1 .explicit
2 .text
3 .ident	"ia64.S, Version 2.1"
4 .ident	"IA-64 ISA artwork by Andy Polyakov <appro@openssl.org>"
5 
6 // Copyright 2001-2018 The OpenSSL Project Authors. All Rights Reserved.
7 //
8 // Licensed under the Apache License 2.0 (the "License").  You may not use
9 // this file except in compliance with the License.  You can obtain a copy
10 // in the file LICENSE in the source distribution or at
11 // https://www.openssl.org/source/license.html
12 
13 //
14 // ====================================================================
15 // Written by Andy Polyakov <appro@openssl.org> for the OpenSSL
16 // project.
17 //
18 // Rights for redistribution and usage in source and binary forms are
19 // granted according to the License. Warranty of any kind is disclaimed.
20 // ====================================================================
21 //
22 // Version 2.x is Itanium2 re-tune. Few words about how Itanium2 is
23 // different from Itanium to this module viewpoint. Most notably, is it
24 // "wider" than Itanium? Can you experience loop scalability as
25 // discussed in commentary sections? Not really:-( Itanium2 has 6
26 // integer ALU ports, i.e. it's 2 ports wider, but it's not enough to
27 // spin twice as fast, as I need 8 IALU ports. Amount of floating point
28 // ports is the same, i.e. 2, while I need 4. In other words, to this
29 // module Itanium2 remains effectively as "wide" as Itanium. Yet it's
30 // essentially different in respect to this module, and a re-tune was
31 // required. Well, because some instruction latencies has changed. Most
32 // noticeably those intensively used:
33 //
34 //			Itanium	Itanium2
35 //	ldf8		9	6		L2 hit
36 //	ld8		2	1		L1 hit
37 //	getf		2	5
38 //	xma[->getf]	7[+1]	4[+0]
39 //	add[->st8]	1[+1]	1[+0]
40 //
41 // What does it mean? You might ratiocinate that the original code
42 // should run just faster... Because sum of latencies is smaller...
43 // Wrong! Note that getf latency increased. This means that if a loop is
44 // scheduled for lower latency (as they were), then it will suffer from
45 // stall condition and the code will therefore turn anti-scalable, e.g.
46 // original bn_mul_words spun at 5*n or 2.5 times slower than expected
47 // on Itanium2! What to do? Reschedule loops for Itanium2? But then
48 // Itanium would exhibit anti-scalability. So I've chosen to reschedule
49 // for worst latency for every instruction aiming for best *all-round*
50 // performance.
51 
52 // Q.	How much faster does it get?
53 // A.	Here is the output from 'openssl speed rsa dsa' for vanilla
54 //	0.9.6a compiled with gcc version 2.96 20000731 (Red Hat
55 //	Linux 7.1 2.96-81):
56 //
57 //	                  sign    verify    sign/s verify/s
58 //	rsa  512 bits   0.0036s   0.0003s    275.3   2999.2
59 //	rsa 1024 bits   0.0203s   0.0011s     49.3    894.1
60 //	rsa 2048 bits   0.1331s   0.0040s      7.5    250.9
61 //	rsa 4096 bits   0.9270s   0.0147s      1.1     68.1
62 //	                  sign    verify    sign/s verify/s
63 //	dsa  512 bits   0.0035s   0.0043s    288.3    234.8
64 //	dsa 1024 bits   0.0111s   0.0135s     90.0     74.2
65 //
66 //	And here is similar output but for this assembler
67 //	implementation:-)
68 //
69 //	                  sign    verify    sign/s verify/s
70 //	rsa  512 bits   0.0021s   0.0001s    549.4   9638.5
71 //	rsa 1024 bits   0.0055s   0.0002s    183.8   4481.1
72 //	rsa 2048 bits   0.0244s   0.0006s     41.4   1726.3
73 //	rsa 4096 bits   0.1295s   0.0018s      7.7    561.5
74 //	                  sign    verify    sign/s verify/s
75 //	dsa  512 bits   0.0012s   0.0013s    891.9    756.6
76 //	dsa 1024 bits   0.0023s   0.0028s    440.4    376.2
77 //
78 //	Yes, you may argue that it's not fair comparison as it's
79 //	possible to craft the C implementation with BN_UMULT_HIGH
80 //	inline assembler macro. But of course! Here is the output
81 //	with the macro:
82 //
83 //	                  sign    verify    sign/s verify/s
84 //	rsa  512 bits   0.0020s   0.0002s    495.0   6561.0
85 //	rsa 1024 bits   0.0086s   0.0004s    116.2   2235.7
86 //	rsa 2048 bits   0.0519s   0.0015s     19.3    667.3
87 //	rsa 4096 bits   0.3464s   0.0053s      2.9    187.7
88 //	                  sign    verify    sign/s verify/s
89 //	dsa  512 bits   0.0016s   0.0020s    613.1    510.5
90 //	dsa 1024 bits   0.0045s   0.0054s    221.0    183.9
91 //
92 //	My code is still way faster, huh:-) And I believe that even
93 //	higher performance can be achieved. Note that as keys get
94 //	longer, performance gain is larger. Why? According to the
95 //	profiler there is another player in the field, namely
96 //	BN_from_montgomery consuming larger and larger portion of CPU
97 //	time as keysize decreases. I therefore consider putting effort
98 //	to assembler implementation of the following routine:
99 //
100 //	void bn_mul_add_mont (BN_ULONG *rp,BN_ULONG *np,int nl,BN_ULONG n0)
101 //	{
102 //	int      i,j;
103 //	BN_ULONG v;
104 //
105 //	for (i=0; i<nl; i++)
106 //		{
107 //		v=bn_mul_add_words(rp,np,nl,(rp[0]*n0)&BN_MASK2);
108 //		nrp++;
109 //		rp++;
110 //		if (((nrp[-1]+=v)&BN_MASK2) < v)
111 //			for (j=0; ((++nrp[j])&BN_MASK2) == 0; j++) ;
112 //		}
113 //	}
114 //
115 //	It might as well be beneficial to implement even combaX
116 //	variants, as it appears as it can literally unleash the
117 //	performance (see comment section to bn_mul_comba8 below).
118 //
119 //	And finally for your reference the output for 0.9.6a compiled
120 //	with SGIcc version 0.01.0-12 (keep in mind that for the moment
121 //	of this writing it's not possible to convince SGIcc to use
122 //	BN_UMULT_HIGH inline assembler macro, yet the code is fast,
123 //	i.e. for a compiler generated one:-):
124 //
125 //	                  sign    verify    sign/s verify/s
126 //	rsa  512 bits   0.0022s   0.0002s    452.7   5894.3
127 //	rsa 1024 bits   0.0097s   0.0005s    102.7   2002.9
128 //	rsa 2048 bits   0.0578s   0.0017s     17.3    600.2
129 //	rsa 4096 bits   0.3838s   0.0061s      2.6    164.5
130 //	                  sign    verify    sign/s verify/s
131 //	dsa  512 bits   0.0018s   0.0022s    547.3    459.6
132 //	dsa 1024 bits   0.0051s   0.0062s    196.6    161.3
133 //
134 //	Oh! Benchmarks were performed on 733MHz Lion-class Itanium
135 //	system running Redhat Linux 7.1 (very special thanks to Ray
136 //	McCaffity of Williams Communications for providing an account).
137 //
138 // Q.	What's the heck with 'rum 1<<5' at the end of every function?
139 // A.	Well, by clearing the "upper FP registers written" bit of the
140 //	User Mask I want to excuse the kernel from preserving upper
141 //	(f32-f128) FP register bank over process context switch, thus
142 //	minimizing bus bandwidth consumption during the switch (i.e.
143 //	after PKI operation completes and the program is off doing
144 //	something else like bulk symmetric encryption). Having said
145 //	this, I also want to point out that it might be good idea
146 //	to compile the whole toolkit (as well as majority of the
147 //	programs for that matter) with -mfixed-range=f32-f127 command
148 //	line option. No, it doesn't prevent the compiler from writing
149 //	to upper bank, but at least discourages to do so. If you don't
150 //	like the idea you have the option to compile the module with
151 //	-Drum=nop.m in command line.
152 //
153 
154 #if defined(_HPUX_SOURCE) && !defined(_LP64)
155 #define	ADDP	addp4
156 #else
157 #define	ADDP	add
158 #endif
159 #ifdef __VMS
160 .alias abort, "decc$abort"
161 #endif
162 
163 #if 1
164 //
165 // bn_[add|sub]_words routines.
166 //
167 // Loops are spinning in 2*(n+5) ticks on Itanium (provided that the
168 // data reside in L1 cache, i.e. 2 ticks away). It's possible to
169 // compress the epilogue and get down to 2*n+6, but at the cost of
170 // scalability (the neat feature of this implementation is that it
171 // shall automagically spin in n+5 on "wider" IA-64 implementations:-)
172 // I consider that the epilogue is short enough as it is to trade tiny
173 // performance loss on Itanium for scalability.
