5 // ; Peephole 1 removed pop %1 push %1 (not push pop)
13 // ; Peephole 2 removed pop %1 push %1 (not push pop)
18 // added by Jean Louis VERN for
24 ; Peephole 2.a removed redundant xch xch
32 ; Peephole 3.a changed mov to clr
42 ; Peephole 3.b changed mov to clr
48 // saving 1 byte, loosing 1 cycle but maybe allowing peephole 3.b to start
53 ; Peephole 3.c changed mov to clr
69 ; Peephole 3.d removed redundant clr
83 ; Peephole 3.e removed redundant clr
99 ; Peephole 3.f removed redundant clr
117 ; Peephole 3.g removed redundant clr
129 ; Peephole 3.h changed mov %3,#0x00 to ...,a
144 ; Peephole 3.i changed mov %4,#0x00 to ...,a
161 ; Peephole 3.j changed mov %5,#0x00 to ...,a
180 ; Peephole 3.k changed mov %6,#0x00 to ...,a
192 ; Peephole 100 removed redundant mov
206 ; Peephole 101 removed redundant mov
221 ; Peephole 102 removed redundant mov
243 ; Peephole 103 removed redundant mov
260 ; Peephole 104 optimized increment (acc not set to r%1, flags undefined)
270 ; Peephole 105 removed redundant mov
280 ; Peephole 106 removed redundant mov
287 ; Peephole 107 removed redundant ljmp
289 } if labelRefCountChange(%1 -1)
296 ; Peephole 108.a removed ljmp by inverse jump logic
299 } if labelInRange(), labelRefCountChange(%1 -1)
306 ; Peephole 108.b removed ljmp by inverse jump logic
309 } if labelInRange(), labelRefCountChange(%1 -1)
316 ; Peephole 108.c removed ljmp by inverse jump logic
319 } if labelInRange(), labelRefCountChange(%1 -1)
326 ; Peephole 108.d removed ljmp by inverse jump logic
329 } if labelInRange(), labelRefCountChange(%2 -1)
336 ; Peephole 108.e removed ljmp by inverse jump logic
339 } if labelInRange(), labelRefCountChange(%2 -1)
345 ; Peephole 112.b changed ljmp to sjmp
358 ; Peephole 113.a optimized misc sequence
363 } if labelRefCount %3 1
374 ; Peephole 113.b optimized misc sequence
380 } if labelRefCount %3 2
389 ; Peephole 115.a jump optimization (acc not set)
393 } if labelRefCount %3 1
402 ; Peephole 115.b jump optimization
405 } if labelRefCountChange(%2 -1)
415 ; Peephole 115.c jump optimization (acc not set)
420 } if labelRefCount %3 2
431 ; Peephole 115.d jump optimization (acc not set)
437 } if labelRefCount %3 3
449 ; Peephole 115.e jump optimization (acc not set)
456 } if labelRefCount %3 4
465 ; Peephole 115.f jump optimization (acc not set)
468 } if labelRefCount(%3 1), labelRefCountChange(%3 -1)
478 ; Peephole 115.g jump optimization (acc not set)
482 } if labelRefCount(%3 2), labelRefCountChange(%3 -2), labelRefCountChange(%4 1)
493 ; Peephole 115.h jump optimization (acc not set)
498 } if labelRefCount(%3 3), labelRefCountChange(%3 -3), labelRefCountChange(%4 2)
510 ; Peephole 115.i jump optimization (acc not set)
516 } if labelRefCount(%3 4), labelRefCountChange(%3 -4), labelRefCountChange(%4 3)
525 ; Peephole 115.j jump optimization (acc not set)
529 } if labelRefCount %3 1
539 ; Peephole 115.k jump optimization (acc not set)
544 } if labelRefCount %3 2
555 ; Peephole 115.l jump optimization (acc not set)
561 } if labelRefCount %3 3
573 ; Peephole 115.m jump optimization (acc not set)
580 } if labelRefCount %3 4
593 ; Peephole 127 removed misc sequence
595 } if labelRefCount %3 0
602 ; Peephole 128 jump optimization
606 // applies to: bug-524691.c --model-large: while (uRight - uLeft > 1)
