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Diffstat (limited to 'lib/Target/X86/X86ISelDAGToDAG.cpp')
-rw-r--r--lib/Target/X86/X86ISelDAGToDAG.cpp65
1 files changed, 40 insertions, 25 deletions
diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp
index b33ced8..117d273 100644
--- a/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -1162,12 +1162,9 @@ SDNode *X86DAGToDAGISel::Select(SDOperand N) {
return NULL;
}
- case ISD::SDIV:
- case ISD::UDIV:
- case ISD::SREM:
- case ISD::UREM: {
- bool isSigned = Opcode == ISD::SDIV || Opcode == ISD::SREM;
- bool isDiv = Opcode == ISD::SDIV || Opcode == ISD::UDIV;
+ case X86ISD::DIV:
+ case X86ISD::IDIV: {
+ bool isSigned = Opcode == X86ISD::IDIV;
if (!isSigned)
switch (NVT) {
default: assert(0 && "Unsupported VT!");
@@ -1275,31 +1272,49 @@ SDNode *X86DAGToDAGISel::Select(SDOperand N) {
SDOperand(CurDAG->getTargetNode(Opc, MVT::Flag, N1, InFlag), 0);
}
- unsigned Reg = isDiv ? LoReg : HiReg;
- SDOperand Result;
- if (Reg == X86::AH && Subtarget->is64Bit()) {
- // Prevent use of AH in a REX instruction by referencing AX instead.
- // Shift it down 8 bits.
- Result = CurDAG->getCopyFromReg(Chain, X86::AX, MVT::i16, InFlag);
- Chain = Result.getValue(1);
- Result = SDOperand(CurDAG->getTargetNode(X86::SHR16ri, MVT::i16, Result,
- CurDAG->getTargetConstant(8, MVT::i8)), 0);
- // Then truncate it down to i8.
- SDOperand SRIdx = CurDAG->getTargetConstant(1, MVT::i32); // SubRegSet 1
- Result = SDOperand(CurDAG->getTargetNode(X86::EXTRACT_SUBREG,
- MVT::i8, Result, SRIdx), 0);
- } else {
- Result = CurDAG->getCopyFromReg(Chain, Reg, NVT, InFlag);
+ // Copy the division (low) result, if it is needed.
+ if (!N.getValue(0).use_empty()) {
+ SDOperand Result = CurDAG->getCopyFromReg(Chain, LoReg, NVT, InFlag);
Chain = Result.getValue(1);
+ InFlag = Result.getValue(2);
+ ReplaceUses(N.getValue(0), Result);
+#ifndef NDEBUG
+ DOUT << std::string(Indent-2, ' ') << "=> ";
+ DEBUG(Result.Val->dump(CurDAG));
+ DOUT << "\n";
+#endif
+ }
+ // Copy the remainder (high) result, if it is needed.
+ if (!N.getValue(1).use_empty()) {
+ SDOperand Result;
+ if (HiReg == X86::AH && Subtarget->is64Bit()) {
+ // Prevent use of AH in a REX instruction by referencing AX instead.
+ // Shift it down 8 bits.
+ Result = CurDAG->getCopyFromReg(Chain, X86::AX, MVT::i16, InFlag);
+ Chain = Result.getValue(1);
+ InFlag = Result.getValue(2);
+ Result = SDOperand(CurDAG->getTargetNode(X86::SHR16ri, MVT::i16, Result,
+ CurDAG->getTargetConstant(8, MVT::i8)), 0);
+ // Then truncate it down to i8.
+ SDOperand SRIdx = CurDAG->getTargetConstant(1, MVT::i32); // SubRegSet 1
+ Result = SDOperand(CurDAG->getTargetNode(X86::EXTRACT_SUBREG,
+ MVT::i8, Result, SRIdx), 0);
+ } else {
+ Result = CurDAG->getCopyFromReg(Chain, HiReg, NVT, InFlag);
+ Chain = Result.getValue(1);
+ InFlag = Result.getValue(2);
+ }
+ ReplaceUses(N.getValue(1), Result);
+#ifndef NDEBUG
+ DOUT << std::string(Indent-2, ' ') << "=> ";
+ DEBUG(Result.Val->dump(CurDAG));
+ DOUT << "\n";
+#endif
}
- ReplaceUses(N.getValue(0), Result);
if (foldedLoad)
ReplaceUses(N1.getValue(1), Chain);
#ifndef NDEBUG
- DOUT << std::string(Indent-2, ' ') << "=> ";
- DEBUG(Result.Val->dump(CurDAG));
- DOUT << "\n";
Indent -= 2;
#endif