void
TR::ARM64SystemLinkage::mapStack(TR::ResolvedMethodSymbol *method)
{
TR::Machine *machine = cg()->machine();
uint32_t stackIndex = 0;
ListIterator<TR::AutomaticSymbol> automaticIterator(&method->getAutomaticList());
TR::AutomaticSymbol *localCursor = automaticIterator.getFirst();
stackIndex = 8; // [sp+0] is for link register
// map non-long/double automatics
while (localCursor != NULL)
{
if (localCursor->getGCMapIndex() < 0
&& localCursor->getDataType() != TR::Int64
&& localCursor->getDataType() != TR::Double)
{
localCursor->setOffset(stackIndex);
stackIndex += (localCursor->getSize() + 3) & (~3);
}
localCursor = automaticIterator.getNext();
}
stackIndex += (stackIndex & 0x4) ? 4 : 0; // align to 8 bytes
automaticIterator.reset();
localCursor = automaticIterator.getFirst();
// map long/double automatics
while (localCursor != NULL)
{
if (localCursor->getDataType() == TR::Int64
|| localCursor->getDataType() == TR::Double)
{
localCursor->setOffset(stackIndex);
stackIndex += (localCursor->getSize() + 7) & (~7);
}
localCursor = automaticIterator.getNext();
}
method->setLocalMappingCursor(stackIndex);
// allocate space for preserved registers (x19-x28, v8-v15)
for (int r = TR::RealRegister::x19; r <= TR::RealRegister::x28; r++)
{
TR::RealRegister *rr = machine->getRealRegister((TR::RealRegister::RegNum)r);
if (rr->getHasBeenAssignedInMethod())
{
stackIndex += 8;
}
}
for (int r = TR::RealRegister::v8; r <= TR::RealRegister::v15; r++)
{
TR::RealRegister *rr = machine->getRealRegister((TR::RealRegister::RegNum)r);
if (rr->getHasBeenAssignedInMethod())
{
stackIndex += 8;
}
}
/*
* Because the rest of the code generator currently expects **all** arguments
* to be passed on the stack, arguments passed in registers must be spilled
* in the callee frame. To map the arguments correctly, we use two loops. The
* first maps the arguments that will come in registers onto the callee stack.
* At the end of this loop, the `stackIndex` is the the size of the frame.
* The second loop then maps the remaining arguments onto the caller frame.
*/
int32_t nextIntArgReg = 0;
int32_t nextFltArgReg = 0;
ListIterator<TR::ParameterSymbol> parameterIterator(&method->getParameterList());
for (TR::ParameterSymbol *parameter = parameterIterator.getFirst();
parameter != NULL && (nextIntArgReg < getProperties().getNumIntArgRegs() || nextFltArgReg < getProperties().getNumFloatArgRegs());
parameter = parameterIterator.getNext())
{
switch (parameter->getDataType())
{
case TR::Int8:
case TR::Int16:
case TR::Int32:
case TR::Int64:
case TR::Address:
if (nextIntArgReg < getProperties().getNumIntArgRegs())
{
nextIntArgReg++;
mapSingleParameter(parameter, stackIndex, true);
}
else
{
nextIntArgReg = getProperties().getNumIntArgRegs() + 1;
}
break;
case TR::Float:
case TR::Double:
if (nextFltArgReg < getProperties().getNumFloatArgRegs())
{
nextFltArgReg++;
mapSingleParameter(parameter, stackIndex, true);
}
else
{
nextFltArgReg = getProperties().getNumFloatArgRegs() + 1;
}
break;
case TR::Aggregate:
TR_ASSERT(false, "Function parameters of aggregate types are not currently supported on AArch64.");
break;
default:
TR_ASSERT(false, "Unknown parameter type.");
}
}
// save the stack frame size, aligned to 16 bytes
stackIndex = (stackIndex + 15) & (~15);
cg()->setFrameSizeInBytes(stackIndex);
nextIntArgReg = 0;
nextFltArgReg = 0;
parameterIterator.reset();
for (TR::ParameterSymbol *parameter = parameterIterator.getFirst();
parameter != NULL && (nextIntArgReg < getProperties().getNumIntArgRegs() || nextFltArgReg < getProperties().getNumFloatArgRegs());
parameter = parameterIterator.getNext())
{
switch (parameter->getDataType())
{
case TR::Int8:
case TR::Int16:
case TR::Int32:
case TR::Int64:
case TR::Address:
if (nextIntArgReg < getProperties().getNumIntArgRegs())
{
nextIntArgReg++;
}
else
{
mapSingleParameter(parameter, stackIndex, false);
}
break;
case TR::Float:
case TR::Double:
if (nextFltArgReg < getProperties().getNumFloatArgRegs())
{
nextFltArgReg++;
}
else
{
mapSingleParameter(parameter, stackIndex, false);
}
break;
case TR::Aggregate:
TR_ASSERT(false, "Function parameters of aggregate types are not currently supported on AArch64.");
break;
default:
TR_ASSERT(false, "Unknown parameter type.");
}
}
}
/**
* @brief Maps symbols in the IL to locations on the stack
* @param method is the method for which symbols are being stack mapped
*
* In general, the shape of a stack frame is as follows:
*
* +-----------------------------+
* | caller frame |
* +-----------------------------+
* | stack arguments |
* +=============================+ <-+ (start of callee frame)
* | saved registers | |
* +-----------------------------+ | frame size
* | locals | |
* +-----------------------------+ <-+- $sp
*
* A symbol is mapped onto the stack by assigning to it an offset from the stack
* pointer. All symbols representing stack allocated values must be mapped,
* including automatics (locals) on the callee frame and stack allocated
* arguments on the caller frame
*
* The algorithm used to map symbols iterates over each symbol in ascending