612 ; Peephole 129.a jump optimization
616 // applies to: _fsdiv.c --xstack: if (mant1 < mant2)
623 ; Peephole 129.b optimized condition
628 // applies to: time.c --xstack: while((days += (LEAP_YEAR(year) ? 366 : 365)) <= epoch)
636 ; Peephole 129.c optimized condition
640 } if notVolatile %1 %2
642 // applies to: _memmove.c --xstack: if (((int)src < (int)dst) && ((((int)src)+acount) > (int)dst))
651 ; Peephole 129.d optimized condition
656 } if notVolatile %1 %2 %3
661 ; Peephole 130 changed target address mode r%1 to ar%1
671 ; Peephole 131 optimized decrement (not caring for c)
676 // ideally the optimizations of rules 132.x should be done in genCmpXX
683 ; Peephole 132.a optimized genCmpGt by inverse logic (acc differs)
687 } if operandsLiteral(%1)
695 ; Peephole 132.b optimized genCmpGt by inverse logic (acc differs)
699 } if operandsLiteral(%1)
707 ; Peephole 132.c optimized genCmpGt by inverse logic (acc differs)
711 } if operandsLiteral(%1)
719 ; Peephole 132.d optimized genCmpGt by inverse logic
723 } if operandsNotRelated('0x00' %2), operandsLiteral(%2)
731 ; Peephole 132.e optimized genCmpLt by inverse logic (carry differs)
735 } if operandsNotRelated('0x00' %2), operandsLiteral(%2)
743 ; Peephole 132.f optimized genCmpLt by inverse logic (carry differs)
747 } if operandsNotRelated('0x00' %2), operandsLiteral(%2)
758 ; Peephole 133 removed redundant moves
771 ; Peephole 134 removed redundant moves
782 ; Peephole 135 removed redundant mov
795 ; Peephole 136 removed redundant move
798 // WTF? Doesn't look sensible to me...
808 // ; Peephole 137 optimized misc jump sequence
812 //} if labelRefCount %4 1
823 // ; Peephole 138 optimized misc jump sequence
828 //} if labelRefCount %4 1
835 ; Peephole 139.a removed redundant mov
845 ; Peephole 139.b removed redundant mov
854 ; Peephole 139.c removed redundant mov
864 ; Peephole 142 removed redundant moves
873 ; Peephole 143.a converted rlc to rl
881 ; Peephole 143.b converted rrc to rc
889 ; Peephole 145.a changed to add without carry
898 ; Peephole 145.b changed to add without carry
903 // 147: Fix compiler output to comply with 8051 instruction set.
907 ; Peephole 147.a changed target address mode r%1 to ar%1
914 ; Peephole 147.b changed target address mode r%1 to ar%1
921 ; Peephole 147.c changed target address mode r%1 to ar%1
931 ; Peephole 150.a removed misc moves via dpl before return
944 ; Peephole 150.b removed misc moves via dph, dpl before return
956 ; Peephole 150.c removed misc moves via dph, dpl before return
971 ; Peephole 150.d removed misc moves via dph, dpl, b before return
984 ; Peephole 150.e removed misc moves via dph, dpl, b before return
998 ; Peephole 150.f removed misc moves via dph, dpl, b before return
1015 ; Peephole 150.g removed misc moves via dph, dpl, b, a before return
1030 ; Peephole 150.h removed misc moves via dph, dpl, b, a before return
1044 ; Peephole 150.i removed misc moves via dph, dpl, b, a before return
1049 // peephole 213.a might revert this
1054 ; Peephole 159 avoided xrl during execution
1063 ; Peephole 160.a removed sjmp by inverse jump logic
1066 } if labelRefCountChange(%1 -1)
1073 ; Peephole 160.b removed sjmp by inverse jump logic
1076 } if labelRefCountChange(%1 -1)
1083 ; Peephole 160.c removed sjmp by inverse jump logic
