1 /// -*- mode: asm; asm-comment-char: ?/; comment-start: "// " -*-
3 /// Large SIMD-based multiplications
5 /// (c) 2016 Straylight/Edgeware
7 ///----- Licensing notice ---------------------------------------------------
9 /// This file is part of Catacomb.
11 /// Catacomb is free software; you can redistribute it and/or modify
12 /// it under the terms of the GNU Library General Public License as
13 /// published by the Free Software Foundation; either version 2 of the
14 /// License, or (at your option) any later version.
16 /// Catacomb is distributed in the hope that it will be useful,
17 /// but WITHOUT ANY WARRANTY; without even the implied warranty of
18 /// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 /// GNU Library General Public License for more details.
21 /// You should have received a copy of the GNU Library General Public
22 /// License along with Catacomb; if not, write to the Free
23 /// Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
24 /// MA 02111-1307, USA.
26 ///--------------------------------------------------------------------------
27 /// External definitions.
30 #include "asm-common.h"
32 ///--------------------------------------------------------------------------
38 ///--------------------------------------------------------------------------
41 /// We define a number of primitive fixed-size multipliers from which we can
42 /// construct more general variable-length multipliers.
44 /// The basic trick is the same throughout. In an operand-scanning
45 /// multiplication, the inner multiplication loop multiplies a
46 /// multiple-precision operand by a single precision factor, and adds the
47 /// result, appropriately shifted, to the result. A `finely integrated
48 /// operand scanning' implementation of Montgomery multiplication also adds
49 /// the product of a single-precision `Montgomery factor' and the modulus,
50 /// calculated in the same pass. The more common `coarsely integrated
51 /// operand scanning' alternates main multiplication and Montgomery passes,
52 /// which requires additional carry propagation.
54 /// Throughout both plain-multiplication and Montgomery stages, then, one of
55 /// the factors remains constant throughout the operation, so we can afford
56 /// to take a little time to preprocess it. The transformation we perform is
57 /// as follows. Let b = 2^16, and B = b^2 = 2^32. Suppose we're given a
58 /// 128-bit factor v = v_0 + v_1 B + v_2 B^2 + v_3 B^3. Split each v_i into
59 /// two sixteen-bit pieces, so v_i = v'_i + v''_i b. These eight 16-bit
60 /// pieces are placed into 32-bit cells, and arranged as two 128-bit SSE
61 /// operands, as follows.
64 /// 0 v'_0 v'_1 v''_0 v''_1
65 /// 16 v'_2 v'_3 v''_2 v''_3
67 /// A `pmuludq' instruction ignores the odd positions in its operands; thus,
68 /// it will act on (say) v'_0 and v''_0 in a single instruction. Shifting
69 /// this vector right by 4 bytes brings v'_1 and v''_1 into position. We can
70 /// multiply such a vector by a full 32-bit scalar to produce two 48-bit
71 /// results in 64-bit fields. The sixteen bits of headroom allows us to add
72 /// many products together before we must deal with carrying; it also allows
73 /// for some calculations to be performed on the above expanded form.
75 /// On 32-bit x86, we are register starved: the expanded operands are kept in
76 /// memory, typically in warm L1 cache.
78 /// We maintain four `carry' registers accumulating intermediate results.
79 /// The registers' precise roles rotate during the computation; we name them
80 /// `c0', `c1', `c2', and `c3'. Each carry register holds two 64-bit halves:
81 /// the register c0, for example, holds c'_0 (low half) and c''_0 (high
82 /// half), and represents the value c_0 = c'_0 + c''_0 b; the carry registers
83 /// collectively represent the value c_0 + c_1 B + c_2 B^2 + c_3 B^3. The
84 /// `pmuluqd' instruction acting on a scalar operand (broadcast across all
85 /// lanes of its vector) and an operand in the expanded form above produces a
86 /// result which can be added directly to the appropriate carry register.
87 /// Following a pass of four multiplications, we perform some limited carry
88 /// propagation: let t = c''_0 mod B, and let d = c'_0 + t b; then we output
89 /// z = d mod B, add (floor(d/B), floor(c''_0/B)) to c1, and cycle the carry
90 /// registers around, so that c1 becomes c0, and the old c0 is (implicitly)
91 /// zeroed becomes c3.
93 ///--------------------------------------------------------------------------
94 /// Macro definitions.
96 .macro mulcore r, s, d0, d1=nil, d2=nil, d3=nil
97 // Load a word r_i from R, multiply by the expanded operand [S], and
98 // leave the pieces of the product in registers D0, D1, D2, D3.
99 movd \d0, \r // (r_i, 0; 0, 0)
101 movdqa \d1, [\s] // (s'_0, s'_1; s''_0, s''_1)
104 movdqa \d3, [\s + 16] // (s'_2, s'_3; s''_2, s''_3)
106 pshufd \d0, \d0, SHUF(3, 0, 3, 0) // (r_i, ?; r_i, ?)
