cfcff5f570
N/A Signed-off-by: zhuyanlin <zhuyanlin1@xiaomi.com>
768 lines
22 KiB
ArmAsm
768 lines
22 KiB
ArmAsm
/****************************************************************************
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* libs/libc/machine/xtensa/arch_strcmp.S
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include "xtensa_asm.h"
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#include <arch/chip/core-isa.h>
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#include <arch/xtensa/xtensa_abi.h>
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/****************************************************************************
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* Pre-processor Macros
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****************************************************************************/
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#define MASK4 0x40404040
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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.section .text
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.begin schedule
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.align 4
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.literal_position
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.global strcmp
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.type strcmp,@function
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.align 4
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strcmp:
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#if XCHAL_HAVE_LOOPS && XCHAL_HAVE_DENSITY && !XCHAL_HAVE_BE && XCHAL_HAVE_FLIX3
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/* Fast version for FLIX3 Little Endian */
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ENTRY(16)
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/* a2 = s1, a3 = s2 */
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l8ui a8, a2, 0 # byte 0 from s1
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l8ui a9, a3, 0 # byte 0 from s2
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movi a10, 3 # mask
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movi a5, 0xfffffffc
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or a11, a2, a3
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movi a4, MASK0 # mask for byte 0
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movi a7, MASK4
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addi a3, a3, -8
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addi a2, a2, -8
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and a5, a5, a2
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bne.w18 a8, a9, .Lretdiff
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l32i a8, a5, 8 # get word from aligned variant of s1
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bany.w18 a11, a10, .Lnot_aligned
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/* s1 is word-aligned; s2 is word-aligned.
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If the zero-overhead loop option is available, use an (almost)
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infinite zero-overhead loop with conditional exits so we only pay
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for taken branches when exiting the loop. */
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/* New algorithm, relying on the fact that all normal ASCII is between
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32 and 127.
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Rather than check all bytes for zero:
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Take one word (4 bytes). Call it w1.
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Shift w1 left by one into w1'.
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Or w1 and w1'. For all normal ASCII bit 6 will be 1; for zero it won't.
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Check that all 4 bit 6's (one for each byte) are one:
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If they are, we are definitely not done.
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If they are not, we are probably done, but need to check for zero. */
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.Laligned:
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/* Loop forever */
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1:
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loop a0, .Laligned_done
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/* First unrolled loop body. */
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l32i a9, a3, 8 # get word from s2
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addi a3, a3, 8 # advance s2 pointer
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slli a5, a8, 1
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or a10, a8, a5
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{l32i a11, a2, 12 # get word from s1+4
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bne.w18 a8, a9, .Lwne2}
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l32i a9, a3, 4 # get word from s2+4
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bnall.w18 a10, a7, .Lprobeq
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/* Second unrolled loop body. */
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slli a5, a11, 1
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or a10, a11, a5
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addi a2, a2, 8 # advance s1 pointer
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mov a8, a11
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bne.w18 a11, a9, .Lwne2
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l32i a8, a2, 8 # get word from s1
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bnall.w18 a10, a7, .Lprobeq2
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.Laligned_done:
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l32i a8, a2, 8 # get word from s1
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j 1b
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.Lnot_aligned:
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xor a11, a2, a3 # compare low two bits of s1 and s2
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bany a11, a10, .Lunaligned # if they have different alignment
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/* s1/s2 are not word-aligned. */
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movi a5, 0xfffffffc
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addi a2, a2, 1 # advance s1
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beqz a9, .Leq # bytes equal, if zero, strings are equal
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addi a3, a3, 1 # advance s2
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and a6, a2, a5
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l32i a8, a6, 8 # get word from s1
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bnone a2, a10, .Laligned # if s1/s2 now aligned
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l8ui a8, a2, 8 # byte 1 from s1
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l8ui a9, a3, 8 # byte 1 from s2
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addi a2, a2, 1 # advance s1
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bne a8, a9, .Lretdiff # if different, return difference
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beqz a8, .Leq # bytes equal, if zero, strings are equal
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addi a3, a3, 1 # advance s2
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and a6, a2, a5
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l32i a8, a6, 8 # get word from s1
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bnone a2, a10, .Laligned # if s1/s2 now aligned
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l8ui a8, a2, 8 # byte 2 from s1
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l8ui a9, a3, 8 # byte 2 from s2
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addi a2, a2, 1 # advance s1
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bne a8, a9, .Lretdiff # if different, return difference
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beqz a8, .Leq # bytes equal, if zero, strings are equal
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addi a3, a3, 1 # advance s2
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l32i a8, a2, 8 # get word from s1
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j .Laligned
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/* s1 and s2 have different alignment.