1086 } if labelRefCountChange(%1 -1)
1093 ; Peephole 160.d removed sjmp by inverse jump logic
1096 } if labelRefCountChange(%1 -1)
1103 ; Peephole 160.e removed sjmp by inverse jump logic
1106 } if labelRefCountChange(%1 -1)
1113 ; Peephole 160.f removed sjmp by inverse jump logic
1116 } if labelRefCountChange(%1 -1)
1125 ; Peephole 166 removed redundant mov
1126 } if notVolatile %1 %2
1133 ; Peephole 167 removed redundant bit moves (c not set to %1)
1142 ; Peephole 168 jump optimization
1145 } if labelRefCountChange(%2 -1)
1152 ; Peephole 169 jump optimization
1155 } if labelRefCountChange(%2 -1)
1164 ; Peephole 170 jump optimization
1167 } if labelRefCount(%3 1), labelRefCountChange(%3 -1)
1177 ; Peephole 171 jump optimization
1181 } if labelRefCount(%3 2), labelRefCountChange(%3 -2), labelRefCountChange(%4 1)
1192 ; Peephole 172 jump optimization
1197 } if labelRefCount(%3 3), labelRefCountChange(%3 -3), labelRefCountChange(%4 2)
1209 ; Peephole 173 jump optimization
1215 } if labelRefCount(%3 4), labelRefCountChange(%3 -4), labelRefCountChange(%4 3)
1225 ; Peephole 174.a optimized decrement (acc not set to %2, flags undefined)
1236 ; Peephole 174.b optimized increment (acc not set to %2, flags undefined)
1245 ; Peephole 174.c optimized increment, removed redundant mov
1250 // this one will screw assignes to volatile/sfr's
1256 ; Peephole 177.a removed redundant mov
1257 } if notVolatile %1 %2
1259 // applies to f.e. scott-add.asm (--model-large)
1265 ; Peephole 177.b removed redundant mov
1268 // applies to f.e. bug-408972.c
1273 ; Peephole 177.c removed redundant move
1275 } if notVolatile %1 %2
1277 // applies to f.e. bug-408972.c
1278 // not before peephole 177.c
1286 ; Peephole 177.d removed redundant move
1287 } if notVolatile(%1 %2),operandsNotRelated(%1 %2 %3)
1289 // applies to f.e. bug-607243.c
1290 // also check notVolatile %3, as it will return FALSE if it's @r%1
1295 ; peephole 177.e removed redundant move
1297 } if notVolatile %2 %3
1303 ; peephole 177.f removed redundant move
1311 ; peephole 177.g optimized mov sequence
1320 ; peephole 177.h optimized mov sequence
1330 ; Peephole 178 removed redundant mov
1335 // rules 179-182 provided by : Frieder <fe@lake.iup.uni-heidelberg.de>
1336 // saving 2 byte, 1 cycle
1341 ; Peephole 179 changed mov to clr
1347 // volatile xdata char t; t=0x01; t=0x03;
1357 ; Peephole 180.a removed redundant mov to dptr
1360 // volatile xdata char t; t=0x01; t=0x03; t=0x01;
1374 ; Peephole 180.b removed redundant mov to dptr
1377 // saving 1 byte, 0 cycles
1381 ; Peephole 181 changed mov to clr
1385 // saving 3 bytes, 2 cycles
1386 // provided by Bernhard Held <bernhard.held@de.westinghouse.com>
1391 ; Peephole 182.a used 16 bit load of DPTR
1395 // saving 3 byte, 2 cycles, return(NULL) profits here
1400 ; Peephole 182.b used 16 bit load of dptr
1404 // saving 3 byte, 2 cycles. Probably obsoleted by 182.b
1409 ; Peephole 182.c used 16 bit load of dptr
1410 mov dptr,#(((%2)<<8) + %1)
1413 // applies to return 0.0; in f.e. sincosf.c
1419 ; Peephole 182.d used 16 bit load of dptr
1420 mov dptr,#(%1&0x00ff)
1428 ; Peephole 183 avoided anl during execution
1437 ; Peephole 184 removed redundant mov
1443 // acc being incremented might cause problems
1447 ; Peephole 185 changed order of increment (acc incremented also!)