108 psrldq \d1, 4 // (s'_1, s''_0; s''_1, 0)
112 movdqa \d2, \d3 // another copy of (s'_2, s'_3; ...)
114 movdqa \d2, \d0 // another copy of (r_i, ?; r_i, ?)
118 psrldq \d3, 4 // (s'_3, s''_2; s''_3, 0)
121 pmuludq \d1, \d0 // (r_i s'_1; r_i s''_1)
124 pmuludq \d3, \d0 // (r_i s'_3; r_i s''_3)
128 pmuludq \d2, \d0 // (r_i s'_2; r_i s''_2)
130 pmuludq \d2, [\s + 16]
133 pmuludq \d0, [\s] // (r_i s'_0; r_i s''_0)
136 .macro accum c0, c1=nil, c2=nil, c3=nil
137 // Accumulate 64-bit pieces in XMM0--XMM3 into the corresponding
138 // carry registers C0--C3. Any or all of C1--C3 may be `nil' to skip
139 // updating that register.
152 .macro mulacc r, s, c0, c1, c2, c3, z3p=nil
153 // Load a word r_i from R, multiply by the expanded operand [S],
154 // and accumulate in carry registers C0, C1, C2, C3. If Z3P is `t'
155 // then C3 notionally contains zero, but needs clearing; in practice,
156 // we store the product directly rather than attempting to add. On
157 // completion, XMM0, XMM1, and XMM2 are clobbered, as is XMM3 if Z3P
160 mulcore \r, \s, xmm0, xmm1, xmm2, \c3
163 mulcore \r, \s, xmm0, xmm1, xmm2, xmm3
164 accum \c0, \c1, \c2, \c3
168 .macro propout d, c, cc=nil
169 // Calculate an output word from C, and store it in D; propagate
170 // carries out from C to CC in preparation for a rotation of the
171 // carry registers. On completion, XMM3 is clobbered. If CC is
172 // `nil', then the contribution which would have been added to it is
174 pshufd xmm3, \c, SHUF(2, 3, 3, 3) // (?, ?; ?, t = c'' mod B)
175 psrldq xmm3, 12 // (t, 0; 0, 0) = (t, 0)
176 pslldq xmm3, 2 // (t b; 0)
177 paddq \c, xmm3 // (c' + t b; c'')
179 psrlq \c, 32 // floor(c/B)
181 paddq \cc, \c // propagate up
185 .macro endprop d, c, t
186 // On entry, C contains a carry register. On exit, the low 32 bits
187 // of the value represented in C are written to D, and the remaining
188 // bits are left at the bottom of T.
190 psllq \t, 16 // (?; c'' b)
191 pslldq \c, 8 // (0; c')
192 paddq \t, \c // (?; c' + c'' b)
193 psrldq \t, 8 // (c' + c'' b; 0) = (c; 0)
195 psrldq \t, 4 // (floor(c/B); 0)
198 .macro expand z, a, b, c=nil, d=nil
199 // On entry, A and C hold packed 128-bit values, and Z is zero. On
200 // exit, A:B and C:D together hold the same values in expanded
201 // form. If C is `nil', then only expand A to A:B.
202 movdqa \b, \a // (a_0, a_1; a_2, a_3)
204 movdqa \d, \c // (c_0, c_1; c_2, c_3)
206 punpcklwd \a, \z // (a'_0, a''_0; a'_1, a''_1)
207 punpckhwd \b, \z // (a'_2, a''_2; a'_3, a''_3)
209 punpcklwd \c, \z // (c'_0, c''_0; c'_1, c''_1)
210 punpckhwd \d, \z // (c'_2, c''_2; c'_3, c''_3)
212 pshufd \a, \a, SHUF(3, 1, 2, 0) // (a'_0, a'_1; a''_0, a''_1)
213 pshufd \b, \b, SHUF(3, 1, 2, 0) // (a'_2, a'_3; a''_2, a''_3)
215 pshufd \c, \c, SHUF(3, 1, 2, 0) // (c'_0, c'_1; c''_0, c''_1)
216 pshufd \d, \d, SHUF(3, 1, 2, 0) // (c'_2, c'_3; c''_2, c''_3)
220 .macro squash c0, c1, c2, c3, t, u, lo, hi=nil
221 // On entry, C0, C1, C2, C3 are carry registers representing a value
222 // Y. On exit, LO holds the low 128 bits of the carry value; C1, C2,
223 // C3, T, and U are clobbered; and the high bits of Y are stored in
224 // HI, if this is not `nil'.
226 // The first step is to eliminate the `double-prime' pieces -- i.e.,
227 // the ones offset by 16 bytes from a 32-bit boundary -- by carrying
228 // them into the 32-bit-aligned pieces above and below. But before
229 // we can do that, we must gather them together.
232 punpcklqdq \t, \c2 // (y'_0; y'_2)
233 punpckhqdq \c0, \c2 // (y''_0; y''_2)
234 punpcklqdq \u, \c3 // (y'_1; y'_3)
235 punpckhqdq \c1, \c3 // (y''_1; y''_3)
237 // Now split the double-prime pieces. The high (up to) 48 bits will
238 // go up; the low 16 bits go down.
