reapply r75408, which eliminates MOV64r0 in favor of using
MOV32r0 + subregs to do the same thing. This should work now
that PR4544 is fixed. Thanks Evan!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75671 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp
index 296a4d3..fcc2c24 100644
--- a/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -1604,7 +1604,7 @@
break;
case MVT::i64:
LoReg = X86::RAX; HiReg = X86::RDX;
- ClrOpcode = X86::MOV64r0;
+ ClrOpcode = ~0U; // NOT USED.
SExtOpcode = X86::CQO;
break;
}
@@ -1643,8 +1643,26 @@
SDValue(CurDAG->getTargetNode(SExtOpcode, dl, MVT::Flag, InFlag),0);
} else {
// Zero out the high part, effectively zero extending the input.
- SDValue ClrNode = SDValue(CurDAG->getTargetNode(ClrOpcode, dl, NVT),
- 0);
+ SDValue ClrNode;
+
+ if (NVT.getSimpleVT() == MVT::i64) {
+ ClrNode = SDValue(CurDAG->getTargetNode(X86::MOV32r0, dl, MVT::i32),
+ 0);
+ // We just did a 32-bit clear, insert it into a 64-bit register to
+ // clear the whole 64-bit reg.
+ SDValue Undef =
+ SDValue(CurDAG->getTargetNode(TargetInstrInfo::IMPLICIT_DEF,
+ dl, MVT::i64), 0);
+ SDValue SubRegNo =
+ CurDAG->getTargetConstant(X86::SUBREG_32BIT, MVT::i32);
+ ClrNode =
+ SDValue(CurDAG->getTargetNode(TargetInstrInfo::INSERT_SUBREG, dl,
+ MVT::i64, Undef, ClrNode, SubRegNo),
+ 0);
+ } else {
+ ClrNode = SDValue(CurDAG->getTargetNode(ClrOpcode, dl, NVT), 0);
+ }
+
InFlag = CurDAG->getCopyToReg(CurDAG->getEntryNode(), dl, HiReg,
ClrNode, InFlag).getValue(1);
}