1452 // char indexed access to: long code table[] = {4,3,2,1};
1474 ; Peephole 186.a optimized movc sequence
1492 // char indexed access to: void* code table[] = {4,3,2,1};
1510 ; Peephole 186.b optimized movc sequence
1524 // char indexed access to: int code table[] = {4,3,2,1};
1538 ; Peephole 186.c optimized movc sequence
1547 // char indexed access to: char code table[] = {4,3,2,1};
1557 ; Peephole 186.d optimized movc sequence
1562 // char indexed access to: int code table[] = {4,3,2,1};
1577 ; Peephole 186.e optimized movc sequence (b, dptr differ)
1595 ; Peephole 187 used a instead of ar%1 for anl
1607 ; Peephole 188 removed redundant mov
1621 ; Peephole 189 removed redundant mov and anl
1624 // rules 190 & 191 need to be in order
1632 ; Peephole 190 removed redundant mov
1646 ; Peephole 191 removed redundant mov
1654 ; Peephole 192 used a instead of ar%1 as source
1670 ; Peephole 193.a optimized misc jump sequence
1680 } if labelRefCount(%3 4), labelRefCountChange(%3 -4), labelRefCountChange(%8 3)
1694 ; Peephole 193.b optimized misc jump sequence
1704 } if labelRefCount(%3 4), labelRefCountChange(%3 -4), labelRefCountChange(%8 3)
1718 ; Peephole 193.c optimized misc jump sequence
1728 } if labelRefCount(%3 4), labelRefCountChange(%3 -4), labelRefCountChange(%8 3)
1739 ; Peephole 194 optimized misc jump sequence
1746 } if labelRefCount(%3 4), labelRefCountChange(%3 -4), labelRefCountChange(%8 3)
1758 ; Peephole 195.a optimized misc jump sequence
1766 } if labelRefCount(%3 3), labelRefCountChange(%3 -3), labelRefCountChange(%8 2)
1778 ; Peephole 195.b optimized misc jump sequence
1786 } if labelRefCount(%3 3), labelRefCountChange(%3 -3), labelRefCountChange(%8 2)
1798 ; Peephole 195.c optimized misc jump sequence
1806 } if labelRefCount(%3 3), labelRefCountChange(%3 -3), labelRefCountChange(%8 2)
1816 ; Peephole 196 optimized misc jump sequence
1822 } if labelRefCount(%3 3), labelRefCountChange(%3 -3), labelRefCountChange(%8 2)
1832 ; Peephole 197.a optimized misc jump sequence
1838 } if labelRefCount(%3 2), labelRefCountChange(%3 -2), labelRefCountChange(%8 1)
1848 ; Peephole 197.b optimized misc jump sequence
1854 } if labelRefCount(%3 2), labelRefCountChange(%3 -2), labelRefCountChange(%8 1)
1864 ; Peephole 197.c optimized misc jump sequence
1870 } if labelRefCount(%3 2), labelRefCountChange(%3 -2), labelRefCountChange(%8 1)
1879 ; Peephole 198.a optimized misc jump sequence
1884 } if labelRefCount(%3 2), labelRefCountChange(%3 -2), labelRefCountChange(%8 1)
1892 ; Peephole 198.b optimized misc jump sequence
1896 } if labelRefCount(%3 1), labelRefCountChange(%3 -1)
1902 ; Peephole 200.a removed redundant sjmp
1904 } if labelRefCountChange(%1 -1)
1911 ; Peephole 200.b removed redundant sjmp
1914 } if labelRefCountChange(%1 -1)
1921 ; Peephole 202 removed redundant push pop
1930 ; Peephole 203 removed mov r%1,_spx
1939 ; Peephole 204 removed redundant mov
1951 ; Peephole 205 optimized misc jump sequence
1955 } if labelRefCount(%2 1), labelRefCountChange(%2 -1), labelRefCountChange(%3 -1)
1960 ; Peephole 206 removed redundant mov %1,%1
1968 ; Peephole 207 removed zero add (acc not set to %1, flags undefined)
1977 ; Peephole 208 removed redundant push pop
1987 ; Peephole 209 optimized increment (acc not set to %1, flags undefined)
1993 mov dptr,#((((%1 >> 8)) <<8) + %1)
1995 ; Peephole 210 simplified expression
2003 ; Peephole 211 removed redundant push %1 pop %1
2011 ; Peephole 212 reduced add sequence to inc
2016 // reverts peephole 159? asx8051 cannot handle, too complex?
