Revert "[RISCV] Use Root instead of N throughout the worklist loop in combineBinOp_VLToVWBinOp_VL. (#99416)"

This reverts commit 0c4023a.

I messed up re-generating the test after the change.

Author: topperc

llvm/lib/Target/RISCV/RISCVISelLowering.cpp

@@ -14998,8 +14998,8 @@ static SDValue combineBinOp_VLToVWBinOp_VL(SDNode *N,
     if (!NodeExtensionHelper::isSupportedRoot(Root, Subtarget))
       return SDValue();
 
-    NodeExtensionHelper LHS(Root, 0, DAG, Subtarget);
-    NodeExtensionHelper RHS(Root, 1, DAG, Subtarget);
+    NodeExtensionHelper LHS(N, 0, DAG, Subtarget);
+    NodeExtensionHelper RHS(N, 1, DAG, Subtarget);
     auto AppendUsersIfNeeded = [&Worklist,
                                 &Inserted](const NodeExtensionHelper &Op) {
       if (Op.needToPromoteOtherUsers()) {
@@ -15016,18 +15016,18 @@ static SDValue combineBinOp_VLToVWBinOp_VL(SDNode *N,
       return SDValue();
 
     SmallVector<NodeExtensionHelper::CombineToTry> FoldingStrategies =
-        NodeExtensionHelper::getSupportedFoldings(Root);
+        NodeExtensionHelper::getSupportedFoldings(N);
 
     assert(!FoldingStrategies.empty() && "Nothing to be folded");
     bool Matched = false;
     for (int Attempt = 0;
-         (Attempt != 1 + NodeExtensionHelper::isCommutative(Root)) && !Matched;
+         (Attempt != 1 + NodeExtensionHelper::isCommutative(N)) && !Matched;
          ++Attempt) {
 
       for (NodeExtensionHelper::CombineToTry FoldingStrategy :
            FoldingStrategies) {
         std::optional<CombineResult> Res =
-            FoldingStrategy(Root, LHS, RHS, DAG, Subtarget);
+            FoldingStrategy(N, LHS, RHS, DAG, Subtarget);
         if (Res) {
           Matched = true;
           CombinesToApply.push_back(*Res);

llvm/test/CodeGen/RISCV/rvv/fixed-vectors-vwmul.ll

@@ -882,41 +882,3 @@ define <2 x i64> @vwmul_vx_v2i64_i64(ptr %x, ptr %y) {
   %g = mul <2 x i64> %e, %f
   ret <2 x i64> %g
 }
-
-define <2 x i16> @vwmul_v2i16_multiuse(ptr %x, ptr %y, ptr %z, ptr %w) {
-; CHECK-LABEL: vwmul_v2i16_multiuse:
-; CHECK:       # %bb.0:
-; CHECK-NEXT:    vsetivli zero, 2, e16, mf4, ta, ma
-; CHECK-NEXT:    vle8.v v8, (a1)
-; CHECK-NEXT:    vle8.v v9, (a2)
-; CHECK-NEXT:    vle8.v v10, (a3)
-; CHECK-NEXT:    vle8.v v11, (a0)
-; CHECK-NEXT:    vsext.vf2 v12, v8
-; CHECK-NEXT:    vsext.vf2 v8, v9
-; CHECK-NEXT:    vsext.vf2 v9, v10
-; CHECK-NEXT:    vsetvli zero, zero, e8, mf8, ta, ma
-; CHECK-NEXT:    vwmul.vv v13, v11, v10
-; CHECK-NEXT:    vsetvli zero, zero, e16, mf4, ta, ma
-; CHECK-NEXT:    vmul.vv v9, v12, v9
-; CHECK-NEXT:    vdivu.vv v8, v12, v8
-; CHECK-NEXT:    vor.vv v9, v13, v9
-; CHECK-NEXT:    vor.vv v8, v9, v8
-; CHECK-NEXT:    ret
-  %a = load <2 x i8>, ptr %x
-  %b = load <2 x i8>, ptr %y
-  %c = load <2 x i8>, ptr %z
-  %d = load <2 x i8>, ptr %w
-
-  %as = sext <2 x i8> %a to <2 x i16>
-  %bs = sext <2 x i8> %b to <2 x i16>
-  %cs = sext <2 x i8> %c to <2 x i16>
-  %ds = sext <2 x i8> %d to <2 x i16>
-
-  %e = mul <2 x i16> %as, %ds
-  %f = mul <2 x i16> %bs, %ds ; shares 1 use with %e
-  %g = udiv <2 x i16> %bs, %cs ; shares 1 use with %f, and no uses with %e
-
-  %h = or <2 x i16> %e, %f
-  %i = or <2 x i16> %h, %g
-  ret <2 x i16> %i
-}