243 psrlq \c0, 16 // high parts of (y''_0; y''_2)
244 psrlq \c1, 16 // high parts of (y''_1; y''_3)
245 psrlq \c2, 32 // low parts of (y''_0; y''_2)
246 psrlq \c3, 32 // low parts of (y''_1; y''_3)
250 pslldq \c1, 8 // high part of (0; y''_1)
252 paddq \t, \c2 // propagate down
254 paddq \t, \c1 // and up: (y_0; y_2)
255 paddq \u, \c0 // (y_1; y_3)
257 psrldq \hi, 8 // high part of (y''_3; 0)
260 // Finally extract the answer. This complicated dance is better than
261 // storing to memory and loading, because the piecemeal stores
262 // inhibit store forwarding.
263 movdqa \c3, \t // (y_0; ?)
264 movdqa \lo, \t // (y^*_0, ?; ?, ?)
265 psrldq \t, 8 // (y_2; 0)
266 psrlq \c3, 32 // (floor(y_0/B); ?)
267 paddq \c3, \u // (y_1 + floor(y_0/B); ?)
268 movdqa \c1, \c3 // (y^*_1, ?; ?, ?)
269 psrldq \u, 8 // (y_3; 0)
270 psrlq \c3, 32 // (floor((y_1 B + y_0)/B^2; ?)
271 paddq \c3, \t // (y_2 + floor((y_1 B + y_0)/B^2; ?)
272 punpckldq \lo, \c3 // (y^*_0, y^*_2; ?, ?)
273 psrlq \c3, 32 // (floor((y_2 B^2 + y_1 B + y_0)/B^3; ?)
274 paddq \c3, \u // (y_3 + floor((y_2 B^2 + y_1 B + y_0)/B^3; ?)
279 punpckldq \c1, \c3 // (y^*_1, y^*_3; ?, ?)
281 psrlq \t, 32 // very high bits of y
283 punpcklqdq \hi, \u // carry up
285 punpckldq \lo, \c1 // y mod B^4
289 // On entry, EDI points to a packed addend A, and XMM4, XMM5, XMM6
290 // hold the incoming carry registers c0, c1, and c2 representing a
293 // On exit, the carry registers, including XMM7, are updated to hold
294 // C + A; XMM0, XMM1, XMM2, and XMM3 are clobbered. The other
295 // registers are preserved.
296 movd xmm0, [edi + 0] // (a_0; 0)
297 movd xmm1, [edi + 4] // (a_1; 0)
298 movd xmm2, [edi + 8] // (a_2; 0)
299 movd xmm7, [edi + 12] // (a_3; 0)
301 paddq xmm4, xmm0 // (c'_0 + a_0; c''_0)
302 paddq xmm5, xmm1 // (c'_1 + a_1; c''_1)
303 paddq xmm6, xmm2 // (c'_2 + a_2; c''_2 + a_3 b)
306 ///--------------------------------------------------------------------------
307 /// Primitive multipliers and related utilities.
310 // On entry, XMM4, XMM5, and XMM6 hold a 144-bit carry in an expanded
311 // form. Store the low 128 bits of the represented carry to [EDI] as
312 // a packed 128-bit value, and leave the remaining 16 bits in the low
313 // 32 bits of XMM4. On exit, XMM3, XMM5 and XMM6 are clobbered.
316 propout [edi + 0], xmm4, xmm5
317 propout [edi + 4], xmm5, xmm6
318 propout [edi + 8], xmm6, nil
319 endprop [edi + 12], xmm6, xmm4
325 // On entry, EDI points to the destination buffer; EAX and EBX point
326 // to the packed operands U and X; ECX and EDX point to the expanded
327 // operands V and Y; and XMM4, XMM5, XMM6 hold the incoming carry
328 // registers c0, c1, and c2; c3 is assumed to be zero.
330 // On exit, we write the low 128 bits of the sum C + U V + X Y to
331 // [EDI], and update the carry registers with the carry out. The
332 // registers XMM0, XMM1, XMM2, XMM3, and XMM7 are clobbered; the
333 // general-purpose registers are preserved.
