llvm-6502/lib/Target/SparcV9/SparcV9RegClassInfo.cpp

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#include "SparcRegClassInfo.h"
#include "llvm/CodeGen/IGNode.h"
#include "llvm/Target/Sparc.h"
#include "llvm/Type.h"
#include <iostream>
using std::cerr;
//-----------------------------------------------------------------------------
// Int Register Class - method for coloring a node in the interference graph.
//
// Algorithm:
// Record the colors/suggested colors of all neighbors.
//
// If there is a suggested color, try to allocate it
// If there is no call interf, try to allocate volatile, then non volatile
// If there is call interf, try to allocate non-volatile. If that fails
// try to allocate a volatile and insert save across calls
// If both above fail, spill.
//
//-----------------------------------------------------------------------------
void SparcIntRegClass::colorIGNode(IGNode * Node, bool IsColorUsedArr[]) const {
LiveRange *LR = Node->getParentLR();
unsigned NumNeighbors = Node->getNumOfNeighbors(); // total # of neighbors
for (unsigned n=0; n < NumNeighbors; n++) { // for each neigh
IGNode *NeighIGNode = Node->getAdjIGNode(n);
LiveRange *NeighLR = NeighIGNode->getParentLR();
if(NeighLR->hasColor()) // if has a color
IsColorUsedArr[NeighLR->getColor()] = true; // record that color
else if (NeighLR->hasSuggestedColor()) {
// if the neighbout can use the suggested color
if(NeighLR->isSuggestedColorUsable())
IsColorUsedArr[NeighLR->getSuggestedColor()] = true;
}
}
if( DEBUG_RA ) {
cerr << "\nColoring LR [CallInt=" << LR->isCallInterference() <<"]:";
printSet(*LR);
}
if( LR->hasSuggestedColor() ) {
unsigned SugCol = LR->getSuggestedColor();
if( ! IsColorUsedArr[ SugCol ] ) {
if( LR->isSuggestedColorUsable() ) {
// if the suggested color is volatile, we should use it only if
// there are no call interferences. Otherwise, it will get spilled.
if (DEBUG_RA)
cerr << "\n -Coloring with sug color: " << SugCol;
LR->setColor( LR->getSuggestedColor() );
return;
}
else if(DEBUG_RA)
cerr << "\n Couldn't alloc Sug col - LR voloatile & calls interf";
}
else if ( DEBUG_RA ) { // can't allocate the suggested col
cerr << " \n Could NOT allocate the suggested color (already used) ";
printSet(*LR); cerr << "\n";
}
}
unsigned SearchStart; // start pos of color in pref-order
bool ColorFound= false; // have we found a color yet?
//if this Node is between calls
if( ! LR->isCallInterference() ) {
// start with volatiles (we can allocate volatiles safely)
SearchStart = SparcIntRegOrder::StartOfAllRegs;
}
else {
// start with non volatiles (no non-volatiles)
SearchStart = SparcIntRegOrder::StartOfNonVolatileRegs;
}
unsigned c=0; // color
// find first unused color
for( c=SearchStart; c < SparcIntRegOrder::NumOfAvailRegs; c++) {
if( ! IsColorUsedArr[ c ] ) { ColorFound = true; break; }
}
if( ColorFound) {
LR->setColor(c); // first color found in preffered order
if (DEBUG_RA) cerr << "\n Colored after first search with col " << c ;
}
// if color is not found because of call interference
// try even finding a volatile color and insert save across calls
//
else if( LR->isCallInterference() )
{
// start from 0 - try to find even a volatile this time
SearchStart = SparcIntRegOrder::StartOfAllRegs;
// find first unused volatile color
for(c=SearchStart; c < SparcIntRegOrder::StartOfNonVolatileRegs; c++) {
if( ! IsColorUsedArr[ c ] ) { ColorFound = true; break; }
}
if (ColorFound) {
LR->setColor(c);
// get the live range corresponding to live var
// since LR span across calls, must save across calls
//
LR->markForSaveAcrossCalls();
if(DEBUG_RA) cerr << "\n Colored after SECOND search with col " << c ;
}
}
// If we couldn't find a color regardless of call interference - i.e., we
// don't have either a volatile or non-volatile color left
//
if (!ColorFound)
LR->markForSpill(); // no color found - must spill
}
//-----------------------------------------------------------------------------
// Float Register Class - method for coloring a node in the interference graph.
//
// Algorithm:
//
// If the LR is a double try to allocate f32 - f63
// If the above fails or LR is single precision
// If the LR does not interfere with a call
// start allocating from f0
// Else start allocating from f6
// If a color is still not found because LR interferes with a call
// Search in f0 - f6. If found mark for spill across calls.
