The purpose of the code in this file is to optimize the register usage.
*/
-#include <stdio.h>
-#include "common.h" // Include everything in the SDCC src directory
-#include "newalloc.h"
-#include "ralloc.h"
-#include "device.h"
-#include "pcode.h"
+#include "main.h"
#include "pcoderegs.h"
#include "pcodeflow.h"
+#include "ralloc.h"
-extern void dbg_dumpregusage(void);
-extern pCode * findPrevInstruction(pCode *pci);
-extern pBranch * pBranchAppend(pBranch *h, pBranch *n);
-void unlinkpCode(pCode *pc);
-extern int pCodeSearchCondition(pCode *pc, unsigned int cond, int contIfSkip);
-char *pCode2str(char *str, int size, pCode *pc);
-void SAFE_snprintf(char **str, size_t *size, const char *format, ...);
-int total_registers_saved=0;
-int register_optimization=1;
-
-/*-----------------------------------------------------------------*
-* void AddRegToFlow(regs *reg, pCodeFlow *pcfl)
-*-----------------------------------------------------------------*/
-/*
-void AddRegToFlow(regs *reg, pCodeFlow *pcfl)
-{
-
- if(!reg || ! pcfl || !isPCFL(pcflow))
- return;
-
- if(!pcfl->registers)
- pcfl->registers = newSet();
-
-}
-*/
-
-
-/*-----------------------------------------------------------------*
-*
-*-----------------------------------------------------------------*/
-void dbg_regusage(set *fregs)
-{
- regs *reg;
- pCode *pcfl;
- pCode *pc;
-
-
- for (reg = setFirstItem(fregs) ; reg ;
- reg = setNextItem(fregs)) {
-
- if(elementsInSet(reg->reglives.usedpCodes)) {
-
- fprintf (stderr, "%s addr=0x%03x rIdx=0x%03x",
- reg->name,
- reg->address,
- reg->rIdx);
-
- pcfl = setFirstItem(reg->reglives.usedpFlows);
- if(pcfl)
- fprintf(stderr, "\n used in seq");
-
- while(pcfl) {
- fprintf(stderr," 0x%03x",pcfl->seq);
- pcfl = setNextItem(reg->reglives.usedpFlows);
- }
-
- pcfl = setFirstItem(reg->reglives.assignedpFlows);
- if(pcfl)
- fprintf(stderr, "\n assigned in seq");
-
- while(pcfl) {
- fprintf(stderr," 0x%03x",pcfl->seq);
- pcfl = setNextItem(reg->reglives.assignedpFlows);
- }
-
- pc = setFirstItem(reg->reglives.usedpCodes);
- if(pc)
- fprintf(stderr, "\n used in instructions ");
-
- while(pc) {
- pcfl = PCODE(PCI(pc)->pcflow);
- if(pcfl)
- fprintf(stderr," 0x%03x:",pcfl->seq);
- fprintf(stderr,"0x%03x",pc->seq);
-
- pc = setNextItem(reg->reglives.usedpCodes);
- }
-
- fprintf(stderr, "\n");
- }
- }
-}
-
-/*-----------------------------------------------------------------*
-*
-*-----------------------------------------------------------------*/
-void dbg_dumpregusage(void)
-{
-
- fprintf(stderr,"*** Register Usage ***\n");
- fprintf(stderr,"InternalRegs:\n");
- dbg_regusage(dynInternalRegs);
- fprintf(stderr,"AllocRegs:\n");
- dbg_regusage(dynAllocRegs);
- fprintf(stderr,"StackRegs:\n");
- dbg_regusage(dynStackRegs);
- fprintf(stderr,"DirectRegs:\n");
- dbg_regusage(dynDirectRegs);
- fprintf(stderr,"DirectBitRegs:\n");
- dbg_regusage(dynDirectBitRegs);
- fprintf(stderr,"ProcessorRegs:\n");
- dbg_regusage(dynProcessorRegs);
-
-}
+static int total_registers_saved=0;
+static int register_optimization=1;
