Remove the hack that turned an {S,U}MUL_LOHI with an unused high

result into a MUL late in the X86 codegen process. ISD::MUL is
once again Legal on X86, so this is no longer needed. And, the
hack was suboptimal; see PR1874 for details.

llvm-svn: 47567

1 files changed, 0 insertions, 9 deletions

diff --git a/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp b/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
index c8b341406ca..75e9faecb29 100644
--- a/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -1224,15 +1224,6 @@ SDNode *X86DAGToDAGISel::Select(SDOperand N) {
       SDOperand N0 = Node->getOperand(0);
       SDOperand N1 = Node->getOperand(1);
 
-      // There are several forms of IMUL that just return the low part and
-      // don't have fixed-register operands. If we don't need the high part,
-      // use these instead. They can be selected with the generated ISel code.
-      if (NVT != MVT::i8 &&
-          N.getValue(1).use_empty()) {
-        N = CurDAG->getNode(ISD::MUL, NVT, N0, N1);
-        break;
-      }
-
       bool isSigned = Opcode == ISD::SMUL_LOHI;
       if (!isSigned)
         switch (NVT) {