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If the zero-overhead loop option is available, use an (almost)
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infinite zero-overhead loop with conditional exits so we only pay
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for taken branches when exiting the loop.
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Note: It is important for this unaligned case to come before the
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code for aligned strings, because otherwise some of the branches
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above cannot reach and have to be transformed to branches around
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jumps. The unaligned code is smaller and the branches can reach
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over it. */
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.Lunaligned:
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movi.n a8, 0 # set up for the maximum loop count
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loop a8, .Lretdiff # loop forever (almost anyway)
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l8ui a8, a2, 8
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l8ui a9, a3, 8
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addi a2, a2, 1
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bne a8, a9, .Lretdiff
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addi a3, a3, 1
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beqz a8, .Lretdiff
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.Lretdiff:
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sub a2, a8, a9
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RET(16)
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.Lprobeq2:
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/* Adjust pointers to account for the loop unrolling. */
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mov a8, a11
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addi a2, a2, -4
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addi a3, a3, 4
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/* align (0 mod 4) */
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.Lprobeq:
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/* Words are probably equal, but check for sure.
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If not, loop over the rest of string using normal algorithm. */
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bnone a8, a4, .Leq # if byte 0 is zero
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movi a5, MASK1 # mask for byte 1
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movi a6, MASK2 # mask for byte 2
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bnone a8, a5, .Leq # if byte 1 is zero
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movi a7, MASK3 # mask for byte 3
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bnone a8, a6, .Leq # if byte 2 is zero
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bnone a8, a7, .Leq # if byte 3 is zero
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/* align (1 mod 4) */
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addi.n a2, a2, 12 # advance s1 pointer
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addi.n a3, a3, 4 # advance s2 pointer
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/* align (1 mod 4) or (2 mod 4) */
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1:
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loop a0, .Lend # loop forever (a4 is bigger than max iters)
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l32i a8, a2, 0 # get word from s1
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l32i a9, a3, 0 # get word from s2
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addi a2, a2, 4 # advance s1 pointer
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bne a8, a9, .Lwne
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bnone a8, a4, .Leq # if byte 0 is zero
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bnone a8, a5, .Leq # if byte 1 is zero
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bnone a8, a6, .Leq # if byte 2 is zero
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bnone a8, a7, .Leq # if byte 3 is zero
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addi a3, a3, 4 # advance s2 pointer
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.Lend:
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j 1b
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/* Words are equal; some byte is zero. */
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.Leq: movi a2, 0 # return equal
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RET(16)
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.Lwne2: /* Words are not equal. On big-endian processors, if none of the
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bytes are zero, the return value can be determined by a simple
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comparison. */
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.Lwne: /* Words are not equal. */
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xor a2, a8, a9 # get word with nonzero in byte that differs
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extui a10, a8, 0, 8
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extui a11, a9, 0, 8
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movi a5, MASK1 # mask for byte 1
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bany.w18 a2, a4, .Ldiff0 # if byte 0 differs
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bnone.w18 a8, a4, .Leq # if byte 0 is zero
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movi a6, MASK2 # mask for byte 2
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bany.w18 a2, a5, .Ldiff1 # if byte 1 differs
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extui a10, a8, 24, 8
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bnone.w18 a8, a5, .Leq # if byte 1 is zero
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extui a11, a9, 24, 8
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bany.w18 a2, a6, .Ldiff2 # if byte 2 differs
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sub a2, a10, a11
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bnone.w18 a8, a6, .Leq # if byte 2 is zero
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/* Little-endian is a little more difficult because can't subtract
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whole words. */
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.Ldiff3:
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/* Bytes 0-2 are equal; byte 3 is different.
