mirror/upx
1
0
Fork 0
mirror of https://github.com/upx/upx synced 2025-09-28 19:06:07 +08:00
Code Issues Releases Wiki Activity

save space aggressively

Browse Source 
committer: jreiser <jreiser> 1140713717 +0000
This commit is contained in:
John Reiser 2006-02-23 16:55:17 +00:00
parent 20e4cbfd13
commit afaf489d99
1 changed files with 24 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

46
src/stub/arm_nrv2b_d32.S
View File

@ -35,16 +35,12 @@
#define tmp r3
#define bits r4
#define off r5
#define g32 r6
#define g1b r6
#define wrnk r7 /* 0xd00 M2_MAX_OFFSET before "wrinkle" */
/* r12 ("ip") is assumed to be a scratch register. */
#define GETBIT \
add bits,bits; beq 1f; 0: \
.subsection 1; \
1: blx g32; b 0b; \
.subsection 0
#define GETBIT blx g1b
#define getnextb(reg) GETBIT; adc reg,reg
#define jnextb0 GETBIT; bcc
@ -53,16 +49,18 @@
ucl_nrv2b_decompress_32: .globl ucl_nrv2b_decompress_32 @ ARM mode
.type ucl_nrv2b_decompress_32, %function
/* error = (*)(char const *src, int len_src, char *dst, int *plen_dst) */
adr r12,1+thumb_nrv2b_d32; bx r12 @ enter THUMB mode
adr r12,1+go_thumb_n2b @ load pc-relative address
bx r12 @ enter THUMB mode
.code 16 @ THUMB mode
thumb_nrv2b_d32:
go_thumb_n2b:
add r1,len,src @ r1= eof_src;
push {r1,r2,r3, r4,r5,r6,r7, lr}
mov bits,#1; neg off,bits @ off= -1 initial condition
lsl bits,#31 @ 1<<31: refill next time
mov wrnk,#0xd
lsl wrnk,#8 @ 0xd00
adr g32,get32 @ load pc-relative address
adr g1b,get1b @ load pc-relative address
b top_n2b
eof_n2b:
@ -78,7 +76,11 @@ lit_n2b:
top_n2b:
jnextb1 lit_n2b
bl ss11 @ len= encoded offset [2..)
mov len,#1 @ the msb
getoff_n2b: @ ss11 len= [2..)
getnextb(len)
jnextb0 getoff_n2b
sub tmp,len,#3 @ set Carry
mov len,#0 @ Carry unaffected
blo offprev_n2b @ ss11 returned 2
@ -88,7 +90,12 @@ top_n2b:
mvn off,off; beq eof_n2b @ off= ~off
offprev_n2b: @ In: 0==len
getnextb(len); getnextb(len); bne plus1_n2b @ two bits; 1,2,3 ==> 2,3,4
bl ss11 @ len= encoded length [2..)
mov len,#1 @ the msb
getlen_n2b: @ ss11 len= [2..)
getnextb(len)
jnextb0 getlen_n2b
add len,#2 @ [2..) ==> [4..);
plus1_n2b:
add len,#1 @ 1,2,3 ==> 2,3,4; [4..) ==> [5..)
@ -103,21 +110,16 @@ copy_n2b:
sub len,#1; bne copy_n2b
b top_n2b
ss11:
mov len,#1 @ the msb
mov r12,lr @ return address; alternate: "push {lr}"
ss11a:
getnextb(len)
jnextb0 ss11a
mov pc,r12 @ return; alternate: "pop {pc}"
.code 32 @ ARM mode for ease of Carry manipulation
get32: @ In: Carry set (unchanged until final adcs)
.code 32 @ ARM mode
get1b: @ Out: Carry= next_bit
adds bits,bits,bits @ shift up, set Carry
bxne lr @ return if reload is not needed
/* In: Carry set (unchanged until final adcs) */
ldrb bits,[src],#1
ldrb tmp, [src],#1; orr bits,bits,tmp,lsl #1*8
ldrb tmp, [src],#1; orr bits,bits,tmp,lsl #2*8
ldrb tmp, [src],#1; orr bits,bits,tmp,lsl #3*8
adcs bits,bits,bits @ Set Carry out
adcs bits,bits,bits @ Carry= next_bit; set bit0 flag from CarryIn
bx lr
.size ucl_nrv2b_decompress_32, .-ucl_nrv2b_decompress_32