summaryrefslogtreecommitdiffstats
path: root/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'llvm/lib/Target/PowerPC/PPCISelLowering.cpp')
-rw-r--r--llvm/lib/Target/PowerPC/PPCISelLowering.cpp472
1 files changed, 472 insertions, 0 deletions
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
new file mode 100644
index 00000000000..d06542d6b11
--- /dev/null
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -0,0 +1,472 @@
+//===-- PPC32ISelLowering.cpp - PPC32 DAG Lowering Implementation ---------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by Chris Lattner and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the PPC32ISelLowering class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "PPC32ISelLowering.h"
+#include "PPC32TargetMachine.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/SelectionDAG.h"
+#include "llvm/Function.h"
+
+using namespace llvm;
+
+PPC32TargetLowering::PPC32TargetLowering(TargetMachine &TM)
+ : TargetLowering(TM) {
+
+ // Fold away setcc operations if possible.
+ setSetCCIsExpensive();
+
+ // Set up the register classes.
+ addRegisterClass(MVT::i32, PPC32::GPRCRegisterClass);
+ addRegisterClass(MVT::f32, PPC32::FPRCRegisterClass);
+ addRegisterClass(MVT::f64, PPC32::FPRCRegisterClass);
+
+ // PowerPC has no intrinsics for these particular operations
+ setOperationAction(ISD::MEMMOVE, MVT::Other, Expand);
+ setOperationAction(ISD::MEMSET, MVT::Other, Expand);
+ setOperationAction(ISD::MEMCPY, MVT::Other, Expand);
+
+ // PowerPC has an i16 but no i8 (or i1) SEXTLOAD
+ setOperationAction(ISD::SEXTLOAD, MVT::i1, Expand);
+ setOperationAction(ISD::SEXTLOAD, MVT::i8, Expand);
+
+ // PowerPC has no SREM/UREM instructions
+ setOperationAction(ISD::SREM, MVT::i32, Expand);
+ setOperationAction(ISD::UREM, MVT::i32, Expand);
+
+ // We don't support sin/cos/sqrt/fmod
+ setOperationAction(ISD::FSIN , MVT::f64, Expand);
+ setOperationAction(ISD::FCOS , MVT::f64, Expand);
+ setOperationAction(ISD::SREM , MVT::f64, Expand);
+ setOperationAction(ISD::FSIN , MVT::f32, Expand);
+ setOperationAction(ISD::FCOS , MVT::f32, Expand);
+ setOperationAction(ISD::SREM , MVT::f32, Expand);
+
+ // If we're enabling GP optimizations, use hardware square root
+ if (!TM.getSubtarget<PPCSubtarget>().isGigaProcessor()) {
+ setOperationAction(ISD::FSQRT, MVT::f64, Expand);
+ setOperationAction(ISD::FSQRT, MVT::f32, Expand);
+ }
+
+ // PowerPC does not have CTPOP or CTTZ
+ setOperationAction(ISD::CTPOP, MVT::i32 , Expand);
+ setOperationAction(ISD::CTTZ , MVT::i32 , Expand);
+
+ // PowerPC does not have Select
+ setOperationAction(ISD::SELECT, MVT::i32, Expand);
+ setOperationAction(ISD::SELECT, MVT::f32, Expand);
+ setOperationAction(ISD::SELECT, MVT::f64, Expand);
+
+ // PowerPC does not have FP_TO_UINT
+ setOperationAction(ISD::FP_TO_UINT, MVT::i32, Expand);
+
+ setSetCCResultContents(ZeroOrOneSetCCResult);
+ addLegalFPImmediate(+0.0); // Necessary for FSEL
+ addLegalFPImmediate(-0.0); //
+
+ computeRegisterProperties();
+}
+
+std::vector<SDOperand>
+PPC32TargetLowering::LowerArguments(Function &F, SelectionDAG &DAG) {
+ //
+ // add beautiful description of PPC stack frame format, or at least some docs
+ //
+ MachineFunction &MF = DAG.getMachineFunction();
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+ MachineBasicBlock& BB = MF.front();
+ std::vector<SDOperand> ArgValues;
+
+ // Due to the rather complicated nature of the PowerPC ABI, rather than a
+ // fixed size array of physical args, for the sake of simplicity let the STL
+ // handle tracking them for us.
