static void CopyAuxInfo( void )
/*****************************/
{
hw_reg_set default_flt_n_seg;
hw_reg_set flt_n_seg;
if( CurrEntry == NULL ) {
// Redefining a built-in calling convention
} else {
CurrInfo = (struct aux_info *)CMemAlloc( sizeof( struct aux_info ) );
*CurrInfo = *CurrAlias;
}
if( AuxInfo.code != NULL ) {
CurrInfo->code = AuxInfo.code;
}
if( AuxInfoFlg.f_near ) {
CurrInfo->cclass &= ~FAR;
}
if( AuxInfoFlg.f_routine_pops ) {
CurrInfo->cclass &= ~CALLER_POPS;
}
if( AuxInfoFlg.f_caller_return ) {
CurrInfo->cclass &= ~ROUTINE_RETURN;
}
if( AuxInfoFlg.f_8087_returns ) {
CurrInfo->cclass &= ~NO_8087_RETURNS;
}
CurrInfo->cclass |= AuxInfo.cclass;
CurrInfo->flags |= AuxInfo.flags;
if( AuxInfo.objname != NULL )
CurrInfo->objname = AuxInfo.objname;
if( AuxInfo.cclass & SPECIAL_RETURN )
CurrInfo->returns = AuxInfo.returns;
if( AuxInfo.cclass & SPECIAL_STRUCT_RETURN )
CurrInfo->streturn = AuxInfo.streturn;
if( AuxInfo.parms != NULL )
CurrInfo->parms = AuxInfo.parms;
if( !HW_CEqual( AuxInfo.save, HW_EMPTY ) ) {
HW_CTurnOn( CurrInfo->save, HW_FULL );
if( !( AuxInfo.cclass & MODIFY_EXACT ) && !CompFlags.save_restore_segregs ) {
HW_Asgn( default_flt_n_seg, WatcallInfo.save );
HW_CAsgn( flt_n_seg, HW_FLTS );
HW_CTurnOn( flt_n_seg, HW_SEGS );
HW_TurnOff( CurrInfo->save, flt_n_seg );
HW_OnlyOn( default_flt_n_seg, flt_n_seg );
HW_TurnOn( CurrInfo->save, default_flt_n_seg );
}
HW_TurnOff( CurrInfo->save, AuxInfo.save );
}
}
static void GetSaveInfo(
void )
{
hw_reg_set modlist;
hw_reg_set default_flt_n_seg;
hw_reg_set flt_n_seg;
struct {
unsigned f_exact : 1;
unsigned f_nomemory : 1;
unsigned f_list : 1;
} have;
have.f_exact = 0;
have.f_nomemory = 0;
have.f_list = 0;
for( ;; ) {
if( !have.f_exact && PragRecog( "exact" ) ) {
CurrInfo->cclass |= MODIFY_EXACT;
have.f_exact = 1;
} else if( !have.f_nomemory && PragRecog( "nomemory" ) ) {
CurrInfo->cclass |= NO_MEMORY_CHANGED;
have.f_nomemory = 1;
} else if( !have.f_list && IS_REGSET( CurToken ) ) {
modlist = PragRegList();
have.f_list = 1;
} else {
break;
}
}
if( have.f_list ) {
HW_Asgn( default_flt_n_seg, DefaultInfo.save );
HW_CTurnOn( CurrInfo->save, HW_FULL );
if( !have.f_exact && !CompFlags.save_restore_segregs ) {
HW_CAsgn( flt_n_seg, HW_FLTS );
HW_CTurnOn( flt_n_seg, HW_SEGS );
HW_TurnOff( CurrInfo->save, flt_n_seg );
HW_OnlyOn( default_flt_n_seg, flt_n_seg );
HW_TurnOn( CurrInfo->save, default_flt_n_seg );
}
HW_TurnOff( CurrInfo->save, modlist );
}
}
void FlowSave( hw_reg_set *preg )
/*******************************/
{
int score;
int i, j;
int best;
int num_blocks;
int num_regs;
int curr_reg;
hw_reg_set *curr_push;
reg_flow_info *reg_info;
block *save;
block *restore;
instruction *ins;
type_class_def reg_type;
HW_CAsgn( flowedRegs, HW_EMPTY );
if( _IsntModel( FLOW_REG_SAVES ) ) return;
if( !HaveDominatorInfo ) return;
// we can't do this if we have push's which are 'live' at the end of a block
// - this flag is set when we see a push being generated for a call in a different
// block
#if _TARGET & _TARG_INTEL
if( CurrProc->targ.never_sp_frame ) return;
#endif
num_regs = CountRegs( *preg );
if( num_regs == 0 ) return;
reg_info = CGAlloc( num_regs * sizeof( reg_flow_info ) );
num_blocks = CountBlocks();
InitBlockArray();
curr_push = PushRegs;
for( curr_reg = 0; curr_reg < num_regs; curr_reg++ ) {
while( !HW_Ovlap( *curr_push, *preg ) ) curr_push++;
HW_Asgn( reg_info[curr_reg].reg, *curr_push );
reg_info[curr_reg].save = NULL;
reg_info[curr_reg].restore = NULL;
#if _TARGET & _TARG_INTEL
if( HW_COvlap( *curr_push, HW_BP ) ) continue; // don't mess with BP - it's magical
#endif
GetRegUsage( ®_info[curr_reg] );
best = 0;
for( i = 0; i < num_blocks; i++ ) {
for( j = 0; j < num_blocks; j++ ) {
if( PairOk( blockArray[i], blockArray[j], ®_info[0], curr_reg ) ) {
// we use the number of blocks dominated by the save block plus
// the number of blocks post-dominated by the restore block as a
// rough metric for determining how much we like a given (valid)
// pair of blocks - the more blocks dominated, the further 'in'
// we have pushed the save, which should be good
score = CountDomBits( &blockArray[i]->dom.dominator );
score += CountDomBits( &blockArray[j]->dom.post_dominator );
if( score > best ) {
best = score;
reg_info[curr_reg].save = blockArray[i];
reg_info[curr_reg].restore = blockArray[j];
}
}
}
}
// so now we know where we are going to save and restore the register
// emit the instructions to do so, and remove reg from the set to push
// in the normal prolog sequence
save = reg_info[curr_reg].save;
restore = reg_info[curr_reg].restore;
if( ( save != NULL && save != HeadBlock ) && ( restore != NULL && !_IsBlkAttr( restore, BLK_RETURN ) ) ) {
reg_type = WD;
#if _TARGET & _TARG_INTEL
if( IsSegReg( reg_info[curr_reg].reg ) ) {
reg_type = U2;
}
#endif
ins = MakeUnary( OP_PUSH, AllocRegName( reg_info[curr_reg].reg ), NULL, reg_type );
ResetGenEntry( ins );
PrefixIns( save->ins.hd.next, ins );
ins = MakeUnary( OP_POP, NULL, AllocRegName( reg_info[curr_reg].reg ), reg_type );
ins->num_operands = 0;
ResetGenEntry( ins );
SuffixIns( restore->ins.hd.prev, ins );
HW_TurnOff( *preg, reg_info[curr_reg].reg );
HW_TurnOn( flowedRegs, reg_info[curr_reg].reg );
FixStackDepth( save, restore );
}
curr_push++;
}
CGFree( reg_info );
}
