X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=src%2Fpic%2Fpeeph.def;h=8e6df14f6100431cd5e0c267ad197babd481eff0;hb=5156ec0bb15ef639c2aa78f616a05e3ab0435813;hp=79f176337a06896c21533fdc09b848a8362abadc;hpb=778f1b919b8f1bc96249966828c4b7b209d1b212;p=fw%2Fsdcc diff --git a/src/pic/peeph.def b/src/pic/peeph.def index 79f17633..8e6df14f 100644 --- a/src/pic/peeph.def +++ b/src/pic/peeph.def @@ -1,83 +1,331 @@ -// ; Peephole 2 removed pop %1 push %1 (not push pop) -// mov %2,%3 -//} +// PIC Port Peep rules +// +// +// INTRODUCTION: +// +// The peep hole optimizer searchs the +// the SDCC generated code for small snippets +// that can be optimized. As a user, you have +// control over this optimization process without +// having to learn the SDCC source code. (However +// you'll still need access to the source since +// these rules are compiled into the source.) +// +// The way it works is you specify the target +// snippet that you want replaced with a more +// efficient snippet that you write. Wild card +// variables allow the rules to be parameterized. +// +// In all of the SDCC ports, labels and operands +// can be wild cards. However, in the PIC even the +// instructions can be wild cards. +// +// EXAMPLE: +// +// Consider Peep Rule 1 as an example. This rule +// replaces some code like: +// +// skpz ;i.e. btfss status,Z +// goto lab1 +// clrw +//lab1: +// +// with: +// +// skpnz ;i.e. btfsc status,Z +// clrw +//lab1 +// +// However, the Rule has four wild cards. +// The first allows the btfss instruction operator +// be anything, not just the Z bit in status register. +// The second wild card applies to a label. +// The third wild card is for an instruction - any +// single instruction can be substituted. +// The fourth wild card is also an instruction. It's +// just an instruction place holder associated with +// a label (think of it as the PIC Port author's laziness +// imposed upon the user). +// +// +// CONDITIONS +// +// There are certain instances where a peep rule may not +// be applicable. Consider this subtle example: +// +// movwf R0 +// movf R0,W +// +// It would seem that the second move is unnecessary. But +// be careful! The movf instruction affects the 'Z' bit. +// So if this sequence is followed by a btfsc status,Z, you +// will have to leave the second move in. +// +// To get around this proble, the peep rule can be followed +// by a conditon: "if NZ". Which is to say, apply the rule +// if Z bit is not needed in the code that follows. The optimizer +// is smart enough to look more than one instruction past the +// target block... +// +// Special commands +// +// +// _NOTBITSKIP_ %1 - Creates a wild card instruction that +// will match all instructions except for +// bit skip instructions (btfsc or btfss) +// _BITSKIP_ %1 - Creates a wild card instruction that only +// will match a bit skip instruction (btfsc +// or btfss) +// _INVERTBITSKIP_ %1 - For the wild card instruction %1, invert +// the state of the bit skip. If %1 is not +// a bit skip instruction, then there's an +// error in the peep rule. +// +// +// + + +// Peep 1 +// Converts +// +// btfss reg1,bit +// goto label +// incf reg2,f +//label +// +// Into: +// +// btfsc reg1,bit +// incf reg2,f +//label +// +// Notice that wild cards will allow any instruction +// besides incf to be used in the above. +// +// Also, notice that this snippet