+ std::vector<unsigned> argVR, argPR, argOp;
+ unsigned ArgOffset = 24;
+ unsigned GPR_remaining = 8;
+ unsigned FPR_remaining = 13;
+ unsigned GPR_idx = 0, FPR_idx = 0;
+ static const unsigned GPR[] = {
+ PPC::R3, PPC::R4, PPC::R5, PPC::R6,
+ PPC::R7, PPC::R8, PPC::R9, PPC::R10,
+ };
+ static const unsigned FPR[] = {
+ PPC::F1, PPC::F2, PPC::F3, PPC::F4, PPC::F5, PPC::F6, PPC::F7,
+ PPC::F8, PPC::F9, PPC::F10, PPC::F11, PPC::F12, PPC::F13
+ };
+
+ // Add DAG nodes to load the arguments... On entry to a function on PPC,
+ // the arguments start at offset 24, although they are likely to be passed
+ // in registers.
+ for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I) {
+ SDOperand newroot, argt;
+ unsigned ObjSize;
+ bool needsLoad = false;
+ bool ArgLive = !I->use_empty();
+ MVT::ValueType ObjectVT = getValueType(I->getType());
+
+ switch (ObjectVT) {
+ default: assert(0 && "Unhandled argument type!");
+ case MVT::i1:
+ case MVT::i8:
+ case MVT::i16:
+ case MVT::i32:
+ ObjSize = 4;
+ if (!ArgLive) break;
+ if (GPR_remaining > 0) {
+ MF.addLiveIn(GPR[GPR_idx]);
+ argt = newroot = DAG.getCopyFromReg(GPR[GPR_idx], MVT::i32,
+ DAG.getRoot());
+ if (ObjectVT != MVT::i32)
+ argt = DAG.getNode(ISD::TRUNCATE, ObjectVT, newroot);
+ } else {
+ needsLoad = true;
+ }
+ break;
+ case MVT::i64: ObjSize = 8;
+ if (!ArgLive) break;
+ if (GPR_remaining > 0) {
+ SDOperand argHi, argLo;
+ MF.addLiveIn(GPR[GPR_idx]);
+ argHi = DAG.getCopyFromReg(GPR[GPR_idx], MVT::i32, DAG.getRoot());
+ // If we have two or more remaining argument registers, then both halves
+ // of the i64 can be sourced from there. Otherwise, the lower half will
+ // have to come off the stack. This can happen when an i64 is preceded
+ // by 28 bytes of arguments.
+ if (GPR_remaining > 1) {
+ MF.addLiveIn(GPR[GPR_idx+1]);
+ argLo = DAG.getCopyFromReg(GPR[GPR_idx+1], MVT::i32, argHi);
+ } else {
+ int FI = MFI->CreateFixedObject(4, ArgOffset+4);
+ SDOperand FIN = DAG.getFrameIndex(FI, MVT::i32);
+ argLo = DAG.getLoad(MVT::i32, DAG.getEntryNode(), FIN,
+ DAG.getSrcValue(NULL));
+ }
+ // Build the outgoing arg thingy
+ argt = DAG.getNode(ISD::BUILD_PAIR, MVT::i64, argLo, argHi);
+ newroot = argLo;
+ } else {
+ needsLoad = true;
+ }
+ break;
+ case MVT::f32:
+ case MVT::f64:
+ ObjSize = (ObjectVT == MVT::f64) ? 8 : 4;
+ if (!ArgLive) break;
+ if (FPR_remaining > 0) {
+ MF.addLiveIn(FPR[FPR_idx]);
+ argt = newroot = DAG.getCopyFromReg(FPR[FPR_idx], ObjectVT,
+ DAG.getRoot());
+ --FPR_remaining;
+ ++FPR_idx;
+ } else {
+ needsLoad = true;
+ }
+ break;
+ }
+
+ // We need to load the argument to a virtual register if we determined above
+ // that we ran out of physical registers of the appropriate type
+ if (needsLoad) {
+ unsigned SubregOffset = 0;
+ if (ObjectVT == MVT::i8 || ObjectVT == MVT::i1) SubregOffset = 3;
+ if (ObjectVT == MVT::i16) SubregOffset = 2;
+ int FI = MFI->CreateFixedObject(ObjSize, ArgOffset);
+ SDOperand FIN = DAG.getFrameIndex(FI, MVT::i32);
+ FIN = DAG.getNode(ISD::ADD, MVT::i32, FIN,
+ DAG.getConstant(SubregOffset, MVT::i32));
+ argt = newroot = DAG.getLoad(ObjectVT, DAG.getEntryNode(), FIN,
+ DAG.getSrcValue(NULL));
+ }
+
+ // Every 4 bytes of argument space consumes one of the GPRs available for
+ // argument passing.
