    vsetvli zero, a0, e16, mf2, ta, ma
+; NOVLOPT-NEXT:    vnclip.wv v8, v10, v12
+; NOVLOPT-NEXT:    ret
+;
+; VLOPT-LABEL: vnclip:
+; VLOPT:       # %bb.0: # %entry
+; VLOPT-NEXT:    vsetvli zero, a0, e16, mf2, ta, ma
+; VLOPT-NEXT:    vwadd.vv v10, v8, v9
+; VLOPT-NEXT:    csrwi vxrm, 0
+; VLOPT-NEXT:    vnclip.wv v8, v10, v12
+; VLOPT-NEXT:    ret
 entry:
   %c = sext <vscale x 2 x i16> %a to <vscale x 2 x i32>
   %d = sext <vscale x 2 x i16> %b to <vscale x 2 x i32>
@@ -88,6 +103,3 @@ entry:
   ret <vscale x 2 x i16> %x
 }
 
-;; NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line:
-; NOVLOPT: {{.*}}
-; VLOPT: {{.*}}

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

@@ -0,0 +1,18 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 5
+# RUN: llc %s -o - -mtriple=riscv64 -mattr=+v -run-pass=riscv-vl-optimizer -verify-machineinstrs | FileCheck %s
+
+---
+name: vnsrl_wv_user
+body: |
+  bb.0:
+    liveins: $x1
+    ; CHECK-LABEL: name: vnsrl_wv_user
+    ; CHECK: liveins: $x1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %vl:gprnox0 = COPY $x1
+    ; CHECK-NEXT: %x:vr = PseudoVADD_VV_MF4 $noreg, $noreg, $noreg, -1, 4 /* e16 */, 0 /* tu, mu */
+    ; CHECK-NEXT: %y:vr = PseudoVNSRL_WV_MF4 $noreg, %x, $noreg, %vl, 4 /* e16 */, 0 /* tu, mu */
+    %vl:gprnox0 = COPY $x1
+    %x:vr = PseudoVADD_VV_MF4 $noreg, $noreg, $noreg, -1, 4 /* e16 */, 0 /* tu, mu */
+    %y:vr = PseudoVNSRL_WV_MF4 $noreg, %x, $noreg, %vl, 4 /* e16 */, 0 /* tu, mu */
+...