diff options
| -rw-r--r-- | lib/Target/X86/X86ISelDAGToDAG.cpp | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp index 9caf1842eb..4bc604b6e4 100644 --- a/lib/Target/X86/X86ISelDAGToDAG.cpp +++ b/lib/Target/X86/X86ISelDAGToDAG.cpp @@ -41,6 +41,9 @@ #include "llvm/ADT/Statistic.h" using namespace llvm; +#include "llvm/Support/CommandLine.h" +static cl::opt<bool> AvoidDupAddrCompute("x86-avoid-dup-address", cl::Hidden); + STATISTIC(NumLoadMoved, "Number of loads moved below TokenFactor"); //===----------------------------------------------------------------------===// @@ -1035,7 +1038,28 @@ bool X86DAGToDAGISel::SelectAddr(SDValue Op, SDValue N, SDValue &Base, SDValue &Scale, SDValue &Index, SDValue &Disp) { X86ISelAddressMode AM; - if (MatchAddress(N, AM)) + bool Done = false; + if (AvoidDupAddrCompute && !N.hasOneUse()) { + unsigned Opcode = N.getOpcode(); + if (Opcode != ISD::Constant && Opcode != ISD::FrameIndex && + Opcode != X86ISD::Wrapper) { + // If we are able to fold N into addressing mode, then we'll allow it even + // if N has multiple uses. In general, addressing computation is used as + // addresses by all of its uses. But watch out for CopyToReg uses, that + // means the address computation is liveout. It will be computed by a LEA + // so we want to avoid computing the address twice. + for (SDNode::use_iterator UI = N.getNode()->use_begin(), + UE = N.getNode()->use_end(); UI != UE; ++UI) { + if (UI->getOpcode() == ISD::CopyToReg) { + MatchAddressBase(N, AM, true, 0); + Done = true; + break; + } + } + } + } + + if (!Done && MatchAddress(N, AM)) return false; MVT VT = N.getValueType(); |