/*-----------------------------------------------------------------*
* void pCodeRegMapLiveRangesInFlow(pCodeFlow *pcfl)
*-----------------------------------------------------------------*/
-void pCodeRegMapLiveRangesInFlow(pCodeFlow *pcfl)
+static void pCodeRegMapLiveRangesInFlow(pCodeFlow *pcfl)
{
pCode *pc=NULL;
- pCode *pcprev=NULL;
regs *reg;
pc = findNextInstruction(pcfl->pc.next);
- while(isPCinFlow(pc,PCODE(pcfl))) {
-
-
+ while(pc && !isPCFL(pc)) {
+ while (pc && !isPCI(pc) && !isPCFL(pc))
+ {
+ pc = pc->next;
+ } // while
+ if (!pc || isPCFL(pc)) continue;
+ assert( isPCI(pc) );
+
reg = getRegFromInstruction(pc);
-
+ #if 0
+ pc->print(stderr, pc);
+ fprintf( stderr, "--> reg %p (%s,%u), inCond/outCond: %x/%x\n",
+ reg, reg ? reg->name : "(null)", reg ? reg->rIdx : -1,
+ PCI(pc)->inCond, PCI(pc)->outCond );
+ #endif
if(reg) {
/*
fprintf(stderr, "flow seq %d, inst seq %d %s ",PCODE(pcfl)->seq,pc->seq,reg->name);
addSetIfnotP(& (PCFL(pcfl)->registers), reg);
- if((PCC_REGISTER | PCC_LITERAL) & PCI(pc)->inCond)
+ if(PCC_REGISTER & PCI(pc)->inCond)
addSetIfnotP(& (reg->reglives.usedpFlows), pcfl);
if(PCC_REGISTER & PCI(pc)->outCond)
addSetIfnotP(& (reg->reglives.assignedpFlows), pcfl);
addSetIfnotP(& (reg->reglives.usedpCodes), pc);
+ reg->wasUsed = 1;
}
- pcprev = pc;
- pc = findNextInstruction(pc->next);
+ //pc = findNextInstruction(pc->next);
+ pc = pc->next;
}
-
+
}
/*-----------------------------------------------------------------*
}
#endif
- // dbg_dumpregusage();
-
}
*-----------------------------------------------------------------*/
static void Remove1pcode(pCode *pc, regs *reg, int debug_code)
{
-
+
pCode *pcn=NULL;
if(!reg || !pc)
}
- if(1){
- /*
- Debug stuff. Comment out the instruction we're about to delete.
- */
+ if(1) {
+ /*
+ * Debug stuff. Comment out the instruction we're about to delete.
+ */
char buff1[256];
size_t size = 256;
- char *pbuff,**ppbuff;
- pbuff = buff1;
- ppbuff = &pbuff;
+ char *pbuff;
+ pbuff = &buff1[0];
- SAFE_snprintf(ppbuff,&size, ";%d", debug_code);
- pCode2str(*ppbuff, size, pc);
+ SNPRINTF(pbuff, size, ";%d", debug_code);
+ size -= strlen(pbuff);
+ pbuff += strlen(pbuff);
+ pCode2str(pbuff, size, pc);
pCodeInsertBefore(pc, newpCodeCharP(buff1));
//fprintf(stderr,"removing instruction:\n%s\n",buff1);
}
* void RemoveRegsFromSet(set *regset)
*
*-----------------------------------------------------------------*/
-void RemoveRegsFromSet(set *regset)
+static void RemoveRegsFromSet(set *regset)
{
regs *reg;
int used;
}
}
+
+static void pic14_ReMapLiveRanges(void)
+{
+ pBlock *pb;
+ if (!the_pFile) return;
+ RegsUnMapLiveRanges();
+ for (pb = the_pFile->pbHead; pb; pb = pb->next)
+ {
+ #if 0
+ pCode *pc = findNextpCode(pb->pcHead, PC_FLOW);
+ if (pc) {
+ pc->print( stderr, pc );
+ } else {
+ fprintf( stderr, "unnamed pBlock\n");
+ }
+ pc = findNextInstruction(pb->pcHead);
+ while (pc) {
+ pc->print( stderr, pc );
+ pc = findNextInstruction(pc->next);;
+ }
+ #endif
+ pCodeRegMapLiveRanges(pb);
+ } // for
+}
+
