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| author | Alan Modra <amodra@gmail.com> | 2013-08-17 18:46:05 +0930 |
|---|---|---|
| committer | Alan Modra <amodra@gmail.com> | 2013-10-04 10:40:22 +0930 |
| commit | 664318c3eb07032e2bfcf47cb2aa3c89280c19e7 (patch) | |
| tree | 338e8a4e5b1215319560caa795ce5830f2f46685 /sysdeps/powerpc/powerpc64/power7/strchrnul.S | |
| parent | 43b84013714c46e6dcae4a5564c5527777ad5e08 (diff) | |
| download | glibc-664318c3eb07032e2bfcf47cb2aa3c89280c19e7.tar.gz | |
PowerPC LE strchr
http://sourceware.org/ml/libc-alpha/2013-08/msg00101.html
Adds little-endian support to optimised strchr assembly. I've also
tweaked the big-endian code a little. In power7/strchr.S there's a
check in the tail of the function that we didn't match 0 before
finding a c match, done by comparing leading zero counts. It's just
as valid, and quicker, to compare the raw output from cmpb.
Another little tweak is to use rldimi/insrdi in place of rlwimi for
the power7 strchr functions. Since rlwimi is cracked, it is a few
cycles slower. rldimi can be used on the 32-bit power7 functions
too.
* sysdeps/powerpc/powerpc64/power7/strchr.S (strchr): Add little-endian
support. Correct typos, formatting. Optimize tail. Use insrdi
rather than rlwimi.
* sysdeps/powerpc/powerpc32/power7/strchr.S: Likewise.
* sysdeps/powerpc/powerpc64/power7/strchrnul.S (__strchrnul): Add
little-endian support. Correct typos.
* sysdeps/powerpc/powerpc32/power7/strchrnul.S: Likewise. Use insrdi
rather than rlwimi.
* sysdeps/powerpc/powerpc64/strchr.S (rTMP4, rTMP5): Define. Use
in loop and entry code to keep "and." results.
(strchr): Add little-endian support. Comment. Move cntlzd
earlier in tail.
* sysdeps/powerpc/powerpc32/strchr.S: Likewise.
Diffstat (limited to 'sysdeps/powerpc/powerpc64/power7/strchrnul.S')
| -rw-r--r-- | sysdeps/powerpc/powerpc64/power7/strchrnul.S | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/sysdeps/powerpc/powerpc64/power7/strchrnul.S b/sysdeps/powerpc/powerpc64/power7/strchrnul.S index 9dbc51b0d1..df457525e2 100644 --- a/sysdeps/powerpc/powerpc64/power7/strchrnul.S +++ b/sysdeps/powerpc/powerpc64/power7/strchrnul.S @@ -27,8 +27,8 @@ ENTRY (__strchrnul) clrrdi r8,r3,3 /* Align the address to doubleword boundary. */ /* Replicate byte to doubleword. */ - rlwimi r4,r4,8,16,23 - rlwimi r4,r4,16,0,15 + insrdi r4,r4,8,48 + insrdi r4,r4,16,32 insrdi r4,r4,32,0 rlwinm r6,r3,3,26,28 /* Calculate padding. */ @@ -44,10 +44,17 @@ ENTRY (__strchrnul) /* Move the doublewords left and right to discard the bits that are not part of the string and to bring them back as zeros. */ +#ifdef __LITTLE_ENDIAN__ + srd r10,r10,r6 + srd r9,r9,r6 + sld r10,r10,r6 + sld r9,r9,r6 +#else sld r10,r10,r6 sld r9,r9,r6 srd r10,r10,r6 srd r9,r9,r6 +#endif or r5,r9,r10 /* OR the results to speed things up. */ cmpdi cr7,r5,0 /* If r5 == 0, no c or null bytes have been found. */ @@ -97,7 +104,7 @@ L(loop): bne cr6,L(done) /* The c/null byte must be in the second doubleword. Adjust the - address again and move the result of cmpb to r10 so we can calculate + address again and move the result of cmpb to r5 so we can calculate the pointer. */ mr r5,r10 addi r8,r8,8 @@ -106,7 +113,13 @@ L(loop): 0xff in the same position as the c/null byte in the original doubleword from the string. Use that to calculate the pointer. */ L(done): +#ifdef __LITTLE_ENDIAN__ + addi r0,r5,-1 + andc r0,r0,r5 + popcntd r0,r0 +#else cntlzd r0,r5 /* Count leading zeros before the match. */ +#endif srdi r0,r0,3 /* Convert leading zeros to bytes. */ add r3,r8,r0 /* Return address of matching c/null byte. */ blr |