* src/pic/gen.c (popGetExternal): augmented to also create references

  to external variables (not only labels),
  (genCall): comment on plan to reduce PAGESEL overhead,
  (genFunction, genEndFunction): also save/restore FSR around interrupt
  handling code, removed lots of unused code
  (genDivOneByte): release acquired temp register
* src/pic/glue.c (pic14createInterruptVect): adadt to new signature
  of popGetExternal
* device/lib/pic/libsdcc/shadowregs.c: NEW, provide storage location
  for registers that need to be saved during interrupts (FSR, STATUS,
  PCLATH; W needs special handling), currently only FSR is used

git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@4708 4a8a32a2-be11-0410-ad9d-d568d2c75423

diff --git a/ChangeLog b/ChangeLog
index fce6989f3c4a6654e0aa1b6c14292afab5e7a145..bb2951e4dcaaa72255e4d31375a63bd48ef154b7 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+2007-03-22 Raphael Neider <rneider AT web.de>
+
+       * src/pic/gen.c (popGetExternal): augmented to also create references
+         to external variables (not only labels),
+         (genCall): comment on plan to reduce PAGESEL overhead,
+         (genFunction, genEndFunction): also save/restore FSR around interrupt
+         handling code, removed lots of unused code
+         (genDivOneByte): release acquired temp register
+       * src/pic/glue.c (pic14createInterruptVect): adadt to new signature
+         of popGetExternal
+       * device/lib/pic/libsdcc/shadowregs.c: NEW, provide storage location
+         for registers that need to be saved during interrupts (FSR, STATUS,
+         PCLATH; W needs special handling), currently only FSR is used
+
 2007-03-22 Raphael Neider <rneider AT web.de>
 
        * device/include/pic/pic14devices.txt: 16f688 has only one config word

diff --git a/device/lib/pic/libsdcc/shadowregs.c b/device/lib/pic/libsdcc/shadowregs.c
new file mode 100644 (file)
index 0000000..8824ba5
--- /dev/null
+++ b/device/lib/pic/libsdcc/shadowregs.c
@@ -0,0 +1,19 @@
+/*
+ * shadowregs.c - provide shadow register for use during interrupts
+ *
+ * (c) 2007 by Raphael Neider <rneider @ web.de>
+ * 
+ * This file is part of SDCC's pic14 library and distributed under
+ * the terms of the GPLv2 with linking exception; see COPYING in some
+ * parent directory for details.
+ */
+
+/* 
+ * We should make sure these always reside in the same bank,
+ * so that we can save two BANKSELs in the interrupt entry code.
+ */
+
+unsigned char __sdcc_saved_fsr;
+//unsigned char __sdcc_saved_pclath;
+//unsigned char __sdcc_saved_status;
+

diff --git a/src/pic/gen.c b/src/pic/gen.c
index cfbd202863db2b4e8998f631b2215d03c82d02f0..fb514994de2692dc1787786dd2d4ed9d27581249 100644 (file)
--- a/src/pic/gen.c
+++ b/src/pic/gen.c
@@ -1272,9 +1272,15 @@ pCodeOp *popGetWithString(char *str, int isExtern)
        return pcop;
 }
 
-pCodeOp *popGetExternal (char *str)
+pCodeOp *popGetExternal (char *str, int isReg)
 {
-       pCodeOp *pcop = popGetWithString (str, 1);
+       pCodeOp *pcop;
+       
+       if (isReg) {
+           pcop = newpCodeOpRegFromStr(str);
+       } else {
+           pcop = popGetWithString (str, 1);
+       }
        
        if (str) {
          symbol *sym;
@@ -1830,7 +1836,7 @@ static void call_libraryfunc (char *name)
     /* library code might reside in different page... */
     emitpcode (POC_PAGESEL, popGetWithString (name, 1));
     /* call the library function */
-    emitpcode (POC_CALL, popGetExternal (name));
+    emitpcode (POC_CALL, popGetExternal (name, 0));
     /* might return from different page... */
     emitpcode (POC_PAGESEL, popGetWithString ("$", 0));
 