336 mulacc [eax + 0], ecx, xmm4, xmm5, xmm6, xmm7, t
337 mulacc [ebx + 0], edx, xmm4, xmm5, xmm6, xmm7
338 propout [edi + 0], xmm4, xmm5
340 mulacc [eax + 4], ecx, xmm5, xmm6, xmm7, xmm4, t
341 mulacc [ebx + 4], edx, xmm5, xmm6, xmm7, xmm4
342 propout [edi + 4], xmm5, xmm6
344 mulacc [eax + 8], ecx, xmm6, xmm7, xmm4, xmm5, t
345 mulacc [ebx + 8], edx, xmm6, xmm7, xmm4, xmm5
346 propout [edi + 8], xmm6, xmm7
348 mulacc [eax + 12], ecx, xmm7, xmm4, xmm5, xmm6, t
349 mulacc [ebx + 12], edx, xmm7, xmm4, xmm5, xmm6
350 propout [edi + 12], xmm7, xmm4
357 // On entry, EDI points to the destination buffer, which also
358 // contains an addend A to accumulate; EAX and EBX point to the
359 // packed operands U and X; ECX and EDX point to the expanded
360 // operands V and Y; and XMM4, XMM5, XMM6 hold the incoming carry
361 // registers c0, c1, and c2 representing a carry-in C; c3 is assumed
364 // On exit, we write the low 128 bits of the sum A + C + U V + X Y to
365 // [EDI], and update the carry registers with the carry out. The
366 // registers XMM0, XMM1, XMM2, XMM3, and XMM7 are clobbered; the
367 // general-purpose registers are preserved.
372 mulacc [eax + 0], ecx, xmm4, xmm5, xmm6, xmm7
373 mulacc [ebx + 0], edx, xmm4, xmm5, xmm6, xmm7
374 propout [edi + 0], xmm4, xmm5
376 mulacc [eax + 4], ecx, xmm5, xmm6, xmm7, xmm4, t
377 mulacc [ebx + 4], edx, xmm5, xmm6, xmm7, xmm4
378 propout [edi + 4], xmm5, xmm6
380 mulacc [eax + 8], ecx, xmm6, xmm7, xmm4, xmm5, t
381 mulacc [ebx + 8], edx, xmm6, xmm7, xmm4, xmm5
382 propout [edi + 8], xmm6, xmm7
384 mulacc [eax + 12], ecx, xmm7, xmm4, xmm5, xmm6, t
385 mulacc [ebx + 12], edx, xmm7, xmm4, xmm5, xmm6
386 propout [edi + 12], xmm7, xmm4
393 // On entry, EDI points to the destination buffer; EBX points to a
394 // packed operand X; and EDX points to an expanded operand Y.
396 // On exit, we write the low 128 bits of the product X Y to [EDI],
397 // and set the carry registers XMM4, XMM5, XMM6 to the carry out.
398 // The registers XMM0, XMM1, XMM2, XMM3, and XMM7 are clobbered; the
399 // general-purpose registers are preserved.
402 mulcore [ebx + 0], edx, xmm4, xmm5, xmm6, xmm7
403 propout [edi + 0], xmm4, xmm5
405 mulacc [ebx + 4], edx, xmm5, xmm6, xmm7, xmm4, t
406 propout [edi + 4], xmm5, xmm6
408 mulacc [ebx + 8], edx, xmm6, xmm7, xmm4, xmm5, t
409 propout [edi + 8], xmm6, xmm7
411 mulacc [ebx + 12], edx, xmm7, xmm4, xmm5, xmm6, t
412 propout [edi + 12], xmm7, xmm4
419 // On entry, EDI points to the destination buffer; EBX points to a
420 // packed operand X; EDX points to an expanded operand Y; and XMM4,
421 // XMM5, XMM6 hold the incoming carry registers c0, c1, and c2,
422 // representing a carry-in C; c3 is assumed to be zero.
424 // On exit, we write the low 128 bits of the sum C + X Y to [EDI],
425 // and update the carry registers with the carry out. The registers
426 // XMM0, XMM1, XMM2, XMM3, and XMM7 are clobbered; the
427 // general-purpose registers are preserved.
430 mulacc [ebx + 0], edx, xmm4, xmm5, xmm6, xmm7, t
431 propout [edi + 0], xmm4, xmm5
433 mulacc [ebx + 4], edx, xmm5, xmm6, xmm7, xmm4, t
434 propout [edi + 4], xmm5, xmm6
436 mulacc [ebx + 8], edx, xmm6, xmm7, xmm4, xmm5, t
437 propout [edi + 8], xmm6, xmm7
439 mulacc [ebx + 12], edx, xmm7, xmm4, xmm5, xmm6, t
440 propout [edi + 12], xmm7, xmm4
447 // On entry, EDI points to the destination buffer, which also
448 // contains an addend A to accumulate; EBX points to a packed operand
449 // X; and EDX points to an expanded operand Y.
451 // On exit, we write the low 128 bits of the sum A + X Y to [EDI],
452 // and set the carry registers XMM4, XMM5, XMM6 to the carry out.
453 // The registers XMM0, XMM1, XMM2, XMM3, and XMM7 are clobbered; the
454 // general-purpose registers are preserved.