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For little-endian need to have a sign bit for the difference. */
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RET(16)
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.Ldiff0:
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/* Byte 0 is different. */
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sub a2, a10, a11
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RET(16)
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.Ldiff1:
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/* Byte 0 is equal; byte 1 is different. */
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extui a10, a8, 8, 8
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extui a11, a9, 8, 8
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sub a2, a10, a11
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RET(16)
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.Ldiff2:
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/* Bytes 0-1 are equal; byte 2 is different. */
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extui a10, a8, 16, 8
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extui a11, a9, 16, 8
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sub a2, a10, a11
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RET(16)
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#else
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#if XCHAL_HAVE_LOOPS && XCHAL_HAVE_DENSITY && !XCHAL_HAVE_BE && XCHAL_HAVE_PDX4
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/* Fast version for FLIX3 Little Endian */
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ENTRY(16)
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/* a2 = s1, a3 = s2 */
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l8ui a8, a2, 0 # byte 0 from s1
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l8ui a9, a3, 0 # byte 0 from s2
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movi a10, 3 # mask
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movi a5, 0xfffffffc
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or a11, a2, a3
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movi a4, MASK0 # mask for byte 0
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movi a7, MASK4
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addi a3, a3, -8
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addi a2, a2, -8
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and a5, a5, a2
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bne.w15 a8, a9, .Lretdiff
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l32i a8, a5, 8 # get word from aligned variant of s1
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bany.w15 a11, a10, .Lnot_aligned
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/* s1 is word-aligned; s2 is word-aligned.
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If the zero-overhead loop option is available, use an (almost)
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infinite zero-overhead loop with conditional exits so we only pay
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for taken branches when exiting the loop. */
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/* New algorithm, relying on the fact that all normal ASCII is between
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32 and 127.
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Rather than check all bytes for zero:
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Take one word (4 bytes). Call it w1.
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Shift w1 left by one into w1'.
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Or w1 and w1'. For all normal ASCII bit 6 will be 1; for zero it won't.
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Check that all 4 bit 6's (one for each byte) are one:
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If they are, we are definitely not done.
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If they are not, we are probably done, but need to check for zero. */
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.Laligned:
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/* Loop forever */
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1:
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loop a0, .Laligned_done
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/* First unrolled loop body. */
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l32i a9, a3, 8 # get word from s2
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addi a3, a3, 8 # advance s2 pointer
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slli a5, a8, 1
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or a10, a8, a5
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{
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bne.w15 a8, a9, .Lwne2
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l32i a11, a2, 12 # get word from s1+4
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nop
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nop
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}
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l32i a9, a3, 4 # get word from s2+4
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bnall.w15 a10, a7, .Lprobeq
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/* Second unrolled loop body. */
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slli a5, a11, 1
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or a10, a11, a5
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addi a2, a2, 8 # advance s1 pointer
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mov a8, a11
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bne.w15 a11, a9, .Lwne2
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l32i a8, a2, 8 # get word from s1
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bnall.w15 a10, a7, .Lprobeq2
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.Laligned_done:
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l32i a8, a2, 8 # get word from s1
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j 1b
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.Lnot_aligned:
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xor a11, a2, a3 # compare low two bits of s1 and s2
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bany a11, a10, .Lunaligned # if they have different alignment
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/* s1/s2 are not word-aligned. */
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movi a5, 0xfffffffc
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addi a2, a2, 1 # advance s1
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beqz a9, .Leq # bytes equal, if zero, strings are equal
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addi a3, a3, 1 # advance s2
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and a6, a2, a5
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l32i a8, a6, 8 # get word from s1
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bnone a2, a10, .Laligned # if s1/s2 now aligned
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l8ui a8, a2, 8 # byte 1 from s1
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l8ui a9, a3, 8 # byte 1 from s2
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addi a2, a2, 1 # advance s1
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bne a8, a9, .Lretdiff # if different, return difference
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beqz a8, .Leq # bytes equal, if zero, strings are equal
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addi a3, a3, 1 # advance s2
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and a6, a2, a5
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l32i a8, a6, 8 # get word from s1
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bnone a2, a10, .Laligned # if s1/s2 now aligned
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l8ui a8, a2, 8 # byte 2 from s1
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l8ui a9, a3, 8 # byte 2 from s2
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addi a2, a2, 1 # advance s1
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bne a8, a9, .Lretdiff # if different, return difference
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beqz a8, .Leq # bytes equal, if zero, strings are equal
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addi a3, a3, 1 # advance s2
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l32i a8, a2, 8 # get word from s1
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j .Laligned
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/* s1 and s2 have different alignment.
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If the zero-overhead loop option is available, use an (almost)
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infinite zero-overhead loop with conditional exits so we only pay
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for taken branches when exiting the loop.