174 //
175 // BN_ULONG bn_add_words(BN_ULONG *rp, BN_ULONG *ap, BN_ULONG *bp,int num)
176 //
177 .global	bn_add_words#
178 .proc	bn_add_words#
179 .align	64
180 .skip	32	// makes the loop body aligned at 64-byte boundary
181 bn_add_words:
182 	.prologue
183 	.save	ar.pfs,r2
184 { .mii;	alloc		r2=ar.pfs,4,12,0,16
185 	cmp4.le		p6,p0=r35,r0	};;
186 { .mfb;	mov		r8=r0			// return value
187 (p6)	br.ret.spnt.many	b0	};;
188 
189 { .mib;	sub		r10=r35,r0,1
190 	.save	ar.lc,r3
191 	mov		r3=ar.lc
192 	brp.loop.imp	.L_bn_add_words_ctop,.L_bn_add_words_cend-16
193 					}
194 { .mib;	ADDP		r14=0,r32		// rp
195 	.save	pr,r9
196 	mov		r9=pr		};;
197 	.body
198 { .mii;	ADDP		r15=0,r33		// ap
199 	mov		ar.lc=r10
200 	mov		ar.ec=6		}
201 { .mib;	ADDP		r16=0,r34		// bp
202 	mov		pr.rot=1<<16	};;
203 
204 .L_bn_add_words_ctop:
205 { .mii;	(p16)	ld8		r32=[r16],8	  // b=*(bp++)
206 	(p18)	add		r39=r37,r34
207 	(p19)	cmp.ltu.unc	p56,p0=r40,r38	}
208 { .mfb;	(p0)	nop.m		0x0
209 	(p0)	nop.f		0x0
210 	(p0)	nop.b		0x0		}
211 { .mii;	(p16)	ld8		r35=[r15],8	  // a=*(ap++)
212 	(p58)	cmp.eq.or	p57,p0=-1,r41	  // (p20)
213 	(p58)	add		r41=1,r41	} // (p20)
214 { .mfb;	(p21)	st8		[r14]=r42,8	  // *(rp++)=r
215 	(p0)	nop.f		0x0
216 	br.ctop.sptk	.L_bn_add_words_ctop	};;
217 .L_bn_add_words_cend:
218 
219 { .mii;
220 (p59)	add		r8=1,r8		// return value
221 	mov		pr=r9,0x1ffff
222 	mov		ar.lc=r3	}
223 { .mbb;	nop.b		0x0
224 	br.ret.sptk.many	b0	};;
225 .endp	bn_add_words#
226 
227 //
228 // BN_ULONG bn_sub_words(BN_ULONG *rp, BN_ULONG *ap, BN_ULONG *bp,int num)
229 //
230 .global	bn_sub_words#
231 .proc	bn_sub_words#
232 .align	64
233 .skip	32	// makes the loop body aligned at 64-byte boundary
234 bn_sub_words:
235 	.prologue
236 	.save	ar.pfs,r2
237 { .mii;	alloc		r2=ar.pfs,4,12,0,16
238 	cmp4.le		p6,p0=r35,r0	};;
239 { .mfb;	mov		r8=r0			// return value
240 (p6)	br.ret.spnt.many	b0	};;
241 
242 { .mib;	sub		r10=r35,r0,1
243 	.save	ar.lc,r3
244 	mov		r3=ar.lc
245 	brp.loop.imp	.L_bn_sub_words_ctop,.L_bn_sub_words_cend-16
246 					}
247 { .mib;	ADDP		r14=0,r32		// rp
248 	.save	pr,r9
249 	mov		r9=pr		};;
250 	.body
251 { .mii;	ADDP		r15=0,r33		// ap
252 	mov		ar.lc=r10
253 	mov		ar.ec=6		}
254 { .mib;	ADDP		r16=0,r34		// bp
255 	mov		pr.rot=1<<16	};;
256 
257 .L_bn_sub_words_ctop:
258 { .mii;	(p16)	ld8		r32=[r16],8	  // b=*(bp++)
259 	(p18)	sub		r39=r37,r34
260 	(p19)	cmp.gtu.unc	p56,p0=r40,r38	}
261 { .mfb;	(p0)	nop.m		0x0
262 	(p0)	nop.f		0x0
263 	(p0)	nop.b		0x0		}
264 { .mii;	(p16)	ld8		r35=[r15],8	  // a=*(ap++)
265 	(p58)	cmp.eq.or	p57,p0=0,r41	  // (p20)
266 	(p58)	add		r41=-1,r41	} // (p20)
267 { .mbb;	(p21)	st8		[r14]=r42,8	  // *(rp++)=r
268 	(p0)	nop.b		0x0
269 	br.ctop.sptk	.L_bn_sub_words_ctop	};;
270 .L_bn_sub_words_cend:
271 
272 { .mii;
273 (p59)	add		r8=1,r8		// return value
274 	mov		pr=r9,0x1ffff
275 	mov		ar.lc=r3	}
276 { .mbb;	nop.b		0x0
277 	br.ret.sptk.many	b0	};;
278 .endp	bn_sub_words#
279 #endif
280 
281 #if 0
282 #define XMA_TEMPTATION
283 #endif
284 
285 #if 1
286 //
287 // BN_ULONG bn_mul_words(BN_ULONG *rp, BN_ULONG *ap, int num, BN_ULONG w)
288 //
289 .global	bn_mul_words#
290 .proc	bn_mul_words#
291 .align	64
292 .skip	32	// makes the loop body aligned at 64-byte boundary
293 bn_mul_words:
294 	.prologue
295 	.save	ar.pfs,r2
296 #ifdef XMA_TEMPTATION
297 { .mfi;	alloc		r2=ar.pfs,4,0,0,0	};;
298 #else
299 { .mfi;	alloc		r2=ar.pfs,4,12,0,16	};;
300 #endif
301 { .mib;	mov		r8=r0			// return value
302 	cmp4.le		p6,p0=r34,r0
303 (p6)	br.ret.spnt.many	b0		};;
304 
305 { .mii;	sub	r10=r34,r0,1
306 	.save	ar.lc,r3
307 	mov	r3=ar.lc
308 	.save	pr,r9
309 	mov	r9=pr			};;
310 
311 	.body
312 { .mib;	setf.sig	f8=r35	// w
313 	mov		pr.rot=0x800001<<16
314 			// ------^----- serves as (p50) at first (p27)
315 	brp.loop.imp	.L_bn_mul_words_ctop,.L_bn_mul_words_cend-16
316 					}
317 
318 #ifndef XMA_TEMPTATION
319 
320 { .mmi;	ADDP		r14=0,r32	// rp
321 	ADDP		r15=0,r33	// ap
322 	mov		ar.lc=r10	}
323 { .mmi;	mov		r40=0		// serves as r35 at first (p27)
324 	mov		ar.ec=13	};;
325 
326 // This loop spins in 2*(n+12) ticks. It's scheduled for data in Itanium
327 // L2 cache (i.e. 9 ticks away) as floating point load/store instructions
328 // bypass L1 cache and L2 latency is actually best-case scenario for
329 // ldf8. The loop is not scalable and shall run in 2*(n+12) even on
330 // "wider" IA-64 implementations. It's a trade-off here. n+24 loop
331 // would give us ~5% in *overall* performance improvement on "wider"
332 // IA-64, but would hurt Itanium for about same because of longer
333 // epilogue. As it's a matter of few percents in either case I've
334 // chosen to trade the scalability for development time (you can see
335 // this very instruction sequence in bn_mul_add_words loop which in
336 // turn is scalable).
337 .L_bn_mul_words_ctop:
338 { .mfi;	(p25)	getf.sig	r36=f52			// low
339 	(p21)	xmpy.lu		f48=f37,f8
340 	(p28)	cmp.ltu		p54,p50=r41,r39	}
341 { .mfi;	(p16)	ldf8		f32=[r15],8
342 	(p21)	xmpy.hu		f40=f37,f8
343 	(p0)	nop.i		0x0		};;
344 { .mii;	(p25)	getf.sig	r32=f44			// high
345 	.pred.rel	"mutex",p50,p54
346 	(p50)	add		r40=r38,r35		// (p27)
347 	(p54)	add		r40=r38,r35,1	}	// (p27)
348 { .mfb;	(p28)	st8		[r14]=r41,8
349 	(p0)	nop.f		0x0
350 	br.ctop.sptk	.L_bn_mul_words_ctop	};;
351 .L_bn_mul_words_cend:
352 
353 { .mii;	nop.m		0x0
354 .pred.rel	"mutex",p51,p55
355 (p51)	add		r8=r36,r0
356 (p55)	add		r8=r36,r0,1	}
357 { .mfb;	nop.m	0x0
358 	nop.f	0x0
359 	nop.b	0x0			}
360 
361 #else	// XMA_TEMPTATION
362 
363 	setf.sig	f37=r0	// serves as carry at (p18) tick
364 	mov		ar.lc=r10
365 	mov		ar.ec=5;;
366 
367 // Most of you examining this code very likely wonder why in the name
368 // of Intel the following loop is commented out? Indeed, it looks so
369 // neat that you find it hard to believe that it's something wrong
370 // with it, right? The catch is that every iteration depends on the
371 // result from previous one and the latter isn't available instantly.
372 // The loop therefore spins at the latency of xma minus 1, or in other
373 // words at 6*(n+4) ticks:-( Compare to the "production" loop above
374 // that runs in 2*(n+11) where the low latency problem is worked around
375 // by moving the dependency to one-tick latent integer ALU. Note that
376 // "distance" between ldf8 and xma is not latency of ldf8, but the
377 // *difference* between xma and ldf8 latencies.
