void Emit(char * filename)
{
Var * var;
EmitOpen(filename);
VarUse();
if (Verbose(NULL)) {
PrintHeader(1, "Variables");
for(var = VarFirst(); var != NULL; var = VarNext(var)) {
if (var->write >= 1 || var->read >= 1) {
if (var->mode == INSTR_VAR && !VarIsReg(var) && !VarIsLabel(var)) {
PrintVar(var); PrintEOL();
}
}
}
PrintHeader(1, "Output");
} // verbose
EmitLabels();
//TODO: ProcessUsedProc
// if (!EmitProc(&ROOT_PROC)) goto failure;
EmitProc(&ROOT_PROC);
EmitProcedures();
EmitAsmIncludes();
EmitInstrOp(INSTR_CODE_END, NULL, NULL, NULL);
VarEmitAlloc();
EmitInstrOp(INSTR_SRC_END, NULL, NULL, NULL);
EmitClose();
}
void PrintDelete()
{
UInt8 color;
if (G_VERBOSE) {
color = PrintColor(OPTIMIZE_COLOR);
Print(" => void"); PrintEOL();
PrintColor(color);
}
}
void VarSetPrint(VarSet * set)
{
VarTuple * tuple;
UInt16 cnt, i;
for(cnt = set->count, tuple = set->arr, i = 0; cnt>0; cnt--, tuple++, i++) {
PrintVar(tuple->key);
PrintEOL();
}
}
void PrintInsert(Instr * i)
{
UInt8 color;
if (G_VERBOSE) {
color = PrintColor(OPTIMIZE_COLOR);
Print(" + | ");
EmitInstrInline(i);
PrintColor(color);
PrintEOL();
}
}
Bool OptimizeLoop(Var * proc, InstrBlock * header, InstrBlock * end)
/*
1. Find loop (starting with inner loops)
- Every jump to label preceding the jump (backjump) forms a label
- In nested labels, we encounter the backjump first
<code1>
l1@
<code2>
l2@
<code3>
if.. l2@
<code4>
if.. l3@
<code5>
2. Select variable to put to register
- Most used variable should be used
- Some variables are already moved to index register (this is considered use too)
3. Compute cost of moving the variable to register
*/
{
Instr * i, initial, ti, * last_mod;
Var * top_var, * reg, * top_reg, * orig_result;
UInt16 r, regi, changed;
UInt32 var_size;
Int32 q, top_q, n;
Bool init, top_init;
InstrBlock * blk, * last_mod_blk;
InstrBlock * blk_exit;
Bool var_modified;
Bool verbose;
Rule * rule;
UInt8 color;
blk_exit = end->next;
G_VERBOSE = verbose = Verbose(proc);
VarResetUse();
InstrVarUse(header, blk_exit);
InstrVarLoopDependent(header, end);
// When processing, we assign var to register
for(regi = 0; regi < CPU->REG_CNT; regi++) CPU->REG[regi]->var = NULL;
while(top_var = FindMostUsedVar()) {
// if (Verbose(proc)) {
// Print("Most user var: "); PrintVar(top_var); PrintEOL();
// }
top_var->read = top_var->write = 0;
var_size = VarByteSize(top_var);
//====== Select the best register for the given variable
// let %A,%A => index -3
// use of register instead of variable -1
// spill +3
top_q = 0; top_reg = NULL; top_init = false;
for(regi = 0; regi < CPU->REG_CNT; regi++) {
reg = CPU->REG[regi];
if (FlagOn(reg->submode, SUBMODE_IN|SUBMODE_OUT)) continue; // exclude input/output registers
if (reg->type->range.max == 1) continue; // exclude flag registers
if (var_size != VarByteSize(reg)) continue; // exclude registers with different byte size
if (reg->var != NULL) continue;
if (InstrRule2(INSTR_LET, reg, top_var, NULL)) {
// if (StrEqual(reg->name, "x") && StrEqual(top_var->name, "i")) {
// Print(" ");
// }
q = UsageQuotient(header, end, top_var, reg, &init);
if (q < top_q) {
top_q = q;
top_reg = reg;
top_init = init;
}
}
}
if (top_reg == NULL) continue;
reg = top_reg;
if (Verbose(proc)) {
color = PrintColor(OPTIMIZE_COLOR);
PrintFmt("*** Loop %d..%d\n", header->seq_no, end->seq_no);
Print("Var: "); PrintVarVal(top_var); PrintEOL();
Print("Register: "); PrintVarName(top_reg); PrintEOL();
PrintFmt("Quotient: %d\n", top_q);
PrintColor(color);
}
//TODO: If there is Let reg = var and var is not top_var, we need to spill store
//=== Replace the use of registers
// PrintProc(proc);
ResetValues();
initial.op = INSTR_LET; initial.result = top_reg; initial.arg1 = top_var; initial.arg2 = NULL;
var_modified = false;
// Generate instruction initializing the register used to replace the variable
// before the start of the loop.
