diff --git a/src/cc65/codeopt.c b/src/cc65/codeopt.c index 30ffd6054..0656aebc8 100644 --- a/src/cc65/codeopt.c +++ b/src/cc65/codeopt.c @@ -180,7 +180,75 @@ static unsigned OptShift1 (CodeSeg* S) -static unsigned OptShift2 (CodeSeg* S) +static unsigned OptShift2(CodeSeg* S) +/* A call to the asrax1 routines may get replaced by something simpler, if + * X is not used later: + * + * cmp #$80 + * ror a + * + */ +{ + unsigned Changes = 0; + unsigned I; + + /* Generate register info */ + CS_GenRegInfo (S); + + /* Walk over the entries */ + I = 0; + while (I < CS_GetEntryCount (S)) { + + unsigned Count; + + /* Get next entry */ + CodeEntry* E = CS_GetEntry (S, I); + + /* Check for the sequence */ + if (E->OPC == OP65_JSR && + strncmp (E->Arg, "asrax", 5) == 0 && + strlen (E->Arg) == 6 && + IsDigit (E->Arg[5]) && + (Count = (E->Arg[5] - '0')) >= 1 && + Count * 100 <= S->CodeSizeFactor && + !RegXUsed (S, I+1)) { + + CodeEntry* X; + unsigned J = I+1; + + /* Generate the replacement sequence */ + while (Count--) { + /* cmp #$80 */ + X = NewCodeEntry (OP65_CMP, AM65_IMM, "$80", 0, E->LI); + CS_InsertEntry (S, X, J++); + + /* ror a */ + X = NewCodeEntry (OP65_ROR, AM65_ACC, "a", 0, E->LI); + CS_InsertEntry (S, X, J++); + } + + /* Delete the call to asrax */ + CS_DelEntry (S, I); + + /* Remember, we had changes */ + ++Changes; + } + + /* Next entry */ + ++I; + + } + + /* Free the register info */ + CS_FreeRegInfo (S); + + /* Return the number of changes made */ + return Changes; +} + + + +static unsigned OptShift3 (CodeSeg* S) /* A call to the shraxN routine may get replaced by one or more lsr insns * if the value of X is zero. */ @@ -255,7 +323,7 @@ static unsigned GetShiftType (const char* Sub) -static unsigned OptShift3 (CodeSeg* S) +static unsigned OptShift4 (CodeSeg* S) /* Search for the sequence * * lda xxx @@ -376,7 +444,7 @@ static unsigned OptShift3 (CodeSeg* S) -static unsigned OptShift4 (CodeSeg* S) +static unsigned OptShift5 (CodeSeg* S) /* Inline the shift subroutines. */ { unsigned Changes = 0; @@ -1415,8 +1483,9 @@ static OptFunc DOptPush2 = { OptPush2, "OptPush2", 50, 0, static OptFunc DOptPushPop = { OptPushPop, "OptPushPop", 0, 0, 0, 0, 0, 0 }; static OptFunc DOptShift1 = { OptShift1, "OptShift1", 100, 0, 0, 0, 0, 0 }; static OptFunc DOptShift2 = { OptShift2, "OptShift2", 100, 0, 0, 0, 0, 0 }; -static OptFunc DOptShift3 = { OptShift3, "OptShift3", 110, 0, 0, 0, 0, 0 }; -static OptFunc DOptShift4 = { OptShift4, "OptShift4", 200, 0, 0, 0, 0, 0 }; +static OptFunc DOptShift3 = { OptShift3, "OptShift3", 100, 0, 0, 0, 0, 0 }; +static OptFunc DOptShift4 = { OptShift4, "OptShift4", 110, 0, 0, 0, 0, 0 }; +static OptFunc DOptShift5 = { OptShift5, "OptShift5", 200, 0, 0, 0, 0, 0 }; static OptFunc DOptSize1 = { OptSize1, "OptSize1", 100, 0, 0, 0, 0, 0 }; static OptFunc DOptSize2 = { OptSize2, "OptSize2", 100, 0, 0, 0, 0, 0 }; static OptFunc DOptStackOps = { OptStackOps, "OptStackOps", 100, 0, 0, 0, 0, 0 }; @@ -1510,6 +1579,7 @@ static OptFunc* OptFuncs[] = { &DOptShift2, &DOptShift3, &DOptShift4, + &DOptShift5, &DOptSize1, &DOptSize2, &DOptStackOps,