github.com/mattn/go@v0.0.0-20171011075504-07f7db3ea99f/src/crypto/sha256/sha256block_s390x.s (about)

     1  // Copyright 2016 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 "textflag.h"
     6  
     7  // func featureCheck() bool
     8  TEXT ·featureCheck(SB),NOSPLIT,$16-1
     9  	LA	tmp-16(SP), R1
    10  	XOR	R0, R0         // query function code is 0
    11  	WORD    $0xB93E0006    // KIMD (R6 is ignored)
    12  	MOVBZ	tmp-16(SP), R4 // get the first byte
    13  	AND	$0x20, R4      // bit 2 (big endian) for SHA256
    14  	CMPBEQ	R4, $0, nosha256
    15  	MOVB	$1, ret+0(FP)
    16  	RET
    17  nosha256:
    18  	MOVB	$0, ret+0(FP)
    19  	RET
    20  
    21  // func block(dig *digest, p []byte)
    22  TEXT ·block(SB),NOSPLIT,$0-32
    23  	MOVBZ	·useAsm(SB), R4
    24  	LMG	dig+0(FP), R1, R3 // R2 = &p[0], R3 = len(p)
    25  	CMPBNE	R4, $1, generic
    26  	MOVBZ	$2, R0        // SHA256 function code
    27  loop:
    28  	WORD	$0xB93E0002   // KIMD R2
    29  	BVS	loop          // continue if interrupted
    30  done:
    31  	XOR	R0, R0        // restore R0
    32  	RET
    33  generic:
    34  	BR	·blockGeneric(SB)