460 movd xmm7, [edi + 12]
462 mulacc [ebx + 0], edx, xmm4, xmm5, xmm6, xmm7
463 propout [edi + 0], xmm4, xmm5
465 mulacc [ebx + 4], edx, xmm5, xmm6, xmm7, xmm4, t
466 propout [edi + 4], xmm5, xmm6
468 mulacc [ebx + 8], edx, xmm6, xmm7, xmm4, xmm5, t
469 propout [edi + 8], xmm6, xmm7
471 mulacc [ebx + 12], edx, xmm7, xmm4, xmm5, xmm6, t
472 propout [edi + 12], xmm7, xmm4
479 // On entry, EDI points to the destination buffer, which also
480 // contains an addend A to accumulate; EBX points to a packed operand
481 // X; EDX points to an expanded operand Y; and XMM4, XMM5, XMM6 hold
482 // the incoming carry registers c0, c1, and c2, representing a
483 // carry-in C; c3 is assumed to be zero.
485 // On exit, we write the low 128 bits of the sum A + C + X Y to
486 // [EDI], and update the carry registers with the carry out. The
487 // registers XMM0, XMM1, XMM2, XMM3, and XMM7 are clobbered; the
488 // general-purpose registers are preserved.
493 mulacc [ebx + 0], edx, xmm4, xmm5, xmm6, xmm7
494 propout [edi + 0], xmm4, xmm5
496 mulacc [ebx + 4], edx, xmm5, xmm6, xmm7, xmm4, t
497 propout [edi + 4], xmm5, xmm6
499 mulacc [ebx + 8], edx, xmm6, xmm7, xmm4, xmm5, t
500 propout [edi + 8], xmm6, xmm7
502 mulacc [ebx + 12], edx, xmm7, xmm4, xmm5, xmm6, t
503 propout [edi + 12], xmm7, xmm4
510 // On entry, EDI points to the destination buffer; EAX and EBX point
511 // to the packed operands U and N; ECX and ESI point to the expanded
512 // operands V and M; and EDX points to a place to store an expanded
513 // result Y (32 bytes, at a 16-byte boundary). The stack pointer
514 // must be 12 modulo 16, as is usual for modern x86 ABIs.
516 // On exit, we write Y = U V M mod B to [EDX], and the low 128 bits
517 // of the sum U V + N Y to [EDI], leaving the remaining carry in
518 // XMM4, XMM5, and XMM6. The registers XMM0, XMM1, XMM2, XMM3, and
519 // XMM7 are clobbered; the general-purpose registers are preserved.
520 stalloc 48 + 12 // space for the carries
523 // Calculate W = U V, and leave it in the destination. Stash the
524 // carry pieces for later.
525 mulcore [eax + 0], ecx, xmm4, xmm5, xmm6, xmm7
526 propout [edi + 0], xmm4, xmm5
532 // On entry, EDI points to the destination buffer, which also
533 // contains an addend A to accumulate; EAX and EBX point to the
534 // packed operands U and N; ECX and ESI point to the expanded
535 // operands V and M; and EDX points to a place to store an expanded
536 // result Y (32 bytes, at a 16-byte boundary). The stack pointer
537 // must be 12 modulo 16, as is usual for modern x86 ABIs.
539 // On exit, we write Y = (A + U V) M mod B to [EDX], and the low 128
540 // bits of the sum A + U V + N Y to [EDI], leaving the remaining
541 // carry in XMM4, XMM5, and XMM6. The registers XMM0, XMM1, XMM2,
542 // XMM3, and XMM7 are clobbered; the general-purpose registers are
544 stalloc 48 + 12 // space for the carries
550 movd xmm7, [edi + 12]
552 // Calculate W = U V, and leave it in the destination. Stash the
553 // carry pieces for later.
554 mulacc [eax + 0], ecx, xmm4, xmm5, xmm6, xmm7
555 propout [edi + 0], xmm4, xmm5
557 5: mulacc [eax + 4], ecx, xmm5, xmm6, xmm7, xmm4, t
558 propout [edi + 4], xmm5, xmm6
560 mulacc [eax + 8], ecx, xmm6, xmm7, xmm4, xmm5, t
561 propout [edi + 8], xmm6, xmm7
563 mulacc [eax + 12], ecx, xmm7, xmm4, xmm5, xmm6, t
564 propout [edi + 12], xmm7, xmm4
566 movdqa [esp + 0], xmm4
567 movdqa [esp + 16], xmm5
568 movdqa [esp + 32], xmm6
570 // Calculate Y = W M.
571 mulcore [edi + 0], esi, xmm4, xmm5, xmm6, xmm7
573 mulcore [edi + 4], esi, xmm0, xmm1, xmm2
574 accum xmm5, xmm6, xmm7
576 mulcore [edi + 8], esi, xmm0, xmm1
579 mulcore [edi + 12], esi, xmm0
582 // That's lots of pieces. Now we have to assemble the answer.
583 squash xmm4, xmm5, xmm6, xmm7, xmm0, xmm1, xmm4
587 expand xmm2, xmm4, xmm1
588 movdqa [edx + 0], xmm4
589 movdqa [edx + 16], xmm1
591 // Initialize the carry from the value for W we calculated earlier.
595 movd xmm7, [edi + 12]
597 // Finish the calculation by adding the Montgomery product.
