diff options
Diffstat (limited to 'arch/arm/lib/findbit.S')
| -rw-r--r-- | arch/arm/lib/findbit.S | 76 |
1 files changed, 52 insertions, 24 deletions
diff --git a/arch/arm/lib/findbit.S b/arch/arm/lib/findbit.S index f055d56ea68..64f6bc1a913 100644 --- a/arch/arm/lib/findbit.S +++ b/arch/arm/lib/findbit.S @@ -25,14 +25,18 @@ ENTRY(_find_first_zero_bit_le) teq r1, #0 beq 3f mov r2, #0 -1: ldrb r3, [r0, r2, lsr #3] +1: + ARM( ldrb r3, [r0, r2, lsr #3] ) + THUMB( lsr r3, r2, #3 ) + THUMB( ldrb r3, [r0, r3] ) eors r3, r3, #0xff @ invert bits - bne .found @ any now set - found zero bit + bne .L_found @ any now set - found zero bit add r2, r2, #8 @ next bit pointer 2: cmp r2, r1 @ any more? blo 1b 3: mov r0, r1 @ no free bits - RETINSTR(mov,pc,lr) + mov pc, lr +ENDPROC(_find_first_zero_bit_le) /* * Purpose : Find next 'zero' bit @@ -43,13 +47,16 @@ ENTRY(_find_next_zero_bit_le) beq 3b ands ip, r2, #7 beq 1b @ If new byte, goto old routine - ldrb r3, [r0, r2, lsr #3] + ARM( ldrb r3, [r0, r2, lsr #3] ) + THUMB( lsr r3, r2, #3 ) + THUMB( ldrb r3, [r0, r3] ) eor r3, r3, #0xff @ now looking for a 1 bit movs r3, r3, lsr ip @ shift off unused bits - bne .found + bne .L_found orr r2, r2, #7 @ if zero, then no bits here add r2, r2, #1 @ align bit pointer b 2b @ loop for next bit +ENDPROC(_find_next_zero_bit_le) /* * Purpose : Find a 'one' bit @@ -59,14 +66,18 @@ ENTRY(_find_first_bit_le) teq r1, #0 beq 3f mov r2, #0 -1: ldrb r3, [r0, r2, lsr #3] +1: + ARM( ldrb r3, [r0, r2, lsr #3] ) + THUMB( lsr r3, r2, #3 ) + THUMB( ldrb r3, [r0, r3] ) movs r3, r3 - bne .found @ any now set - found zero bit + bne .L_found @ any now set - found zero bit add r2, r2, #8 @ next bit pointer 2: cmp r2, r1 @ any more? blo 1b 3: mov r0, r1 @ no free bits - RETINSTR(mov,pc,lr) + mov pc, lr +ENDPROC(_find_first_bit_le) /* * Purpose : Find next 'one' bit @@ -77,12 +88,15 @@ ENTRY(_find_next_bit_le) beq 3b ands ip, r2, #7 beq 1b @ If new byte, goto old routine - ldrb r3, [r0, r2, lsr #3] + ARM( ldrb r3, [r0, r2, lsr #3] ) + THUMB( lsr r3, r2, #3 ) + THUMB( ldrb r3, [r0, r3] ) movs r3, r3, lsr ip @ shift off unused bits - bne .found + bne .L_found orr r2, r2, #7 @ if zero, then no bits here add r2, r2, #1 @ align bit pointer b 2b @ loop for next bit +ENDPROC(_find_next_bit_le) #ifdef __ARMEB__ @@ -91,14 +105,17 @@ ENTRY(_find_first_zero_bit_be) beq 3f mov r2, #0 1: eor r3, r2, #0x18 @ big endian byte ordering - ldrb r3, [r0, r3, lsr #3] + ARM( ldrb r3, [r0, r3, lsr #3] ) + THUMB( lsr r3, #3 ) + THUMB( ldrb r3, [r0, r3] ) eors r3, r3, #0xff @ invert bits - bne .found @ any now set - found zero bit + bne .L_found @ any now set - found zero bit add r2, r2, #8 @ next bit pointer 2: cmp r2, r1 @ any more? blo 1b 3: mov r0, r1 @ no free bits - RETINSTR(mov,pc,lr) + mov pc, lr +ENDPROC(_find_first_zero_bit_be) ENTRY(_find_next_zero_bit_be) teq r1, #0 @@ -106,27 +123,33 @@ ENTRY(_find_next_zero_bit_be) ands ip, r2, #7 beq 1b @ If new byte, goto old routine eor r3, r2, #0x18 @ big endian byte ordering - ldrb r3, [r0, r3, lsr #3] + ARM( ldrb r3, [r0, r3, lsr #3] ) + THUMB( lsr r3, #3 ) + THUMB( ldrb r3, [r0, r3] ) eor r3, r3, #0xff @ now looking for a 1 bit movs r3, r3, lsr ip @ shift off unused bits - bne .found + bne .L_found orr r2, r2, #7 @ if zero, then no bits here add r2, r2, #1 @ align bit pointer b 2b @ loop for next bit +ENDPROC(_find_next_zero_bit_be) ENTRY(_find_first_bit_be) teq r1, #0 beq 3f mov r2, #0 1: eor r3, r2, #0x18 @ big endian byte ordering - ldrb r3, [r0, r3, lsr #3] + ARM( ldrb r3, [r0, r3, lsr #3] ) + THUMB( lsr r3, #3 ) + THUMB( ldrb r3, [r0, r3] ) movs r3, r3 - bne .found @ any now set - found zero bit + bne .L_found @ any now set - found zero bit add r2, r2, #8 @ next bit pointer 2: cmp r2, r1 @ any more? blo 1b 3: mov r0, r1 @ no free bits - RETINSTR(mov,pc,lr) + mov pc, lr +ENDPROC(_find_first_bit_be) ENTRY(_find_next_bit_be) teq r1, #0 @@ -134,22 +157,25 @@ ENTRY(_find_next_bit_be) ands ip, r2, #7 beq 1b @ If new byte, goto old routine eor r3, r2, #0x18 @ big endian byte ordering - ldrb r3, [r0, r3, lsr #3] + ARM( ldrb r3, [r0, r3, lsr #3] ) + THUMB( lsr r3, #3 ) + THUMB( ldrb r3, [r0, r3] ) movs r3, r3, lsr ip @ shift off unused bits - bne .found + bne .L_found orr r2, r2, #7 @ if zero, then no bits here add r2, r2, #1 @ align bit pointer b 2b @ loop for next bit +ENDPROC(_find_next_bit_be) #endif /* * One or more bits in the LSB of r3 are assumed to be set. */ -.found: +.L_found: #if __LINUX_ARM_ARCH__ >= 5 - rsb r1, r3, #0 - and r3, r3, r1 + rsb r0, r3, #0 + and r3, r3, r0 clz r3, r3 rsb r3, r3, #31 add r0, r2, r3 @@ -164,5 +190,7 @@ ENTRY(_find_next_bit_be) addeq r2, r2, #1 mov r0, r2 #endif - RETINSTR(mov,pc,lr) + cmp r1, r0 @ Clamp to maxbit + movlo r0, r1 + mov pc, lr |