Index: llvm/include/llvm/Target/GlobalISel/Combine.td
===================================================================
--- llvm/include/llvm/Target/GlobalISel/Combine.td
+++ llvm/include/llvm/Target/GlobalISel/Combine.td
@@ -416,10 +416,11 @@
 
 // Fold ptr2int(int2ptr(x)) -> x
 def i2p_to_p2i: GICombineRule<
-  (defs root:$root, register_matchinfo:$info),
-  (match (wip_match_opcode G_PTRTOINT):$root,
-    [{ return Helper.matchCombineP2IToI2P(*${root}, ${info}); }]),
-  (apply [{ Helper.applyCombineP2IToI2P(*${root}, ${info}); }])
+  (defs root:$dst, register_matchinfo:$info),
+  (match (G_INTTOPTR $t, $ptr),
+         (G_PTRTOINT $dst, $t):$mi,
+    [{ ${info} = ${ptr}.getReg(); }]),
+  (apply [{ Helper.applyCombineP2IToI2P(*${mi}, ${info}); }])
 >;
 
 // Fold add ptrtoint(x), y -> ptrtoint (ptr_add x), y
@@ -529,10 +530,11 @@
 
 // Fold (fneg (fneg x)) -> x.
 def fneg_fneg_fold: GICombineRule <
-  (defs root:$root, register_matchinfo:$matchinfo),
-  (match (wip_match_opcode G_FNEG):$root,
-         [{ return Helper.matchCombineFNegOfFNeg(*${root}, ${matchinfo}); }]),
-  (apply [{ return Helper.replaceSingleDefInstWithReg(*${root}, ${matchinfo}); }])
+  (defs root:$dst, register_matchinfo:$matchinfo),
+  (match (G_FNEG $t, $src),
+         (G_FNEG $dst, $t):$mi,
+         [{ ${matchinfo} = ${src}.getReg(); }]),
+  (apply [{ return Helper.replaceSingleDefInstWithReg(*${mi}, ${matchinfo}); }])
 >;
 
 // Fold (unmerge(merge x, y, z)) -> z, y, z.
@@ -554,10 +556,11 @@
 
 // Fold (fabs (fabs x)) -> (fabs x).
 def fabs_fabs_fold: GICombineRule<
-  (defs root:$root, register_matchinfo:$matchinfo),
-  (match (wip_match_opcode G_FABS):$root,
-         [{ return Helper.matchCombineFAbsOfFAbs(*${root}, ${matchinfo}); }]),
-  (apply [{ return Helper.replaceSingleDefInstWithReg(*${root}, ${matchinfo}); }])
+  (defs root:$dst, register_matchinfo:$matchinfo),
+  (match (G_FABS $abs, $src),
+         (G_FABS $dst, $abs):$mi,
+         [{ ${matchinfo} = ${abs}.getReg(); }]),
+  (apply [{ return Helper.replaceSingleDefInstWithReg(*${mi}, ${matchinfo}); }])
 >;
 
 // Fold (fabs (fneg x)) -> (fabs x).
Index: llvm/utils/TableGen/GlobalISel/CodeExpansions.h
===================================================================
--- llvm/utils/TableGen/GlobalISel/CodeExpansions.h
+++ llvm/utils/TableGen/GlobalISel/CodeExpansions.h
@@ -24,9 +24,9 @@
 
 public:
   void declare(StringRef Name, StringRef Expansion) {
-    bool Inserted = Expansions.try_emplace(Name, Expansion).second;
-    assert(Inserted && "Declared variable twice");
-    (void)Inserted;
+    // Duplicates are not inserted. The expansion refers to different operands
+    // but to the same virtual register.
+    Expansions.try_emplace(Name, Expansion);
   }
 
   std::string lookup(StringRef Variable) const {
Index: llvm/utils/TableGen/GlobalISel/GIMatchTree.cpp
===================================================================
--- llvm/utils/TableGen/GlobalISel/GIMatchTree.cpp
+++ llvm/utils/TableGen/GlobalISel/GIMatchTree.cpp
@@ -762,17 +762,18 @@
 
 void GIMatchTreeVRegDefPartitioner::generatePartitionSelectorCode(
     raw_ostream &OS, StringRef Indent) const {
-  OS << Indent << "Partition = -1\n"
-     << Indent << "if (MIs.size() <= NewInstrID) MIs.resize(NewInstrID + 1);\n"
+  OS << Indent << "Partition = -1;\n"
+     << Indent << "if (MIs.size() <= " << NewInstrID << ") MIs.resize("
+     << (NewInstrID + 1) << ");\n"
      << Indent << "MIs[" << NewInstrID << "] = nullptr;\n"
-     << Indent << "if (MIs[" << InstrID << "].getOperand(" << OpIdx
-     << ").isReg()))\n"
+     << Indent << "if (MIs[" << InstrID << "]->getOperand(" << OpIdx
+     << ").isReg())\n"
      << Indent << "  MIs[" << NewInstrID << "] = MRI.getVRegDef(MIs[" << InstrID
-     << "].getOperand(" << OpIdx << ").getReg()));\n";
+     << "]->getOperand(" << OpIdx << ").getReg());\n";
 
   for (const auto &Pair : ResultToPartition)
     OS << Indent << "if (MIs[" << NewInstrID << "] "
-       << (Pair.first ? "==" : "!=")
+       << (Pair.first ? "!=" : "==")
        << " nullptr) Partition = " << Pair.second << ";\n";
 
   OS << Indent << "if (Partition == -1) return false;\n";