* src/pic/pcode.c (sameBank,FixRegisterBanking): optimize banksels

  based on absolute register address, patch by Alex Blond

git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@4595 4a8a32a2-be11-0410-ad9d-d568d2c75423

diff --git a/ChangeLog b/ChangeLog
index 46c0dd588153fc9db26247abaa46c041519958c8..1fc1679e5bb11e9ffcdc048e32a4e048c601ad3a 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2007-01-25 Raphael Neider <rneider AT web.de>
+
+       * src/pic/pcode.c (sameBank,FixRegisterBanking): optimize banksels
+         based on absolute register address, patch by Alex Blond
+
 2007-01-22 Raphael Neider <rneider AT web.de>
 
        * src/pic/glue.c (pic14emitRegularMap): mark initialized symbols as

diff --git a/src/pic/pcode.c b/src/pic/pcode.c
index 82e5397109ed6ca2d255bad1d5112810706e15c8..48c1928f5f6d14a719476f405b71ce29d5a20526 100644 (file)
--- a/src/pic/pcode.c
+++ b/src/pic/pcode.c
@@ -4629,7 +4629,7 @@ static void insertBankSel(pCodeInstruction  *pci, const char *name)
 
 /*-----------------------------------------------------------------*/
 /*-----------------------------------------------------------------*/
-static int sameBank(regs *reg, const char *new_bank, const char *cur_bank)
+static int sameBank(regs *reg, regs *previous_reg, const char *new_bank, const char *cur_bank, unsigned max_mask)
 {
     if (!cur_bank) return 0;
 
@@ -4639,6 +4639,9 @@ static int sameBank(regs *reg, const char *new_bank, const char *cur_bank)
     if (cur_bank[0] == '(' && reg && reg->name && !strncmp(reg->name, &cur_bank[1], strlen(reg->name))) return 1;
     if (cur_bank[0] == '(' && new_bank && !strncmp(new_bank, &cur_bank[1], strlen(new_bank))) return 1;
     
+    if (previous_reg && reg && previous_reg->isFixed && reg->isFixed && ((previous_reg->address & max_mask) == (reg->address & max_mask)))     // only if exists 
+      return 1;  // if we have address info, we use it for banksel optimization
+
     // XXX: identify '(regname + X)' and '(regname + Y)'
     
     return ((reg && reg->name && !strcmp(reg->name, cur_bank)) || (new_bank && !strcmp(new_bank, cur_bank)));
@@ -4651,6 +4654,7 @@ void FixRegisterBanking(pBlock *pb)
     pCode *pc;
     pCodeInstruction *pci;
     regs *reg;
+    regs *previous_reg;                // contains the previous variable access info
     const char *cur_bank, *new_bank;
     unsigned cur_mask, new_mask, max_mask;
     int allRAMmshared;
@@ -4660,6 +4664,7 @@ void FixRegisterBanking(pBlock *pb)
     max_mask = pic14_getPIC()->bankMask;
     cur_mask = max_mask;
     cur_bank = NULL;
+    previous_reg = NULL;
 
     allRAMmshared = pic14_allRAMShared();
 
@@ -4668,6 +4673,7 @@ void FixRegisterBanking(pBlock *pb)
        // this one has a label---might check bank at all jumps here...
        if (isPCI(pc) && (PCI(pc)->label || PCI(pc)->op == POC_CALL)) {
            addpCodeComment(pc->prev, "BANKOPT3 drop assumptions: PCI with label or call found");
+            previous_reg = NULL;
            cur_bank = NULL; // start new flow
            cur_mask = max_mask;
        }
@@ -4675,6 +4681,7 @@ void FixRegisterBanking(pBlock *pb)
        // this one is/might be a label or BANKSEL---assume nothing
        if (isPCL(pc) || isPCASMDIR(pc)) {
            addpCodeComment(pc->prev, "BANKOPT4 drop assumptions: label or ASMDIR found");
+            previous_reg = NULL;
            cur_bank = NULL;
            cur_mask = max_mask;
        }
@@ -4722,7 +4729,7 @@ void FixRegisterBanking(pBlock *pb)
                    // is in (as well as the previous registers)
                    cur_mask &= new_mask;
 
-                   if (sameBank(reg, new_bank, cur_bank)) {
+                   if (sameBank(reg, previous_reg, new_bank, cur_bank, max_mask)) {
                        // no BANKSEL required
                        addpCodeComment(pc->prev, "BANKOPT2 BANKSEL dropped; %s present in same bank as %s", new_bank, cur_bank);
                        continue;
@@ -4731,6 +4738,7 @@ void FixRegisterBanking(pBlock *pb)
 
                cur_mask = new_mask;
                cur_bank = new_bank;
+               previous_reg = reg;
                insertBankSel(pci, cur_bank);
            } // if
        } // if