+ if (GPR_remaining > 0) {
+ unsigned delta = (GPR_remaining > 1 && ObjSize == 8) ? 2 : 1;
+ GPR_remaining -= delta;
+ GPR_idx += delta;
+ }
+ ArgOffset += ObjSize;
+ if (newroot.Val)
+ DAG.setRoot(newroot.getValue(1));
+
+ ArgValues.push_back(argt);
+ }
+
+ // If the function takes variable number of arguments, make a frame index for
+ // the start of the first vararg value... for expansion of llvm.va_start.
+ if (F.isVarArg()) {
+ VarArgsFrameIndex = MFI->CreateFixedObject(4, ArgOffset);
+ SDOperand FIN = DAG.getFrameIndex(VarArgsFrameIndex, MVT::i32);
+ // If this function is vararg, store any remaining integer argument regs
+ // to their spots on the stack so that they may be loaded by deferencing the
+ // result of va_next.
+ std::vector<SDOperand> MemOps;
+ for (; GPR_remaining > 0; --GPR_remaining, ++GPR_idx) {
+ MF.addLiveIn(GPR[GPR_idx]);
+ SDOperand Val = DAG.getCopyFromReg(GPR[GPR_idx], MVT::i32, DAG.getRoot());
+ SDOperand Store = DAG.getNode(ISD::STORE, MVT::Other, Val.getValue(1),
+ Val, FIN, DAG.getSrcValue(NULL));
+ MemOps.push_back(Store);
+ // Increment the address by four for the next argument to store
+ SDOperand PtrOff = DAG.getConstant(4, getPointerTy());
+ FIN = DAG.getNode(ISD::ADD, MVT::i32, FIN, PtrOff);
+ }
+ DAG.setRoot(DAG.getNode(ISD::TokenFactor, MVT::Other, MemOps));
+ }
+
+ // Finally, inform the code generator which regs we return values in.
+ switch (getValueType(F.getReturnType())) {
+ default: assert(0 && "Unknown type!");
+ case MVT::isVoid: break;
+ case MVT::i1:
+ case MVT::i8:
+ case MVT::i16:
+ case MVT::i32:
+ MF.addLiveOut(PPC::R3);
+ break;
+ case MVT::i64:
+ MF.addLiveOut(PPC::R3);
+ MF.addLiveOut(PPC::R4);
+ break;
+ case MVT::f32:
+ case MVT::f64:
+ MF.addLiveOut(PPC::F1);
+ break;
+ }
+
+ return ArgValues;
+}
+
+std::pair<SDOperand, SDOperand>
+PPC32TargetLowering::LowerCallTo(SDOperand Chain,
+ const Type *RetTy, bool isVarArg,
+ unsigned CallingConv, bool isTailCall,
+ SDOperand Callee, ArgListTy &Args,
+ SelectionDAG &DAG) {
+ // args_to_use will accumulate outgoing args for the ISD::CALL case in
+ // SelectExpr to use to put the arguments in the appropriate registers.
+ std::vector<SDOperand> args_to_use;
+
+ // Count how many bytes are to be pushed on the stack, including the linkage
+ // area, and parameter passing area.
+ unsigned NumBytes = 24;
+
+ if (Args.empty()) {
+ Chain = DAG.getNode(ISD::CALLSEQ_START, MVT::Other, Chain,
+ DAG.getConstant(NumBytes, getPointerTy()));
+ } else {
+ for (unsigned i = 0, e = Args.size(); i != e; ++i)
+ switch (getValueType(Args[i].second)) {
+ default: assert(0 && "Unknown value type!");
+ case MVT::i1:
+ case MVT::i8:
+ case MVT::i16:
+ case MVT::i32:
+ case MVT::f32:
+ NumBytes += 4;
+ break;
+ case MVT::i64:
+ case MVT::f64:
+ NumBytes += 8;
+ break;
+ }
+
+ // Just to be safe, we'll always reserve the full 24 bytes of linkage area
+ // plus 32 bytes of argument space in case any called code gets funky on us.
+ // (Required by ABI to support var arg)
+ if (NumBytes < 56) NumBytes = 56;
+
+ // Adjust the stack pointer for the new arguments...
