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Use more compact loops.

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This commit is contained in:
Sven Michael Klose
2020-11-01 22:59:07 +01:00
committed by greg-king5
parent 99c0815cdb
commit f59cb9af06
13 changed files with 90 additions and 94 deletions
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15
libsrc/common/memcmp.s
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@@ -13,11 +13,11 @@ _memcmp:
; Calculate (-count-1) and store it into ptr3. This is some overhead here but
; saves time in the compare loop
eor #$FF
sta ptr3
txa
eor #$FF
sta ptr3+1
inx
stx ptr3+1
tax
inx
stx ptr3 ; Save count with each byte incremented separately
; Get the pointer parameters
@@ -33,7 +33,7 @@ _memcmp:
; Head of compare loop: Test for the end condition
Loop: inx ; Bump low byte of (-count-1)
Loop: dex ; Bump low byte of (-count-1)
beq BumpHiCnt ; Jump on overflow
; Do the compare
@@ -53,7 +53,7 @@ Comp: lda (ptr1),y
; Entry on low counter byte overflow
BumpHiCnt:
inc ptr3+1 ; Bump high byte of (-count-1)
dec ptr3+1 ; Bump high byte of (-count-1)
bne Comp ; Jump if not done
jmp return0 ; Count is zero, areas are identical
@@ -67,4 +67,3 @@ NotEqual:
Greater:
ldx #$01 ; Make result positive
rts

22
libsrc/common/strncat.s
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@@ -5,17 +5,17 @@
; char* strncat (char* dest, const char* src, size_t n);
;
.export _strncat
.import popax, popptr1
.importzp ptr1, ptr2, ptr3, tmp1, tmp2
.macpack cpu
.export _strncat
.import popax, popptr1
.importzp ptr1, ptr2, ptr3, tmp1, tmp2
.macpack cpu
_strncat:
eor #$FF ; one's complement to count upwards
sta tmp1
txa
eor #$FF
sta tmp2
inx
stx tmp2
tax
inx
stx tmp1 ; save count with each byte incremented separately
jsr popptr1 ; get src
@@ -49,9 +49,9 @@ L2: sty ptr2
L3: ldy #0
ldx tmp1 ; low counter byte
L4: inx
L4: dex
bne L5
inc tmp2
dec tmp2
beq L6 ; jump if done
L5: lda (ptr1),y
sta (ptr2),y

18
libsrc/common/strncpy.s
View File

@@ -10,11 +10,11 @@
.proc _strncpy
eor #$FF
sta tmp1
txa
eor #$FF
sta tmp2 ; Store -size - 1
inx
stx tmp2
tax
inx
stx tmp1 ; save count with each byte incremented separately
jsr popptr1 ; get src
jsr popax ; get dest
@@ -26,9 +26,9 @@
ldx tmp1 ; Load low byte of ones complement of size
ldy #$00
L1: inx
L1: dex
bne L2
inc tmp2
dec tmp2
beq L9
L2: lda (ptr1),y ; Copy one character
@@ -42,7 +42,7 @@ L2: lda (ptr1),y ; Copy one character
; Fill the remaining bytes.
L3: inx ; Counter low byte
L3: dex ; Counter low byte
beq L6 ; Branch on overflow
L4: sta (ptr2),y ; Clear one byte
L5: iny ; Bump pointer
@@ -52,7 +52,7 @@ L5: iny ; Bump pointer
; Bump the counter high byte
L6: inc tmp2
L6: dec tmp2
bne L4
; Done, return dest

20
libsrc/common/strnicmp.s
View File

@@ -15,17 +15,11 @@
_strnicmp:
_strncasecmp:
; Convert the given counter value in a/x from a downward counter into an
; upward counter, so we can increment the counter in the loop below instead
; of decrementing it. This adds some overhead now, but is cheaper than
; executing a more complex test in each iteration of the loop. We do also
; correct the value by one, so we can do the test on top of the loop.
eor #$FF
sta ptr3
txa
eor #$FF
sta ptr3+1
inx
stx ptr3+1
tax
inx
stx ptr3 ; save count with each byte incremented separately
; Get the remaining arguments
@@ -40,7 +34,7 @@ _strncasecmp:
; Start of compare loop. Check the counter.
Loop: inc ptr3
Loop: dec ptr3
beq IncHi ; increment high byte
; Compare a byte from the strings
@@ -79,7 +73,7 @@ L2: ldx tmp1
; Increment hi byte
IncHi: inc ptr3+1
IncHi: dec ptr3+1
bne Comp ; jump if counter not zero
; Exit code if strings are equal. a/x not set