root/src/pkg/crypto/sha1/sha1block_386.s

// Copyright 2013 The Go Authors.  All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

#include "../../../cmd/ld/textflag.h"

// SHA1 block routine. See sha1block.go for Go equivalent.
//
// There are 80 rounds of 4 types:
//   - rounds 0-15 are type 1 and load data (ROUND1 macro).
//   - rounds 16-19 are type 1 and do not load data (ROUND1x macro).
//   - rounds 20-39 are type 2 and do not load data (ROUND2 macro).
//   - rounds 40-59 are type 3 and do not load data (ROUND3 macro).
//   - rounds 60-79 are type 4 and do not load data (ROUND4 macro).
//
// Each round loads or shuffles the data, then computes a per-round
// function of b, c, d, and then mixes the result into and rotates the
// five registers a, b, c, d, e holding the intermediate results.
//
// The register rotation is implemented by rotating the arguments to
// the round macros instead of by explicit move instructions.

// Like sha1block_amd64.s, but we keep the data and limit pointers on the stack.
// To free up the word pointer (R10 on amd64, DI here), we add it to e during
// LOAD/SHUFFLE instead of during MIX.
//
// The stack holds the intermediate word array - 16 uint32s - at 0(SP) up to 64(SP).
// The saved a, b, c, d, e (R11 through R15 on amd64) are at 64(SP) up to 84(SP).
// The saved limit pointer (DI on amd64) is at 84(SP).
// The saved data pointer (SI on amd64) is at 88(SP).

#define LOAD(index, e) \
        MOVL    88(SP), SI; \
        MOVL    (index*4)(SI), DI; \
        BSWAPL  DI; \
        MOVL    DI, (index*4)(SP); \
        ADDL    DI, e

#define SHUFFLE(index, e) \
        MOVL    (((index)&0xf)*4)(SP), DI; \
        XORL    (((index-3)&0xf)*4)(SP), DI; \
        XORL    (((index-8)&0xf)*4)(SP), DI; \
        XORL    (((index-14)&0xf)*4)(SP), DI; \
        ROLL    $1, DI; \
        MOVL    DI, (((index)&0xf)*4)(SP); \
        ADDL    DI, e

#define FUNC1(a, b, c, d, e) \
        MOVL    d, DI; \
        XORL    c, DI; \
        ANDL    b, DI; \
        XORL    d, DI

#define FUNC2(a, b, c, d, e) \
        MOVL    b, DI; \
        XORL    c, DI; \
        XORL    d, DI

#define FUNC3(a, b, c, d, e) \
        MOVL    b, SI; \
        ORL     c, SI; \
        ANDL    d, SI; \
        MOVL    b, DI; \
        ANDL    c, DI; \
        ORL     SI, DI

#define FUNC4 FUNC2

#define MIX(a, b, c, d, e, const) \
        ROLL    $30, b; \
        ADDL    DI, e; \
        MOVL    a, SI; \
        ROLL    $5, SI; \
        LEAL    const(e)(SI*1), e

#define ROUND1(a, b, c, d, e, index) \
        LOAD(index, e); \
        FUNC1(a, b, c, d, e); \
        MIX(a, b, c, d, e, 0x5A827999)

#define ROUND1x(a, b, c, d, e, index) \
        SHUFFLE(index, e); \
        FUNC1(a, b, c, d, e); \
        MIX(a, b, c, d, e, 0x5A827999)

#define ROUND2(a, b, c, d, e, index) \
        SHUFFLE(index, e); \
        FUNC2(a, b, c, d, e); \
        MIX(a, b, c, d, e, 0x6ED9EBA1)

#define ROUND3(a, b, c, d, e, index) \
        SHUFFLE(index, e); \
        FUNC3(a, b, c, d, e); \
        MIX(a, b, c, d, e, 0x8F1BBCDC)

#define ROUND4(a, b, c, d, e, index) \
        SHUFFLE(index, e); \
        FUNC4(a, b, c, d, e); \
        MIX(a, b, c, d, e, 0xCA62C1D6)

// func block(dig *digest, p []byte)
TEXT ·block(SB),NOSPLIT,$92-16
        MOVL    dig+0(FP),      BP
        MOVL    p+4(FP),        SI
        MOVL    p_len+8(FP),    DX
        SHRL    $6,             DX
        SHLL    $6,             DX
        
        LEAL    (SI)(DX*1),     DI
        MOVL    (0*4)(BP),      AX
        MOVL    (1*4)(BP),      BX
        MOVL    (2*4)(BP),      CX
        MOVL    (3*4)(BP),      DX
        MOVL    (4*4)(BP),      BP

        CMPL    SI,             DI
        JEQ     end

        MOVL    DI,     84(SP)

loop:
        MOVL    SI,     88(SP)

        MOVL    AX,     64(SP)
        MOVL    BX,     68(SP)
        MOVL    CX,     72(SP)
        MOVL    DX,     76(SP)
        MOVL    BP,     80(SP)

