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authorEvan Cheng <evan.cheng@apple.com>2007-02-21 21:18:14 +0000
committerEvan Cheng <evan.cheng@apple.com>2007-02-21 21:18:14 +0000
commitf46847172afea92d73829147a6d9d18cde45ffd7 (patch)
tree21889ac1f10db24222e8751dacfb426633c71393
parent07d49acbf93709381430560f86e279a0af724462 (diff)
ELF / PIC requires GOT be in the EBX register during calls via PLT GOT pointer.
Add implicit uses of EBX to calls to ensure liveintervalanalysis does not treat the GOT in EBX move as dead upon definition. This should fix PR1207. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34470 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r--lib/Target/X86/X86ISelLowering.cpp14
1 files changed, 14 insertions, 0 deletions
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 49f5cde9bc..839eb8a8ab 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -794,6 +794,8 @@ SDOperand X86TargetLowering::LowerCCCCallTo(SDOperand Op, SelectionDAG &DAG,
InFlag = Chain.getValue(1);
}
+ // ELF / PIC requires GOT in the EBX register before function calls via PLT
+ // GOT pointer.
if (getTargetMachine().getRelocationModel() == Reloc::PIC_ &&
Subtarget->isPICStyleGOT()) {
Chain = DAG.getCopyToReg(Chain, X86::EBX,
@@ -825,6 +827,11 @@ SDOperand X86TargetLowering::LowerCCCCallTo(SDOperand Op, SelectionDAG &DAG,
for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i)
Ops.push_back(DAG.getRegister(RegsToPass[i].first,
RegsToPass[i].second.getValueType()));
+
+ // Add an implicit use GOT pointer in EBX.
+ if (getTargetMachine().getRelocationModel() == Reloc::PIC_ &&
+ Subtarget->isPICStyleGOT())
+ Ops.push_back(DAG.getRegister(X86::EBX, getPointerTy()));
if (InFlag.Val)
Ops.push_back(InFlag);
@@ -1788,6 +1795,8 @@ SDOperand X86TargetLowering::LowerFastCCCallTo(SDOperand Op, SelectionDAG &DAG,
} else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee))
Callee = DAG.getTargetExternalSymbol(S->getSymbol(), getPointerTy());
+ // ELF / PIC requires GOT in the EBX register before function calls via PLT
+ // GOT pointer.
if (getTargetMachine().getRelocationModel() == Reloc::PIC_ &&
Subtarget->isPICStyleGOT()) {
Chain = DAG.getCopyToReg(Chain, X86::EBX,
@@ -1809,6 +1818,11 @@ SDOperand X86TargetLowering::LowerFastCCCallTo(SDOperand Op, SelectionDAG &DAG,
Ops.push_back(DAG.getRegister(RegsToPass[i].first,
RegsToPass[i].second.getValueType()));
+ // Add an implicit use GOT pointer in EBX.
+ if (getTargetMachine().getRelocationModel() == Reloc::PIC_ &&
+ Subtarget->isPICStyleGOT())
+ Ops.push_back(DAG.getRegister(X86::EBX, getPointerTy()));
+
if (InFlag.Val)
Ops.push_back(InFlag);