378 .L_bn_mul_words_ctop:
379 { .mfi;	(p16)	ldf8		f32=[r33],8
380 	(p18)	xma.hu		f38=f34,f8,f39	}
381 { .mfb;	(p20)	stf8		[r32]=f37,8
382 	(p18)	xma.lu		f35=f34,f8,f39
383 	br.ctop.sptk	.L_bn_mul_words_ctop	};;
384 .L_bn_mul_words_cend:
385 
386 	getf.sig	r8=f41		// the return value
387 
388 #endif	// XMA_TEMPTATION
389 
390 { .mii;	nop.m		0x0
391 	mov		pr=r9,0x1ffff
392 	mov		ar.lc=r3	}
393 { .mfb;	rum		1<<5		// clear um.mfh
394 	nop.f		0x0
395 	br.ret.sptk.many	b0	};;
396 .endp	bn_mul_words#
397 #endif
398 
399 #if 1
400 //
401 // BN_ULONG bn_mul_add_words(BN_ULONG *rp, BN_ULONG *ap, int num, BN_ULONG w)
402 //
403 .global	bn_mul_add_words#
404 .proc	bn_mul_add_words#
405 .align	64
406 .skip	48	// makes the loop body aligned at 64-byte boundary
407 bn_mul_add_words:
408 	.prologue
409 	.save	ar.pfs,r2
410 { .mmi;	alloc		r2=ar.pfs,4,4,0,8
411 	cmp4.le		p6,p0=r34,r0
412 	.save	ar.lc,r3
413 	mov		r3=ar.lc	};;
414 { .mib;	mov		r8=r0		// return value
415 	sub		r10=r34,r0,1
416 (p6)	br.ret.spnt.many	b0	};;
417 
418 { .mib;	setf.sig	f8=r35		// w
419 	.save	pr,r9
420 	mov		r9=pr
421 	brp.loop.imp	.L_bn_mul_add_words_ctop,.L_bn_mul_add_words_cend-16
422 					}
423 	.body
424 { .mmi;	ADDP		r14=0,r32	// rp
425 	ADDP		r15=0,r33	// ap
426 	mov		ar.lc=r10	}
427 { .mii;	ADDP		r16=0,r32	// rp copy
428 	mov		pr.rot=0x2001<<16
429 			// ------^----- serves as (p40) at first (p27)
430 	mov		ar.ec=11	};;
431 
432 // This loop spins in 3*(n+10) ticks on Itanium and in 2*(n+10) on
433 // Itanium 2. Yes, unlike previous versions it scales:-) Previous
434 // version was performing *all* additions in IALU and was starving
435 // for those even on Itanium 2. In this version one addition is
436 // moved to FPU and is folded with multiplication. This is at cost
437 // of propagating the result from previous call to this subroutine
438 // to L2 cache... In other words negligible even for shorter keys.
439 // *Overall* performance improvement [over previous version] varies
440 // from 11 to 22 percent depending on key length.
441 .L_bn_mul_add_words_ctop:
442 .pred.rel	"mutex",p40,p42
443 { .mfi;	(p23)	getf.sig	r36=f45			// low
444 	(p20)	xma.lu		f42=f36,f8,f50		// low
445 	(p40)	add		r39=r39,r35	}	// (p27)
446 { .mfi;	(p16)	ldf8		f32=[r15],8		// *(ap++)
447 	(p20)	xma.hu		f36=f36,f8,f50		// high
448 	(p42)	add		r39=r39,r35,1	};;	// (p27)
449 { .mmi;	(p24)	getf.sig	r32=f40			// high
450 	(p16)	ldf8		f46=[r16],8		// *(rp1++)
451 	(p40)	cmp.ltu		p41,p39=r39,r35	}	// (p27)
452 { .mib;	(p26)	st8		[r14]=r39,8		// *(rp2++)
453 	(p42)	cmp.leu		p41,p39=r39,r35		// (p27)
454 	br.ctop.sptk	.L_bn_mul_add_words_ctop};;
455 .L_bn_mul_add_words_cend:
456 
457 { .mmi;	.pred.rel	"mutex",p40,p42
458 (p40)	add		r8=r35,r0
459 (p42)	add		r8=r35,r0,1
460 	mov		pr=r9,0x1ffff	}
461 { .mib;	rum		1<<5		// clear um.mfh
462 	mov		ar.lc=r3
463 	br.ret.sptk.many	b0	};;
464 .endp	bn_mul_add_words#
465 #endif
466 
467 #if 1
468 //
469 // void bn_sqr_words(BN_ULONG *rp, BN_ULONG *ap, int num)
470 //
471 .global	bn_sqr_words#
472 .proc	bn_sqr_words#
473 .align	64
474 .skip	32	// makes the loop body aligned at 64-byte boundary
475 bn_sqr_words:
476 	.prologue
477 	.save	ar.pfs,r2
478 { .mii;	alloc		r2=ar.pfs,3,0,0,0
479 	sxt4		r34=r34		};;
480 { .mii;	cmp.le		p6,p0=r34,r0
481 	mov		r8=r0		}	// return value
482 { .mfb;	ADDP		r32=0,r32
483 	nop.f		0x0
484 (p6)	br.ret.spnt.many	b0	};;
485 
486 { .mii;	sub	r10=r34,r0,1
487 	.save	ar.lc,r3
488 	mov	r3=ar.lc
489 	.save	pr,r9
490 	mov	r9=pr			};;
491 
492 	.body
493 { .mib;	ADDP		r33=0,r33
494 	mov		pr.rot=1<<16
495 	brp.loop.imp	.L_bn_sqr_words_ctop,.L_bn_sqr_words_cend-16
496 					}
497 { .mii;	add		r34=8,r32
498 	mov		ar.lc=r10
499 	mov		ar.ec=18	};;
500 
501 // 2*(n+17) on Itanium, (n+17) on "wider" IA-64 implementations. It's
502 // possible to compress the epilogue (I'm getting tired to write this
503 // comment over and over) and get down to 2*n+16 at the cost of
504 // scalability. The decision will very likely be reconsidered after the
505 // benchmark program is profiled. I.e. if performance gain on Itanium
506 // will appear larger than loss on "wider" IA-64, then the loop should
507 // be explicitly split and the epilogue compressed.
508 .L_bn_sqr_words_ctop:
509 { .mfi;	(p16)	ldf8		f32=[r33],8
510 	(p25)	xmpy.lu		f42=f41,f41
511 	(p0)	nop.i		0x0		}
512 { .mib;	(p33)	stf8		[r32]=f50,16
513 	(p0)	nop.i		0x0
514 	(p0)	nop.b		0x0		}
515 { .mfi;	(p0)	nop.m		0x0
516 	(p25)	xmpy.hu		f52=f41,f41
517 	(p0)	nop.i		0x0		}
518 { .mib;	(p33)	stf8		[r34]=f60,16
519 	(p0)	nop.i		0x0
520 	br.ctop.sptk	.L_bn_sqr_words_ctop	};;
521 .L_bn_sqr_words_cend:
522 
523 { .mii;	nop.m		0x0
524 	mov		pr=r9,0x1ffff
525 	mov		ar.lc=r3	}
526 { .mfb;	rum		1<<5		// clear um.mfh
527 	nop.f		0x0
528 	br.ret.sptk.many	b0	};;
529 .endp	bn_sqr_words#
530 #endif
531 
532 #if 1
533 // Apparently we win nothing by implementing special bn_sqr_comba8.
534 // Yes, it is possible to reduce the number of multiplications by
535 // almost factor of two, but then the amount of additions would
536 // increase by factor of two (as we would have to perform those
537 // otherwise performed by xma ourselves). Normally we would trade
538 // anyway as multiplications are way more expensive, but not this
539 // time... Multiplication kernel is fully pipelined and as we drain
540 // one 128-bit multiplication result per clock cycle multiplications
541 // are effectively as inexpensive as additions. Special implementation
542 // might become of interest for "wider" IA-64 implementation as you'll
543 // be able to get through the multiplication phase faster (there won't
544 // be any stall issues as discussed in the commentary section below and
545 // you therefore will be able to employ all 4 FP units)... But these
546 // Itanium days it's simply too hard to justify the effort so I just
547 // drop down to bn_mul_comba8 code:-)
548 //
549 // void bn_sqr_comba8(BN_ULONG *r, BN_ULONG *a)
550 //
551 .global	bn_sqr_comba8#
552 .proc	bn_sqr_comba8#
553 .align	64
554 bn_sqr_comba8:
555 	.prologue
556 	.save	ar.pfs,r2
557 #if defined(_HPUX_SOURCE) && !defined(_LP64)
558 { .mii;	alloc	r2=ar.pfs,2,1,0,0
559 	addp4	r33=0,r33
560 	addp4	r32=0,r32		};;
561 { .mii;
562 #else
563 { .mii;	alloc	r2=ar.pfs,2,1,0,0
564 #endif
565 	mov	r34=r33
566 	add	r14=8,r33		};;
567 	.body
568 { .mii;	add	r17=8,r34
569 	add	r15=16,r33
570 	add	r18=16,r34		}
571 { .mfb;	add	r16=24,r33
572 	br	.L_cheat_entry_point8	};;
573 .endp	bn_sqr_comba8#
574 #endif
575 
576 #if 1
577 // I've estimated this routine to run in ~120 ticks, but in reality
578 // (i.e. according to ar.itc) it takes ~160 ticks. Are those extra
579 // cycles consumed for instructions fetch? Or did I misinterpret some
580 // clause in Itanium µ-architecture manual? Comments are welcomed and
581 // highly appreciated.
582 //
583 // On Itanium 2 it takes ~190 ticks. This is because of stalls on
584 // result from getf.sig. I do nothing about it at this point for
585 // reasons depicted below.
586 //
587 // However! It should be noted that even 160 ticks is darn good result
588 // as it's over 10 (yes, ten, spelled as t-e-n) times faster than the
589 // C version (compiled with gcc with inline assembler). I really
590 // kicked compiler's butt here, didn't I? Yeah! This brings us to the
591 // following statement. It's damn shame that this routine isn't called
592 // very often nowadays! According to the profiler most CPU time is
593 // consumed by bn_mul_add_words called from BN_from_montgomery. In
594 // order to estimate what we're missing, I've compared the performance
595 // of this routine against "traditional" implementation, i.e. against
596 // following routine:
597 //
598 // void bn_mul_comba8(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b)
599 // {	r[ 8]=bn_mul_words(    &(r[0]),a,8,b[0]);
600 //	r[ 9]=bn_mul_add_words(&(r[1]),a,8,b[1]);
601 //	r[10]=bn_mul_add_words(&(r[2]),a,8,b[2]);
602 //	r[11]=bn_mul_add_words(&(r[3]),a,8,b[3]);
603 //	r[12]=bn_mul_add_words(&(r[4]),a,8,b[4]);
604 //	r[13]=bn_mul_add_words(&(r[5]),a,8,b[5]);
605 //	r[14]=bn_mul_add_words(&(r[6]),a,8,b[6]);
606 //	r[15]=bn_mul_add_words(&(r[7]),a,8,b[7]);
607 // }
608 //
609 // The one below is over 8 times faster than the one above:-( Even
610 // more reasons to "combafy" bn_mul_add_mont...