@@ -2626,6 +2632,16 @@ static void genCall (iCode *ic)
        /* make the call */
        sym = OP_SYMBOL(IC_LEFT(ic));
        name = sym->rname[0] ? sym->rname : sym->name;
+       /*
+        * As SDCC emits code as soon as it reaches the end of each
+        * function's definition, prototyped functions that are implemented
+        * after the current one are always considered EXTERN, which
+        * introduces many unneccessary PAGESEL instructions.
+        * XXX: Use a post pass to iterate over all `CALL _name' statements
+        * and insert `PAGESEL _name' and `PAGESEL $' around the CALL
+        * only iff there is no definition of the function in the whole
+        * file (might include this in the PAGESEL pass).
+        */
        isExtern = IS_EXTERN(sym->etype) || pic14_inISR;
        if (isExtern) {
                /* Extern functions and ISRs maybe on a different page;
@@ -2877,74 +2893,25 @@ static void genFunction (iCode *ic)
        pic14_inISR = 0;
        if (IFFUNC_ISISR(sym->type)) {
                pic14_inISR = 1;
-       /*  already done in pic14createInterruptVect() - delete me
-       addpCode2pBlock(pb,newpCode(POC_GOTO,newpCodeOp("END_OF_INTERRUPT+1",PO_STR)));
-       emitpcodeNULLop(POC_NOP);
-       emitpcodeNULLop(POC_NOP);
-       emitpcodeNULLop(POC_NOP);
-               */
                emitpcode(POC_MOVWF,  popCopyReg(&pc_wsave));
                emitpcode(POC_SWAPFW, popCopyReg(&pc_status));
+               /* XXX: Why? Does this assume that ssave and psave reside
+                * in a shared bank or bank0? We cannot guarantee the
+                * latter...
+                */
                emitpcode(POC_CLRF,   popCopyReg(&pc_status));
                emitpcode(POC_MOVWF,  popCopyReg(&pc_ssave));
+               //emitpcode(POC_MOVWF,  popGetExternal("___sdcc_saved_status",1 ));
                emitpcode(POC_MOVFW,  popCopyReg(&pc_pclath));
+               /* during an interrupt PCLATH must be cleared before a goto or call statement */
+               emitpcode(POC_CLRF,   popCopyReg(&pc_pclath));
                emitpcode(POC_MOVWF,  popCopyReg(&pc_psave));
-               emitpcode(POC_CLRF,   popCopyReg(&pc_pclath));/* during an interrupt PCLATH must be cleared before a goto or call statement */
+               //emitpcode(POC_MOVWF,  popGetExternal("___sdcc_saved_pclath", 1));
+               emitpcode(POC_MOVFW,  popCopyReg(&pc_fsr));
+               emitpcode(POC_MOVWF,  popGetExternal("___sdcc_saved_fsr", 1));
                
                pBlockConvert2ISR(pb);
                pic14_hasInterrupt = 1;
-#if 0  
-               if (!inExcludeList("acc"))              
-                       pic14_emitcode ("push","acc");  
-               if (!inExcludeList("b"))
-                       pic14_emitcode ("push","b");
-               if (!inExcludeList("dpl"))
-                       pic14_emitcode ("push","dpl");
-               if (!inExcludeList("dph"))
-                       pic14_emitcode ("push","dph");
-               if (options.model == MODEL_FLAT24 && !inExcludeList("dpx"))
-               {
-                       pic14_emitcode ("push", "dpx");
-                       /* Make sure we're using standard DPTR */
-                       pic14_emitcode ("push", "dps");
-                       pic14_emitcode ("mov", "dps, #0x00");
-                       if (options.stack10bit)
-                       { 
-                               /* This ISR could conceivably use DPTR2. Better save it. */
-                               pic14_emitcode ("push", "dpl1");
-                               pic14_emitcode ("push", "dph1");
-                               pic14_emitcode ("push", "dpx1");
-                       }
-               }
-               /* if this isr has no bank i.e. is going to
-               run with bank 0 , then we need to save more
-               registers :-) */
-               if (!FUNC_REGBANK(sym->type)) {
-                       
-               /* if this function does not call any other
-               function then we can be economical and
-                       save only those registers that are used */
-                       if (! IFFUNC_HASFCALL(sym->type)) {
-                               int i;
-                               
-                               /* if any registers used */
-                               if (sym->regsUsed) {
-                                       /* save the registers used */
-                                       for ( i = 0 ; i < sym->regsUsed->size ; i++) {
-                                               if (bitVectBitValue(sym->regsUsed,i) ||
-                                                       (pic14_ptrRegReq && (i == R0_IDX || i == R1_IDX)) )
-                                                       pic14_emitcode("push","junk");//"%s",pic14_regWithIdx(i)->dname);               
-                                       }
-                               }
-                               
-                       } else {
-                       /* this function has    a function call cannot
-                       determines register usage so we will have the
-                               entire bank */
-                               saverbank(0,ic,FALSE);
-                       }       
-               }
-#endif
        } else {
        /* if callee-save to be used for this function
                then save the registers being used in this function */
@@ -3089,40 +3056,19 @@ registers :-) */
                                unsaverbank(0,ic,FALSE);
                        }       
                }
-#if 0
-               if (options.model == MODEL_FLAT24 && !inExcludeList("dpx"))
-               {
-                       if (options.stack10bit)
-                       {
-                               pic14_emitcode ("pop", "dpx1");
-                               pic14_emitcode ("pop", "dph1");
-                               pic14_emitcode ("pop", "dpl1");
-                       } 
-                       pic14_emitcode ("pop", "dps");
-                       pic14_emitcode ("pop", "dpx");
-               }
-               if (!inExcludeList("dph"))
-                       pic14_emitcode ("pop","dph");
-               if (!inExcludeList("dpl"))
-                       pic14_emitcode ("pop","dpl");
-               if (!inExcludeList("b"))
-                       pic14_emitcode ("pop","b");
-               if (!inExcludeList("acc"))
-                       pic14_emitcode ("pop","acc");
-               
-               if (IFFUNC_ISCRITICAL(sym->type))
-                       pic14_emitcode("setb","ea");
-#endif
                
