hoist check for IsTailCall to callers. Eliminate redundant check for

x86-64: GOT-style PIC is never used on x86-64.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75090 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2009-07-09 02:46:53 +00:00
parent 951bf7d74f
commit e3ee6f1e1f

View File

@ -1321,22 +1321,18 @@ X86TargetLowering::NameDecorationForFORMAL_ARGUMENTS(SDValue Op) {
/// CallRequiresGOTInRegister - Check whether the call requires the GOT pointer
/// in a register before calling.
static bool CallRequiresGOTPtrInReg(const TargetMachine &TM,
bool IsTailCall) {
static bool CallRequiresGOTPtrInReg(const TargetMachine &TM) {
const X86Subtarget &Subtarget = TM.getSubtarget<X86Subtarget>();
return !IsTailCall && !Subtarget.is64Bit() &&
TM.getRelocationModel() == Reloc::PIC_ &&
return TM.getRelocationModel() == Reloc::PIC_ &&
Subtarget.isPICStyleGOT();
}
/// CallRequiresFnAddressInReg - Check whether the call requires the function
/// address to be loaded in a register.
static bool CallRequiresFnAddressInReg(const TargetMachine &TM,
bool IsTailCall) {
static bool CallRequiresFnAddressInReg(const TargetMachine &TM) {
const X86Subtarget &Subtarget = TM.getSubtarget<X86Subtarget>();
return !Subtarget.is64Bit() && IsTailCall &&
TM.getRelocationModel() == Reloc::PIC_ &&
return TM.getRelocationModel() == Reloc::PIC_ &&
Subtarget.isPICStyleGOT();
}
@ -1808,7 +1804,7 @@ SDValue X86TargetLowering::LowerCALL(SDValue Op, SelectionDAG &DAG) {
// ELF / PIC requires GOT in the EBX register before function calls via PLT
// GOT pointer.
if (CallRequiresGOTPtrInReg(getTargetMachine(), IsTailCall)) {
if (!IsTailCall && CallRequiresGOTPtrInReg(getTargetMachine())) {
Chain = DAG.getCopyToReg(Chain, dl, X86::EBX,
DAG.getNode(X86ISD::GlobalBaseReg,
DebugLoc::getUnknownLoc(),
@ -1823,7 +1819,7 @@ SDValue X86TargetLowering::LowerCALL(SDValue Op, SelectionDAG &DAG) {
// calls on PIC/GOT architectures. Normally we would just put the address of
// GOT into ebx and then call target@PLT. But for tail calls ebx would be
// restored (since ebx is callee saved) before jumping to the target@PLT.
if (CallRequiresFnAddressInReg(getTargetMachine(), IsTailCall)) {
if (IsTailCall && CallRequiresFnAddressInReg(getTargetMachine())) {
// Note: The actual moving to ecx is done further down.
GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee);
if (G && !G->getGlobal()->hasHiddenVisibility() &&