611 //
612 // And yes, this routine really made me wish there were an optimizing
613 // assembler! It also feels like it deserves a dedication.
614 //
615 //	To my wife for being there and to my kids...
616 //
617 // void bn_mul_comba8(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b)
618 //
619 #define	carry1	r14
620 #define	carry2	r15
621 #define	carry3	r34
622 .global	bn_mul_comba8#
623 .proc	bn_mul_comba8#
624 .align	64
625 bn_mul_comba8:
626 	.prologue
627 	.save	ar.pfs,r2
628 #if defined(_HPUX_SOURCE) && !defined(_LP64)
629 { .mii;	alloc	r2=ar.pfs,3,0,0,0
630 	addp4	r33=0,r33
631 	addp4	r34=0,r34		};;
632 { .mii;	addp4	r32=0,r32
633 #else
634 { .mii;	alloc   r2=ar.pfs,3,0,0,0
635 #endif
636 	add	r14=8,r33
637 	add	r17=8,r34		}
638 	.body
639 { .mii;	add	r15=16,r33
640 	add	r18=16,r34
641 	add	r16=24,r33		}
642 .L_cheat_entry_point8:
643 { .mmi;	add	r19=24,r34
644 
645 	ldf8	f32=[r33],32		};;
646 
647 { .mmi;	ldf8	f120=[r34],32
648 	ldf8	f121=[r17],32		}
649 { .mmi;	ldf8	f122=[r18],32
650 	ldf8	f123=[r19],32		};;
651 { .mmi;	ldf8	f124=[r34]
652 	ldf8	f125=[r17]		}
653 { .mmi;	ldf8	f126=[r18]
654 	ldf8	f127=[r19]		}
655 
656 { .mmi;	ldf8	f33=[r14],32
657 	ldf8	f34=[r15],32		}
658 { .mmi;	ldf8	f35=[r16],32;;
659 	ldf8	f36=[r33]		}
660 { .mmi;	ldf8	f37=[r14]
661 	ldf8	f38=[r15]		}
662 { .mfi;	ldf8	f39=[r16]
663 // -------\ Entering multiplier's heaven /-------
664 // ------------\                    /------------
665 // -----------------\          /-----------------
666 // ----------------------\/----------------------
667 		xma.hu	f41=f32,f120,f0		}
668 { .mfi;		xma.lu	f40=f32,f120,f0		};; // (*)
669 { .mfi;		xma.hu	f51=f32,f121,f0		}
670 { .mfi;		xma.lu	f50=f32,f121,f0		};;
671 { .mfi;		xma.hu	f61=f32,f122,f0		}
672 { .mfi;		xma.lu	f60=f32,f122,f0		};;
673 { .mfi;		xma.hu	f71=f32,f123,f0		}
674 { .mfi;		xma.lu	f70=f32,f123,f0		};;
675 { .mfi;		xma.hu	f81=f32,f124,f0		}
676 { .mfi;		xma.lu	f80=f32,f124,f0		};;
677 { .mfi;		xma.hu	f91=f32,f125,f0		}
678 { .mfi;		xma.lu	f90=f32,f125,f0		};;
679 { .mfi;		xma.hu	f101=f32,f126,f0	}
680 { .mfi;		xma.lu	f100=f32,f126,f0	};;
681 { .mfi;		xma.hu	f111=f32,f127,f0	}
682 { .mfi;		xma.lu	f110=f32,f127,f0	};;//
683 // (*)	You can argue that splitting at every second bundle would
684 //	prevent "wider" IA-64 implementations from achieving the peak
685 //	performance. Well, not really... The catch is that if you
686 //	intend to keep 4 FP units busy by splitting at every fourth
687 //	bundle and thus perform these 16 multiplications in 4 ticks,
688 //	the first bundle *below* would stall because the result from
689 //	the first xma bundle *above* won't be available for another 3
690 //	ticks (if not more, being an optimist, I assume that "wider"
691 //	implementation will have same latency:-). This stall will hold
692 //	you back and the performance would be as if every second bundle
693 //	were split *anyway*...
694 { .mfi;	getf.sig	r16=f40
695 		xma.hu	f42=f33,f120,f41
696 	add		r33=8,r32		}
697 { .mfi;		xma.lu	f41=f33,f120,f41	};;
698 { .mfi;	getf.sig	r24=f50
699 		xma.hu	f52=f33,f121,f51	}
700 { .mfi;		xma.lu	f51=f33,f121,f51	};;
701 { .mfi;	st8		[r32]=r16,16
702 		xma.hu	f62=f33,f122,f61	}
703 { .mfi;		xma.lu	f61=f33,f122,f61	};;
704 { .mfi;		xma.hu	f72=f33,f123,f71	}
705 { .mfi;		xma.lu	f71=f33,f123,f71	};;
706 { .mfi;		xma.hu	f82=f33,f124,f81	}
707 { .mfi;		xma.lu	f81=f33,f124,f81	};;
708 { .mfi;		xma.hu	f92=f33,f125,f91	}
709 { .mfi;		xma.lu	f91=f33,f125,f91	};;
710 { .mfi;		xma.hu	f102=f33,f126,f101	}
711 { .mfi;		xma.lu	f101=f33,f126,f101	};;
712 { .mfi;		xma.hu	f112=f33,f127,f111	}
713 { .mfi;		xma.lu	f111=f33,f127,f111	};;//
714 //-------------------------------------------------//
715 { .mfi;	getf.sig	r25=f41
716 		xma.hu	f43=f34,f120,f42	}
717 { .mfi;		xma.lu	f42=f34,f120,f42	};;
718 { .mfi;	getf.sig	r16=f60
719 		xma.hu	f53=f34,f121,f52	}
720 { .mfi;		xma.lu	f52=f34,f121,f52	};;
721 { .mfi;	getf.sig	r17=f51
722 		xma.hu	f63=f34,f122,f62
723 	add		r25=r25,r24		}
724 { .mfi;		xma.lu	f62=f34,f122,f62
725 	mov		carry1=0		};;
726 { .mfi;	cmp.ltu		p6,p0=r25,r24
727 		xma.hu	f73=f34,f123,f72	}
728 { .mfi;		xma.lu	f72=f34,f123,f72	};;
729 { .mfi;	st8		[r33]=r25,16
730 		xma.hu	f83=f34,f124,f82
731 (p6)	add		carry1=1,carry1		}
732 { .mfi;		xma.lu	f82=f34,f124,f82	};;
733 { .mfi;		xma.hu	f93=f34,f125,f92	}
734 { .mfi;		xma.lu	f92=f34,f125,f92	};;
735 { .mfi;		xma.hu	f103=f34,f126,f102	}
736 { .mfi;		xma.lu	f102=f34,f126,f102	};;
737 { .mfi;		xma.hu	f113=f34,f127,f112	}
738 { .mfi;		xma.lu	f112=f34,f127,f112	};;//
739 //-------------------------------------------------//
740 { .mfi;	getf.sig	r18=f42
741 		xma.hu	f44=f35,f120,f43
742 	add		r17=r17,r16		}
743 { .mfi;		xma.lu	f43=f35,f120,f43	};;
744 { .mfi;	getf.sig	r24=f70
745 		xma.hu	f54=f35,f121,f53	}
746 { .mfi;	mov		carry2=0
747 		xma.lu	f53=f35,f121,f53	};;
748 { .mfi;	getf.sig	r25=f61
749 		xma.hu	f64=f35,f122,f63
750 	cmp.ltu		p7,p0=r17,r16		}
751 { .mfi;	add		r18=r18,r17
752 		xma.lu	f63=f35,f122,f63	};;
753 { .mfi;	getf.sig	r26=f52
754 		xma.hu	f74=f35,f123,f73
755 (p7)	add		carry2=1,carry2		}
756 { .mfi;	cmp.ltu		p7,p0=r18,r17
757 		xma.lu	f73=f35,f123,f73
758 	add		r18=r18,carry1		};;
759 { .mfi;
760 		xma.hu	f84=f35,f124,f83
761 (p7)	add		carry2=1,carry2		}
762 { .mfi;	cmp.ltu		p7,p0=r18,carry1
763 		xma.lu	f83=f35,f124,f83	};;
764 { .mfi;	st8		[r32]=r18,16
765 		xma.hu	f94=f35,f125,f93
766 (p7)	add		carry2=1,carry2		}
767 { .mfi;		xma.lu	f93=f35,f125,f93	};;
768 { .mfi;		xma.hu	f104=f35,f126,f103	}
769 { .mfi;		xma.lu	f103=f35,f126,f103	};;
770 { .mfi;		xma.hu	f114=f35,f127,f113	}
