diff --git a/llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h b/llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h
--- a/llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h
+++ b/llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h
@@ -784,6 +784,9 @@
   /// Match shifts greater or equal to the bitwidth of the operation.
   bool matchShiftsTooBig(MachineInstr &MI);
 
+  /// Match constant LHS ops that should be commuted.
+  bool matchCommuteConstantToRHS(MachineInstr &MI);
+
 private:
   /// Given a non-indexed load or store instruction \p MI, find an offset that
   /// can be usefully and legally folded into it as a post-indexing operation.
diff --git a/llvm/include/llvm/Target/GlobalISel/Combine.td b/llvm/include/llvm/Target/GlobalISel/Combine.td
--- a/llvm/include/llvm/Target/GlobalISel/Combine.td
+++ b/llvm/include/llvm/Target/GlobalISel/Combine.td
@@ -389,9 +389,8 @@
 // TODO: handle compares (currently not marked as isCommutable)
 def commute_constant_to_rhs : GICombineRule<
   (defs root:$root),
-  (match (wip_match_opcode G_ADD, G_MUL, G_AND, G_OR, G_XOR):$root, [{
-    return getIConstantVRegVal(${root}->getOperand(1).getReg(), MRI).has_value();
-  }]),
+  (match (wip_match_opcode G_ADD, G_MUL, G_AND, G_OR, G_XOR):$root,
+    [{ return Helper.matchCommuteConstantToRHS(*${root}); }]),
   (apply [{
     Observer.changingInstr(*${root});
     Register LHSReg = ${root}->getOperand(1).getReg();
diff --git a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
--- a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
@@ -6013,6 +6013,25 @@
   return matchUnaryPredicate(MRI, ShiftReg, IsShiftTooBig);
 }
 
+bool CombinerHelper::matchCommuteConstantToRHS(MachineInstr &MI) {
+  Register LHS = MI.getOperand(1).getReg();
+  Register RHS = MI.getOperand(2).getReg();
+  auto *LHSDef = MRI.getVRegDef(LHS);
+  if (getIConstantVRegVal(LHS, MRI).has_value())
+    return true;
+
+  // LHS may be a G_CONSTANT_FOLD_BARRIER. If so we commute
+  // as long as we don't already have a constant on the RHS.
+  if (LHSDef->getOpcode() != TargetOpcode::G_CONSTANT_FOLD_BARRIER)
+    return false;
+  auto *RHSDef = MRI.getVRegDef(RHS);
+  if (RHSDef->getOpcode() != TargetOpcode::G_CONSTANT_FOLD_BARRIER &&
+      !getIConstantVRegVal(RHS, MRI).has_value())
+    return true;
+
+  return false;
+}
+
 bool CombinerHelper::tryCombine(MachineInstr &MI) {
   if (tryCombineCopy(MI))
     return true;
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/combine-const-fold-barrier-rhs.mir b/llvm/test/CodeGen/AArch64/GlobalISel/combine-const-fold-barrier-rhs.mir
new file mode 100644
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/combine-const-fold-barrier-rhs.mir
@@ -0,0 +1,82 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 2
+# RUN: llc -mtriple aarch64 -run-pass=aarch64-prelegalizer-combiner -verify-machineinstrs %s -o - | FileCheck %s
+---
+name:            cfb_lhs
+alignment:       4
+tracksRegLiveness: true
+body:             |
+  bb.1:
+    liveins: $w0
+
+    ; CHECK-LABEL: name: cfb_lhs
+    ; CHECK: liveins: $w0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s32) = COPY $w0
+    ; CHECK-NEXT: %cst:_(s32) = G_CONSTANT i32 1
+    ; CHECK-NEXT: %cfb:_(s32) = G_CONSTANT_FOLD_BARRIER %cst
+    ; CHECK-NEXT: %add:_(s32) = G_ADD [[COPY]], %cfb
+    ; CHECK-NEXT: $w0 = COPY %add(s32)
+    ; CHECK-NEXT: RET_ReallyLR
+    %0:_(s32) = COPY $w0
+    %cst:_(s32) = G_CONSTANT i32 1
+    %cfb:_(s32) = G_CONSTANT_FOLD_BARRIER %cst
+    %cst2:_(s32) = G_CONSTANT i32 2
+    %add:_(s32) = G_ADD %cfb, %0
+    $w0 = COPY %add
+    RET_ReallyLR
+
+...
+---
+name:            cfb_lhs_cfb_already_rhs
+alignment:       4
+tracksRegLiveness: true
+body:             |
+  bb.1:
+    liveins: $w0
+
+    ; CHECK-LABEL: name: cfb_lhs_cfb_already_rhs
+    ; CHECK: liveins: $w0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %cst:_(s32) = G_CONSTANT i32 1
+    ; CHECK-NEXT: %cfb:_(s32) = G_CONSTANT_FOLD_BARRIER %cst
+    ; CHECK-NEXT: %cst2:_(s32) = G_CONSTANT i32 2
+    ; CHECK-NEXT: %cfb2:_(s32) = G_CONSTANT_FOLD_BARRIER %cst2
+    ; CHECK-NEXT: %add:_(s32) = G_ADD %cfb, %cfb2
+    ; CHECK-NEXT: $w0 = COPY %add(s32)
+    ; CHECK-NEXT: RET_ReallyLR
+    %0:_(s32) = COPY $w0
+    %cst:_(s32) = G_CONSTANT i32 1
+    %cfb:_(s32) = G_CONSTANT_FOLD_BARRIER %cst
+    %cst2:_(s32) = G_CONSTANT i32 2
+    %cfb2:_(s32) = G_CONSTANT_FOLD_BARRIER %cst2
+    %add:_(s32) = G_ADD %cfb, %cfb2
+    $w0 = COPY %add
+    RET_ReallyLR
+
+...
+---
+name:            cfb_lhs_cst_on_rhs
+alignment:       4
+tracksRegLiveness: true
+body:             |
+  bb.1:
+    liveins: $w0
+
+    ; CHECK-LABEL: name: cfb_lhs_cst_on_rhs
+    ; CHECK: liveins: $w0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %cst:_(s32) = G_CONSTANT i32 1
+    ; CHECK-NEXT: %cfb:_(s32) = G_CONSTANT_FOLD_BARRIER %cst
+    ; CHECK-NEXT: %cst2:_(s32) = G_CONSTANT i32 2
+    ; CHECK-NEXT: %add:_(s32) = G_ADD %cfb, %cst2
+    ; CHECK-NEXT: $w0 = COPY %add(s32)
+    ; CHECK-NEXT: RET_ReallyLR
+    %0:_(s32) = COPY $w0
+    %cst:_(s32) = G_CONSTANT i32 1
+    %cfb:_(s32) = G_CONSTANT_FOLD_BARRIER %cst
+    %cst2:_(s32) = G_CONSTANT i32 2
+    %add:_(s32) = G_ADD %cfb, %cst2
+    $w0 = COPY %add
+    RET_ReallyLR
+
+...