598 mulacc [ebx + 0], edx, xmm4, xmm5, xmm6, xmm7
599 propout [edi + 0], xmm4, xmm5
601 mulacc [ebx + 4], edx, xmm5, xmm6, xmm7, xmm4, t
602 propout [edi + 4], xmm5, xmm6
604 mulacc [ebx + 8], edx, xmm6, xmm7, xmm4, xmm5, t
605 propout [edi + 8], xmm6, xmm7
607 mulacc [ebx + 12], edx, xmm7, xmm4, xmm5, xmm6, t
608 propout [edi + 12], xmm7, xmm4
610 // Add add on the carry we calculated earlier.
611 paddq xmm4, [esp + 0]
612 paddq xmm5, [esp + 16]
613 paddq xmm6, [esp + 32]
615 // And, with that, we're done.
622 // On entry, EDI points to the destination buffer holding a packed
623 // value W; EBX points to a packed operand N; ESI points to an
624 // expanded operand M; and EDX points to a place to store an expanded
625 // result Y (32 bytes, at a 16-byte boundary).
627 // On exit, we write Y = W M mod B to [EDX], and the low 128 bits
628 // of the sum W + N Y to [EDI], leaving the remaining carry in
629 // XMM4, XMM5, and XMM6. The registers XMM0, XMM1, XMM2, XMM3, and
630 // XMM7 are clobbered; the general-purpose registers are preserved.
633 // Calculate Y = W M.
634 mulcore [edi + 0], esi, xmm4, xmm5, xmm6, xmm7
636 mulcore [edi + 4], esi, xmm0, xmm1, xmm2
637 accum xmm5, xmm6, xmm7
639 mulcore [edi + 8], esi, xmm0, xmm1
642 mulcore [edi + 12], esi, xmm0
645 // That's lots of pieces. Now we have to assemble the answer.
646 squash xmm4, xmm5, xmm6, xmm7, xmm0, xmm1, xmm4
650 expand xmm2, xmm4, xmm1
651 movdqa [edx + 0], xmm4
652 movdqa [edx + 16], xmm1
654 // Initialize the carry from W.
658 movd xmm7, [edi + 12]
660 // Finish the calculation by adding the Montgomery product.
661 mulacc [ebx + 0], edx, xmm4, xmm5, xmm6, xmm7
662 propout [edi + 0], xmm4, xmm5
664 mulacc [ebx + 4], edx, xmm5, xmm6, xmm7, xmm4, t
665 propout [edi + 4], xmm5, xmm6
667 mulacc [ebx + 8], edx, xmm6, xmm7, xmm4, xmm5, t
668 propout [edi + 8], xmm6, xmm7
670 mulacc [ebx + 12], edx, xmm7, xmm4, xmm5, xmm6, t
671 propout [edi + 12], xmm7, xmm4
673 // And, with that, we're done.
678 ///--------------------------------------------------------------------------
679 /// Bulk multipliers.
681 FUNC(mpx_umul4_x86_avx)
685 // and drop through...
689 FUNC(mpx_umul4_x86_sse2)
690 // void mpx_umul4_x86_sse2(mpw *dv, const mpw *av, const mpw *avl,
691 // const mpw *bv, const mpw *bvl);
693 // Build a stack frame. Arguments will be relative to EBP, as
702 // Locals are relative to ESP, as follows.
704 // esp + 0 expanded Y (32 bytes)
705 // esp + 32 (top of locals)
715 // Prepare for the first iteration.
716 mov esi, [ebp + 32] // -> bv[0]
718 movdqu xmm0, [esi] // bv[0]
719 mov edi, [ebp + 20] // -> dv[0]
720 mov ecx, edi // outer loop dv cursor
721 expand xmm7, xmm0, xmm1
722 mov ebx, [ebp + 24] // -> av[0]
723 mov eax, [ebp + 28] // -> av[m] = av limit
724 mov edx, esp // -> expanded Y = bv[0]
725 movdqa [esp + 0], xmm0 // bv[0] expanded low
726 movdqa [esp + 16], xmm1 // bv[0] expanded high
732 cmp ebx, eax // all done?
736 // Continue with the first iteration.
740 cmp ebx, eax // all done?
743 // Write out the leftover carry. There can be no tail here.
745 cmp esi, [ebp + 36] // more passes to do?
749 // Set up for the next pass.
750 1: movdqu xmm0, [esi] // bv[i]
751 mov edi, ecx // -> dv[i]
753 expand xmm7, xmm0, xmm1
754 mov ebx, [ebp + 24] // -> av[0]
755 movdqa [esp + 0], xmm0 // bv[i] expanded low
756 movdqa [esp + 16], xmm1 // bv[i] expanded high
762 cmp ebx, eax // done yet?
773 // Finish off this pass. There was no tail on the previous pass, and
774 // there can be none on this pass.
789 FUNC(mpxmont_mul4_x86_avx)
793 // and drop through...