771 { .mfi;	mov		carry1=0
772 		xma.lu	f113=f35,f127,f113
773 	add		r25=r25,r24		};;//
774 //-------------------------------------------------//
775 { .mfi;	getf.sig	r27=f43
776 		xma.hu	f45=f36,f120,f44
777 	cmp.ltu		p6,p0=r25,r24		}
778 { .mfi;		xma.lu	f44=f36,f120,f44
779 	add		r26=r26,r25		};;
780 { .mfi;	getf.sig	r16=f80
781 		xma.hu	f55=f36,f121,f54
782 (p6)	add		carry1=1,carry1		}
783 { .mfi;		xma.lu	f54=f36,f121,f54	};;
784 { .mfi;	getf.sig	r17=f71
785 		xma.hu	f65=f36,f122,f64
786 	cmp.ltu		p6,p0=r26,r25		}
787 { .mfi;		xma.lu	f64=f36,f122,f64
788 	add		r27=r27,r26		};;
789 { .mfi;	getf.sig	r18=f62
790 		xma.hu	f75=f36,f123,f74
791 (p6)	add		carry1=1,carry1		}
792 { .mfi;	cmp.ltu		p6,p0=r27,r26
793 		xma.lu	f74=f36,f123,f74
794 	add		r27=r27,carry2		};;
795 { .mfi;	getf.sig	r19=f53
796 		xma.hu	f85=f36,f124,f84
797 (p6)	add		carry1=1,carry1		}
798 { .mfi;		xma.lu	f84=f36,f124,f84
799 	cmp.ltu		p6,p0=r27,carry2	};;
800 { .mfi;	st8		[r33]=r27,16
801 		xma.hu	f95=f36,f125,f94
802 (p6)	add		carry1=1,carry1		}
803 { .mfi;		xma.lu	f94=f36,f125,f94	};;
804 { .mfi;		xma.hu	f105=f36,f126,f104	}
805 { .mfi;	mov		carry2=0
806 		xma.lu	f104=f36,f126,f104
807 	add		r17=r17,r16		};;
808 { .mfi;		xma.hu	f115=f36,f127,f114
809 	cmp.ltu		p7,p0=r17,r16		}
810 { .mfi;		xma.lu	f114=f36,f127,f114
811 	add		r18=r18,r17		};;//
812 //-------------------------------------------------//
813 { .mfi;	getf.sig	r20=f44
814 		xma.hu	f46=f37,f120,f45
815 (p7)	add		carry2=1,carry2		}
816 { .mfi;	cmp.ltu		p7,p0=r18,r17
817 		xma.lu	f45=f37,f120,f45
818 	add		r19=r19,r18		};;
819 { .mfi;	getf.sig	r24=f90
820 		xma.hu	f56=f37,f121,f55	}
821 { .mfi;		xma.lu	f55=f37,f121,f55	};;
822 { .mfi;	getf.sig	r25=f81
823 		xma.hu	f66=f37,f122,f65
824 (p7)	add		carry2=1,carry2		}
825 { .mfi;	cmp.ltu		p7,p0=r19,r18
826 		xma.lu	f65=f37,f122,f65
827 	add		r20=r20,r19		};;
828 { .mfi;	getf.sig	r26=f72
829 		xma.hu	f76=f37,f123,f75
830 (p7)	add		carry2=1,carry2		}
831 { .mfi;	cmp.ltu		p7,p0=r20,r19
832 		xma.lu	f75=f37,f123,f75
833 	add		r20=r20,carry1		};;
834 { .mfi;	getf.sig	r27=f63
835 		xma.hu	f86=f37,f124,f85
836 (p7)	add		carry2=1,carry2		}
837 { .mfi;		xma.lu	f85=f37,f124,f85
838 	cmp.ltu		p7,p0=r20,carry1	};;
839 { .mfi;	getf.sig	r28=f54
840 		xma.hu	f96=f37,f125,f95
841 (p7)	add		carry2=1,carry2		}
842 { .mfi;	st8		[r32]=r20,16
843 		xma.lu	f95=f37,f125,f95	};;
844 { .mfi;		xma.hu	f106=f37,f126,f105	}
845 { .mfi;	mov		carry1=0
846 		xma.lu	f105=f37,f126,f105
847 	add		r25=r25,r24		};;
848 { .mfi;		xma.hu	f116=f37,f127,f115
849 	cmp.ltu		p6,p0=r25,r24		}
850 { .mfi;		xma.lu	f115=f37,f127,f115
851 	add		r26=r26,r25		};;//
852 //-------------------------------------------------//
853 { .mfi;	getf.sig	r29=f45
854 		xma.hu	f47=f38,f120,f46
855 (p6)	add		carry1=1,carry1		}
856 { .mfi;	cmp.ltu		p6,p0=r26,r25
857 		xma.lu	f46=f38,f120,f46
858 	add		r27=r27,r26		};;
859 { .mfi;	getf.sig	r16=f100
860 		xma.hu	f57=f38,f121,f56
861 (p6)	add		carry1=1,carry1		}
862 { .mfi;	cmp.ltu		p6,p0=r27,r26
863 		xma.lu	f56=f38,f121,f56
864 	add		r28=r28,r27		};;
865 { .mfi;	getf.sig	r17=f91
866 		xma.hu	f67=f38,f122,f66
867 (p6)	add		carry1=1,carry1		}
868 { .mfi;	cmp.ltu		p6,p0=r28,r27
869 		xma.lu	f66=f38,f122,f66
870 	add		r29=r29,r28		};;
871 { .mfi;	getf.sig	r18=f82
872 		xma.hu	f77=f38,f123,f76
873 (p6)	add		carry1=1,carry1		}
874 { .mfi;	cmp.ltu		p6,p0=r29,r28
875 		xma.lu	f76=f38,f123,f76
876 	add		r29=r29,carry2		};;
877 { .mfi;	getf.sig	r19=f73
878 		xma.hu	f87=f38,f124,f86
879 (p6)	add		carry1=1,carry1		}
880 { .mfi;		xma.lu	f86=f38,f124,f86
881 	cmp.ltu		p6,p0=r29,carry2	};;
882 { .mfi;	getf.sig	r20=f64
883 		xma.hu	f97=f38,f125,f96
884 (p6)	add		carry1=1,carry1		}
885 { .mfi;	st8		[r33]=r29,16
886 		xma.lu	f96=f38,f125,f96	};;
887 { .mfi;	getf.sig	r21=f55
888 		xma.hu	f107=f38,f126,f106	}
889 { .mfi;	mov		carry2=0
890 		xma.lu	f106=f38,f126,f106
891 	add		r17=r17,r16		};;
892 { .mfi;		xma.hu	f117=f38,f127,f116
893 	cmp.ltu		p7,p0=r17,r16		}
894 { .mfi;		xma.lu	f116=f38,f127,f116
895 	add		r18=r18,r17		};;//
896 //-------------------------------------------------//
897 { .mfi;	getf.sig	r22=f46
898 		xma.hu	f48=f39,f120,f47
899 (p7)	add		carry2=1,carry2		}
900 { .mfi;	cmp.ltu		p7,p0=r18,r17
901 		xma.lu	f47=f39,f120,f47
902 	add		r19=r19,r18		};;
903 { .mfi;	getf.sig	r24=f110
904 		xma.hu	f58=f39,f121,f57
905 (p7)	add		carry2=1,carry2		}
906 { .mfi;	cmp.ltu		p7,p0=r19,r18
907 		xma.lu	f57=f39,f121,f57
908 	add		r20=r20,r19		};;
909 { .mfi;	getf.sig	r25=f101
910 		xma.hu	f68=f39,f122,f67
911 (p7)	add		carry2=1,carry2		}
912 { .mfi;	cmp.ltu		p7,p0=r20,r19
913 		xma.lu	f67=f39,f122,f67
914 	add		r21=r21,r20		};;
915 { .mfi;	getf.sig	r26=f92
916 		xma.hu	f78=f39,f123,f77
917 (p7)	add		carry2=1,carry2		}
918 { .mfi;	cmp.ltu		p7,p0=r21,r20
919 		xma.lu	f77=f39,f123,f77
920 	add		r22=r22,r21		};;
921 { .mfi;	getf.sig	r27=f83
922 		xma.hu	f88=f39,f124,f87
923 (p7)	add		carry2=1,carry2		}
924 { .mfi;	cmp.ltu		p7,p0=r22,r21
925 		xma.lu	f87=f39,f124,f87
926 	add		r22=r22,carry1		};;
927 { .mfi;	getf.sig	r28=f74
928 		xma.hu	f98=f39,f125,f97
929 (p7)	add		carry2=1,carry2		}
930 { .mfi;		xma.lu	f97=f39,f125,f97
931 	cmp.ltu		p7,p0=r22,carry1	};;
932 { .mfi;	getf.sig	r29=f65
933 		xma.hu	f108=f39,f126,f107
934 (p7)	add		carry2=1,carry2		}
935 { .mfi;	st8		[r32]=r22,16
936 		xma.lu	f107=f39,f126,f107	};;
937 { .mfi;	getf.sig	r30=f56
938 		xma.hu	f118=f39,f127,f117	}
939 { .mfi;		xma.lu	f117=f39,f127,f117	};;//
940 //-------------------------------------------------//
941 // Leaving multiplier's heaven... Quite a ride, huh?