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|
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Note: It is important for this unaligned case to come before the
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code for aligned strings, because otherwise some of the branches
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above cannot reach and have to be transformed to branches around
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jumps. The unaligned code is smaller and the branches can reach
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over it. */
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.Lunaligned:
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movi.n a8, 0 # set up for the maximum loop count
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loop a8, .Lretdiff # loop forever (almost anyway)
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l8ui a8, a2, 8
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l8ui a9, a3, 8
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addi a2, a2, 1
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bne a8, a9, .Lretdiff
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addi a3, a3, 1
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beqz a8, .Lretdiff
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.Lretdiff:
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sub a2, a8, a9
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RET(16)
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.Lprobeq2:
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/* Adjust pointers to account for the loop unrolling. */
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mov a8, a11
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addi a2, a2, -4
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addi a3, a3, 4
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/* align (0 mod 4) */
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.Lprobeq:
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/* Words are probably equal, but check for sure.
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If not, loop over the rest of string using normal algorithm. */
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bnone a8, a4, .Leq # if byte 0 is zero
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movi a5, MASK1 # mask for byte 1
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movi a6, MASK2 # mask for byte 2
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bnone a8, a5, .Leq # if byte 1 is zero
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movi a7, MASK3 # mask for byte 3
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bnone a8, a6, .Leq # if byte 2 is zero
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bnone a8, a7, .Leq # if byte 3 is zero
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/* align (1 mod 4) */
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addi.n a2, a2, 12 # advance s1 pointer
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addi.n a3, a3, 4 # advance s2 pointer
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/* align (1 mod 4) or (2 mod 4) */
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1:
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loop a0, .Lend # loop forever (a4 is bigger than max iters)
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l32i a8, a2, 0 # get word from s1
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l32i a9, a3, 0 # get word from s2
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addi a2, a2, 4 # advance s1 pointer
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bne a8, a9, .Lwne
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bnone a8, a4, .Leq # if byte 0 is zero
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bnone a8, a5, .Leq # if byte 1 is zero
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bnone a8, a6, .Leq # if byte 2 is zero
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bnone a8, a7, .Leq # if byte 3 is zero
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addi a3, a3, 4 # advance s2 pointer
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.Lend:
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j 1b
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/* Words are equal; some byte is zero. */
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.Leq: movi a2, 0 # return equal
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RET(16)
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.Lwne2: /* Words are not equal. On big-endian processors, if none of the
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bytes are zero, the return value can be determined by a simple
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comparison. */
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.Lwne: /* Words are not equal. */
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xor a2, a8, a9 # get word with nonzero in byte that differs
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extui a10, a8, 0, 8
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extui a11, a9, 0, 8
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movi a5, MASK1 # mask for byte 1
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bany.w15 a2, a4, .Ldiff0 # if byte 0 differs
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bnone.w15 a8, a4, .Leq # if byte 0 is zero
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movi a6, MASK2 # mask for byte 2
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bany.w15 a2, a5, .Ldiff1 # if byte 1 differs
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extui a10, a8, 24, 8
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bnone.w15 a8, a5, .Leq # if byte 1 is zero
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extui a11, a9, 24, 8
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bany.w15 a2, a6, .Ldiff2 # if byte 2 differs
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sub a2, a10, a11
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bnone.w15 a8, a6, .Leq # if byte 2 is zero
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/* Little-endian is a little more difficult because can't subtract
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whole words. */
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.Ldiff3:
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/* Bytes 0-2 are equal; byte 3 is different.