// We only do this, if the variable is not initialized inside the loop.
// if (FlagOn(top_var->flags, VarUninitialized) && !top_init) {
// top_init = true;
// }
if (top_init) {
LoopInsertPrologue(proc, header, INSTR_LET, top_reg, top_var, NULL);
VarSetSrcInstr(top_reg, &initial);
}
r = 0;
last_mod = NULL;
for(blk = header; blk != blk_exit; blk = blk->next) {
if (verbose) PrintBlockHeader(blk);
for(i = blk->first, n=0; i != NULL; i = i->next) {
retry:
n++;
if (i->op == INSTR_LINE) {
if (verbose) { PrintInstrLine(n); EmitInstrInline(i); PrintEOL(); }
continue;
}
// Delete unnecessary assignment
if (i->op == INSTR_LET) {
if (!InVar(i->arg1) && !OutVar(i->result) && VarContains(i->result, i->arg1)) {
del:
if (verbose) { PrintInstrLine(n); EmitInstrInline(i); }
del2: if (verbose) { PrintDelete(); }
i = InstrDelete(blk, i);
if (i == NULL) break;
goto retry; //continue;
}
}
// Load the register with variable if necessary
if (InstrReadsVar(i, top_var)) {
if (!VarContains(top_reg, top_var)) {
if (!(i->op == INSTR_LET && i->result == top_reg && i->arg1 == top_var)) {
InstrInsertRule(blk, i, INSTR_LET, top_reg, top_var, NULL);
}
}
}
if (i->op == INSTR_LET && (i->result == top_var && i->arg1 == top_reg)) {
r++;
goto del;
}
if (InstrSpill(i, top_var)) {
InstrInsertRule(blk, i, INSTR_LET, top_var, top_reg, NULL);
}
if (verbose) { PrintInstrLine(n); EmitInstrInline(i); }
orig_result = i->result;
memcpy(&ti, i, sizeof(Instr));
changed = VarTestReplace(&ti.result, top_var, reg);
r += changed;
changed += VarTestReplace(&ti.arg1, top_var, reg);
changed += VarTestReplace(&ti.arg2, top_var, reg);
// If the instruction used variable, that contains same value as replaced register, use the register instead
if (ti.arg1 != reg && VarContains(ti.arg1, reg)) {
changed += VarTestReplace(&ti.result, ti.arg1, reg);
changed += VarTestReplace(&ti.arg2, ti.arg1, reg);
changed += VarTestReplace(&ti.arg1, ti.arg1, reg);
}
if (changed > 0) {
if (i->op == INSTR_LET && ti.result == ti.arg1) {
goto del2;
}
rule = InstrRule(&ti);
if (rule != NULL && (i->rule->cycles >= rule->cycles)) {
InstrReplaceVar(i, top_var, top_reg);
if (i->arg1 != reg && VarContains(i->arg1, reg)) {
VarTestReplace(&i->result, i->arg1, reg);
VarTestReplace(&i->arg2, i->arg1, reg);
VarTestReplace(&i->arg1, i->arg1, reg);
}
i->rule = rule;
CheckInstr(i);
PrintChange(i);
}
}
if (verbose) PrintEOL();
ResetValue(i->result);
if (orig_result == top_var) {
// if (!InstrIsSelfReferencing(i)) {
VarSetSrcInstr(i->result, &initial);
// } else {
// VarSetSrcInstr(i->result, NULL);
// }
last_mod = i; last_mod_blk = blk;
} else {
VarSetSrcInstr(i->result, i);
}
}
}
// Value of register is not known at the end of loop, but it is not initialized at the beginning of the loop
// We must load it before first use.
if (!top_init && last_mod) {
InstrInsertRule(last_mod_blk, last_mod->next, INSTR_LET, top_var, top_reg, NULL);
}
// If we replaced some destination by the register, store the register to destination
if (r > 0) {
// There may be exit label as part of the loop
// We need to spill after it
if (!VarIsConst(top_var)) {
if (blk_exit == NULL || blk_exit->callers != NULL || blk_exit->from != end) {
blk_exit = InstrBlockAlloc();
blk_exit->to = end->to;
blk_exit->next = end->to;
end->next = blk_exit;
end->to = blk_exit;
}
InstrInsertRule(blk_exit, blk_exit->first, INSTR_LET, top_var, top_reg, NULL);
}
// InstrInsert(blk_exit, blk_exit->first, INSTR_LET, top_var, top_reg, NULL);
}
if (FlagOn(top_var->flags, VarLoopDependent)) {
reg->flags |= VarLoopDependent;
}
return true;
}
return false;
}
void VM_Dsr::EOL( QString /*value*/, long line, long level )
{
PrintEOL( line, level );
}