797 FUNC(mpxmont_mul4_x86_sse2)
798 // void mpxmont_mul4_x86_sse2(mpw *dv, const mpw *av, const mpw *bv,
799 // const mpw *nv, size_t n, const mpw *mi);
801 // Build a stack frame. Arguments will be relative to EBP, as
808 // ebp + 36 n (nonzero multiple of 4)
811 // Locals are relative to ESP, which 16-byte aligned, as follows.
813 // esp + 0 expanded V (32 bytes)
814 // esp + 32 expanded M (32 bytes)
815 // esp + 64 expanded Y (32 bytes)
816 // esp + 96 outer loop dv
817 // esp + 100 outer loop bv
818 // esp + 104 av limit (mostly in ESI)
819 // esp + 108 bv limit
820 // esp + 112 (top of locals)
830 // Establish the expanded operands.
832 mov ecx, [ebp + 28] // -> bv
833 mov edx, [ebp + 40] // -> mi
834 movdqu xmm0, [ecx] // bv[0]
835 movdqu xmm2, [edx] // mi
836 expand xmm7, xmm0, xmm1, xmm2, xmm3
837 movdqa [esp + 0], xmm0 // bv[0] expanded low
838 movdqa [esp + 16], xmm1 // bv[0] expanded high
839 movdqa [esp + 32], xmm2 // mi expanded low
840 movdqa [esp + 48], xmm3 // mi expanded high
842 // Set up the outer loop state and prepare for the first iteration.
843 mov edx, [ebp + 36] // n
844 mov eax, [ebp + 24] // -> U = av[0]
845 mov ebx, [ebp + 32] // -> X = nv[0]
846 mov edi, [ebp + 20] // -> Z = dv[0]
848 lea ecx, [ecx + 4*edx] // -> bv[n/4] = bv limit
849 lea edx, [eax + 4*edx] // -> av[n/4] = av limit
853 lea ecx, [esp + 0] // -> expanded V = bv[0]
854 lea esi, [esp + 32] // -> expanded M = mi
855 lea edx, [esp + 64] // -> space for Y
857 mov esi, [esp + 104] // recover av limit
861 cmp eax, esi // done already?
866 // Complete the first inner loop.
871 cmp eax, esi // done yet?
874 // Still have carries left to propagate.
876 movd [edi + 16], xmm4
879 // Embark on the next iteration. (There must be one. If n = 1, then
880 // we would have bailed above, to label 8. Similarly, the subsequent
881 // iterations can fall into the inner loop immediately.)
882 1: mov eax, [esp + 100] // -> bv[i - 1]
883 mov edi, [esp + 96] // -> Z = dv[i]
884 add eax, 16 // -> bv[i]
887 cmp eax, [esp + 108] // done yet?
889 movdqu xmm0, [eax] // bv[i]
890 mov ebx, [ebp + 32] // -> X = nv[0]
891 lea esi, [esp + 32] // -> expanded M = mi
892 mov eax, [ebp + 24] // -> U = av[0]
893 expand xmm7, xmm0, xmm1
894 movdqa [esp + 0], xmm0 // bv[i] expanded low
895 movdqa [esp + 16], xmm1 // bv[i] expanded high
897 mov esi, [esp + 104] // recover av limit
904 // Complete the next inner loop.
912 // Still have carries left to propagate, and they overlap the
913 // previous iteration's final tail, so read that in and add it.
917 movd [edi + 16], xmm4
922 // First iteration was short. Write out the carries and we're done.
923 // (This could be folded into the main loop structure, but that would
924 // penalize small numbers more.)
926 movd [edi + 16], xmm4
938 FUNC(mpxmont_redc4_x86_avx)
942 // and drop through...
946 FUNC(mpxmont_redc4_x86_sse2)
947 // void mpxmont_redc4_x86_sse2(mpw *dv, mpw *dvl, const mpw *nv,
948 // size_t n, const mpw *mi);
950 // Build a stack frame. Arguments will be relative to EBP, as
956 // ebp + 32 n (nonzero multiple of 4)
959 // Locals are relative to ESP, as follows.
961 // esp + 0 outer loop dv
962 // esp + 4 outer dv limit
963 // esp + 8 blocks-of-4 dv limit
964 // esp + 12 expanded M (32 bytes)
965 // esp + 44 expanded Y (32 bytes)
966 // esp + 76 (top of locals)
976 // Establish the expanded operands and the blocks-of-4 dv limit.
977 mov edi, [ebp + 20] // -> Z = dv[0]
979 mov eax, [ebp + 24] // -> dv[n] = dv limit
980 sub eax, edi // length of dv in bytes
981 mov edx, [ebp + 36] // -> mi
982 movdqu xmm0, [edx] // mi
983 and eax, ~15 // mask off the tail end
984 expand xmm7, xmm0, xmm1
985 add eax, edi // find limit
986 movdqa [esp + 12], xmm0 // mi expanded low
987 movdqa [esp + 28], xmm1 // mi expanded high
990 // Set up the outer loop state and prepare for the first iteration.
