aboutsummaryrefslogtreecommitdiffstats
path: root/modules/alg_ia32/mp_muladd.S
blob: 53b210d256ec8779686191bdb7b5cc05e3de4e44 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
/*************************************************
* Multiply/Add Algorithm Source File             *
* (C) 1999-2006 The Botan Project                *
*************************************************/

#include <botan/asm_macr.h>

START_LISTING(mp_muladd.S)

START_FUNCTION(bigint_mul_add_words)
   SPILL_REGS()
#define PUSHED 4

#define LOOP_CTR ESI
   ASSIGN(LOOP_CTR, ARG(3)) /* x_size */
   ZEROIZE(EDI)

   ASSIGN(ECX, ARG(1)) /* z[] */
   ASSIGN(EBX, ARG(2)) /* x[] */
   ASSIGN(EBP, ARG(4)) /* y */

#define MULADD_OP(N)                       \
   ASSIGN(EAX, ARRAY4(EBX, N))           ; \
   MUL(EBP)                              ; \
   ADD_W_CARRY(EAX, EDX, EDI)            ; \
   ASSIGN(EDI, EDX)                      ; \
   ADD_W_CARRY(ARRAY4(ECX, N), EDI, EAX) ;

   JUMP_IF_ZERO(LOOP_CTR, .MUL_ADD_DONE)
   JUMP_IF_LT(LOOP_CTR, 8, .MULADD1_LOOP)

START_LOOP(.MULADD8)
   MULADD_OP(0)
   MULADD_OP(1)
   MULADD_OP(2)
   MULADD_OP(3)
   MULADD_OP(4)
   MULADD_OP(5)
   MULADD_OP(6)
   MULADD_OP(7)

   SUB_IMM(LOOP_CTR, 8)
   ADD_IMM(EBX, 32)
   ADD_IMM(ECX, 32)
LOOP_UNTIL_LT(LOOP_CTR, 8, .MULADD8)

   JUMP_IF_ZERO(LOOP_CTR, .MUL_ADD_DONE)

START_LOOP(.MULADD1)
   MULADD_OP(0)

   SUB_IMM(LOOP_CTR, 1)
   ADD_IMM(EBX, 4)
   ADD_IMM(ECX, 4)
LOOP_UNTIL_EQ(LOOP_CTR, 0, .MULADD1)

.MUL_ADD_DONE:

   ASSIGN(EAX, EDI)
#undef PUSHED
   RESTORE_REGS()
END_FUNCTION(bigint_mul_add_words)