X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FCallingConvLower.cpp;h=23c0d542560ec0a0ce1cb10af997bb3f54daf092;hb=114db87382813de635450d88dded16511aea1fda;hp=56ecde0936c04b5af64b2462b19d6429ca55d01a;hpb=ded375f282a873c0852422f070e65a97f9a4ef74;p=oota-llvm.git

diff --git a/lib/CodeGen/CallingConvLower.cpp b/lib/CodeGen/CallingConvLower.cpp
index 56ecde0936c..23c0d542560 100644
--- a/lib/CodeGen/CallingConvLower.cpp
+++ b/lib/CodeGen/CallingConvLower.cpp
@@ -14,9 +14,11 @@
 
 #include "llvm/CodeGen/CallingConvLower.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/SaveAndRestore.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/TargetRegisterInfo.h"
@@ -30,14 +32,15 @@ CCState::CCState(CallingConv::ID CC, bool isVarArg, MachineFunction &mf,
       CallOrPrologue(Unknown) {
   // No stack is used.
   StackOffset = 0;
+  MaxStackArgAlign = 1;
 
   clearByValRegsInfo();
   UsedRegs.resize((TRI.getNumRegs()+31)/32);
 }
 
-// HandleByVal - Allocate space on the stack large enough to pass an argument
-// by value. The size and alignment information of the argument is encoded in
-// its parameter attribute.
+/// Allocate space on the stack large enough to pass an argument by value.
+/// The size and alignment information of the argument is encoded in
+/// its parameter attribute.
 void CCState::HandleByVal(unsigned ValNo, MVT ValVT,
                           MVT LocVT, CCValAssign::LocInfo LocInfo,
                           int MinSize, int MinAlign,
@@ -55,13 +58,13 @@ void CCState::HandleByVal(unsigned ValNo, MVT ValVT,
   addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
 }
 
-/// MarkAllocated - Mark a register and all of its aliases as allocated.
+/// Mark a register and all of its aliases as allocated.
 void CCState::MarkAllocated(unsigned Reg) {
   for (MCRegAliasIterator AI(Reg, &TRI, true); AI.isValid(); ++AI)
     UsedRegs[*AI/32] |= 1 << (*AI&31);
 }
 
-/// AnalyzeFormalArguments - Analyze an array of argument values,
+/// Analyze an array of argument values,
 /// incorporating info about the formals into this state.
 void
 CCState::AnalyzeFormalArguments(const SmallVectorImpl<ISD::InputArg> &Ins,
@@ -81,8 +84,8 @@ CCState::AnalyzeFormalArguments(const SmallVectorImpl<ISD::InputArg> &Ins,
   }
 }
 
-/// CheckReturn - Analyze the return values of a function, returning true if
-/// the return can be performed without sret-demotion, and false otherwise.
+/// Analyze the return values of a function, returning true if the return can
+/// be performed without sret-demotion and false otherwise.
 bool CCState::CheckReturn(const SmallVectorImpl<ISD::OutputArg> &Outs,
                           CCAssignFn Fn) {
   // Determine which register each value should be copied into.
@@ -95,7 +98,7 @@ bool CCState::CheckReturn(const SmallVectorImpl<ISD::OutputArg> &Outs,
   return true;
 }
 
-/// AnalyzeReturn - Analyze the returned values of a return,
+/// Analyze the returned values of a return,
 /// incorporating info about the result values into this state.
 void CCState::AnalyzeReturn(const SmallVectorImpl<ISD::OutputArg> &Outs,
                             CCAssignFn Fn) {
@@ -113,7 +116,7 @@ void CCState::AnalyzeReturn(const SmallVectorImpl<ISD::OutputArg> &Outs,
   }
 }
 
-/// AnalyzeCallOperands - Analyze the outgoing arguments to a call,
+/// Analyze the outgoing arguments to a call,
 /// incorporating info about the passed values into this state.
 void CCState::AnalyzeCallOperands(const SmallVectorImpl<ISD::OutputArg> &Outs,
                                   CCAssignFn Fn) {
@@ -131,8 +134,7 @@ void CCState::AnalyzeCallOperands(const SmallVectorImpl<ISD::OutputArg> &Outs,
   }
 }
 
-/// AnalyzeCallOperands - Same as above except it takes vectors of types
-/// and argument flags.
+/// Same as above except it takes vectors of types and argument flags.
 void CCState::AnalyzeCallOperands(SmallVectorImpl<MVT> &ArgVTs,
                                   SmallVectorImpl<ISD::ArgFlagsTy> &Flags,
                                   CCAssignFn Fn) {
@@ -150,8 +152,8 @@ void CCState::AnalyzeCallOperands(SmallVectorImpl<MVT> &ArgVTs,
   }
 }
 
