llvm-mirror/lib/Target/Sparc/SparcRegClassInfo.cpp
Ruchira Sasanka dcac0518dd Added code so that colorIGNode does not unnecessarily reserve unusable
Suggested colors for neighbors.

llvm-svn: 921
2001-10-19 21:41:16 +00:00

327 lines
9.0 KiB
C++

#include "llvm/CodeGen/IGNode.h"
#include "SparcInternals.h"
#include "llvm/Target/Sparc.h"
//-----------------------------------------------------------------------------
// Int Register Class
//-----------------------------------------------------------------------------
void SparcIntRegClass::colorIGNode(IGNode * Node, bool IsColorUsedArr[]) const
{
/* 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.
*/
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 ) {
cout << "\nColoring LR [CallInt=" << LR->isCallInterference() <<"]:";
LR->printSet();
}
if( LR->hasSuggestedColor() ) {
unsigned SugCol = LR->getSuggestedColor();
// cout << "\n -Has sug color: " << SugCol;
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)
cout << "\n -Coloring with sug color: " << SugCol;
LR->setColor( LR->getSuggestedColor() );
return;
}
else if(DEBUG_RA)
cout << "\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) ";
LR->printSet(); cerr << endl;
}
}
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) cout << "\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) cout << "\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
if( DEBUG_RA)
UltraSparcRegInfo::printReg( LR );
}
//-----------------------------------------------------------------------------
// Float Register Class
//-----------------------------------------------------------------------------
// find 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 *const LR,
unsigned Start,
unsigned End,
bool IsColorUsedArr[] ) const
{
bool ColorFound = false;
unsigned c;
if( LR->getTypeID() == Type::DoubleTyID ) {
// find first unused color for a double
for( c=Start; c < End ;c+= 2){
if( ! IsColorUsedArr[ c ] && ! IsColorUsedArr[ c+1 ])
{ ColorFound=true; break; }
}
} else {
// find first unused color for a single
for( c=Start; c < End; c++) {
if( ! IsColorUsedArr[ c ] ) { ColorFound=true; break; }
}
}
if( ColorFound ) return c;
else return -1;
}
void SparcFloatRegClass::colorIGNode(IGNode * Node,bool IsColorUsedArr[]) const
{
/* 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
*/
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->getTypeID() == Type::DoubleTyID )
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->getTypeID() == Type::DoubleTyID )
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 ";
LR->printSet(); cerr << endl;
}
}
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)
if( LR->getTypeID() == Type::DoubleTyID )
ColorFound = findFloatColor( LR, 32, 64, IsColorUsedArr );
if( ColorFound >= 0 ) {
LR->setColor(ColorFound);
if( DEBUG_RA) UltraSparcRegInfo::printReg( LR );
return;
}
else { // the above fails or LR is single precision
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 ) {
LR->setColor(ColorFound);
if( DEBUG_RA) UltraSparcRegInfo::printReg( LR );
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();
if( DEBUG_RA) UltraSparcRegInfo::printReg( LR );
return;
}
// we are here because no color could be found
LR->markForSpill(); // no color found - must spill
if( DEBUG_RA) UltraSparcRegInfo::printReg( LR );
}