942 
943 { .mii;	getf.sig	r31=f47
944 	add		r25=r25,r24
945 	mov		carry1=0		};;
946 { .mii;		getf.sig	r16=f111
947 	cmp.ltu		p6,p0=r25,r24
948 	add		r26=r26,r25		};;
949 { .mfb;		getf.sig	r17=f102	}
950 { .mii;
951 (p6)	add		carry1=1,carry1
952 	cmp.ltu		p6,p0=r26,r25
953 	add		r27=r27,r26		};;
954 { .mfb;	nop.m	0x0				}
955 { .mii;
956 (p6)	add		carry1=1,carry1
957 	cmp.ltu		p6,p0=r27,r26
958 	add		r28=r28,r27		};;
959 { .mii;		getf.sig	r18=f93
960 		add		r17=r17,r16
961 		mov		carry3=0	}
962 { .mii;
963 (p6)	add		carry1=1,carry1
964 	cmp.ltu		p6,p0=r28,r27
965 	add		r29=r29,r28		};;
966 { .mii;		getf.sig	r19=f84
967 		cmp.ltu		p7,p0=r17,r16	}
968 { .mii;
969 (p6)	add		carry1=1,carry1
970 	cmp.ltu		p6,p0=r29,r28
971 	add		r30=r30,r29		};;
972 { .mii;		getf.sig	r20=f75
973 		add		r18=r18,r17	}
974 { .mii;
975 (p6)	add		carry1=1,carry1
976 	cmp.ltu		p6,p0=r30,r29
977 	add		r31=r31,r30		};;
978 { .mfb;		getf.sig	r21=f66		}
979 { .mii;	(p7)	add		carry3=1,carry3
980 		cmp.ltu		p7,p0=r18,r17
981 		add		r19=r19,r18	}
982 { .mfb;	nop.m	0x0				}
983 { .mii;
984 (p6)	add		carry1=1,carry1
985 	cmp.ltu		p6,p0=r31,r30
986 	add		r31=r31,carry2		};;
987 { .mfb;		getf.sig	r22=f57		}
988 { .mii;	(p7)	add		carry3=1,carry3
989 		cmp.ltu		p7,p0=r19,r18
990 		add		r20=r20,r19	}
991 { .mfb;	nop.m	0x0				}
992 { .mii;
993 (p6)	add		carry1=1,carry1
994 	cmp.ltu		p6,p0=r31,carry2	};;
995 { .mfb;		getf.sig	r23=f48		}
996 { .mii;	(p7)	add		carry3=1,carry3
997 		cmp.ltu		p7,p0=r20,r19
998 		add		r21=r21,r20	}
999 { .mii;
1000 (p6)	add		carry1=1,carry1		}
1001 { .mfb;	st8		[r33]=r31,16		};;
1002 
1003 { .mfb;	getf.sig	r24=f112		}
1004 { .mii;	(p7)	add		carry3=1,carry3
1005 		cmp.ltu		p7,p0=r21,r20
1006 		add		r22=r22,r21	};;
1007 { .mfb;	getf.sig	r25=f103		}
1008 { .mii;	(p7)	add		carry3=1,carry3
1009 		cmp.ltu		p7,p0=r22,r21
1010 		add		r23=r23,r22	};;
1011 { .mfb;	getf.sig	r26=f94			}
1012 { .mii;	(p7)	add		carry3=1,carry3
1013 		cmp.ltu		p7,p0=r23,r22
1014 		add		r23=r23,carry1	};;
1015 { .mfb;	getf.sig	r27=f85			}
1016 { .mii;	(p7)	add		carry3=1,carry3
1017 		cmp.ltu		p7,p8=r23,carry1};;
1018 { .mii;	getf.sig	r28=f76
1019 	add		r25=r25,r24
1020 	mov		carry1=0		}
1021 { .mii;		st8		[r32]=r23,16
1022 	(p7)	add		carry2=1,carry3
1023 	(p8)	add		carry2=0,carry3	};;
1024 
1025 { .mfb;	nop.m	0x0				}
1026 { .mii;	getf.sig	r29=f67
1027 	cmp.ltu		p6,p0=r25,r24
1028 	add		r26=r26,r25		};;
1029 { .mfb;	getf.sig	r30=f58			}
1030 { .mii;
1031 (p6)	add		carry1=1,carry1
1032 	cmp.ltu		p6,p0=r26,r25
1033 	add		r27=r27,r26		};;
1034 { .mfb;		getf.sig	r16=f113	}
1035 { .mii;
1036 (p6)	add		carry1=1,carry1
1037 	cmp.ltu		p6,p0=r27,r26
1038 	add		r28=r28,r27		};;
1039 { .mfb;		getf.sig	r17=f104	}
1040 { .mii;
1041 (p6)	add		carry1=1,carry1
1042 	cmp.ltu		p6,p0=r28,r27
1043 	add		r29=r29,r28		};;
1044 { .mfb;		getf.sig	r18=f95		}
1045 { .mii;
1046 (p6)	add		carry1=1,carry1
1047 	cmp.ltu		p6,p0=r29,r28
1048 	add		r30=r30,r29		};;
1049 { .mii;		getf.sig	r19=f86
1050 		add		r17=r17,r16
1051 		mov		carry3=0	}
1052 { .mii;
1053 (p6)	add		carry1=1,carry1
1054 	cmp.ltu		p6,p0=r30,r29
1055 	add		r30=r30,carry2		};;
1056 { .mii;		getf.sig	r20=f77
1057 		cmp.ltu		p7,p0=r17,r16
1058 		add		r18=r18,r17	}
1059 { .mii;
1060 (p6)	add		carry1=1,carry1
1061 	cmp.ltu		p6,p0=r30,carry2	};;
1062 { .mfb;		getf.sig	r21=f68		}
1063 { .mii;	st8		[r33]=r30,16
1064 (p6)	add		carry1=1,carry1		};;
1065 
1066 { .mfb;	getf.sig	r24=f114		}
1067 { .mii;	(p7)	add		carry3=1,carry3
1068 		cmp.ltu		p7,p0=r18,r17
1069 		add		r19=r19,r18	};;
1070 { .mfb;	getf.sig	r25=f105		}
1071 { .mii;	(p7)	add		carry3=1,carry3
1072 		cmp.ltu		p7,p0=r19,r18
1073 		add		r20=r20,r19	};;
1074 { .mfb;	getf.sig	r26=f96			}
1075 { .mii;	(p7)	add		carry3=1,carry3
1076 		cmp.ltu		p7,p0=r20,r19
1077 		add		r21=r21,r20	};;
1078 { .mfb;	getf.sig	r27=f87			}
1079 { .mii;	(p7)	add		carry3=1,carry3
1080 		cmp.ltu		p7,p0=r21,r20
1081 		add		r21=r21,carry1	};;
1082 { .mib;	getf.sig	r28=f78
1083 	add		r25=r25,r24		}
1084 { .mib;	(p7)	add		carry3=1,carry3
1085 		cmp.ltu		p7,p8=r21,carry1};;
1086 { .mii;		st8		[r32]=r21,16
1087 	(p7)	add		carry2=1,carry3
1088 	(p8)	add		carry2=0,carry3	}
1089 
1090 { .mii;	mov		carry1=0
1091 	cmp.ltu		p6,p0=r25,r24
1092 	add		r26=r26,r25		};;
1093 { .mfb;		getf.sig	r16=f115	}
1094 { .mii;
1095 (p6)	add		carry1=1,carry1
1096 	cmp.ltu		p6,p0=r26,r25
1097 	add		r27=r27,r26		};;
1098 { .mfb;		getf.sig	r17=f106	}
1099 { .mii;
1100 (p6)	add		carry1=1,carry1
1101 	cmp.ltu		p6,p0=r27,r26
1102 	add		r28=r28,r27		};;
1103 { .mfb;		getf.sig	r18=f97		}
1104 { .mii;
1105 (p6)	add		carry1=1,carry1
1106 	cmp.ltu		p6,p0=r28,r27
1107 	add		r28=r28,carry2		};;
1108 { .mib;		getf.sig	r19=f88
1109 		add		r17=r17,r16	}
1110 { .mib;
1111 (p6)	add		carry1=1,carry1
1112 	cmp.ltu		p6,p0=r28,carry2	};;
1113 { .mii;	st8		[r33]=r28,16
1114 (p6)	add		carry1=1,carry1		}
1115 
1116 { .mii;		mov		carry2=0
1117 		cmp.ltu		p7,p0=r17,r16
1118 		add		r18=r18,r17	};;
1119 { .mfb;	getf.sig	r24=f116		}
1120 { .mii;	(p7)	add		carry2=1,carry2
1121 		cmp.ltu		p7,p0=r18,r17
1122 		add		r19=r19,r18	};;
1123 { .mfb;	getf.sig	r25=f107		}
1124 { .mii;	(p7)	add		carry2=1,carry2
1125 		cmp.ltu		p7,p0=r19,r18
1126 		add		r19=r19,carry1	};;
1127 { .mfb;	getf.sig	r26=f98			}
1128 { .mii;	(p7)	add		carry2=1,carry2
1129 		cmp.ltu		p7,p0=r19,carry1};;
1130 { .mii;		st8		[r32]=r19,16
1131 	(p7)	add		carry2=1,carry2	}
1132 
1133 { .mfb;	add		r25=r25,r24		};;
1134 
1135 { .mfb;		getf.sig	r16=f117	}
1136 { .mii;	mov		carry1=0
1137 	cmp.ltu		p6,p0=r25,r24
1138 	add		r26=r26,r25		};;
1139 { .mfb;		getf.sig	r17=f108	}
1140 { .mii;
1141 (p6)	add		carry1=1,carry1
1142 	cmp.ltu		p6,p0=r26,r25
1143 	add		r26=r26,carry2		};;
1144 { .mfb;	nop.m	0x0				}
1145 { .mii;
1146 (p6)	add		carry1=1,carry1
1147 	cmp.ltu		p6,p0=r26,carry2	};;
1148 { .mii;	st8		[r33]=r26,16
1149 (p6)	add		carry1=1,carry1		}
1150 
1151 { .mfb;		add		r17=r17,r16	};;
1152 { .mfb;	getf.sig	r24=f118		}
1153 { .mii;		mov		carry2=0
1154 		cmp.ltu		p7,p0=r17,r16
1155 		add		r17=r17,carry1	};;
1156 { .mii;	(p7)	add		carry2=1,carry2
1157 		cmp.ltu		p7,p0=r17,carry1};;
1158 { .mii;		st8		[r32]=r17
1159 	(p7)	add		carry2=1,carry2	};;
1160 { .mfb;	add		r24=r24,carry2		};;
1161 { .mib;	st8		[r33]=r24		}
1162 
1163 { .mib;	rum		1<<5		// clear um.mfh
1164 	br.ret.sptk.many	b0	};;
1165 .endp	bn_mul_comba8#
1166 #undef	carry3
1167 #undef	carry2
1168 #undef	carry1
1169 #endif
1170 
1171 #if 1
1172 // It's possible to make it faster (see comment to bn_sqr_comba8), but
1173 // I reckon it doesn't worth the effort. Basically because the routine
1174 // (actually both of them) practically never called... So I just play
1175 // same trick as with bn_sqr_comba8.