// If a color is still not fond, mark for spilling
//
//----------------------------------------------------------------------------
void SparcFloatRegClass::colorIGNode(IGNode * Node,bool IsColorUsedArr[]) const{
LiveRange *LR = Node->getParentLR();
unsigned NumNeighbors = Node->getNumOfNeighbors(); // total # of neighbors
for(unsigned n=0; n < NumNeighbors; n++) { // for each neigh
IGNode *NeighIGNode = Node->getAdjIGNode(n);
LiveRange *NeighLR = NeighIGNode->getParentLR();
if( NeighLR->hasColor() ) { // if neigh has a color
IsColorUsedArr[ NeighLR->getColor() ] = true; // record that color
if (NeighLR->getType() == Type::DoubleTy)
IsColorUsedArr[ (NeighLR->getColor()) + 1 ] = true;
}
else if( NeighLR->hasSuggestedColor() ) { // if neigh has sugg color
if( NeighLR-> isSuggestedColorUsable() ) {
// if the neighbout can use the suggested color
IsColorUsedArr[ NeighLR->getSuggestedColor() ] = true;
if (NeighLR->getType() == Type::DoubleTy)
IsColorUsedArr[ (NeighLR->getSuggestedColor()) + 1 ] = true;
}
}
}
// **NOTE: We don't check for call interferences in allocating suggested
// color in this class since ALL registers are volatile. If this fact
// changes, we should change the following part
//- see SparcIntRegClass::colorIGNode()
if( LR->hasSuggestedColor() ) {
if( ! IsColorUsedArr[ LR->getSuggestedColor() ] ) {
LR->setColor( LR->getSuggestedColor() );
return;
} else if (DEBUG_RA) { // can't allocate the suggested col
cerr << " Could NOT allocate the suggested color for LR ";
printSet(*LR); cerr << "\n";
}
}
int ColorFound = -1; // have we found a color yet?
bool isCallInterf = LR->isCallInterference();
// if value is a double - search the double only reigon (f32 - f63)
// i.e. we try to allocate f32 - f63 first for doubles since singles
// cannot go there. By doing that, we provide more space for singles
// in f0 - f31
//
if (LR->getType() == Type::DoubleTy)
ColorFound = findFloatColor( LR, 32, 64, IsColorUsedArr );
if( ColorFound >= 0 ) { // if we could find a color
LR->setColor(ColorFound);
return;
} else {
// if we didn't find a color becuase the LR was single precision or
// all f32-f63 range is filled, we try to allocate a register from
// the f0 - f31 region
unsigned SearchStart; // start pos of color in pref-order
//if this Node is between calls (i.e., no call interferences )
if( ! isCallInterf ) {
// start with volatiles (we can allocate volatiles safely)
SearchStart = SparcFloatRegOrder::StartOfAllRegs;
}
else {
// start with non volatiles (no non-volatiles)
SearchStart = SparcFloatRegOrder::StartOfNonVolatileRegs;
}
ColorFound = findFloatColor( LR, SearchStart, 32, IsColorUsedArr );
}
if( ColorFound >= 0 ) { // if we could find a color
LR->setColor(ColorFound);
return;
}
else if( isCallInterf ) {
// We are here because there is a call interference and no non-volatile
// color could be found.
// Now try to allocate even a volatile color
ColorFound = findFloatColor( LR, SparcFloatRegOrder::StartOfAllRegs,
SparcFloatRegOrder::StartOfNonVolatileRegs,
IsColorUsedArr);
}
if( ColorFound >= 0 ) {
LR->setColor(ColorFound); // first color found in preffered order
LR->markForSaveAcrossCalls();
} else {
// we are here because no color could be found
LR->markForSpill(); // no color found - must spill
}
}
//-----------------------------------------------------------------------------
// Helper method for coloring a node of Float Reg class.
// Finds the first available color in the range [Start,End] depending on the
// type of the Node (i.e., float/double)
//-----------------------------------------------------------------------------
int SparcFloatRegClass::findFloatColor(const LiveRange *LR,
unsigned Start, unsigned End,
bool IsColorUsedArr[]) const {
bool ColorFound = false;
unsigned c;
if (LR->getType() == Type::DoubleTy) {
// find first unused color for a double
for (c=Start; c < End ; c+= 2)
if (!IsColorUsedArr[c] && !IsColorUsedArr[c+1])
return c;
} else {
// find first unused color for a single
for (c = Start; c < End; c++)
if (!IsColorUsedArr[c])
return c;
}
return -1;
}