[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, 5 insertions, 30 deletions

diff --git a/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp b/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp
index 02e787f77ab..08e5ddd0342 100644
--- a/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp
+++ b/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp
@@ -20,14 +20,16 @@ using namespace llvm;
 MipsLegalizerInfo::MipsLegalizerInfo(const MipsSubtarget &ST) {
   using namespace TargetOpcode;
 
+  const LLT s1 = LLT::scalar(1);
   const LLT s32 = LLT::scalar(32);
-  const LLT s64 = LLT::scalar(64);
   const LLT p0 = LLT::pointer(0, 32);
 
   getActionDefinitionsBuilder(G_ADD)
       .legalFor({s32})
-      .minScalar(0, s32)
-      .customFor({s64});
+      .clampScalar(0, s32, s32);
+
+  getActionDefinitionsBuilder(G_UADDE)
+      .lowerFor({{s32, s1}});
 
   getActionDefinitionsBuilder({G_LOAD, G_STORE})
       .legalForCartesianProduct({p0, s32}, {p0});
@@ -66,33 +68,6 @@ bool MipsLegalizerInfo::legalizeCustom(MachineInstr &MI,
   MIRBuilder.setInstr(MI);
 
   switch (MI.getOpcode()) {
-  case G_ADD: {
-    unsigned Size = MRI.getType(MI.getOperand(0).getReg()).getSizeInBits();
-
-    const LLT sHalf = LLT::scalar(Size / 2);
-
-    unsigned RHSLow = MRI.createGenericVirtualRegister(sHalf);
-    unsigned RHSHigh = MRI.createGenericVirtualRegister(sHalf);
-    unsigned LHSLow = MRI.createGenericVirtualRegister(sHalf);
-    unsigned LHSHigh = MRI.createGenericVirtualRegister(sHalf);
-    unsigned ResLow = MRI.createGenericVirtualRegister(sHalf);
-    unsigned ResHigh = MRI.createGenericVirtualRegister(sHalf);
-    unsigned Carry = MRI.createGenericVirtualRegister(sHalf);
-    unsigned TmpResHigh = MRI.createGenericVirtualRegister(sHalf);
-
-    MIRBuilder.buildUnmerge({RHSLow, RHSHigh}, MI.getOperand(2).getReg());
-    MIRBuilder.buildUnmerge({LHSLow, LHSHigh}, MI.getOperand(1).getReg());
-
-    MIRBuilder.buildAdd(TmpResHigh, LHSHigh, RHSHigh);
-    MIRBuilder.buildAdd(ResLow, LHSLow, RHSLow);
-    MIRBuilder.buildICmp(CmpInst::ICMP_ULT, Carry, ResLow, LHSLow);
-    MIRBuilder.buildAdd(ResHigh, TmpResHigh, Carry);
-
-    MIRBuilder.buildMerge(MI.getOperand(0).getReg(), {ResLow, ResHigh});
-
-    MI.eraseFromParent();
-    break;
-  }
   default:
     return false;
   }