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For little-endian need to have a sign bit for the difference. */
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RET(16)
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.Ldiff0:
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/* Byte 0 is different. */
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sub a2, a10, a11
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RET(16)
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.Ldiff1:
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/* Byte 0 is equal; byte 1 is different. */
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extui a10, a8, 8, 8
|
|
extui a11, a9, 8, 8
|
|
sub a2, a10, a11
|
|
RET(16)
|
|
|
|
.Ldiff2:
|
|
/* Bytes 0-1 are equal; byte 2 is different. */
|
|
extui a10, a8, 16, 8
|
|
extui a11, a9, 16, 8
|
|
sub a2, a10, a11
|
|
RET(16)
|
|
|
|
|
|
#else /* Not FLIX3 */
|
|
ENTRY(16)
|
|
/* a2 = s1, a3 = s2 */
|
|
|
|
l8ui a8, a2, 0 # byte 0 from s1
|
|
l8ui a9, a3, 0 # byte 0 from s2
|
|
movi a10, 3 # mask
|
|
bne a8, a9, .Lretdiff
|
|
|
|
or a11, a2, a3
|
|
bnone a11, a10, .Laligned
|
|
|
|
xor a11, a2, a3 # compare low two bits of s1 and s2
|
|
bany a11, a10, .Lunaligned # if they have different alignment
|
|
|
|
/* s1/s2 are not word-aligned. */
|
|
addi a2, a2, 1 # advance s1
|
|
beqz a8, .Leq # bytes equal, if zero, strings are equal
|
|
addi a3, a3, 1 # advance s2
|
|
bnone a2, a10, .Laligned # if s1/s2 now aligned
|
|
l8ui a8, a2, 0 # byte 1 from s1
|
|
l8ui a9, a3, 0 # byte 1 from s2
|
|
addi a2, a2, 1 # advance s1
|
|
bne a8, a9, .Lretdiff # if different, return difference
|
|
beqz a8, .Leq # bytes equal, if zero, strings are equal
|
|
addi a3, a3, 1 # advance s2
|
|
bnone a2, a10, .Laligned # if s1/s2 now aligned
|
|
l8ui a8, a2, 0 # byte 2 from s1
|
|
l8ui a9, a3, 0 # byte 2 from s2
|
|
addi a2, a2, 1 # advance s1
|
|
bne a8, a9, .Lretdiff # if different, return difference
|
|
beqz a8, .Leq # bytes equal, if zero, strings are equal
|
|
addi a3, a3, 1 # advance s2
|
|
j .Laligned
|
|
|
|
/* s1 and s2 have different alignment.
|
|
|
|
If the zero-overhead loop option is available, use an (almost)
|
|
infinite zero-overhead loop with conditional exits so we only pay
|
|
for taken branches when exiting the loop.
|
|
|
|
Note: It is important for this unaligned case to come before the
|
|
code for aligned strings, because otherwise some of the branches
|
|
above cannot reach and have to be transformed to branches around
|
|
jumps. The unaligned code is smaller and the branches can reach
|
|
over it. */
|
|
|
|
.align 4
|
|
#if XCHAL_HAVE_LOOPS
|
|
#if XCHAL_HAVE_DENSITY
|
|
/* (2 mod 4) alignment for loop instruction */
|
|
#else
|
|
/* (1 mod 4) alignment for loop instruction */
|
|
.byte 0
|
|
.byte 0
|
|
#endif
|
|
#endif
|
|
.Lunaligned:
|
|
#if XCHAL_HAVE_LOOPS
|
|
#if XCHAL_HAVE_DENSITY
|
|
_movi.n a8, 0 # set up for the maximum loop count
|
|
#else
|
|
_movi a8, 0 # set up for the maximum loop count
|
|
#endif
|
|
loop a8, .Lretdiff # loop forever (almost anyway)
|
|
#endif
|
|
.Lnextbyte:
|
|
l8ui a8, a2, 0
|
|
l8ui a9, a3, 0
|
|
addi a2, a2, 1
|
|
bne a8, a9, .Lretdiff
|
|
addi a3, a3, 1
|
|
#if XCHAL_HAVE_LOOPS
|
|
beqz a8, .Lretdiff
|
|
#else
|
|
bnez a8, .Lnextbyte
|
|
#endif
|
|
.Lretdiff:
|
|
sub a2, a8, a9
|
|
RET(16)
|
|
|
|
/* s1 is word-aligned; s2 is word-aligned.
|
|
|
|
If the zero-overhead loop option is available, use an (almost)
|
|
infinite zero-overhead loop with conditional exits so we only pay
|
|
for taken branches when exiting the loop. */
|
|
|
|
/* New algorithm, relying on the fact that all normal ASCII is between
|
|
32 and 127.
|
|
|
|
Rather than check all bytes for zero:
|
|
Take one word (4 bytes). Call it w1.
|
|
Shift w1 left by one into w1'.
|
|
Or w1 and w1'. For all normal ASCII bit 6 will be 1; for zero it won't.
|
|
Check that all 4 bit 6's (one for each byte) are one:
|
|
If they are, we are definitely not done.