2018 mov %1,#(( %2 >> 8 ) ^ 0x80)
2020 ; Peephole 213.a inserted fix
2026 mov %1,#(( %2 + %3 >> 8 ) ^ 0x80)
2028 ; Peephole 213.b inserted fix
2029 mov %1,#((%2 + %3) >> 8)
2040 ; Peephole 214 reduced some extra moves
2042 } if operandsNotSame
2049 ; Peephole 215 removed some moves
2052 } if operandsNotSame
2064 ; Peephole 216.a simplified clear (2 bytes)
2083 ; Peephole 216.b simplified clear (3 bytes)
2107 ; Peephole 216.c simplified clear (4 bytes)
2124 ; Peephole 219.a removed redundant clear
2145 ; Peephole 219.b removed redundant clear
2153 ; Peephole 220.a removed bogus DPS set
2161 ; Peephole 220.b removed bogus DPS set
2166 mov %1 + %2,(%2 + %1)
2168 ; Peephole 221.a remove redundant move
2172 mov (%1 + %2 + %3),((%2 + %1) + %3)
2174 ; Peephole 221.b remove redundant move
2181 ; Peephole 222 removed dec/inc pair
2192 ; Peephole 223.a removed redundant dph/dpl moves
2193 } if notVolatile %1 %2
2203 ; Peephole 223.b removed redundant dph/dpl moves
2219 ; Peephole 225 removed redundant move to acc
2231 ; Peephole 226.a removed unnecessary clr
2247 ; Peephole 226.b removed unnecessary clr
2266 ; Peephole 227.a replaced inefficient 32 bit clear
2293 ; Peephole 227.b replaced inefficient 32 constant
2316 ; Peephole 227.c replaced inefficient 16 bit clear
2333 ; Peephole 227.d replaced inefficient 16 bit constant
2342 // this last peephole often removes the last mov from 227.a - 227.d
2347 ; Peephole 227.e removed redundant mov to dptr
2354 ; Peephole 232 using movc to read xdata (--xram-movc)
2362 ; Peephole 233 using _gptrgetc instead of _gptrget (--xram-movc)
2372 ; Peephole 234.a loading dpl directly from a(ccumulator), r%1 not set
2385 ; Peephole 234.b loading dph directly from a(ccumulator), r%1 not set
2392 // 14 rules by Fiorenzo D. Ramaglia <fd.ramaglia@tin.it>
2397 ; Peephole 236.a used r%1 instead of ar%1
2404 ; Peephole 236.b used r%1 instead of ar%1
2411 ; Peephole 236.c used r%1 instead of ar%1
2418 ; Peephole 236.d used r%1 instead of ar%1
2425 ; Peephole 236.e used r%1 instead of ar%1
2432 ; Peephole 236.f used r%1 instead of ar%1
2439 ; Peephole 236.g used r%1 instead of ar%1
2446 ; Peephole 236.h used r%1 instead of ar%1
2453 ; Peephole 236.i used r%1 instead of ar%1
2460 ; Peephole 236.j used r%1 instead of ar%1
2467 ; Peephole 236.k used r%1 instead of ar%1
2474 ; Peephole 236.l used r%1 instead of ar%1
2481 ; Peephole 236.m used r%1 instead of ar%1
2488 ; Peephole 236.n used r%1 instead of ar%1
2499 ; Peephole 237.a removed sjmp to ret
2505 } if labelRefCountChange(%1 -1)
2516 ; Peephole 237.b removed sjmp to ret
2524 } if labelRefCountChange(%1 -1)
2526 // applies to f.e. device/lib/log10f.c
2552 ; Peephole 238.a removed 4 redundant moves
2553 } if operandsNotSame8 %1 %2 %3 %4 %5 %6 %7 %8
2555 // applies to device/lib/log10f.c
2570 ; Peephole 238.b removed 3 redundant moves
2571 } if operandsNotSame7 %1 %2 %3 %4 %5 %6 %7
2573 // applies to f.e. device/lib/time.c
2589 ; Peephole 238.c removed 2 redundant moves
2590 } if operandsNotSame4 %1 %2 %3 %4
2592 // applies to f.e. support/regression/tests/bug-524209.c
2605 ; Peephole 238.d removed 3 redundant moves
2606 } if operandsNotSame6 %1 %2 %3 %4 %5 %6
2608 // applies to f.e. ser_ir.asm
2612 ; Peephole 239 used a instead of acc
2620 ; Peephole 240 use clr instead of addc a,#0
2625 // peepholes 241.a to 241.d and 241.e to 241.h need to be in order
2637 ; Peephole 241.a optimized compare
2646 } if labelRefCountChange(%1 -1)
2648 // applies to generic pointer compare
