split getSameExtensionOpcode

Author: sun-jacobi

llvm/lib/Target/RISCV/RISCVISelLowering.cpp

@@ -13457,30 +13457,54 @@ struct NodeExtensionHelper {
     return NarrowVT;
   }
 
-  /// Return the opcode required to materialize the folding for
-  /// both operands for \p Opcode.
-  /// Put differently, get the opcode to materialize:
-  /// - ExtKind::SExt: \p Opcode(sext(a), sext(b)) -> newOpcode(a, b)
-  /// - ExtKind::ZExt: \p Opcode(zext(a), zext(b)) -> newOpcode(a, b)
-  /// \pre \p Opcode represents a supported root (\see ::isSupportedRoot()).
-  static unsigned getSameExtensionOpcode(unsigned Opcode, ExtKind SupportsExt) {
+  /// Get the opcode to materialize:
+  /// Opcode(sext(a), sext(b)) -> newOpcode(a, b)
+  static unsigned getSExtOpcode(unsigned Opcode) {
     switch (Opcode) {
     case ISD::ADD:
     case RISCVISD::ADD_VL:
     case RISCVISD::VWADD_W_VL:
     case RISCVISD::VWADDU_W_VL:
-      return SupportsExt == ExtKind::SExt ? RISCVISD::VWADD_VL
-                                          : RISCVISD::VWADDU_VL;
+      return RISCVISD::VWADD_VL;
+    case ISD::SUB:
+    case RISCVISD::SUB_VL:
+    case RISCVISD::VWSUB_W_VL:
+    case RISCVISD::VWSUBU_W_VL:
+      return RISCVISD::VWSUB_VL;
     case ISD::MUL:
     case RISCVISD::MUL_VL:
-      return SupportsExt == ExtKind::SExt ? RISCVISD::VWMUL_VL
-                                          : RISCVISD::VWMULU_VL;
+      return RISCVISD::VWMUL_VL;
+    default:
+      llvm_unreachable("Unexpected opcode");
+    }
+  }
+
+  /// Get the opcode to materialize:
+  /// Opcode(zext(a), zext(b)) -> newOpcode(a, b)
+  static unsigned getZExtOpcode(unsigned Opcode) {
+    switch (Opcode) {
+    case ISD::ADD:
+    case RISCVISD::ADD_VL:
+    case RISCVISD::VWADD_W_VL:
+    case RISCVISD::VWADDU_W_VL:
+      return RISCVISD::VWADDU_VL;
     case ISD::SUB:
     case RISCVISD::SUB_VL:
     case RISCVISD::VWSUB_W_VL:
     case RISCVISD::VWSUBU_W_VL:
-      return SupportsExt == ExtKind::SExt ? RISCVISD::VWSUB_VL
-                                          : RISCVISD::VWSUBU_VL;
+      return RISCVISD::VWSUBU_VL;
+    case ISD::MUL:
+    case RISCVISD::MUL_VL:
+      return RISCVISD::VWMULU_VL;
+    default:
+      llvm_unreachable("Unexpected opcode");
+    }
+  }
+
+  /// Get the opcode to materialize:
+  /// Opcode(fpext(a), fpext(b)) -> newOpcode(a, b)
+  static unsigned getFPExtOpcode(unsigned Opcode) {
+    switch (Opcode) {
     case RISCVISD::FADD_VL:
     case RISCVISD::VFWADD_W_VL:
       return RISCVISD::VFWADD_VL;
@@ -13835,19 +13859,16 @@ canFoldToVWWithSameExtensionImpl(SDNode *Root, const NodeExtensionHelper &LHS,
   if (!LHS.areVLAndMaskCompatible(Root, DAG, Subtarget) ||
       !RHS.areVLAndMaskCompatible(Root, DAG, Subtarget))
     return std::nullopt;
-  if (AllowExtMask & ExtKind::ZExt && LHS.SupportsZExt && RHS.SupportsZExt)
-    return CombineResult(NodeExtensionHelper::getSameExtensionOpcode(
-                             Root->getOpcode(), ExtKind::ZExt),
+  if ((AllowExtMask & ExtKind::ZExt) && LHS.SupportsZExt && RHS.SupportsZExt)
+    return CombineResult(NodeExtensionHelper::getZExtOpcode(Root->getOpcode()),
                          Root, LHS, /*LHSExt=*/{ExtKind::ZExt}, RHS,
                          /*RHSExt=*/{ExtKind::ZExt});
-  if (AllowExtMask & ExtKind::SExt && LHS.SupportsSExt && RHS.SupportsSExt)
-    return CombineResult(NodeExtensionHelper::getSameExtensionOpcode(
-                             Root->getOpcode(), ExtKind::SExt),
+  if ((AllowExtMask & ExtKind::SExt) && LHS.SupportsSExt && RHS.SupportsSExt)
+    return CombineResult(NodeExtensionHelper::getSExtOpcode(Root->getOpcode()),
                          Root, LHS, /*LHSExt=*/{ExtKind::SExt}, RHS,
                          /*RHSExt=*/{ExtKind::SExt});
-  if (AllowExtMask & ExtKind::FPExt && RHS.SupportsFPExt)
-    return CombineResult(NodeExtensionHelper::getSameExtensionOpcode(
-                             Root->getOpcode(), ExtKind::FPExt),
+  if ((AllowExtMask & ExtKind::FPExt) && RHS.SupportsFPExt)
+    return CombineResult(NodeExtensionHelper::getFPExtOpcode(Root->getOpcode()),
                          Root, LHS, /*LHSExt=*/{ExtKind::FPExt}, RHS,
                          /*RHSExt=*/{ExtKind::FPExt});
   return std::nullopt;