|
|
If they are not, we are probably done, but need to check for zero. */
|
|
|
|
.align 4
|
|
#if XCHAL_HAVE_LOOPS
|
|
#if XCHAL_HAVE_CONST16
|
|
/* (2 mod 4) alignment for loop instruction */
|
|
.byte 0
|
|
#endif
|
|
.Laligned:
|
|
movi a4, MASK0 # mask for byte 0
|
|
movi a7, MASK4
|
|
|
|
/* Loop forever */
|
|
1:
|
|
loop a0, .Laligned_done
|
|
|
|
/* First unrolled loop body. */
|
|
l32i a8, a2, 0 # get word from s1
|
|
l32i a9, a3, 0 # get word from s2
|
|
slli a5, a8, 1
|
|
bne a8, a9, .Lwne2
|
|
or a9, a8, a5
|
|
bnall a9, a7, .Lprobeq
|
|
|
|
/* Second unrolled loop body. */
|
|
l32i a8, a2, 4 # get word from s1+4
|
|
l32i a9, a3, 4 # get word from s2+4
|
|
slli a5, a8, 1
|
|
bne a8, a9, .Lwne2
|
|
or a9, a8, a5
|
|
bnall a9, a7, .Lprobeq2
|
|
|
|
addi a2, a2, 8 # advance s1 pointer
|
|
addi a3, a3, 8 # advance s2 pointer
|
|
.Laligned_done:
|
|
j 1b
|
|
|
|
.Lprobeq2:
|
|
/* Adjust pointers to account for the loop unrolling. */
|
|
addi a2, a2, 4
|
|
addi a3, a3, 4
|
|
|
|
#else /* !XCHAL_HAVE_LOOPS */
|
|
|
|
.Laligned:
|
|
movi a4, MASK0 # mask for byte 0
|
|
movi a7, MASK4
|
|
j .Lfirstword
|
|
.Lnextword:
|
|
addi a2, a2, 4 # advance s1 pointer
|
|
addi a3, a3, 4 # advance s2 pointer
|
|
.Lfirstword:
|
|
l32i a8, a2, 0 # get word from s1
|
|
l32i a9, a3, 0 # get word from s2
|
|
slli a5, a8, 1
|
|
bne a8, a9, .Lwne2
|
|
or a9, a8, a5
|
|
ball a9, a7, .Lnextword
|
|
#endif /* !XCHAL_HAVE_LOOPS */
|
|
|
|
/* align (0 mod 4) */
|
|
.Lprobeq:
|
|
/* Words are probably equal, but check for sure.
|
|
If not, loop over the rest of string using normal algorithm. */
|
|
|
|
bnone a8, a4, .Leq # if byte 0 is zero
|
|
movi a5, MASK1 # mask for byte 1
|
|
movi a6, MASK2 # mask for byte 2
|
|
bnone a8, a5, .Leq # if byte 1 is zero
|
|
movi a7, MASK3 # mask for byte 3
|
|
bnone a8, a6, .Leq # if byte 2 is zero
|
|
bnone a8, a7, .Leq # if byte 3 is zero
|
|
/* align (1 mod 4) */
|
|
#if XCHAL_HAVE_DENSITY
|
|
addi.n a2, a2, 4 # advance s1 pointer
|
|
addi.n a3, a3, 4 # advance s2 pointer
|
|
/* align (1 mod 4) or (2 mod 4) */
|
|
#else
|
|
addi a2, a2, 4 # advance s1 pointer
|
|
addi a3, a3, 4 # advance s2 pointer
|
|
or a1, a1, a1 # nop
|
|
#if XCHAL_HAVE_CONST16
|
|
or a1, a1, a1 # nop
|
|
#endif
|
|
/* align (2 mod 4) */
|
|
#endif /* XCHAL_HAVE_DENSITY */
|
|
#if XCHAL_HAVE_LOOPS
|
|
1:
|
|
loop a0, .Leq # loop forever (a4 is bigger than max iters)
|
|
l32i a8, a2, 0 # get word from s1
|
|
l32i a9, a3, 0 # get word from s2
|
|
addi a2, a2, 4 # advance s1 pointer
|
|
bne a8, a9, .Lwne
|
|
bnone a8, a4, .Leq # if byte 0 is zero
|
|
bnone a8, a5, .Leq # if byte 1 is zero
|
|
bnone a8, a6, .Leq # if byte 2 is zero
|
|
bnone a8, a7, .Leq # if byte 3 is zero
|
|
addi a3, a3, 4 # advance s2 pointer
|
|
j 1b
|
|
#else /* !XCHAL_HAVE_LOOPS */