2659 ; Peephole 241.b optimized compare
2667 } if labelRefCountChange(%1 -1)
2669 // applies to f.e. time.c
2679 ; Peephole 241.c optimized compare
2686 } if labelRefCountChange(%1 -1)
2688 // applies to f.e. malloc.c
2697 ; Peephole 241.d optimized compare
2703 } if labelRefCountChange(%1 -1)
2705 // applies to f.e. j = (k!=0x1000);
2706 // with volatile idata long k;
2721 ; Peephole 241.e optimized compare
2733 } if labelRefCountChange(%2 -1)
2735 // applies to f.e. j = (p!=NULL);
2736 // with volatile idata char *p;
2749 ; Peephole 241.f optimized compare
2759 } if labelRefCountChange(%2 -1)
2761 // applies to f.e. j = (k!=0x1000);
2762 // with volatile idata int k;
2773 ; Peephole 241.g optimized compare
2781 } if labelRefCountChange(%2 -1)
2783 // applies to f.e. vprintf.asm (--stack-auto)
2792 ; Peephole 241.h optimized compare
2798 } if labelRefCountChange(%2 -1)
2800 // applies to f.e. scott-bool1.c
2809 ; Peephole 242.a avoided branch jnz to jz
2812 } if labelRefCount %1 1
2814 // applies to f.e. scott-bool1.c
2825 ; Peephole 242.b avoided branch jnz to jz
2828 } if labelRefCount %1 1
2830 // applies to f.e. logic.c
2845 ; Peephole 242.c avoided branch jnz to jz
2848 } if labelRefCount %1 1
2850 // applies to f.e. vprintf.c
2851 // this is a rare case, usually the "tail increment" is noticed earlier
2858 ; Peephole 243 avoided branch to sjmp
2863 } if labelInRange(), labelRefCountChange(%3 -1), labelRefCountChange(%5 1)
2865 // applies to f.e. simplefloat.c (saving 1 cycle)
2870 ; Peephole 244.a moving first to a instead of r%1
2875 // applies to f.e. _itoa.c (saving 1 cycle)
2880 ; Peephole 244.b moving first to a instead of r%1
2886 // applies to f.e. bug-460010.c (saving 1 cycle)
2892 ; Peephole 244.c loading dpl from a instead of r%1
2901 ; Peephole 244.d loading dph from a instead of r%1
2905 // this one is safe but disables 245.a 245.b
2906 // please remove 245 if 245.a 245.b are found to be safe
2907 // applies to f.e. scott-compare.c
2918 ; Peephole 245 optimized complement (r%1 and acc set needed?)
2923 } if labelRefCount(%2 1), labelRefCountChange(%2 -1)
2925 // this one will not be triggered if 245 is present
2926 // please remove 245 if 245.a 245.b are found to be safe
2927 // applies to f.e. vprintf.c
2939 ; Peephole 245.a optimized conditional jump (r%1 and acc not set!)
2941 } if labelRefCount(%2 1), labelRefCountChange(%2 -1)
2943 // this one will not be triggered if 245 is present
2944 // please remove 245 if 245.a 245.b are found to be safe
2945 // applies to f.e. scott-compare.c
2957 ; Peephole 245.b optimized conditional jump (r%1 and acc not set!)
2959 } if labelRefCount(%2 1), labelRefCountChange(%2 -1)
2962 // rules 246.x apply to f.e. bitfields.c
2975 ; Peephole 246.a combined clr/clr
2992 ; Peephole 246.b combined set/set
3010 ; Peephole 246.c combined set/clr
3028 ; Peephole 246.d combined clr/set
3047 ; Peephole 246.e combined set/clr/clr
3067 ; Peephole 246.f combined set/clr/set
3087 ; Peephole 246.g combined clr/set/clr
3106 ; Peephole 246.h combined clr/set/set
3114 // rules 247.x apply to f.e. bitfields.c
3127 ; Peephole 247.a combined clr/clr
3144 ; Peephole 247.b combined set/set
3162 ; Peephole 247.c combined set/clr
3180 ; Peephole 247.d combined clr/set
3199 ; Peephole 247.e combined set/clr/clr
3219 ; Peephole 247.f combined set/clr/set
3239 ; Peephole 247.g combined clr/set/clr
3258 ; Peephole 247.h combined clr/set/set
3264 // Peepholes 248.x have to be compatible with the keyword volatile.
