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author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/alpha/lib/strrchr.S | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/alpha/lib/strrchr.S')
-rw-r--r-- | kernel/arch/alpha/lib/strrchr.S | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/kernel/arch/alpha/lib/strrchr.S b/kernel/arch/alpha/lib/strrchr.S new file mode 100644 index 000000000..1970dc07c --- /dev/null +++ b/kernel/arch/alpha/lib/strrchr.S @@ -0,0 +1,87 @@ +/* + * arch/alpha/lib/strrchr.S + * Contributed by Richard Henderson (rth@tamu.edu) + * + * Return the address of the last occurrence of a given character + * within a null-terminated string, or null if it is not found. + */ + +#include <asm/regdef.h> + + .set noreorder + .set noat + + .align 3 + .ent strrchr + .globl strrchr +strrchr: + .frame sp, 0, ra + .prologue 0 + + zapnot a1, 1, a1 # e0 : zero extend our test character + mov zero, t6 # .. e1 : t6 is last match aligned addr + sll a1, 8, t5 # e0 : replicate our test character + mov zero, t8 # .. e1 : t8 is last match byte compare mask + or t5, a1, a1 # e0 : + ldq_u t0, 0(a0) # .. e1 : load first quadword + sll a1, 16, t5 # e0 : + andnot a0, 7, v0 # .. e1 : align source addr + or t5, a1, a1 # e0 : + lda t4, -1 # .. e1 : build garbage mask + sll a1, 32, t5 # e0 : + cmpbge zero, t0, t1 # .. e1 : bits set iff byte == zero + mskqh t4, a0, t4 # e0 : + or t5, a1, a1 # .. e1 : character replication complete + xor t0, a1, t2 # e0 : make bytes == c zero + cmpbge zero, t4, t4 # .. e1 : bits set iff byte is garbage + cmpbge zero, t2, t3 # e0 : bits set iff byte == c + andnot t1, t4, t1 # .. e1 : clear garbage from null test + andnot t3, t4, t3 # e0 : clear garbage from char test + bne t1, $eos # .. e1 : did we already hit the terminator? + + /* Character search main loop */ +$loop: + ldq t0, 8(v0) # e0 : load next quadword + cmovne t3, v0, t6 # .. e1 : save previous comparisons match + cmovne t3, t3, t8 # e0 : + addq v0, 8, v0 # .. e1 : + xor t0, a1, t2 # e0 : + cmpbge zero, t0, t1 # .. e1 : bits set iff byte == zero + cmpbge zero, t2, t3 # e0 : bits set iff byte == c + beq t1, $loop # .. e1 : if we havnt seen a null, loop + + /* Mask out character matches after terminator */ +$eos: + negq t1, t4 # e0 : isolate first null byte match + and t1, t4, t4 # e1 : + subq t4, 1, t5 # e0 : build a mask of the bytes up to... + or t4, t5, t4 # e1 : ... and including the null + + and t3, t4, t3 # e0 : mask out char matches after null + cmovne t3, t3, t8 # .. e1 : save it, if match found + cmovne t3, v0, t6 # e0 : + + /* Locate the address of the last matched character */ + + /* Retain the early exit for the ev4 -- the ev5 mispredict penalty + is 5 cycles -- the same as just falling through. */ + beq t8, $retnull # .. e1 : + + and t8, 0xf0, t2 # e0 : binary search for the high bit set + cmovne t2, t2, t8 # .. e1 (zdb) + cmovne t2, 4, t2 # e0 : + and t8, 0xcc, t1 # .. e1 : + cmovne t1, t1, t8 # e0 : + cmovne t1, 2, t1 # .. e1 : + and t8, 0xaa, t0 # e0 : + cmovne t0, 1, t0 # .. e1 (zdb) + addq t2, t1, t1 # e0 : + addq t6, t0, v0 # .. e1 : add our aligned base ptr to the mix + addq v0, t1, v0 # e0 : + ret # .. e1 : + +$retnull: + mov zero, v0 # e0 : + ret # .. e1 : + + .end strrchr |