|
|
|
|
j .Lfirstword2
|
|
.Lnextword2:
|
|
addi a3, a3, 4 # advance s2 pointer
|
|
.Lfirstword2:
|
|
l32i a8, a2, 0 # get word from s1
|
|
l32i a9, a3, 0 # get word from s2
|
|
addi a2, a2, 4 # advance s1 pointer
|
|
bne a8, a9, .Lwne
|
|
bnone a8, a4, .Leq # if byte 0 is zero
|
|
bnone a8, a5, .Leq # if byte 1 is zero
|
|
bnone a8, a6, .Leq # if byte 2 is zero
|
|
bany a8, a7, .Lnextword2 # if byte 3 is zero
|
|
#endif /* !XCHAL_HAVE_LOOPS */
|
|
|
|
/* Words are equal; some byte is zero. */
|
|
.Leq: movi a2, 0 # return equal
|
|
RET(16)
|
|
|
|
.Lwne2: /* Words are not equal. On big-endian processors, if none of the
|
|
bytes are zero, the return value can be determined by a simple
|
|
comparison. */
|
|
#if XCHAL_HAVE_BE
|
|
or a10, a8, a5
|
|
bnall a10, a7, .Lsomezero
|
|
bgeu a8, a9, .Lposreturn
|
|
movi a2, -1
|
|
RET(16)
|
|
.Lposreturn:
|
|
movi a2, 1
|
|
RET(16)
|
|
.Lsomezero: # There is probably some zero byte.
|
|
#endif /* XCHAL_HAVE_BE */
|
|
.Lwne: /* Words are not equal. */
|
|
xor a2, a8, a9 # get word with nonzero in byte that differs
|
|
bany a2, a4, .Ldiff0 # if byte 0 differs
|
|
movi a5, MASK1 # mask for byte 1
|
|
bnone a8, a4, .Leq # if byte 0 is zero
|
|
bany a2, a5, .Ldiff1 # if byte 1 differs
|
|
movi a6, MASK2 # mask for byte 2
|
|
bnone a8, a5, .Leq # if byte 1 is zero
|
|
bany a2, a6, .Ldiff2 # if byte 2 differs
|
|
bnone a8, a6, .Leq # if byte 2 is zero
|
|
#if XCHAL_HAVE_BE
|
|
.Ldiff3:
|
|
.Ldiff2:
|
|
.Ldiff1:
|
|
/* Byte 0 is equal (at least) and there is a difference before a zero
|
|
byte. Just subtract words to get the return value.
|
|
The high order equal bytes cancel, leaving room for the sign. */
|
|
sub a2, a8, a9
|
|
RET(16)
|
|
|
|
.Ldiff0:
|
|
/* Need to make room for the sign, so can't subtract whole words. */
|
|
extui a10, a8, 24, 8
|
|
extui a11, a9, 24, 8
|
|
sub a2, a10, a11
|
|
RET(16)
|
|
|
|
#else /* !XCHAL_HAVE_BE */
|
|
/* Little-endian is a little more difficult because can't subtract
|
|
whole words. */
|
|
.Ldiff3:
|
|
/* Bytes 0-2 are equal; byte 3 is different.
|
|
For little-endian need to have a sign bit for the difference. */
|
|
extui a10, a8, 24, 8
|
|
extui a11, a9, 24, 8
|
|
sub a2, a10, a11
|
|
RET(16)
|
|
|
|
.Ldiff0:
|
|
/* Byte 0 is different. */
|
|
extui a10, a8, 0, 8
|
|
extui a11, a9, 0, 8
|
|
sub a2, a10, a11
|
|
RET(16)
|
|
|
|
.Ldiff1:
|
|
/* Byte 0 is equal; byte 1 is different. */
|
|
extui a10, a8, 8, 8
|
|
extui a11, a9, 8, 8
|
|
sub a2, a10, a11
|
|
RET(16)
|
|
|
|
.Ldiff2:
|
|
/* Bytes 0-1 are equal; byte 2 is different. */
|
|
extui a10, a8, 16, 8
|
|
extui a11, a9, 16, 8
|
|
sub a2, a10, a11
|
|
RET(16)
|
|
|
|
#endif /* !XCHAL_HAVE_BE */
|
|
#endif /* FLIX3 */
|
|
#endif /* FLIX3 */
|
|
|
|
.end schedule
|
|
.size strcmp, . - strcmp
|
|
|