                /* if debug then send end of function */
                if (options.debug && debugFile && currFunc) {
                        debugFile->writeEndFunction (currFunc, ic, 1);
                }
                
-               pic14_emitcode ("reti","");
+               emitpcode(POC_MOVFW,  popGetExternal("___sdcc_saved_fsr", 1));
+               emitpcode(POC_MOVWF,  popCopyReg(&pc_fsr));
+               //emitpcode(POC_MOVFW,  popGetExternal("___sdcc_saved_pclath", 1));
                emitpcode(POC_MOVFW,  popCopyReg(&pc_psave));
                emitpcode(POC_MOVWF,  popCopyReg(&pc_pclath));
-               emitpcode(POC_CLRF,   popCopyReg(&pc_status));
+               emitpcode(POC_CLRF,   popCopyReg(&pc_status)); // see genFunction
+               //emitpcode(POC_SWAPFW, popGetExternal("___sdcc_saved_status", 1));
                emitpcode(POC_SWAPFW, popCopyReg(&pc_ssave));
                emitpcode(POC_MOVWF,  popCopyReg(&pc_status));
                emitpcode(POC_SWAPF,  popCopyReg(&pc_wsave));
@@ -3452,6 +3398,7 @@ static void genDivOneByte (operand *left,
                emitSKPNC;
                emitpcode(POC_GOTO, popGetLabel(lbl->key));
                emitpcode(POC_DECF, popGet(AOP(result),0));
+               popReleaseTempReg(temp);
        #endif
        }
        else

diff --git a/src/pic/glue.c b/src/pic/glue.c
index 51050ae07dd27508946cd1a39b1aaeac97e633e1..b3d2f4da6be4722ebcc9e701e6f5e01d520268ee 100644 (file)
--- a/src/pic/glue.c
+++ b/src/pic/glue.c
@@ -968,7 +968,7 @@ pic14emitMaps ()
 /*-----------------------------------------------------------------*/
 /* createInterruptVect - creates the interrupt vector              */
 /*-----------------------------------------------------------------*/
-pCodeOp *popGetExternal (char *str);
+pCodeOp *popGetExternal (char *str, int isReg);
 static void
 pic14createInterruptVect (struct dbuf_s * vBuf)
 {
@@ -1002,7 +1002,7 @@ pic14createInterruptVect (struct dbuf_s * vBuf)
        dbuf_printf (vBuf, "\tnop\n"); /* first location for used by incircuit debugger */
        dbuf_printf (vBuf, "\tpagesel __sdcc_gsinit_startup\n");
        dbuf_printf (vBuf, "\tgoto\t__sdcc_gsinit_startup\n");
-       popGetExternal("__sdcc_gsinit_startup");
+       popGetExternal("__sdcc_gsinit_startup", 0);
 }