* address order. Using the frame shape depicted above as a general example:
* locals are mapped first, registers second. The algorithm is:
*
* 1. Set stackIndex to 0
* 2. For each symbol that must be mapped onto the **callee** stack frame,
* starting at the lowest address:
* a. set stackIndex as the symbol offset
* b. increment stackIndex by the size of the symbol's type
* plus alignment requirements
* 3. Increment stackIndex by the necessary amount to account for the stack
* space required for saved registers
* 4. Save stackIndex as the size of the callee stack frame
* 5. For each symbol that must be mapped onto the **caller** stack frame,
* starting at the lowest address:
* a. set the symbol offset as the current stack index
* b. increment the stack index by the size of the symbol's type,
* plus alignment requirements
*/
void TR::ARMSystemLinkage::mapStack(TR::ResolvedMethodSymbol *method)
{
uint32_t stackIndex = 0;
ListIterator<TR::AutomaticSymbol> automaticIterator(&method->getAutomaticList());
TR::AutomaticSymbol *localCursor = automaticIterator.getFirst();
// map non-double automatics
while (localCursor != NULL)
{
if (localCursor->getGCMapIndex() < 0 &&
localCursor->getDataType() != TR::Double)
{
localCursor->setOffset(stackIndex);
stackIndex += (localCursor->getSize()+3)&(~3);
}
localCursor = automaticIterator.getNext();
}
stackIndex += (stackIndex & 0x4) ? 4 : 0; // align to 8 bytes
automaticIterator.reset();
localCursor = automaticIterator.getFirst();
// map double automatics
while (localCursor != NULL)
{
if (localCursor->getDataType() == TR::Double)
{
localCursor->setOffset(stackIndex);
stackIndex += (localCursor->getSize()+7)&(~7);
}
localCursor = automaticIterator.getNext();
}
method->setLocalMappingCursor(stackIndex);
// allocate space for preserved registers and link register (9 registers total)
stackIndex += 9*4;
/*
* Because the rest of the code generator currently expects **all** arguments
* to be passed on the stack, arguments passed in registers must be spilled
* in the callee frame. To map the arguments correctly, we use two loops. The
* first maps the arguments that will come in registers onto the callee stack.
* At the end of this loop, the `stackIndex` is the the size of the frame.
* The second loop then maps the remaining arguments onto the caller frame.
*/
auto nextIntArgReg = 0;
auto nextFltArgReg = 0;
ListIterator<TR::ParameterSymbol> parameterIterator(&method->getParameterList());
for (TR::ParameterSymbol *parameter = parameterIterator.getFirst();
parameter!=NULL && (nextIntArgReg < getProperties().getNumIntArgRegs() || nextFltArgReg < getProperties().getNumFloatArgRegs());
parameter=parameterIterator.getNext())
{
switch (parameter->getDataType())
{
case TR::Int8:
case TR::Int16:
case TR::Int32:
case TR::Address:
if (nextIntArgReg < getProperties().getNumIntArgRegs())
{
nextIntArgReg++;
mapSingleParameter(parameter, stackIndex);
}
else
{
nextIntArgReg = getProperties().getNumIntArgRegs() + 1;
}
break;
case TR::Int64:
nextIntArgReg += nextIntArgReg & 0x1; // round to next even number
if (nextIntArgReg + 1 < getProperties().getNumIntArgRegs())
{
nextIntArgReg += 2;
mapSingleParameter(parameter, stackIndex);
}
else
{
nextIntArgReg = getProperties().getNumIntArgRegs() + 1;
}
break;
case TR::Float:
comp()->failCompilation<UnsupportedParameterType>("Compiling methods with a single precision floating point parameter is not supported");
break;
case TR::Double:
if (nextFltArgReg < getProperties().getNumFloatArgRegs())
{
nextFltArgReg += 1;
mapSingleParameter(parameter, stackIndex);
}
else
{
nextFltArgReg = getProperties().getNumFloatArgRegs() + 1;
}
break;
case TR::Aggregate:
TR_ASSERT(false, "Function parameters of aggregate types are not currently supported on ARM.");
}
}
// save the stack frame size, aligned to 8 bytes
stackIndex = (stackIndex + 7)&(~7);
cg()->setFrameSizeInBytes(stackIndex);
nextIntArgReg = 0;
nextFltArgReg = 0;
parameterIterator.reset();
for (TR::ParameterSymbol *parameter = parameterIterator.getFirst();
parameter!=NULL && (nextIntArgReg < getProperties().getNumIntArgRegs() || nextFltArgReg < getProperties().getNumFloatArgRegs());
parameter=parameterIterator.getNext())
{
switch (parameter->getDataType())
{
case TR::Int8:
case TR::Int16:
case TR::Int32:
case TR::Address:
if (nextIntArgReg < getProperties().getNumIntArgRegs())
{
nextIntArgReg++;
}
else
{
mapSingleParameter(parameter, stackIndex);
}
break;
case TR::Int64:
nextIntArgReg += stackIndex & 0x1; // round to next even number
if (nextIntArgReg + 1 < getProperties().getNumIntArgRegs())
{
nextIntArgReg += 2;
}
else
{
mapSingleParameter(parameter, stackIndex);
}
break;
case TR::Float:
comp()->failCompilation<UnsupportedParameterType>("Compiling methods with a single precision floating point parameter is not supported");
break;
case TR::Double:
if (nextFltArgReg < getProperties().getNumFloatArgRegs())
{
nextFltArgReg += 1;
}
else
{
mapSingleParameter(parameter, stackIndex);
}
break;
case TR::Aggregate:
TR_ASSERT(false, "Function parameters of aggregate types are not currently supported on ARM.");
}
}
}