+ // These operations are automatically eliminated by the prolog/epilog pass
+ Chain = DAG.getNode(ISD::CALLSEQ_START, MVT::Other, Chain,
+ DAG.getConstant(NumBytes, getPointerTy()));
+
+ // Set up a copy of the stack pointer for use loading and storing any
+ // arguments that may not fit in the registers available for argument
+ // passing.
+ SDOperand StackPtr = DAG.getCopyFromReg(PPC::R1, MVT::i32,
+ DAG.getEntryNode());
+
+ // Figure out which arguments are going to go in registers, and which in
+ // memory. Also, if this is a vararg function, floating point operations
+ // must be stored to our stack, and loaded into integer regs as well, if
+ // any integer regs are available for argument passing.
+ unsigned ArgOffset = 24;
+ unsigned GPR_remaining = 8;
+ unsigned FPR_remaining = 13;
+
+ std::vector<SDOperand> MemOps;
+ for (unsigned i = 0, e = Args.size(); i != e; ++i) {
+ // PtrOff will be used to store the current argument to the stack if a
+ // register cannot be found for it.
+ SDOperand PtrOff = DAG.getConstant(ArgOffset, getPointerTy());
+ PtrOff = DAG.getNode(ISD::ADD, MVT::i32, StackPtr, PtrOff);
+ MVT::ValueType ArgVT = getValueType(Args[i].second);
+
+ switch (ArgVT) {
+ default: assert(0 && "Unexpected ValueType for argument!");
+ case MVT::i1:
+ case MVT::i8:
+ case MVT::i16:
+ // Promote the integer to 32 bits. If the input type is signed use a
+ // sign extend, otherwise use a zero extend.
+ if (Args[i].second->isSigned())
+ Args[i].first =DAG.getNode(ISD::SIGN_EXTEND, MVT::i32, Args[i].first);
+ else
+ Args[i].first =DAG.getNode(ISD::ZERO_EXTEND, MVT::i32, Args[i].first);
+ // FALL THROUGH
+ case MVT::i32:
+ if (GPR_remaining > 0) {
+ args_to_use.push_back(Args[i].first);
+ --GPR_remaining;
+ } else {
+ MemOps.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain,
+ Args[i].first, PtrOff,
+ DAG.getSrcValue(NULL)));
+ }
+ ArgOffset += 4;
+ break;
+ case MVT::i64:
+ // If we have one free GPR left, we can place the upper half of the i64
+ // in it, and store the other half to the stack. If we have two or more
+ // free GPRs, then we can pass both halves of the i64 in registers.
+ if (GPR_remaining > 0) {
+ SDOperand Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32,
+ Args[i].first, DAG.getConstant(1, MVT::i32));
+ SDOperand Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, MVT::i32,
+ Args[i].first, DAG.getConstant(0, MVT::i32));
+ args_to_use.push_back(Hi);
+ --GPR_remaining;
+ if (GPR_remaining > 0) {
+ args_to_use.push_back(Lo);
+ --GPR_remaining;
+ } else {
+ SDOperand ConstFour = DAG.getConstant(4, getPointerTy());
+ PtrOff = DAG.getNode(ISD::ADD, MVT::i32, PtrOff, ConstFour);
+ MemOps.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain,
+ Lo, PtrOff, DAG.getSrcValue(NULL)));
+ }
+ } else {
+ MemOps.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain,
+ Args[i].first, PtrOff,
+ DAG.getSrcValue(NULL)));
+ }
+ ArgOffset += 8;
+ break;
+ case MVT::f32:
+ case MVT::f64:
+ if (FPR_remaining > 0) {
+ args_to_use.push_back(Args[i].first);
+ --FPR_remaining;
+ if (isVarArg) {
+ SDOperand Store = DAG.getNode(ISD::STORE, MVT::Other, Chain,
+ Args[i].first, PtrOff,
+ DAG.getSrcValue(NULL));
+ MemOps.push_back(Store);
+ // Float varargs are always shadowed in available integer registers
+ if (GPR_remaining > 0) {
+ SDOperand Load = DAG.getLoad(MVT::i32, Store, PtrOff,
+ DAG.getSrcValue(NULL));
+ MemOps.push_back(Load);
+ args_to_use.push_back(Load);
+ --GPR_remaining;
+ }
+ if (GPR_remaining > 0 && MVT::f64 == ArgVT) {
+ SDOperand ConstFour = DAG.getConstant(4, getPointerTy());
+ PtrOff = DAG.getNode(ISD::ADD, MVT::i32, PtrOff, ConstFour);
+ SDOperand Load = DAG.getLoad(MVT::i32, Store, PtrOff,
+ DAG.getSrcValue(NULL));
+ MemOps.push_back(Load);
+ args_to_use.push_back(Load);
+ --GPR_remaining;
+ }
+ } else {
+ // If we have any FPRs remaining, we may also have GPRs remaining.