3265 // They optimize typical accesses to memory mapped I/O devices:
3266 // volatile xdata char t; t|=0x01;
3279 ; Peephole 248.a optimized or to xdata
3284 // volatile xdata char t; t&=0x01;
3297 ; Peephole 248.b optimized and to xdata
3302 // volatile xdata char t; t^=0x01;
3315 ; Peephole 248.c optimized xor to xdata
3320 // volatile xdata char t; t|=0x01; t&=~0x01; t|=0x01;
3342 ; Peephole 248.d optimized or/and/or to volatile xdata
3354 // volatile xdata char t; t&=~0x01; t|=0x01; t&=~0x01;
3376 ; Peephole 248.e optimized and/or/and to volatile xdata
3388 // volatile xdata char t; t|=0x01; t&=~0x01;
3404 ; Peephole 248.f optimized or/and to volatile xdata
3413 // volatile xdata char t; t&=~0x01; t|=0x01;
3429 ; Peephole 248.g optimized and/or to volatile xdata
3438 // volatile xdata char t; t^=0x01; t^=0x01;
3454 ; Peephole 248.h optimized xor/xor to volatile xdata
3463 // Peeepholes 248.i to 248.m are like 248.d to 248.h except they apply to bitfields:
3464 // xdata struct { unsigned b0:1; unsigned b1:1; unsigned b2:1; } xport;
3465 // xport.b0=1; xport.b0=0; xport.b0=1;
3486 ; Peephole 248.i optimized or/and/or to xdata bitfield
3515 ; Peephole 248.j optimized and/or/and to xdata bitfield
3539 ; Peephole 248.k optimized or/and to xdata bitfield
3560 ; Peephole 248.l optimized and/or to xdata bitfield
3581 ; Peephole 248.m optimized xor/xor to xdata bitfield
3592 ; Peephole 249.a jump optimization
3593 } if labelRefCount(%1 1), labelRefCountChange(%1 -1)
3599 ; Peephole 249.b jump optimization
3600 } if labelRefCount(%1 1), labelRefCountChange(%1 -1)
3603 // This allows non-interrupt and interrupt code to safely compete
3604 // for a resource without the non-interrupt code having to disable
3606 // volatile bit resource_is_free;
3607 // if( resource_is_free ) {
3608 // resource_is_free=0; do_something; resource_is_free=1;
3615 ; Peephole 250.a using atomic test and clear
3619 } if labelRefCount(%3 0), labelRefCountChange(%3 1)
3627 ; Peephole 250.b using atomic test and clear
3631 } if labelRefCount %2 1
3634 // not before peephole 250.b
3638 ; Peephole 251.a replaced ljmp to ret with ret
3640 } if labelIsReturnOnly(), labelRefCountChange(%5 -1)
3642 // not before peephole 250.b
3646 ; Peephole 251.b replaced sjmp to ret with ret
3648 } if labelIsReturnOnly(), labelRefCountChange(%5 -1)
3650 // applies to shifts.c and when accessing arrays with an unsigned integer index
3651 // saving 1 byte, 2 cycles
3661 ; Peephole 252 optimized left shift
3670 // applies to: void test( char c ) { if( c ) func1(); else func2(); }
3675 ; Peephole 253.a replaced lcall/ret with ljmp
3679 // applies to: void test( char c ) { if( c ) func1(); else func2(); }
3685 ; Peephole 253.b replaced lcall/ret with ljmp
3688 } if labelRefCount %2 0
3690 // applies to f.e. scott-bool1.c
3696 ; Peephole 253.c replaced lcall with ljmp
3703 // applies to f.e. funptrs.c
3704 // saves one byte if %1 is a register or @register
3710 ; Peephole 254 optimized left shift
3714 // applies to f.e. switch.c
3727 ; Peephole 255 optimized jump table index calculation
3729 cjne a,#(%1+0x01),.+1
3738 // applies to f.e. jump tables and scott-bool1.c.
