[llvm-commits] [llvm] r131942 - /llvm/trunk/lib/Target/Mips/MipsISelLowering.cpp
Akira Hatanaka
ahatanak at gmail.com
Mon May 23 17:23:52 PDT 2011
Author: ahatanak
Date: Mon May 23 19:23:52 2011
New Revision: 131942
URL: http://llvm.org/viewvc/llvm-project?rev=131942&view=rev
Log:
Simplify offset calculation of stack frame objects for $gp restore location and
variable arguments in LowerCall and LowerFormalArguments. This should also fix
the bug in which handling of variable arguments is incorrect when the front-end
optimizes away unused fixed arguments.
Modified:
llvm/trunk/lib/Target/Mips/MipsISelLowering.cpp
Modified: llvm/trunk/lib/Target/Mips/MipsISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Mips/MipsISelLowering.cpp?rev=131942&r1=131941&r2=131942&view=diff
==============================================================================
--- llvm/trunk/lib/Target/Mips/MipsISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/Mips/MipsISelLowering.cpp Mon May 23 19:23:52 2011
@@ -13,6 +13,7 @@
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "mips-lower"
+//#include <algorithm>
#include "MipsISelLowering.h"
#include "MipsMachineFunction.h"
#include "MipsTargetMachine.h"
@@ -1064,7 +1065,6 @@
// With EABI is it possible to have 16 args on registers.
SmallVector<std::pair<unsigned, SDValue>, 16> RegsToPass;
SmallVector<SDValue, 8> MemOpChains;
- unsigned NextStackOffset = (Subtarget->isABI_EABI() ? 0 : 16);
MipsFI->setHasCall();
@@ -1125,11 +1125,8 @@
// This guarantees that when allocating Local Area the firsts
// 16 bytes which are alwayes reserved won't be overwritten
// if O32 ABI is used. For EABI the first address is zero.
- unsigned ArgSize = VA.getValVT().getSizeInBits()/8;
- NextStackOffset = VA.getLocMemOffset();
- LastFI = MFI->CreateFixedObject(ArgSize, NextStackOffset, true);
- NextStackOffset += ArgSize;
-
+ LastFI = MFI->CreateFixedObject(VA.getValVT().getSizeInBits()/8,
+ VA.getLocMemOffset(), true);
SDValue PtrOff = DAG.getFrameIndex(LastFI, getPointerTy());
// emit ISD::STORE whichs stores the
@@ -1236,6 +1233,12 @@
// Function can have an arbitrary number of calls, so
// hold the LastArgStackLoc with the biggest offset.
int MaxCallFrameSize = MipsFI->getMaxCallFrameSize();
+ unsigned NextStackOffset = CCInfo.getNextStackOffset();
+
+ // For O32, a minimum of four words (16 bytes) of argument space is
+ // allocated.
+ if (Subtarget->isABI_O32())
+ NextStackOffset = std::max(NextStackOffset, (unsigned)16);
if (MaxCallFrameSize < (int)NextStackOffset) {
MipsFI->setMaxCallFrameSize(NextStackOffset);
@@ -1318,9 +1321,6 @@
// Used with vargs to acumulate store chains.
std::vector<SDValue> OutChains;
- // Keep track of the last register used for arguments
- unsigned ArgRegEnd = 0;
-
// Assign locations to all of the incoming arguments.
SmallVector<CCValAssign, 16> ArgLocs;
CCState CCInfo(CallConv, isVarArg, getTargetMachine(),
@@ -1331,8 +1331,6 @@
else
CCInfo.AnalyzeFormalArguments(Ins, CC_Mips);
- unsigned NextStackOffset = (Subtarget->isABI_EABI() ? 0 : 16);
- EVT LastRegArgValVT;
int LastFI = 0;// MipsFI->LastInArgFI is 0 at the entry of this function.
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
@@ -1341,8 +1339,7 @@
// Arguments stored on registers
if (VA.isRegLoc()) {
EVT RegVT = VA.getLocVT();
- ArgRegEnd = VA.getLocReg();
- LastRegArgValVT = VA.getValVT();
+ unsigned ArgReg = VA.getLocReg();
TargetRegisterClass *RC = 0;
if (RegVT == MVT::i32)
@@ -1357,7 +1354,7 @@
// Transform the arguments stored on
// physical registers into virtual ones
- unsigned Reg = AddLiveIn(DAG.getMachineFunction(), ArgRegEnd, RC);
+ unsigned Reg = AddLiveIn(DAG.getMachineFunction(), ArgReg, RC);
SDValue ArgValue = DAG.getCopyFromReg(Chain, dl, Reg, RegVT);
// If this is an 8 or 16-bit value, it has been passed promoted
@@ -1396,9 +1393,6 @@
// sanity check
assert(VA.isMemLoc());
- // The last argument is not a register anymore
- ArgRegEnd = 0;
-
// The stack pointer offset is relative to the caller stack frame.
