github.com/icodeface/tls@v0.0.0-20230910023335-34df9250cd12/internal/bytealg/indexbyte_arm.s (about)

     1  // Copyright 2018 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  #include "go_asm.h"
     6  #include "textflag.h"
     7  
     8  TEXT ·IndexByte(SB),NOSPLIT,$0-20
     9  	MOVW	b_base+0(FP), R0
    10  	MOVW	b_len+4(FP), R1
    11  	MOVBU	c+12(FP), R2	// byte to find
    12  	MOVW	R0, R4		// store base for later
    13  	ADD	R0, R1		// end
    14  
    15  _loop:
    16  	CMP	R0, R1
    17  	B.EQ	_notfound
    18  	MOVBU.P	1(R0), R3
    19  	CMP	R2, R3
    20  	B.NE	_loop
    21  
    22  	SUB	$1, R0		// R0 will be one beyond the position we want
    23  	SUB	R4, R0		// remove base
    24  	MOVW    R0, ret+16(FP)
    25  	RET
    26  
    27  _notfound:
    28  	MOVW	$-1, R0
    29  	MOVW	R0, ret+16(FP)
    30  	RET
    31  
    32  TEXT ·IndexByteString(SB),NOSPLIT,$0-16
    33  	MOVW	s_base+0(FP), R0
    34  	MOVW	s_len+4(FP), R1
    35  	MOVBU	c+8(FP), R2	// byte to find
    36  	MOVW	R0, R4		// store base for later
    37  	ADD	R0, R1		// end
    38  
    39  _sib_loop:
    40  	CMP	R0, R1
    41  	B.EQ	_sib_notfound
    42  	MOVBU.P	1(R0), R3
    43  	CMP	R2, R3
    44  	B.NE	_sib_loop
    45  
    46  	SUB	$1, R0		// R0 will be one beyond the position we want
    47  	SUB	R4, R0		// remove base
    48  	MOVW	R0, ret+12(FP)
    49  	RET
    50  
    51  _sib_notfound:
    52  	MOVW	$-1, R0
    53  	MOVW	R0, ret+12(FP)
    54  	RET