GlobalISel: select G_VASTART on iOS AArch64.
The AAPCS ABI is substantially more complicated so that's coming in a separate
patch. For now we can generate correct code for iOS though.
llvm-svn: 294493
diff --git a/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp b/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp
index 21d80ca..6981194 100644
--- a/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp
+++ b/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp
@@ -14,6 +14,7 @@
#include "AArch64InstructionSelector.h"
#include "AArch64InstrInfo.h"
+#include "AArch64MachineFunctionInfo.h"
#include "AArch64RegisterBankInfo.h"
#include "AArch64RegisterInfo.h"
#include "AArch64Subtarget.h"
@@ -440,6 +441,38 @@
}
}
+bool AArch64InstructionSelector::selectVaStartAAPCS(
+ MachineInstr &I, MachineFunction &MF, MachineRegisterInfo &MRI) const {
+ return false;
+}
+
+bool AArch64InstructionSelector::selectVaStartDarwin(
+ MachineInstr &I, MachineFunction &MF, MachineRegisterInfo &MRI) const {
+ AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
+ unsigned ListReg = I.getOperand(0).getReg();
+
+ unsigned ArgsAddrReg = MRI.createVirtualRegister(&AArch64::GPR64RegClass);
+
+ auto MIB =
+ BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(AArch64::ADDXri))
+ .addDef(ArgsAddrReg)
+ .addFrameIndex(FuncInfo->getVarArgsStackIndex())
+ .addImm(0)
+ .addImm(0);
+
+ constrainSelectedInstRegOperands(*MIB, TII, TRI, RBI);
+
+ MIB = BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(AArch64::STRXui))
+ .addUse(ArgsAddrReg)
+ .addUse(ListReg)
+ .addImm(0)
+ .addMemOperand(*I.memoperands_begin());
+
+ constrainSelectedInstRegOperands(*MIB, TII, TRI, RBI);
+ I.eraseFromParent();
+ return true;
+}
+
bool AArch64InstructionSelector::select(MachineInstr &I) const {
assert(I.getParent() && "Instruction should be in a basic block!");
assert(I.getParent()->getParent() && "Instruction should be in a function!");
@@ -1125,6 +1158,9 @@
I.eraseFromParent();
return true;
}
+ case TargetOpcode::G_VASTART:
+ return STI.isTargetDarwin() ? selectVaStartDarwin(I, MF, MRI)
+ : selectVaStartAAPCS(I, MF, MRI);
}
return false;