991 mov ecx, [ebp + 32] // n
992 mov ebx, [ebp + 28] // -> X = nv[0]
993 lea edx, [edi + 4*ecx] // -> dv[n/4] = outer dv limit
994 lea ecx, [ebx + 4*ecx] // -> nv[n/4] = nv limit
997 lea esi, [esp + 12] // -> expanded M = mi
998 lea edx, [esp + 44] // -> space for Y
1002 cmp ebx, ecx // done already?
1006 // Complete the first inner loop.
1010 cmp ebx, ecx // done yet?
1013 // Still have carries left to propagate.
1015 mov esi, [esp + 8] // -> dv blocks limit
1016 mov edx, [ebp + 24] // dv limit
1027 // Continue carry propagation until the end of the buffer.
1029 mov eax, 0 // preserves flags
1038 // Deal with the tail end.
1040 mov eax, 0 // preserves flags
1046 // All done for this iteration. Start the next. (This must have at
1047 // least one follow-on iteration, or we'd not have started this outer
1049 8: mov edi, [esp + 0] // -> dv[i - 1]
1050 mov ebx, [ebp + 28] // -> X = nv[0]
1051 lea edx, [esp + 44] // -> space for Y
1052 lea esi, [esp + 12] // -> expanded M = mi
1053 add edi, 16 // -> Z = dv[i]
1054 cmp edi, [esp + 4] // all done yet?
1072 ///--------------------------------------------------------------------------
1073 /// Testing and performance measurement.
1083 .macro cystore c, v, n
1091 mov [ebx + ecx*8], eax
1092 mov [ebx + ecx*8 + 4], edx
1095 .macro testprologue n
1105 mov [esp + 104], eax
1107 // esp + 0 = v expanded
1108 // esp + 32 = y expanded
1109 // esp + 64 = ? expanded
1110 // esp + 96 = cycles
1111 // esp + 104 = count
1123 .macro testldcarry c
1125 movdqu xmm4, [ecx + 0] // (c'_0; c''_0)
1126 movdqu xmm5, [ecx + 16] // (c'_1; c''_1)
1127 movdqu xmm6, [ecx + 32] // (c'_2; c''_2)
1130 .macro testexpand v=nil, y=nil
1135 expand xmm7, xmm0, xmm1
1136 movdqa [esp + 0], xmm0
1137 movdqa [esp + 16], xmm1
1142 expand xmm7, xmm2, xmm3
1143 movdqa [esp + 32], xmm2
1144 movdqa [esp + 48], xmm3
1148 .macro testtop u=nil, x=nil, mode=nil
1155 .ifeqs "\mode", "mont"
1162 .ifeqs "\mode", "mont"
1170 cystore esp + 96, \cyv, esp + 104
1174 .macro testcarryout c
1176 movdqu [ecx + 0], xmm4
1177 movdqu [ecx + 16], xmm5
1178 movdqu [ecx + 32], xmm6
1182 testprologue [ebp + 44]
1183 testldcarry [ebp + 24]
1184 testexpand [ebp + 36], [ebp + 40]
1186 testtop [ebp + 28], [ebp + 32]
1189 testcarryout [ebp + 24]
1194 testprologue [ebp + 44]
1195 testldcarry [ebp + 24]
1196 testexpand [ebp + 36], [ebp + 40]
1198 testtop [ebp + 28], [ebp + 32]
1201 testcarryout [ebp + 24]
1206 testprologue [ebp + 36]
1207 testldcarry [ebp + 24]
1208 testexpand nil, [ebp + 32]
1210 testtop nil, [ebp + 28]
1213 testcarryout [ebp + 24]
1218 testprologue [ebp + 36]
1219 testldcarry [ebp + 24]
1220 testexpand nil, [ebp + 32]
1222 testtop nil, [ebp + 28]
1225 testcarryout [ebp + 24]
1230 testprologue [ebp + 48]
1231 testexpand [ebp + 40], [ebp + 44]
1233 testtop [ebp + 32], [ebp + 36], mont
1237 movdqa xmm0, [esp + 64]
1238 movdqa xmm1, [esp + 80]
1240 movdqu [edi + 16], xmm1
1241 testcarryout [ebp + 24]
1246 testprologue [ebp + 48]
1247 testexpand [ebp + 40], [ebp + 44]
1249 testtop [ebp + 32], [ebp + 36], mont
1253 movdqa xmm0, [esp + 64]
1254 movdqa xmm1, [esp + 80]
1256 movdqu [edi + 16], xmm1
1257 testcarryout [ebp + 24]
1262 testprologue [ebp + 40]
1263 testexpand nil, [ebp + 36]
1265 testtop nil, [ebp + 32], mont
1269 movdqa xmm0, [esp + 64]
1270 movdqa xmm1, [esp + 80]
1272 movdqu [edi + 16], xmm1
1273 testcarryout [ebp + 24]
1279 ///----- That's all, folks --------------------------------------------------