[MIPS GlobalISel] Lower G_UADDE and narrowScalar G_ADD

Lower G_UADDE and legalize G_ADD using narrowScalar on MIPS32.

Differential Revision: https://reviews.llvm.org/D54580

llvm-svn: 349346

1 files changed, 18 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 890ef52dd3d..4492175d11e 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -1119,6 +1119,24 @@ LegalizerHelper::lower(MachineInstr &MI, unsigned TypeIdx, LLT Ty) {
   case TargetOpcode::G_CTTZ:
   case TargetOpcode::G_CTPOP:
     return lowerBitCount(MI, TypeIdx, Ty);
+  case G_UADDE: {
+    unsigned Res = MI.getOperand(0).getReg();
+    unsigned CarryOut = MI.getOperand(1).getReg();
+    unsigned LHS = MI.getOperand(2).getReg();
+    unsigned RHS = MI.getOperand(3).getReg();
+    unsigned CarryIn = MI.getOperand(4).getReg();
+
+    unsigned TmpRes = MRI.createGenericVirtualRegister(Ty);
+    unsigned ZExtCarryIn = MRI.createGenericVirtualRegister(Ty);
+
+    MIRBuilder.buildAdd(TmpRes, LHS, RHS);
+    MIRBuilder.buildZExt(ZExtCarryIn, CarryIn);
+    MIRBuilder.buildAdd(Res, TmpRes, ZExtCarryIn);
+    MIRBuilder.buildICmp(CmpInst::ICMP_ULT, CarryOut, Res, LHS);
+
+    MI.eraseFromParent();
+    return Legalized;
+  }
   }
 }