3739 // similar peepholes can be constructed for other instructions
3740 // after which a flag or a register is known (like: djnz, cjne, jnc)
3748 ; Peephole 256.a removed redundant clr c
3749 } if labelRefCount %2 0
3751 // applies to f.e. logf.c
3759 ; Peephole 256.b removed redundant clr a
3760 } if labelRefCount %2 0
3762 // applies to f.e. bug-905492.c
3770 ; Peephole 256.c loading %3 with zero from a
3772 } if labelRefCount %2 0
3774 // applies to f.e. malloc.c
3784 ; Peephole 256.d loading %3 with zero from a
3786 } if labelRefCount(%2 0),operandsNotRelated('a' %4)
3799 ; Peephole 256.e loading %3 with zero from a
3801 } if labelRefCount(%2 0),operandsNotRelated('a' %4 %6)
3816 ; Peephole 256.f loading %2 with zero from a
3818 } if labelRefCount(%2 0),operandsNotRelated('a' %4 %6 %8)
3821 // unsigned char i=8; do{ } while(--i != 0);
3822 // this currently only applies if i is kept in a register
3827 ; Peephole 257 optimized decrement with compare
3832 // in_byte<<=1; if(in_bit) in_byte|=1;
3833 // helps f.e. reading data on a 3-wire (SPI) bus
3844 ; Peephole 258.a optimized bitbanging
3850 } if notVolatile(%1), labelRefCountChange(%3 -1)
3852 // in_byte<<=1; if(in_bit) in_byte|=1;
3863 ; Peephole 258.b optimized bitbanging
3869 } if labelRefCountChange(%3 -1)
3871 // in_byte>>=1; if(in_bit) in_byte|=0x80;
3883 ; Peephole 258.c optimized bitbanging
3889 } if notVolatile(%1), labelRefCountChange(%3 -1)
3891 // in_byte>>=1; if(in_bit) in_byte|=0x80;
3903 ; Peephole 258.d optimized bitbanging
3909 } if labelRefCountChange(%3 -1)
3911 // out_bit=out_byte&0x80; out_byte<<=1;
3912 // helps f.e. writing data on a 3-wire (SPI) bus
3922 ; Peephole 258.e optimized bitbanging
3928 // out_bit=out_byte&0x01; out_byte>>=1;
3939 ; Peephole 258.f optimized bitbanging
3946 // Peepholes 259.x rely on the correct labelRefCount. Otherwise they are
3947 // not compatible with peepholes 250.x
3948 // Peepholes 250.x add jumps to a previously unused label. If the
3949 // labelRefCount is not increased, peepholes 259.x are (mistakenly) applied.
3950 // (Mail on sdcc-devel 2004-10-25)
3952 // applies to f.e. vprintf.c
3959 ; Peephole 259.a removed redundant label %2 and ret
3961 } if labelRefCount %2 0
3963 // applies to f.e. gets.c
3970 ; Peephole 259.b removed redundant label %2 and ret
3972 } if labelRefCount %2 0
3974 // optimizing jumptables
3975 // Please note: to enable peephole 260.x you currently have to set
3976 // the environment variable SDCC_SJMP_JUMPTABLE
3988 ; Peephole 260.a used sjmp in jumptable
3999 // optimizing jumptables
4012 ; Peephole 260.b used sjmp in jumptable
4024 // optimizing jumptables
4038 ; Peephole 260.c used sjmp in jumptable
4051 // optimizing jumptables
4066 ; Peephole 260.d used sjmp in jumptable
4080 // optimizing jumptables
4096 ; Peephole 260.e used sjmp in jumptable
4111 // optimizing jumptables
4129 ; Peephole 260.f used sjmp in jumptable
4146 // optimizing jumptables
4165 ; Peephole 260.g used sjmp in jumptable
4183 // optimizing jumptables
4203 ; Peephole 260.h used sjmp in jumptable
4222 // optimizing jumptables
4243 ; Peephole 260.i used sjmp in jumptable
4263 // optimizing jumptables
4285 ; Peephole 260.j used sjmp in jumptable
4306 // optimizing jumptables
4329 ; Peephole 260.k used sjmp in jumptable
4351 // optimizing jumptables
4375 ; Peephole 260.l used sjmp in jumptable
4398 // optimizing jumptables
4423 ; Peephole 260.m used sjmp in jumptable
4447 // applies to: a = (a << 1) | (a >> 15);
4461 ; Peephole 261.a optimized left rol
4469 // applies to: a = (a << 15) | (a >> 1);
4483 ; Peephole 261.b optimized right rol
4495 ; Peephole 262 removed redundant cpl c
4504 ; Peephole 263.a optimized loading const
4513 ; Peephole 263.b optimized loading const
4521 ; Peephole 263.c optimized loading const
4525 // should be one of the last peepholes
4529 ; Peephole 300 removed redundant label %1
4530 } if labelRefCount(%1 0)