/*-----------------------------------------------------------------*
* void RemoveUnusedRegisters(void)
*
void RemoveUnusedRegisters(void)
{
/* First, get rid of registers that are used only one time */
+ pic14_ReMapLiveRanges();
//RemoveRegsFromSet(dynInternalRegs);
RemoveRegsFromSet(dynAllocRegs);
/*-----------------------------------------------------------------*
*
*-----------------------------------------------------------------*/
-int regUsedinRange(pCode *pc1, pCode *pc2, regs *reg)
+static int regUsedinRange(pCode *pc1, pCode *pc2, regs *reg)
{
int i=0;
regs *testreg;
return 0;
}
-int regIsSpecial (regs *reg, int mayBeGlobal)
+static int regIsSpecial (regs *reg, int mayBeGlobal)
{
if (!reg) return 0;
*
*
*-----------------------------------------------------------------*/
-int pCodeOptime2pCodes(pCode *pc1, pCode *pc2, pCode *pcfl_used, regs *reg, int can_free, int optimize_level)
+static int pCodeOptime2pCodes(pCode *pc1, pCode *pc2, pCode *pcfl_used, regs *reg, int can_free, int optimize_level)
{
pCode *pct1, *pct2;
regs *reg1, *reg2;
int t = total_registers_saved;
+
+ if (!isPCI(pc1) || !isPCI(pc2)) return 0;
+ if (PCI(pc1)->pcflow != PCI(pc2)->pcflow) return 0;
- if(pc2->seq < pc1->seq) {
+ if (pc2->seq < pc1->seq) {
pct1 = pc2;
pc2 = pc1;
pc1 = pct1;
}
+
+ /* disable this optimization for now -- it's buggy */
+ if (pic14_options.disable_df) return 0;
//fprintf(stderr,"pCodeOptime2pCodes\n");
//pc1->print(stderr,pc1);
//pc2->print(stderr,pc2);
-
+
if((PCI(pc1)->op == POC_CLRF) && (PCI(pc2)->op == POC_MOVFW) ){
+ /*
+ * CLRF sets Z
+ * MOVFW affects Z
+ * MOVWF does not touch Z
+ * MOVLW does not touch Z
+ */
pCode *newpc;
- int regUsed = 0;
- int wUsed = 0;
- int wSaved = 0;
/*
clrf reg ; pc1
stuff...
*/
DFPRINTF((stderr, " optimising CLRF reg ... MOVF reg,W to ... MOVLW 0\n"));
pct2 = findNextInstruction(pc2->next);
-
- if(pct2 && PCI(pct2)->op == POC_MOVWF) {
- wSaved = wUsed = 1; /* Maybe able to replace with clrf pc2->next->reg. */
- } else {
- wUsed = pCodeSearchCondition(pct2,PCC_W,1) > 0;
- }
- regUsed = regUsedinRange(pct2,0,reg);
- if ((regUsed&&wUsed) || (pCodeSearchCondition(pct2,PCC_Z,0) > 1)) {
- /* Do not optimise as exisiting code is required. */
- } else {
- /* Can optimise. */
- if(regUsed) {
- newpc = newpCode(POC_CLRF, PCI(pc1)->pcop);
- } else if(wSaved && !wUsed) {
- newpc = newpCode(POC_CLRF, PCI(pct2)->pcop);
- pct2->destruct(pct2);
- } else {
- newpc = newpCode(POC_MOVLW, newpCodeOpLit(0));
- }
+ if (pCodeSearchCondition(pct2, PCC_Z, 0) == -1) {
+ /* Z is definitely overwritten before use */
+ newpc = newpCode(POC_MOVLW, newpCodeOpLit(0));
pCodeInsertAfter(pc2, newpc);
PCI(newpc)->pcflow = PCFL(pcfl_used);
newpc->seq = pc2->seq;
//fprintf (stderr, "%s:%d(%s): Remove2pcodes (CLRF reg, ..., MOVF reg,W)\n", __FILE__, __LINE__, __FUNCTION__);
- Remove2pcodes(pcfl_used, pc1, pc2, reg, can_free);
- total_registers_saved++; // debugging stats.
+ //Remove2pcodes(pcfl_used, pc2, NULL, reg, 0);
+ pc2->destruct(pc2);
+ //total_registers_saved++; // debugging stats.
