[MIPS GlobalISel] Select G_UMULH

Legalize G_UMULO and select G_UMULH for MIPS32.

Differential Revision: https://reviews.llvm.org/D58714

llvm-svn: 355177

3 files changed, 25 insertions, 1 deletions

diff --git a/llvm/lib/Target/Mips/MipsInstructionSelector.cpp b/llvm/lib/Target/Mips/MipsInstructionSelector.cpp
index c97fac9d21b..92a62b5186b 100644
--- a/llvm/lib/Target/Mips/MipsInstructionSelector.cpp
+++ b/llvm/lib/Target/Mips/MipsInstructionSelector.cpp
@@ -139,6 +139,26 @@ bool MipsInstructionSelector::select(MachineInstr &I,
   using namespace TargetOpcode;
 
   switch (I.getOpcode()) {
+  case G_UMULH: {
+    unsigned PseudoMULTuReg = MRI.createVirtualRegister(&Mips::ACC64RegClass);
+    MachineInstr *PseudoMULTu, *PseudoMove;
+
+    PseudoMULTu = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::PseudoMULTu))
+                      .addDef(PseudoMULTuReg)
+                      .add(I.getOperand(1))
+                      .add(I.getOperand(2));
+    if (!constrainSelectedInstRegOperands(*PseudoMULTu, TII, TRI, RBI))
+      return false;
+
+    PseudoMove = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::PseudoMFHI))
+                     .addDef(I.getOperand(0).getReg())
+                     .addUse(PseudoMULTuReg);
+    if (!constrainSelectedInstRegOperands(*PseudoMove, TII, TRI, RBI))
+      return false;
+
+    I.eraseFromParent();
+    return true;
+  }
   case G_GEP: {
     MI = BuildMI(MBB, I, I.getDebugLoc(), TII.get(Mips::ADDu))
              .add(I.getOperand(0))
diff --git a/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp b/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp
index dd87d01777e..1da43b0b6df 100644
--- a/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp
+++ b/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp
@@ -32,9 +32,12 @@ MipsLegalizerInfo::MipsLegalizerInfo(const MipsSubtarget &ST) {
       .legalFor({s32})
       .minScalar(0, s32);
 
-  getActionDefinitionsBuilder({G_UADDO, G_UADDE, G_USUBO, G_USUBE})
+  getActionDefinitionsBuilder({G_UADDO, G_UADDE, G_USUBO, G_USUBE, G_UMULO})
       .lowerFor({{s32, s1}});
 
+  getActionDefinitionsBuilder(G_UMULH)
+      .legalFor({s32});
+
   getActionDefinitionsBuilder({G_LOAD, G_STORE})
       .legalForTypesWithMemDesc({{s32, p0, 8, 8},
                                  {s32, p0, 16, 8},
diff --git a/llvm/lib/Target/Mips/MipsRegisterBankInfo.cpp b/llvm/lib/Target/Mips/MipsRegisterBankInfo.cpp
index c463ca11ea5..214dd106869 100644
--- a/llvm/lib/Target/Mips/MipsRegisterBankInfo.cpp
+++ b/llvm/lib/Target/Mips/MipsRegisterBankInfo.cpp
@@ -86,6 +86,7 @@ MipsRegisterBankInfo::getInstrMapping(const MachineInstr &MI) const {
   case G_ADD:
   case G_SUB:
   case G_MUL:
+  case G_UMULH:
   case G_LOAD:
   case G_STORE:
   case G_ZEXTLOAD: