diff options
Diffstat (limited to 'llvm/lib/Target/X86')
| -rw-r--r-- | llvm/lib/Target/X86/README.txt | 18 | ||||
| -rw-r--r-- | llvm/lib/Target/X86/X86FrameInfo.cpp | 15 | ||||
| -rw-r--r-- | llvm/lib/Target/X86/X86ISelLowering.cpp | 41 | ||||
| -rw-r--r-- | llvm/lib/Target/X86/X86ISelLowering.h | 2 |
4 files changed, 43 insertions, 33 deletions
diff --git a/llvm/lib/Target/X86/README.txt b/llvm/lib/Target/X86/README.txt index e67fab10904..a305ae6ec55 100644 --- a/llvm/lib/Target/X86/README.txt +++ b/llvm/lib/Target/X86/README.txt @@ -895,24 +895,6 @@ compare: //===---------------------------------------------------------------------===// -Linux is missing some basic tail call support: - -#include <math.h> -double foo(double a) { return sin(a); } - -This compiles into this on x86-64 Linux (but not darwin): -foo: - subq $8, %rsp - call sin - addq $8, %rsp - ret -vs: - -foo: - jmp sin - -//===---------------------------------------------------------------------===// - Tail call optimization improvements: Tail call optimization currently pushes all arguments on the top of the stack (their normal place for non-tail call optimized calls) that source from the callers arguments diff --git a/llvm/lib/Target/X86/X86FrameInfo.cpp b/llvm/lib/Target/X86/X86FrameInfo.cpp index 494e9050282..c47b0fa6970 100644 --- a/llvm/lib/Target/X86/X86FrameInfo.cpp +++ b/llvm/lib/Target/X86/X86FrameInfo.cpp @@ -712,10 +712,17 @@ void X86FrameInfo::emitEpilogue(MachineFunction &MF, // Jump to label or value in register. if (RetOpcode == X86::TCRETURNdi || RetOpcode == X86::TCRETURNdi64) { - BuildMI(MBB, MBBI, DL, TII.get((RetOpcode == X86::TCRETURNdi) - ? X86::TAILJMPd : X86::TAILJMPd64)). - addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset(), - JumpTarget.getTargetFlags()); + MachineInstrBuilder MIB = + BuildMI(MBB, MBBI, DL, TII.get((RetOpcode == X86::TCRETURNdi) + ? X86::TAILJMPd : X86::TAILJMPd64)); + if (JumpTarget.isGlobal()) + MIB.addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset(), + JumpTarget.getTargetFlags()); + else { + assert(JumpTarget.isSymbol()); + MIB.addExternalSymbol(JumpTarget.getSymbolName(), + JumpTarget.getTargetFlags()); + } } else if (RetOpcode == X86::TCRETURNmi || RetOpcode == X86::TCRETURNmi64) { MachineInstrBuilder MIB = BuildMI(MBB, MBBI, DL, TII.get((RetOpcode == X86::TCRETURNmi) diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp index 6d6d83d5578..bc6d84eeec1 100644 --- a/llvm/lib/Target/X86/X86ISelLowering.cpp +++ b/llvm/lib/Target/X86/X86ISelLowering.cpp @@ -1338,6 +1338,23 @@ X86TargetLowering::LowerReturn(SDValue Chain, MVT::Other, &RetOps[0], RetOps.size()); } +bool X86TargetLowering::isUsedByReturnOnly(SDNode *N) const { + if (N->getNumValues() != 1) + return false; + if (!N->hasNUsesOfValue(1, 0)) + return false; + + SDNode *Copy = *N->use_begin(); + if (Copy->getOpcode() != ISD::CopyToReg) + return false; + for (SDNode::use_iterator UI = Copy->use_begin(), UE = Copy->use_end(); + UI != UE; ++UI) + if (UI->getOpcode() != X86ISD::RET_FLAG) + return false; + + return true; +} + /// LowerCallResult - Lower the result values of a call into the /// appropriate copies out of appropriate physical registers. /// @@ -2142,17 +2159,19 @@ X86TargetLowering::LowerCall(SDValue Chain, SDValue Callee, } else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) { unsigned char OpFlags = 0; - // On ELF targets, in either X86-64 or X86-32 mode, direct calls to external - // symbols should go through the PLT. - if (Subtarget->isTargetELF() && - getTargetMachine().getRelocationModel() == Reloc::PIC_) { - OpFlags = X86II::MO_PLT; - } else if (Subtarget->isPICStyleStubAny() && - Subtarget->getDarwinVers() < 9) { - // PC-relative references to external symbols should go through $stub, - // unless we're building with the leopard linker or later, which - // automatically synthesizes these stubs. - OpFlags = X86II::MO_DARWIN_STUB; + if (!isTailCall) { + // On ELF targets, in either X86-64 or X86-32 mode, direct calls to + // external symbols should go through the PLT. + if (Subtarget->isTargetELF() && + getTargetMachine().getRelocationModel() == Reloc::PIC_) { + OpFlags = X86II::MO_PLT; + } else if (Subtarget->isPICStyleStubAny() && + Subtarget->getDarwinVers() < 9) { + // PC-relative references to external symbols should go through $stub, + // unless we're building with the leopard linker or later, which + // automatically synthesizes these stubs. + OpFlags = X86II::MO_DARWIN_STUB; + } } Callee = DAG.getTargetExternalSymbol(S->getSymbol(), getPointerTy(), diff --git a/llvm/lib/Target/X86/X86ISelLowering.h b/llvm/lib/Target/X86/X86ISelLowering.h index b5217020136..edcdceb39a5 100644 --- a/llvm/lib/Target/X86/X86ISelLowering.h +++ b/llvm/lib/Target/X86/X86ISelLowering.h @@ -805,6 +805,8 @@ namespace llvm { const SmallVectorImpl<SDValue> &OutVals, DebugLoc dl, SelectionDAG &DAG) const; + virtual bool isUsedByReturnOnly(SDNode *N) const; + virtual bool CanLowerReturn(CallingConv::ID CallConv, bool isVarArg, const SmallVectorImpl<ISD::OutputArg> &Outs, |
