Index: llvm/lib/Target/PowerPC/PPCISelLowering.h
===================================================================
--- llvm/lib/Target/PowerPC/PPCISelLowering.h
+++ llvm/lib/Target/PowerPC/PPCISelLowering.h
@@ -1103,7 +1103,6 @@
     SDValue LowerEXTRACT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) const;
     SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG) const;
     SDValue LowerINTRINSIC_VOID(SDValue Op, SelectionDAG &DAG) const;
-    SDValue LowerREM(SDValue Op, SelectionDAG &DAG) const;
     SDValue LowerBSWAP(SDValue Op, SelectionDAG &DAG) const;
     SDValue LowerATOMIC_CMP_SWAP(SDValue Op, SelectionDAG &DAG) const;
     SDValue LowerSCALAR_TO_VECTOR(SDValue Op, SelectionDAG &DAG) const;
Index: llvm/lib/Target/PowerPC/PPCISelLowering.cpp
===================================================================
--- llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -260,15 +260,16 @@
 
   // PowerPC has no SREM/UREM instructions unless we are on P9
   // On P9 we may use a hardware instruction to compute the remainder.
-  // The instructions are not legalized directly because in the cases where the
-  // result of both the remainder and the division is required it is more
-  // efficient to compute the remainder from the result of the division rather
-  // than use the remainder instruction.
+  // When the result of both the remainder and the division is required it is
+  // more efficient to compute the remainder from the result of the division
+  // rather than use the remainder instruction. The instructions are legalized
+  // directly because the DivRemPairsPass performs the transformation at the IR
+  // level.
   if (Subtarget.isISA3_0()) {
-    setOperationAction(ISD::SREM, MVT::i32, Custom);
-    setOperationAction(ISD::UREM, MVT::i32, Custom);
-    setOperationAction(ISD::SREM, MVT::i64, Custom);
-    setOperationAction(ISD::UREM, MVT::i64, Custom);
+    setOperationAction(ISD::SREM, MVT::i32, Legal);
+    setOperationAction(ISD::UREM, MVT::i32, Legal);
+    setOperationAction(ISD::SREM, MVT::i64, Legal);
+    setOperationAction(ISD::UREM, MVT::i64, Legal);
   } else {
     setOperationAction(ISD::SREM, MVT::i32, Expand);
     setOperationAction(ISD::UREM, MVT::i32, Expand);
@@ -10370,18 +10371,6 @@
   return SDValue();
 }
 
-SDValue PPCTargetLowering::LowerREM(SDValue Op, SelectionDAG &DAG) const {
-  // Check for a DIV with the same operands as this REM.
-  for (auto UI : Op.getOperand(1)->uses()) {
-    if ((Op.getOpcode() == ISD::SREM && UI->getOpcode() == ISD::SDIV) ||
-        (Op.getOpcode() == ISD::UREM && UI->getOpcode() == ISD::UDIV))
-      if (UI->getOperand(0) == Op.getOperand(0) &&
-          UI->getOperand(1) == Op.getOperand(1))
-        return SDValue();
-  }
-  return Op;
-}
-
 // Lower scalar BSWAP64 to xxbrd.
 SDValue PPCTargetLowering::LowerBSWAP(SDValue Op, SelectionDAG &DAG) const {
   SDLoc dl(Op);
@@ -10999,9 +10988,6 @@
 
   case ISD::INTRINSIC_VOID:
     return LowerINTRINSIC_VOID(Op, DAG);
-  case ISD::SREM:
-  case ISD::UREM:
-    return LowerREM(Op, DAG);
   case ISD::BSWAP:
     return LowerBSWAP(Op, DAG);
   case ISD::ATOMIC_CMP_SWAP:
Index: llvm/test/CodeGen/PowerPC/ppc64-P9-mod.ll
===================================================================
--- llvm/test/CodeGen/PowerPC/ppc64-P9-mod.ll
+++ llvm/test/CodeGen/PowerPC/ppc64-P9-mod.ll
@@ -1,6 +1,9 @@
-; RUN: llc < %s -mtriple=powerpc64le-unknown-linux-gnu -mcpu=pwr9 -verify-machineinstrs | FileCheck %s
-; RUN: llc < %s -mtriple=powerpc64-unknown-linux-gnu -mcpu=pwr9 -verify-machineinstrs | FileCheck %s
-; RUN: llc < %s -mtriple=powerpc64le-unknown-linux-gnu -mcpu=pwr8 | FileCheck %s -check-prefix=CHECK-PWR8 -implicit-check-not mod[us][wd]
+; RUN: opt < %s -div-rem-pairs -mtriple=powerpc64le-unknown-linux-gnu -mcpu=pwr9 | \
+; RUN:   llc -verify-machineinstrs | FileCheck %s
+; RUN: opt < %s -div-rem-pairs -mtriple=powerpc64-unknown-linux-gnu -mcpu=pwr9 | \
+; RUN:   llc -verify-machineinstrs | FileCheck %s
+; RUN: opt < %s -div-rem-pairs -mtriple=powerpc64le-unknown-linux-gnu -mcpu=pwr8 | \
+; RUN:   llc -verify-machineinstrs | FileCheck %s -check-prefix=CHECK-PWR8 -implicit-check-not mod[us][wd]
 
 @mod_resultsw = local_unnamed_addr global i32 0, align 4
 @mod_resultud = local_unnamed_addr global i64 0, align 8
@@ -232,9 +235,6 @@
 }
 
 ; Function Attrs: norecurse nounwind
-; FIXME On power 9 this test will still produce modsw because the divide is in
-; a different block than the remainder. Due to the nature of the SDAG we cannot
-; see the div in the other block.
 define void @blocks_modulo_div_sw(i32 signext %a, i32 signext %b, i32 signext %c) local_unnamed_addr {
 entry:
   %div = sdiv i32 %a, %b
@@ -250,8 +250,12 @@
 if.end:                                           ; preds = %if.then, %entry
   ret void
 ; CHECK-LABEL: blocks_modulo_div_sw
+; CHECK-NOT: modsw
 ; CHECK: div
-; CHECK: modsw {{[0-9]+}}, 3, 4
+; CHECK-NOT: modsw
+; CHECK: mull
+; CHECK-NOT: modsw
+; CHECK: sub
 ; CHECK: blr
 ; CHECK-PWR8-LABEL: blocks_modulo_div_sw
 ; CHECK-PWR8: div
@@ -260,4 +264,3 @@
 ; CHECK-PWR8: blr
 }
 
-