is not valid if +// it follows another skip + +replace restart { + _NOTBITSKIP_ %1 + _BITSKIP_ %2 + goto %3 + %4 +%3: %5 +} by { + ; peep 1 - test/jump to test/skip + %1 + _INVERTBITSKIP_ %2 + %4 +%3: %5 +} + +replace restart { + _NOTBITSKIP_ %1 + _BITSKIP_ %2 + goto %3 +%4: %5 +%3: %6 +} by { + ; peep 1b - test/jump to test/skip + %1 + _INVERTBITSKIP_ %2 +%4: %5 +%3: %6 +} + + +//bogus test for pcode +//replace restart { +// movf %1,w ;comment at end +//%4: movf %1,w +// RETURN +// clrf INDF +// movlw 0xa5 +// movf fsr,w +// incf indf,f +// %2 +//} by { +// ; peep test remove redundant move +//%4: movf %1,w ;another comment +// %2 +//} if AYBABTU %3 + + +// peep 2 +replace restart { + movwf %1 + movf %1,w +} by { + ; peep 2 - Removed redundant move + movwf %1 +} if NZ + +// peep 3 +replace restart { + decf %1,f + movf %1,w + btfss STATUS,z + goto %2 +} by { + ; peep 3 - decf/mov/skpz to decfsz + decfsz %1,f + goto %2 +} + + +replace restart { + movf %1,w + movf %1,w +} by { + ; peep 4 - Removed redundant move + movf %1,w +} + + +replace restart { + movlw %1 + movwf %2 + movlw %1 +} by { + ; peep 5 - Removed redundant move + movlw %1 + movwf %2 +} + +replace restart { + movwf %1 + movwf %1 +} by { + ; peep 6 - Removed redundant move + movwf %1 +} -// peep 1 replace restart { - skpz - goto %1 - incf %2,f -%1: + movlw 0 + iorwf %1,w } by { - ;peep 1 - skpnz - incf %2,f -%1: + ; peep 7 - Removed redundant move + movf %1,w } -// like peep1 replace restart { - skpz - goto %1 -%2: - incf %3,f -%1: + movf %1,w + movwf %2 + decf %2,f } by { - ;peep 2 - skpnz -%2: - incf %3,f -%1: + ; peep 8 - Removed redundant move + decf %1,w + movwf %2 } replace restart { - skpnz - goto %1 - incf %2,f -%1: + movwf %1 + movf %2,w + xorwf %1,w } by { - ;peep 3 - skpz - incf %2,f -%1: + ; peep 9a - Removed redundant move + movwf %1 + xorwf %2,w } replace restart { - skpnz - goto %1 -%2: - incf %3,f -%1: + movwf %1 + movf %2,w + iorwf %1,w } by { - ;peep 4 - skpz -%2: - incf %3,f -%1: + ; peep 9b - Removed redundant move + movwf %1 + iorwf %2,w } -// peep 5 replace restart { - skpc - goto %1 - incf %2,f -%1: + movf %1,w + movwf %2 + movf %2,w } by { - ;peep 5 - skpnc - incf %2,f -%1: + ; peep 9c - Removed redundant move + movf %1,w + movwf %2 } -// peep 6 replace restart { - skpnc - goto %1 - incf %2,f -%1: + movwf %1 + movf %1,w + movwf %2 +} by { + ; peep 9d - Removed redundant move + movwf %1 + movwf %2 +} if NZ + +// From: Frieder Ferlemann + +replace restart { + iorlw 0 +} by { + ; peep 10a - Removed unnecessary iorlw +} if NZ + +// From: Frieder Ferlemann + +replace restart { + xorlw 0 +} by { + ; peep 10b - Removed unnecessary xorlw +} if NZ + +// From: Frieder Ferlemann + +replace restart { + movf %1,w + movwf %1 +} by { + ; peep 11 - Removed redundant move + movf %1,w +} + +replace restart { + comf %1,w + movwf %1 +} by { + ; peep 12 - Removed redundant move + comf %1,f +} + +replace restart { + clrf %1 + rlf %1,f + movlw 0x01 + xorwf %1,f + movf %1,w + btfss STATUS,2 + goto %2 + +} by { + ; peep 13 - Optimized carry sequence + clrf %1 + incf %1,F + btfss status,C + goto %2 + clrf %1 + +} + +replace restart { + clrf %1 + rlf %1,f + movlw 0x01 + xorwf %1,f + movf %1,w + btfsc STATUS,2 + goto %2 + } by { - ;peep 6 - skpc - incf %2,f -%1: + ; peep 13a - Optimized carry sequence + clrf %1 + incf %1,F + btfsc status,C + goto %2 + clrf %1 + }