+ // Args passed in FPRs consume either 1 (f32) or 2 (f64) available
+ // GPRs.
+ if (GPR_remaining > 0) {
+ args_to_use.push_back(DAG.getNode(ISD::UNDEF, MVT::i32));
+ --GPR_remaining;
+ }
+ if (GPR_remaining > 0 && MVT::f64 == ArgVT) {
+ args_to_use.push_back(DAG.getNode(ISD::UNDEF, MVT::i32));
+ --GPR_remaining;
+ }
+ }
+ } else {
+ MemOps.push_back(DAG.getNode(ISD::STORE, MVT::Other, Chain,
+ Args[i].first, PtrOff,
+ DAG.getSrcValue(NULL)));
+ }
+ ArgOffset += (ArgVT == MVT::f32) ? 4 : 8;
+ break;
+ }
+ }
+ if (!MemOps.empty())
+ Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, MemOps);
+ }
+
+ std::vector<MVT::ValueType> RetVals;
+ MVT::ValueType RetTyVT = getValueType(RetTy);
+ if (RetTyVT != MVT::isVoid)
+ RetVals.push_back(RetTyVT);
+ RetVals.push_back(MVT::Other);
+
+ SDOperand TheCall = SDOperand(DAG.getCall(RetVals,
+ Chain, Callee, args_to_use), 0);
+ Chain = TheCall.getValue(RetTyVT != MVT::isVoid);
+ Chain = DAG.getNode(ISD::CALLSEQ_END, MVT::Other, Chain,
+ DAG.getConstant(NumBytes, getPointerTy()));
+ return std::make_pair(TheCall, Chain);
+}
+
+SDOperand PPC32TargetLowering::LowerVAStart(SDOperand Chain, SDOperand VAListP,
+ Value *VAListV, SelectionDAG &DAG) {
+ // vastart just stores the address of the VarArgsFrameIndex slot into the
+ // memory location argument.
+ SDOperand FR = DAG.getFrameIndex(VarArgsFrameIndex, MVT::i32);
+ return DAG.getNode(ISD::STORE, MVT::Other, Chain, FR, VAListP,
+ DAG.getSrcValue(VAListV));
+}
+
+std::pair<SDOperand,SDOperand>
+PPC32TargetLowering::LowerVAArg(SDOperand Chain,
+ SDOperand VAListP, Value *VAListV,
+ const Type *ArgTy, SelectionDAG &DAG) {
+ MVT::ValueType ArgVT = getValueType(ArgTy);
+
+ SDOperand VAList =
+ DAG.getLoad(MVT::i32, Chain, VAListP, DAG.getSrcValue(VAListV));
+ SDOperand Result = DAG.getLoad(ArgVT, Chain, VAList, DAG.getSrcValue(NULL));
+ unsigned Amt;
+ if (ArgVT == MVT::i32 || ArgVT == MVT::f32)
+ Amt = 4;
+ else {
+ assert((ArgVT == MVT::i64 || ArgVT == MVT::f64) &&
+ "Other types should have been promoted for varargs!");
+ Amt = 8;
+ }
+ VAList = DAG.getNode(ISD::ADD, VAList.getValueType(), VAList,
+ DAG.getConstant(Amt, VAList.getValueType()));
+ Chain = DAG.getNode(ISD::STORE, MVT::Other, Chain,
+ VAList, VAListP, DAG.getSrcValue(VAListV));
+ return std::make_pair(Result, Chain);
+}
+
+
+std::pair<SDOperand, SDOperand> PPC32TargetLowering::
+LowerFrameReturnAddress(bool isFrameAddress, SDOperand Chain, unsigned Depth,
+ SelectionDAG &DAG) {
+ assert(0 && "LowerFrameReturnAddress unimplemented");
+ abort();
+}
OpenPOWER on IntegriCloud