1176 //
1177 // void bn_sqr_comba4(BN_ULONG *r, BN_ULONG *a)
1178 //
1179 .global	bn_sqr_comba4#
1180 .proc	bn_sqr_comba4#
1181 .align	64
1182 bn_sqr_comba4:
1183 	.prologue
1184 	.save	ar.pfs,r2
1185 #if defined(_HPUX_SOURCE) && !defined(_LP64)
1186 { .mii;	alloc   r2=ar.pfs,2,1,0,0
1187 	addp4	r32=0,r32
1188 	addp4	r33=0,r33		};;
1189 { .mii;
1190 #else
1191 { .mii;	alloc	r2=ar.pfs,2,1,0,0
1192 #endif
1193 	mov	r34=r33
1194 	add	r14=8,r33		};;
1195 	.body
1196 { .mii;	add	r17=8,r34
1197 	add	r15=16,r33
1198 	add	r18=16,r34		}
1199 { .mfb;	add	r16=24,r33
1200 	br	.L_cheat_entry_point4	};;
1201 .endp	bn_sqr_comba4#
1202 #endif
1203 
1204 #if 1
1205 // Runs in ~115 cycles and ~4.5 times faster than C. Well, whatever...
1206 //
1207 // void bn_mul_comba4(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b)
1208 //
1209 #define	carry1	r14
1210 #define	carry2	r15
1211 .global	bn_mul_comba4#
1212 .proc	bn_mul_comba4#
1213 .align	64
1214 bn_mul_comba4:
1215 	.prologue
1216 	.save	ar.pfs,r2
1217 #if defined(_HPUX_SOURCE) && !defined(_LP64)
1218 { .mii;	alloc   r2=ar.pfs,3,0,0,0
1219 	addp4	r33=0,r33
1220 	addp4	r34=0,r34		};;
1221 { .mii;	addp4	r32=0,r32
1222 #else
1223 { .mii;	alloc	r2=ar.pfs,3,0,0,0
1224 #endif
1225 	add	r14=8,r33
1226 	add	r17=8,r34		}
1227 	.body
1228 { .mii;	add	r15=16,r33
1229 	add	r18=16,r34
1230 	add	r16=24,r33		};;
1231 .L_cheat_entry_point4:
1232 { .mmi;	add	r19=24,r34
1233 
1234 	ldf8	f32=[r33]		}
1235 
1236 { .mmi;	ldf8	f120=[r34]
1237 	ldf8	f121=[r17]		};;
1238 { .mmi;	ldf8	f122=[r18]
1239 	ldf8	f123=[r19]		}
1240 
1241 { .mmi;	ldf8	f33=[r14]
1242 	ldf8	f34=[r15]		}
1243 { .mfi;	ldf8	f35=[r16]
1244 
1245 		xma.hu	f41=f32,f120,f0		}
1246 { .mfi;		xma.lu	f40=f32,f120,f0		};;
1247 { .mfi;		xma.hu	f51=f32,f121,f0		}
1248 { .mfi;		xma.lu	f50=f32,f121,f0		};;
1249 { .mfi;		xma.hu	f61=f32,f122,f0		}
1250 { .mfi;		xma.lu	f60=f32,f122,f0		};;
1251 { .mfi;		xma.hu	f71=f32,f123,f0		}
1252 { .mfi;		xma.lu	f70=f32,f123,f0		};;//
1253 // Major stall takes place here, and 3 more places below. Result from
1254 // first xma is not available for another 3 ticks.
1255 { .mfi;	getf.sig	r16=f40
1256 		xma.hu	f42=f33,f120,f41
1257 	add		r33=8,r32		}
1258 { .mfi;		xma.lu	f41=f33,f120,f41	};;
1259 { .mfi;	getf.sig	r24=f50
1260 		xma.hu	f52=f33,f121,f51	}
1261 { .mfi;		xma.lu	f51=f33,f121,f51	};;
1262 { .mfi;	st8		[r32]=r16,16
1263 		xma.hu	f62=f33,f122,f61	}
1264 { .mfi;		xma.lu	f61=f33,f122,f61	};;
1265 { .mfi;		xma.hu	f72=f33,f123,f71	}
1266 { .mfi;		xma.lu	f71=f33,f123,f71	};;//
1267 //-------------------------------------------------//
1268 { .mfi;	getf.sig	r25=f41
1269 		xma.hu	f43=f34,f120,f42	}
1270 { .mfi;		xma.lu	f42=f34,f120,f42	};;
1271 { .mfi;	getf.sig	r16=f60
1272 		xma.hu	f53=f34,f121,f52	}
1273 { .mfi;		xma.lu	f52=f34,f121,f52	};;
1274 { .mfi;	getf.sig	r17=f51
1275 		xma.hu	f63=f34,f122,f62
1276 	add		r25=r25,r24		}
1277 { .mfi;	mov		carry1=0
1278 		xma.lu	f62=f34,f122,f62	};;
1279 { .mfi;	st8		[r33]=r25,16
1280 		xma.hu	f73=f34,f123,f72
1281 	cmp.ltu		p6,p0=r25,r24		}
1282 { .mfi;		xma.lu	f72=f34,f123,f72	};;//
1283 //-------------------------------------------------//
1284 { .mfi;	getf.sig	r18=f42
1285 		xma.hu	f44=f35,f120,f43
1286 (p6)	add		carry1=1,carry1		}
1287 { .mfi;	add		r17=r17,r16
1288 		xma.lu	f43=f35,f120,f43
1289 	mov		carry2=0		};;
1290 { .mfi;	getf.sig	r24=f70
1291 		xma.hu	f54=f35,f121,f53
1292 	cmp.ltu		p7,p0=r17,r16		}
1293 { .mfi;		xma.lu	f53=f35,f121,f53	};;
1294 { .mfi;	getf.sig	r25=f61
1295 		xma.hu	f64=f35,f122,f63
1296 	add		r18=r18,r17		}
1297 { .mfi;		xma.lu	f63=f35,f122,f63
1298 (p7)	add		carry2=1,carry2		};;
1299 { .mfi;	getf.sig	r26=f52
1300 		xma.hu	f74=f35,f123,f73
1301 	cmp.ltu		p7,p0=r18,r17		}
1302 { .mfi;		xma.lu	f73=f35,f123,f73
1303 	add		r18=r18,carry1		};;
1304 //-------------------------------------------------//
1305 { .mii;	st8		[r32]=r18,16
1306 (p7)	add		carry2=1,carry2
1307 	cmp.ltu		p7,p0=r18,carry1	};;
1308 
1309 { .mfi;	getf.sig	r27=f43	// last major stall
1310 (p7)	add		carry2=1,carry2		};;
1311 { .mii;		getf.sig	r16=f71
1312 	add		r25=r25,r24
1313 	mov		carry1=0		};;
1314 { .mii;		getf.sig	r17=f62
1315 	cmp.ltu		p6,p0=r25,r24
1316 	add		r26=r26,r25		};;
1317 { .mii;
1318 (p6)	add		carry1=1,carry1
1319 	cmp.ltu		p6,p0=r26,r25
1320 	add		r27=r27,r26		};;
1321 { .mii;
1322 (p6)	add		carry1=1,carry1
1323 	cmp.ltu		p6,p0=r27,r26
1324 	add		r27=r27,carry2		};;
1325 { .mii;		getf.sig	r18=f53
1326 (p6)	add		carry1=1,carry1
1327 	cmp.ltu		p6,p0=r27,carry2	};;
1328 { .mfi;	st8		[r33]=r27,16
1329 (p6)	add		carry1=1,carry1		}
1330 
1331 { .mii;		getf.sig	r19=f44
1332 		add		r17=r17,r16
1333 		mov		carry2=0	};;
1334 { .mii;	getf.sig	r24=f72
1335 		cmp.ltu		p7,p0=r17,r16
1336 		add		r18=r18,r17	};;
1337 { .mii;	(p7)	add		carry2=1,carry2
1338 		cmp.ltu		p7,p0=r18,r17
1339 		add		r19=r19,r18	};;
1340 { .mii;	(p7)	add		carry2=1,carry2
1341 		cmp.ltu		p7,p0=r19,r18
1342 		add		r19=r19,carry1	};;
1343 { .mii;	getf.sig	r25=f63
1344 	(p7)	add		carry2=1,carry2
1345 		cmp.ltu		p7,p0=r19,carry1};;
1346 { .mii;		st8		[r32]=r19,16
1347 	(p7)	add		carry2=1,carry2	}
1348 
1349 { .mii;	getf.sig	r26=f54
1350 	add		r25=r25,r24
1351 	mov		carry1=0		};;
1352 { .mii;		getf.sig	r16=f73
1353 	cmp.ltu		p6,p0=r25,r24
1354 	add		r26=r26,r25		};;
1355 { .mii;
1356 (p6)	add		carry1=1,carry1
1357 	cmp.ltu		p6,p0=r26,r25
1358 	add		r26=r26,carry2		};;
1359 { .mii;		getf.sig	r17=f64
1360 (p6)	add		carry1=1,carry1
1361 	cmp.ltu		p6,p0=r26,carry2	};;
1362 { .mii;	st8		[r33]=r26,16
1363 (p6)	add		carry1=1,carry1		}
1364 
1365 { .mii;	getf.sig	r24=f74
1366 		add		r17=r17,r16
1367 		mov		carry2=0	};;
1368 { .mii;		cmp.ltu		p7,p0=r17,r16
1369 		add		r17=r17,carry1	};;
1370 
1371 { .mii;	(p7)	add		carry2=1,carry2
1372 		cmp.ltu		p7,p0=r17,carry1};;
1373 { .mii;		st8		[r32]=r17,16
1374 	(p7)	add		carry2=1,carry2	};;
1375 
1376 { .mii;	add		r24=r24,carry2		};;
1377 { .mii;	st8		[r33]=r24		}
1378 
1379 { .mib;	rum		1<<5		// clear um.mfh
1380 	br.ret.sptk.many	b0	};;
1381 .endp	bn_mul_comba4#
1382 #undef	carry2
1383 #undef	carry1
1384 #endif
1385 
1386 #if 1
1387 //
1388 // BN_ULONG bn_div_words(BN_ULONG h, BN_ULONG l, BN_ULONG d)
1389 //
1390 // In the nutshell it's a port of my MIPS III/IV implementation.
