[arm-fast-isel] Add support for the llvm.frameaddress() intrinsic.
Patch by Jush Lu <jush.msn@gmail.com>.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157696 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMFastISel.cpp b/lib/Target/ARM/ARMFastISel.cpp
index c13f283..2d2d401 100644
--- a/lib/Target/ARM/ARMFastISel.cpp
+++ b/lib/Target/ARM/ARMFastISel.cpp
@@ -2406,6 +2406,42 @@
// FIXME: Handle more intrinsics.
switch (I.getIntrinsicID()) {
default: return false;
+ case Intrinsic::frameaddress: {
+ MachineFrameInfo *MFI = FuncInfo.MF->getFrameInfo();
+ MFI->setFrameAddressIsTaken(true);
+
+ unsigned LdrOpc;
+ const TargetRegisterClass *RC;
+ if (isThumb2) {
+ LdrOpc = ARM::t2LDRi12;
+ RC = (const TargetRegisterClass*)&ARM::tGPRRegClass;
+ } else {
+ LdrOpc = ARM::LDRi12;
+ RC = (const TargetRegisterClass*)&ARM::GPRRegClass;
+ }
+
+ const ARMBaseRegisterInfo *RegInfo =
+ static_cast<const ARMBaseRegisterInfo*>(TM.getRegisterInfo());
+ unsigned FramePtr = RegInfo->getFrameRegister(*(FuncInfo.MF));
+ unsigned SrcReg = FramePtr;
+
+ // Recursively load frame address
+ // ldr r0 [fp]
+ // ldr r0 [r0]
+ // ldr r0 [r0]
+ // ...
+ unsigned DestReg;
+ unsigned Depth = cast<ConstantInt>(I.getOperand(0))->getZExtValue();
+ while (Depth--) {
+ DestReg = createResultReg(RC);
+ AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
+ TII.get(LdrOpc), DestReg)
+ .addReg(SrcReg).addImm(0));
+ SrcReg = DestReg;
+ }
+ UpdateValueMap(&I, DestReg);
+ return true;
+ }
case Intrinsic::memcpy:
case Intrinsic::memmove: {
const MemTransferInst &MTI = cast<MemTransferInst>(I);