}
} else if((PCI(pc1)->op == POC_CLRF) && (PCI(pc2)->op == POC_IORFW) ){
DFPRINTF((stderr, " optimising CLRF/IORFW\n"));
pct2 = findNextInstruction(pc2->next);
- if(pCodeSearchCondition(pct2, PCC_Z,0) > 0) {
+ /* We must ensure that Z is destroyed before being read---IORLW must be performed unless this is proven. */
+ if (pCodeSearchCondition(pct2, PCC_Z, 0) != -1) {
pct2 = newpCode(POC_IORLW, newpCodeOpLit(0));
pct2->seq = pc2->seq;
PCI(pct2)->pcflow = PCFL(pcfl_used);
if (reg2 && !regIsSpecial (reg2, 1) && !regUsedinRange(pc1,pc2,reg2)) {
pCode *pct3 = findNextInstruction(pct2->next);
/* Check following instructions are not relying on the use of W or the Z flag condiction */
- if ((pCodeSearchCondition(pct3,PCC_Z,0) < 1) || (pCodeSearchCondition(pct3,PCC_W,0) < 1)) {
+ /* XXX: We must ensure that this value is destroyed before use---otherwise it might be used in
+ * subsequent flows (checking for < 1 is insufficient). */
+ if ((pCodeSearchCondition(pct3,PCC_Z,0) == -1) && (pCodeSearchCondition(pct3,PCC_W,0) == -1)) {
DFPRINTF((stderr, " optimising MOVF reg ... MOVF reg,W MOVWF reg2 to MOVWF reg2 ...\n"));
pct2->seq = pc1->seq;
unlinkpCode(pct2);
/*-----------------------------------------------------------------*
* void pCodeRegOptimeRegUsage(pBlock *pb)
*-----------------------------------------------------------------*/
-void OptimizeRegUsage(set *fregs, int optimize_multi_uses, int optimize_level)
+static void OptimizeRegUsage(set *fregs, int optimize_multi_uses, int optimize_level)
{
regs *reg;
int used;
fprintf(stderr,"Reg: %s\n",reg->name);
*/
+ /* Catch inconsistently set-up live ranges
+ * (see tracker items #1469504 + #1474602)
+ * FIXME: Actually we should rather fix the
+ * computation of the liveranges instead...
+ */
+ if (!reg || !reg->reglives.usedpFlows
+ || !reg->reglives.assignedpFlows)
+ {
+ //fprintf( stderr, "skipping reg w/o liveranges: %s\n", reg ? reg->name : "(unknown)");
+ continue;
+ }
+
if(reg->type == REG_SFR || reg->type == REG_STK || reg->isPublic || reg->isExtern|| reg->isFixed) {
//fprintf(stderr,"skipping SFR: %s\n",reg->name);
continue;
}
-
+
pcfl_used = setFirstItem(reg->reglives.usedpFlows);
pcfl_assigned = setFirstItem(reg->reglives.assignedpFlows);
if(pc1 && isPCI(pc1) && ( (pcfl1 = PCI(pc1)->pcflow) != NULL) ) {
- //while(rset2 && searching) {
if(rset2) {
pc2 = rset2->item;
}
}
- rset1 = rset1->next;
+ rset1 = rset2;
}
}
}
int passes;
int saved = 0;
int t = total_registers_saved;
-
+
+#if 0
+ /* This is currently broken (need rewrite to correctly
+ * handle arbitrary pCodeOps instead of registers only). */
+ if (!pic14_options.disable_df)
+ optimizeDataflow ();
+#endif
+
if(!register_optimization)
return;
#define OPT_PASSES 4
if(total_registers_saved == t)
DFPRINTF((stderr, "No registers saved on this pass\n"));
-
-
- /*
- fprintf(stderr,"dynamically allocated regs:\n");
- dbg_regusage(dynAllocRegs);
- fprintf(stderr,"stack regs:\n");
- dbg_regusage(dynStackRegs);
- fprintf(stderr,"direct regs:\n");
- dbg_regusage(dynDirectRegs);
- */
}
* void RegsUnMapLiveRanges(set *regset)
*
*-----------------------------------------------------------------*/
-void RegsSetUnMapLiveRanges(set *regset)
+static void RegsSetUnMapLiveRanges(set *regset)
{
regs *reg;
projects / fw / sdcc / blobdiff