        ROUND1(AX, BX, CX, DX, BP, 0)
        ROUND1(BP, AX, BX, CX, DX, 1)
        ROUND1(DX, BP, AX, BX, CX, 2)
        ROUND1(CX, DX, BP, AX, BX, 3)
        ROUND1(BX, CX, DX, BP, AX, 4)
        ROUND1(AX, BX, CX, DX, BP, 5)
        ROUND1(BP, AX, BX, CX, DX, 6)
        ROUND1(DX, BP, AX, BX, CX, 7)
        ROUND1(CX, DX, BP, AX, BX, 8)
        ROUND1(BX, CX, DX, BP, AX, 9)
        ROUND1(AX, BX, CX, DX, BP, 10)
        ROUND1(BP, AX, BX, CX, DX, 11)
        ROUND1(DX, BP, AX, BX, CX, 12)
        ROUND1(CX, DX, BP, AX, BX, 13)
        ROUND1(BX, CX, DX, BP, AX, 14)
        ROUND1(AX, BX, CX, DX, BP, 15)

        ROUND1x(BP, AX, BX, CX, DX, 16)
        ROUND1x(DX, BP, AX, BX, CX, 17)
        ROUND1x(CX, DX, BP, AX, BX, 18)
        ROUND1x(BX, CX, DX, BP, AX, 19)
        
        ROUND2(AX, BX, CX, DX, BP, 20)
        ROUND2(BP, AX, BX, CX, DX, 21)
        ROUND2(DX, BP, AX, BX, CX, 22)
        ROUND2(CX, DX, BP, AX, BX, 23)
        ROUND2(BX, CX, DX, BP, AX, 24)
        ROUND2(AX, BX, CX, DX, BP, 25)
        ROUND2(BP, AX, BX, CX, DX, 26)
        ROUND2(DX, BP, AX, BX, CX, 27)
        ROUND2(CX, DX, BP, AX, BX, 28)
        ROUND2(BX, CX, DX, BP, AX, 29)
        ROUND2(AX, BX, CX, DX, BP, 30)
        ROUND2(BP, AX, BX, CX, DX, 31)
        ROUND2(DX, BP, AX, BX, CX, 32)
        ROUND2(CX, DX, BP, AX, BX, 33)
        ROUND2(BX, CX, DX, BP, AX, 34)
        ROUND2(AX, BX, CX, DX, BP, 35)
        ROUND2(BP, AX, BX, CX, DX, 36)
        ROUND2(DX, BP, AX, BX, CX, 37)
        ROUND2(CX, DX, BP, AX, BX, 38)
        ROUND2(BX, CX, DX, BP, AX, 39)
        
        ROUND3(AX, BX, CX, DX, BP, 40)
        ROUND3(BP, AX, BX, CX, DX, 41)
        ROUND3(DX, BP, AX, BX, CX, 42)
        ROUND3(CX, DX, BP, AX, BX, 43)
        ROUND3(BX, CX, DX, BP, AX, 44)
        ROUND3(AX, BX, CX, DX, BP, 45)
        ROUND3(BP, AX, BX, CX, DX, 46)
        ROUND3(DX, BP, AX, BX, CX, 47)
        ROUND3(CX, DX, BP, AX, BX, 48)
        ROUND3(BX, CX, DX, BP, AX, 49)
        ROUND3(AX, BX, CX, DX, BP, 50)
        ROUND3(BP, AX, BX, CX, DX, 51)
        ROUND3(DX, BP, AX, BX, CX, 52)
        ROUND3(CX, DX, BP, AX, BX, 53)
        ROUND3(BX, CX, DX, BP, AX, 54)
        ROUND3(AX, BX, CX, DX, BP, 55)
        ROUND3(BP, AX, BX, CX, DX, 56)
        ROUND3(DX, BP, AX, BX, CX, 57)
        ROUND3(CX, DX, BP, AX, BX, 58)
        ROUND3(BX, CX, DX, BP, AX, 59)
        
        ROUND4(AX, BX, CX, DX, BP, 60)
        ROUND4(BP, AX, BX, CX, DX, 61)
        ROUND4(DX, BP, AX, BX, CX, 62)
        ROUND4(CX, DX, BP, AX, BX, 63)
        ROUND4(BX, CX, DX, BP, AX, 64)
        ROUND4(AX, BX, CX, DX, BP, 65)
        ROUND4(BP, AX, BX, CX, DX, 66)
        ROUND4(DX, BP, AX, BX, CX, 67)
        ROUND4(CX, DX, BP, AX, BX, 68)
        ROUND4(BX, CX, DX, BP, AX, 69)
        ROUND4(AX, BX, CX, DX, BP, 70)
        ROUND4(BP, AX, BX, CX, DX, 71)
        ROUND4(DX, BP, AX, BX, CX, 72)
        ROUND4(CX, DX, BP, AX, BX, 73)
        ROUND4(BX, CX, DX, BP, AX, 74)
        ROUND4(AX, BX, CX, DX, BP, 75)
        ROUND4(BP, AX, BX, CX, DX, 76)
        ROUND4(DX, BP, AX, BX, CX, 77)
        ROUND4(CX, DX, BP, AX, BX, 78)
        ROUND4(BX, CX, DX, BP, AX, 79)

        ADDL    64(SP), AX
        ADDL    68(SP), BX
        ADDL    72(SP), CX
        ADDL    76(SP), DX
        ADDL    80(SP), BP

        MOVL    88(SP), SI
        ADDL    $64, SI
        CMPL    SI, 84(SP)
        JB      loop

end:
        MOVL    dig+0(FP), DI
        MOVL    AX, (0*4)(DI)
        MOVL    BX, (1*4)(DI)
        MOVL    CX, (2*4)(DI)
        MOVL    DX, (3*4)(DI)
        MOVL    BP, (4*4)(DI)
        RET