-/// AnalyzeCallResult - Analyze the return values of a call,
-/// incorporating info about the passed values into this state.
+/// Analyze the return values of a call, incorporating info about the passed
+/// values into this state.
 void CCState::AnalyzeCallResult(const SmallVectorImpl<ISD::InputArg> &Ins,
                                 CCAssignFn Fn) {
   for (unsigned i = 0, e = Ins.size(); i != e; ++i) {
@@ -167,8 +169,7 @@ void CCState::AnalyzeCallResult(const SmallVectorImpl<ISD::InputArg> &Ins,
   }
 }
 
-/// AnalyzeCallResult - Same as above except it's specialized for calls which
-/// produce a single value.
+/// Same as above except it's specialized for calls that produce a single value.
 void CCState::AnalyzeCallResult(MVT VT, CCAssignFn Fn) {
   if (Fn(0, VT, VT, CCValAssign::Full, ISD::ArgFlagsTy(), *this)) {
 #ifndef NDEBUG
@@ -178,3 +179,72 @@ void CCState::AnalyzeCallResult(MVT VT, CCAssignFn Fn) {
     llvm_unreachable(nullptr);
   }
 }
+
+static bool isValueTypeInRegForCC(CallingConv::ID CC, MVT VT) {
+  if (VT.isVector())
+    return true; // Assume -msse-regparm might be in effect.
+  if (!VT.isInteger())
+    return false;
+  if (CC == CallingConv::X86_VectorCall || CC == CallingConv::X86_FastCall)
+    return true;
+  return false;
+}
+
+void CCState::getRemainingRegParmsForType(SmallVectorImpl<MCPhysReg> &Regs,
+                                          MVT VT, CCAssignFn Fn) {
+  unsigned SavedStackOffset = StackOffset;
+  unsigned SavedMaxStackArgAlign = MaxStackArgAlign;
+  unsigned NumLocs = Locs.size();
+
+  // Set the 'inreg' flag if it is used for this calling convention.
+  ISD::ArgFlagsTy Flags;
+  if (isValueTypeInRegForCC(CallingConv, VT))
+    Flags.setInReg();
+
+  // Allocate something of this value type repeatedly until we get assigned a
+  // location in memory.
+  bool HaveRegParm = true;
+  while (HaveRegParm) {
+    if (Fn(0, VT, VT, CCValAssign::Full, Flags, *this)) {
+#ifndef NDEBUG
+      dbgs() << "Call has unhandled type " << EVT(VT).getEVTString()
+             << " while computing remaining regparms\n";
+#endif
+      llvm_unreachable(nullptr);
+    }
+    HaveRegParm = Locs.back().isRegLoc();
+  }
+
+  // Copy all the registers from the value locations we added.
+  assert(NumLocs < Locs.size() && "CC assignment failed to add location");
+  for (unsigned I = NumLocs, E = Locs.size(); I != E; ++I)
+    if (Locs[I].isRegLoc())
+      Regs.push_back(MCPhysReg(Locs[I].getLocReg()));
+
+  // Clear the assigned values and stack memory. We leave the registers marked
+  // as allocated so that future queries don't return the same registers, i.e.
+  // when i64 and f64 are both passed in GPRs.
+  StackOffset = SavedStackOffset;
+  MaxStackArgAlign = SavedMaxStackArgAlign;
+  Locs.resize(NumLocs);
+}
+
+void CCState::analyzeMustTailForwardedRegisters(
+    SmallVectorImpl<ForwardedRegister> &Forwards, ArrayRef<MVT> RegParmTypes,
+    CCAssignFn Fn) {
+  // Oftentimes calling conventions will not user register parameters for
+  // variadic functions, so we need to assume we're not variadic so that we get
+  // all the registers that might be used in a non-variadic call.
+  SaveAndRestore<bool> SavedVarArg(IsVarArg, false);
+
+  for (MVT RegVT : RegParmTypes) {
+    SmallVector<MCPhysReg, 8> RemainingRegs;
+    getRemainingRegParmsForType(RemainingRegs, RegVT, Fn);
+    const TargetLowering *TL = MF.getSubtarget().getTargetLowering();
+    const TargetRegisterClass *RC = TL->getRegClassFor(RegVT);
+    for (MCPhysReg PReg : RemainingRegs) {
+      unsigned VReg = MF.addLiveIn(PReg, RC);
+      Forwards.push_back(ForwardedRegister(VReg, PReg, RegVT));
+    }
+  }
+}