1391 //
1392 #define	AT	r14
1393 #define	H	r16
1394 #define	HH	r20
1395 #define	L	r17
1396 #define	D	r18
1397 #define	DH	r22
1398 #define	I	r21
1399 
1400 #if 0
1401 // Some preprocessors (most notably HP-UX) appear to be allergic to
1402 // macros enclosed to parenthesis [as these three were].
1403 #define	cont	p16
1404 #define	break	p0	// p20
1405 #define	equ	p24
1406 #else
1407 cont=p16
1408 break=p0
1409 equ=p24
1410 #endif
1411 
1412 .global	abort#
1413 .global	bn_div_words#
1414 .proc	bn_div_words#
1415 .align	64
1416 bn_div_words:
1417 	.prologue
1418 	.save	ar.pfs,r2
1419 { .mii;	alloc		r2=ar.pfs,3,5,0,8
1420 	.save	b0,r3
1421 	mov		r3=b0
1422 	.save	pr,r10
1423 	mov		r10=pr		};;
1424 { .mmb;	cmp.eq		p6,p0=r34,r0
1425 	mov		r8=-1
1426 (p6)	br.ret.spnt.many	b0	};;
1427 
1428 	.body
1429 { .mii;	mov		H=r32		// save h
1430 	mov		ar.ec=0		// don't rotate at exit
1431 	mov		pr.rot=0	}
1432 { .mii;	mov		L=r33		// save l
1433 	mov		r25=r0		// needed if abort is called on VMS
1434 	mov		r36=r0		};;
1435 
1436 .L_divw_shift:	// -vv- note signed comparison
1437 { .mfi;	(p0)	cmp.lt		p16,p0=r0,r34	// d
1438 	(p0)	shladd		r33=r34,1,r0	}
1439 { .mfb;	(p0)	add		r35=1,r36
1440 	(p0)	nop.f		0x0
1441 (p16)	br.wtop.dpnt		.L_divw_shift	};;
1442 
1443 { .mii;	mov		D=r34
1444 	shr.u		DH=r34,32
1445 	sub		r35=64,r36		};;
1446 { .mii;	setf.sig	f7=DH
1447 	shr.u		AT=H,r35
1448 	mov		I=r36			};;
1449 { .mib;	cmp.ne		p6,p0=r0,AT
1450 	shl		H=H,r36
1451 (p6)	br.call.spnt.clr	b0=abort	};;	// overflow, die...
1452 
1453 { .mfi;	fcvt.xuf.s1	f7=f7
1454 	shr.u		AT=L,r35		};;
1455 { .mii;	shl		L=L,r36
1456 	or		H=H,AT			};;
1457 
1458 { .mii;	nop.m		0x0
1459 	cmp.leu		p6,p0=D,H;;
1460 (p6)	sub		H=H,D			}
1461 
1462 { .mlx;	setf.sig	f14=D
1463 	movl		AT=0xffffffff		};;
1464 ///////////////////////////////////////////////////////////
1465 { .mii;	setf.sig	f6=H
1466 	shr.u		HH=H,32;;
1467 	cmp.eq		p6,p7=HH,DH		};;
1468 { .mfb;
1469 (p6)	setf.sig	f8=AT
1470 (p7)	fcvt.xuf.s1	f6=f6
1471 (p7)	br.call.sptk	b6=.L_udiv64_32_b6	};;
1472 
1473 { .mfi;	getf.sig	r33=f8				// q
1474 	xmpy.lu		f9=f8,f14		}
1475 { .mfi;	xmpy.hu		f10=f8,f14
1476 	shrp		H=H,L,32		};;
1477 
1478 { .mmi;	getf.sig	r35=f9				// tl
1479 	getf.sig	r31=f10			};;	// th
1480 
1481 .L_divw_1st_iter:
1482 { .mii;	(p0)	add		r32=-1,r33
1483 	(p0)	cmp.eq		equ,cont=HH,r31		};;
1484 { .mii;	(p0)	cmp.ltu		p8,p0=r35,D
1485 	(p0)	sub		r34=r35,D
1486 	(equ)	cmp.leu		break,cont=r35,H	};;
1487 { .mib;	(cont)	cmp.leu		cont,break=HH,r31
1488 	(p8)	add		r31=-1,r31
1489 (cont)	br.wtop.spnt		.L_divw_1st_iter	};;
1490 ///////////////////////////////////////////////////////////
1491 { .mii;	sub		H=H,r35
1492 	shl		r8=r33,32
1493 	shl		L=L,32			};;
1494 ///////////////////////////////////////////////////////////
1495 { .mii;	setf.sig	f6=H
1496 	shr.u		HH=H,32;;
1497 	cmp.eq		p6,p7=HH,DH		};;
1498 { .mfb;
1499 (p6)	setf.sig	f8=AT
1500 (p7)	fcvt.xuf.s1	f6=f6
1501 (p7)	br.call.sptk	b6=.L_udiv64_32_b6	};;
1502 
1503 { .mfi;	getf.sig	r33=f8				// q
1504 	xmpy.lu		f9=f8,f14		}
1505 { .mfi;	xmpy.hu		f10=f8,f14
1506 	shrp		H=H,L,32		};;
1507 
1508 { .mmi;	getf.sig	r35=f9				// tl
1509 	getf.sig	r31=f10			};;	// th
1510 
1511 .L_divw_2nd_iter:
1512 { .mii;	(p0)	add		r32=-1,r33
1513 	(p0)	cmp.eq		equ,cont=HH,r31		};;
1514 { .mii;	(p0)	cmp.ltu		p8,p0=r35,D
1515 	(p0)	sub		r34=r35,D
1516 	(equ)	cmp.leu		break,cont=r35,H	};;
1517 { .mib;	(cont)	cmp.leu		cont,break=HH,r31
1518 	(p8)	add		r31=-1,r31
1519 (cont)	br.wtop.spnt		.L_divw_2nd_iter	};;
1520 ///////////////////////////////////////////////////////////
1521 { .mii;	sub	H=H,r35
1522 	or	r8=r8,r33
1523 	mov	ar.pfs=r2		};;
1524 { .mii;	shr.u	r9=H,I			// remainder if anybody wants it
1525 	mov	pr=r10,0x1ffff		}
1526 { .mfb;	br.ret.sptk.many	b0	};;
1527 
1528 // Unsigned 64 by 32 (well, by 64 for the moment) bit integer division
1529 // procedure.
1530 //
1531 // inputs:	f6 = (double)a, f7 = (double)b
1532 // output:	f8 = (int)(a/b)
1533 // clobbered:	f8,f9,f10,f11,pred
1534 pred=p15
1535 // This snippet is based on text found in the "Divide, Square
1536 // Root and Remainder" section at
1537 // http://www.intel.com/software/products/opensource/libraries/num.htm.
1538 // Yes, I admit that the referred code was used as template,
1539 // but after I realized that there hardly is any other instruction
1540 // sequence which would perform this operation. I mean I figure that
1541 // any independent attempt to implement high-performance division
1542 // will result in code virtually identical to the Intel code. It
1543 // should be noted though that below division kernel is 1 cycle
1544 // faster than Intel one (note commented splits:-), not to mention
1545 // original prologue (rather lack of one) and epilogue.
1546 .align	32
1547 .skip	16
1548 .L_udiv64_32_b6:
1549 	frcpa.s1	f8,pred=f6,f7;;		// [0]  y0 = 1 / b
1550 
1551 (pred)	fnma.s1		f9=f7,f8,f1		// [5]  e0 = 1 - b * y0
1552 (pred)	fmpy.s1		f10=f6,f8;;		// [5]  q0 = a * y0
1553 (pred)	fmpy.s1		f11=f9,f9		// [10] e1 = e0 * e0
1554 (pred)	fma.s1		f10=f9,f10,f10;;	// [10] q1 = q0 + e0 * q0
1555 (pred)	fma.s1		f8=f9,f8,f8	//;;	// [15] y1 = y0 + e0 * y0
1556 (pred)	fma.s1		f9=f11,f10,f10;;	// [15] q2 = q1 + e1 * q1
1557 (pred)	fma.s1		f8=f11,f8,f8	//;;	// [20] y2 = y1 + e1 * y1
1558 (pred)	fnma.s1		f10=f7,f9,f6;;		// [20] r2 = a - b * q2
1559 (pred)	fma.s1		f8=f10,f8,f9;;		// [25] q3 = q2 + r2 * y2
1560 
1561 	fcvt.fxu.trunc.s1	f8=f8		// [30] q = trunc(q3)
1562 	br.ret.sptk.many	b6;;
1563 .endp	bn_div_words#
1564 #endif
1565