// Since the real stack size is unknown here, a negative SPOffset
// is used so there's a way to adjust these offsets when the stack
@@ -1406,10 +1400,8 @@
// used instead of a direct negative address (which is recorded to
// be used on emitPrologue) to avoid mis-calc of the first stack
// offset on PEI::calculateFrameObjectOffsets.
- unsigned ArgSize = VA.getValVT().getSizeInBits()/8;
- NextStackOffset = VA.getLocMemOffset();
- LastFI = MFI->CreateFixedObject(ArgSize, NextStackOffset, true);
- NextStackOffset += ArgSize;
+ LastFI = MFI->CreateFixedObject(VA.getValVT().getSizeInBits()/8,
+ VA.getLocMemOffset(), true);
// Create load nodes to retrieve arguments from the stack
SDValue FIN = DAG.getFrameIndex(LastFI, getPointerTy());
@@ -1436,44 +1428,27 @@
// must have their values written to the caller stack frame. If the last
// argument was placed in the stack, there's no need to save any register.
if (isVarArg && Subtarget->isABI_O32()) {
- if (ArgRegEnd) {
- // Last named formal argument is passed in register.
+ // Record the frame index of the first variable argument
+ // which is a value necessary to VASTART.
+ unsigned NextStackOffset = CCInfo.getNextStackOffset();
+ LastFI = MFI->CreateFixedObject(4, NextStackOffset, true);
+ MipsFI->setVarArgsFrameIndex(LastFI);
+
+ const unsigned O32IntRegs[] = {
+ Mips::A0, Mips::A1, Mips::A2, Mips::A3
+ };
- // The last register argument that must be saved is Mips::A3
+ // Copy variable arguments passed in registers to stack.
+ for (; NextStackOffset < 16; NextStackOffset += 4) {
TargetRegisterClass *RC = Mips::CPURegsRegisterClass;
- if (LastRegArgValVT == MVT::f64)
- ArgRegEnd++;
-
- if (ArgRegEnd < Mips::A3) {
- // Both the last named formal argument and the first variable
- // argument are passed in registers.
- for (++ArgRegEnd; ArgRegEnd <= Mips::A3; ++ArgRegEnd) {
- unsigned Reg = AddLiveIn(DAG.getMachineFunction(), ArgRegEnd, RC);
- SDValue ArgValue = DAG.getCopyFromReg(Chain, dl, Reg, MVT::i32);
-
- LastFI = MFI->CreateFixedObject(4, (ArgRegEnd-Mips::A0)*4, true);
- SDValue PtrOff = DAG.getFrameIndex(LastFI, getPointerTy());
- OutChains.push_back(DAG.getStore(Chain, dl, ArgValue, PtrOff,
- MachinePointerInfo(),
- false, false, 0));
-
- // Record the frame index of the first variable argument
- // which is a value necessary to VASTART.
- if (!MipsFI->getVarArgsFrameIndex())
- MipsFI->setVarArgsFrameIndex(LastFI);
- }
- } else {
- // Last named formal argument is in register Mips::A3, and the first
- // variable argument is on stack. Record the frame index of the first
- // variable argument.
- LastFI = MFI->CreateFixedObject(4, 16, true);
- MipsFI->setVarArgsFrameIndex(LastFI);
- }
- } else {
- // Last named formal argument and all the variable arguments are passed
- // on stack. Record the frame index of the first variable argument.
+ unsigned Idx = NextStackOffset / 4;
+ unsigned Reg = AddLiveIn(DAG.getMachineFunction(), O32IntRegs[Idx], RC);
+ SDValue ArgValue = DAG.getCopyFromReg(Chain, dl, Reg, MVT::i32);
LastFI = MFI->CreateFixedObject(4, NextStackOffset, true);
- MipsFI->setVarArgsFrameIndex(LastFI);
+ SDValue PtrOff = DAG.getFrameIndex(LastFI, getPointerTy());
+ OutChains.push_back(DAG.getStore(Chain, dl, ArgValue, PtrOff,
+ MachinePointerInfo(),
+ false, false, 0));
}
}
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