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| author | Roland McGrath <roland@hack.frob.com> | 2013-03-12 10:00:53 -0700 |
|---|---|---|
| committer | Roland McGrath <roland@hack.frob.com> | 2013-03-12 17:04:54 -0700 |
| commit | 47c71d9323df1356ac803bdddb7a8f512faf9962 (patch) | |
| tree | 81b6a02312fe301df174d9d3555ea6a23efe945b | |
| parent | 9967e003b32d20441892386f1092d1aded51e1aa (diff) | |
| download | glibc-47c71d9323df1356ac803bdddb7a8f512faf9962.zip glibc-47c71d9323df1356ac803bdddb7a8f512faf9962.tar.gz glibc-47c71d9323df1356ac803bdddb7a8f512faf9962.tar.bz2 | |
ARM: Change register allocation in armv6t2 memchr implementation.
| -rw-r--r-- | ports/ChangeLog.arm | 5 | ||||
| -rw-r--r-- | ports/sysdeps/arm/armv6t2/memchr.S | 30 |
2 files changed, 20 insertions, 15 deletions
diff --git a/ports/ChangeLog.arm b/ports/ChangeLog.arm index 8536181..d24a109 100644 --- a/ports/ChangeLog.arm +++ b/ports/ChangeLog.arm @@ -1,3 +1,8 @@ +2013-03-12 Roland McGrath <roland@hack.frob.com> + + * sysdeps/arm/armv6t2/memchr.S: Change register allocation so ldrd use + is r4,r5 rather than r5,r6; this way ARM mode will allow that ldrd. + 2013-03-11 Joseph Myers <joseph@codesourcery.com> * sysdeps/arm/preconfigure.in: Add comment about diff --git a/ports/sysdeps/arm/armv6t2/memchr.S b/ports/sysdeps/arm/armv6t2/memchr.S index 6d35f47..e253a66 100644 --- a/ports/sysdeps/arm/armv6t2/memchr.S +++ b/ports/sysdeps/arm/armv6t2/memchr.S @@ -83,20 +83,20 @@ ENTRY(memchr) orr r1, r1, r1, lsl #8 @ expand the match word across to all bytes orr r1, r1, r1, lsl #16 - bic r4, r2, #7 @ Number of double words to work with * 8 + bic r6, r2, #7 @ Number of double words to work with * 8 mvns r7, #0 @ all F's movs r3, #0 15: - ldrd r5,r6, [r0],#8 - subs r4, r4, #8 - eor r5,r5, r1 @ Get it so that r5,r6 have 00's where the bytes match the target - eor r6,r6, r1 + ldrd r4,r5, [r0],#8 + subs r6, r6, #8 + eor r4,r4, r1 @ Get it so that r4,r5 have 00's where the bytes match the target + eor r5,r5, r1 + uadd8 r4, r4, r7 @ Parallel add 0xff - sets the GE bits for anything that wasn't 0 + sel r4, r3, r7 @ bytes are 00 for none-00 bytes, or ff for 00 bytes - NOTE INVERSION uadd8 r5, r5, r7 @ Parallel add 0xff - sets the GE bits for anything that wasn't 0 - sel r5, r3, r7 @ bytes are 00 for none-00 bytes, or ff for 00 bytes - NOTE INVERSION - uadd8 r6, r6, r7 @ Parallel add 0xff - sets the GE bits for anything that wasn't 0 - sel r6, r5, r7 @ chained....bytes are 00 for none-00 bytes, or ff for 00 bytes - NOTE INVERSION - cbnz r6, 60f + sel r5, r4, r7 @ chained....bytes are 00 for none-00 bytes, or ff for 00 bytes - NOTE INVERSION + cbnz r5, 60f bne 15b @ (Flags from the subs above) If not run out of bytes then go around again pop {r4,r5,r6,r7} @@ -129,22 +129,22 @@ ENTRY(memchr) 60: @ We're here because the fast path found a hit - now we have to track down exactly which word it was @ r0 points to the start of the double word after the one that was tested - @ r5 has the 00/ff pattern for the first word, r6 has the chained value + @ r4 has the 00/ff pattern for the first word, r5 has the chained value cfi_restore_state - cmp r5, #0 + cmp r4, #0 itte eq - moveq r5, r6 @ the end is in the 2nd word + moveq r4, r5 @ the end is in the 2nd word subeq r0,r0,#3 @ Points to 2nd byte of 2nd word subne r0,r0,#7 @ or 2nd byte of 1st word @ r0 currently points to the 2nd byte of the word containing the hit - tst r5, # CHARTSTMASK(0) @ 1st character + tst r4, # CHARTSTMASK(0) @ 1st character bne 61f adds r0,r0,#1 - tst r5, # CHARTSTMASK(1) @ 2nd character + tst r4, # CHARTSTMASK(1) @ 2nd character ittt eq addeq r0,r0,#1 - tsteq r5, # (3<<15) @ 2nd & 3rd character + tsteq r4, # (3<<15) @ 2nd & 3rd character @ If not the 3rd must be the last one addeq r0,r0,#1 |