ia64.S revision 142425
1.explicit
2.text
3.ident	"ia64.S, Version 2.1"
4.ident	"IA-64 ISA artwork by Andy Polyakov <appro@fy.chalmers.se>"
5
6//
7// ====================================================================
8// Written by Andy Polyakov <appro@fy.chalmers.se> for the OpenSSL
9// project.
10//
11// Rights for redistribution and usage in source and binary forms are
12// granted according to the OpenSSL license. Warranty of any kind is
13// disclaimed.
14// ====================================================================
15//
16// Version 2.x is Itanium2 re-tune. Few words about how Itanum2 is
17// different from Itanium to this module viewpoint. Most notably, is it
18// "wider" than Itanium? Can you experience loop scalability as
19// discussed in commentary sections? Not really:-( Itanium2 has 6
20// integer ALU ports, i.e. it's 2 ports wider, but it's not enough to
21// spin twice as fast, as I need 8 IALU ports. Amount of floating point
22// ports is the same, i.e. 2, while I need 4. In other words, to this
23// module Itanium2 remains effectively as "wide" as Itanium. Yet it's
24// essentially different in respect to this module, and a re-tune was
25// required. Well, because some intruction latencies has changed. Most
26// noticeably those intensively used:
27//
28//			Itanium	Itanium2
29//	ldf8		9	6		L2 hit
30//	ld8		2	1		L1 hit
31//	getf		2	5
32//	xma[->getf]	7[+1]	4[+0]
33//	add[->st8]	1[+1]	1[+0]
34//
35// What does it mean? You might ratiocinate that the original code
36// should run just faster... Because sum of latencies is smaller...
37// Wrong! Note that getf latency increased. This means that if a loop is
38// scheduled for lower latency (as they were), then it will suffer from
39// stall condition and the code will therefore turn anti-scalable, e.g.
40// original bn_mul_words spun at 5*n or 2.5 times slower than expected
41// on Itanium2! What to do? Reschedule loops for Itanium2? But then
42// Itanium would exhibit anti-scalability. So I've chosen to reschedule
43// for worst latency for every instruction aiming for best *all-round*
44// performance.
45
46// Q.	How much faster does it get?
47// A.	Here is the output from 'openssl speed rsa dsa' for vanilla
48//	0.9.6a compiled with gcc version 2.96 20000731 (Red Hat
49//	Linux 7.1 2.96-81):
50//
51//	                  sign    verify    sign/s verify/s
52//	rsa  512 bits   0.0036s   0.0003s    275.3   2999.2
53//	rsa 1024 bits   0.0203s   0.0011s     49.3    894.1
54//	rsa 2048 bits   0.1331s   0.0040s      7.5    250.9
55//	rsa 4096 bits   0.9270s   0.0147s      1.1     68.1
56//	                  sign    verify    sign/s verify/s
57//	dsa  512 bits   0.0035s   0.0043s    288.3    234.8
58//	dsa 1024 bits   0.0111s   0.0135s     90.0     74.2
59//
60//	And here is similar output but for this assembler
61//	implementation:-)
62//
63//	                  sign    verify    sign/s verify/s
64//	rsa  512 bits   0.0021s   0.0001s    549.4   9638.5
65//	rsa 1024 bits   0.0055s   0.0002s    183.8   4481.1
66//	rsa 2048 bits   0.0244s   0.0006s     41.4   1726.3
67//	rsa 4096 bits   0.1295s   0.0018s      7.7    561.5
68//	                  sign    verify    sign/s verify/s
69//	dsa  512 bits   0.0012s   0.0013s    891.9    756.6
70//	dsa 1024 bits   0.0023s   0.0028s    440.4    376.2
71//
72//	Yes, you may argue that it's not fair comparison as it's
73//	possible to craft the C implementation with BN_UMULT_HIGH
74//	inline assembler macro. But of course! Here is the output
75//	with the macro:
76//
77//	                  sign    verify    sign/s verify/s
78//	rsa  512 bits   0.0020s   0.0002s    495.0   6561.0
79//	rsa 1024 bits   0.0086s   0.0004s    116.2   2235.7
80//	rsa 2048 bits   0.0519s   0.0015s     19.3    667.3
81//	rsa 4096 bits   0.3464s   0.0053s      2.9    187.7
82//	                  sign    verify    sign/s verify/s
83//	dsa  512 bits   0.0016s   0.0020s    613.1    510.5
84//	dsa 1024 bits   0.0045s   0.0054s    221.0    183.9
85//
86//	My code is still way faster, huh:-) And I believe that even
87//	higher performance can be achieved. Note that as keys get
88//	longer, performance gain is larger. Why? According to the
89//	profiler there is another player in the field, namely
90//	BN_from_montgomery consuming larger and larger portion of CPU
91//	time as keysize decreases. I therefore consider putting effort
92//	to assembler implementation of the following routine:
93//
94//	void bn_mul_add_mont (BN_ULONG *rp,BN_ULONG *np,int nl,BN_ULONG n0)
95//	{
96//	int      i,j;
97//	BN_ULONG v;
98//
99//	for (i=0; i<nl; i++)
100//		{
101//		v=bn_mul_add_words(rp,np,nl,(rp[0]*n0)&BN_MASK2);
102//		nrp++;
103//		rp++;
104//		if (((nrp[-1]+=v)&BN_MASK2) < v)
105//			for (j=0; ((++nrp[j])&BN_MASK2) == 0; j++) ;
106//		}
107//	}
108//
109//	It might as well be beneficial to implement even combaX
110//	variants, as it appears as it can literally unleash the
111//	performance (see comment section to bn_mul_comba8 below).
112//
113//	And finally for your reference the output for 0.9.6a compiled
114//	with SGIcc version 0.01.0-12 (keep in mind that for the moment
115//	of this writing it's not possible to convince SGIcc to use
116//	BN_UMULT_HIGH inline assembler macro, yet the code is fast,
117//	i.e. for a compiler generated one:-):
118//
119//	                  sign    verify    sign/s verify/s
120//	rsa  512 bits   0.0022s   0.0002s    452.7   5894.3
121//	rsa 1024 bits   0.0097s   0.0005s    102.7   2002.9
122//	rsa 2048 bits   0.0578s   0.0017s     17.3    600.2
123//	rsa 4096 bits   0.3838s   0.0061s      2.6    164.5
124//	                  sign    verify    sign/s verify/s
125//	dsa  512 bits   0.0018s   0.0022s    547.3    459.6
126//	dsa 1024 bits   0.0051s   0.0062s    196.6    161.3
127//
128//	Oh! Benchmarks were performed on 733MHz Lion-class Itanium
129//	system running Redhat Linux 7.1 (very special thanks to Ray
130//	McCaffity of Williams Communications for providing an account).
131//
132// Q.	What's the heck with 'rum 1<<5' at the end of every function?
133// A.	Well, by clearing the "upper FP registers written" bit of the
134//	User Mask I want to excuse the kernel from preserving upper
135//	(f32-f128) FP register bank over process context switch, thus
136//	minimizing bus bandwidth consumption during the switch (i.e.
137//	after PKI opration completes and the program is off doing
138//	something else like bulk symmetric encryption). Having said
139//	this, I also want to point out that it might be good idea
140//	to compile the whole toolkit (as well as majority of the
141//	programs for that matter) with -mfixed-range=f32-f127 command
142//	line option. No, it doesn't prevent the compiler from writing
143//	to upper bank, but at least discourages to do so. If you don't
144//	like the idea you have the option to compile the module with
145//	-Drum=nop.m in command line.
146//
147
148#if defined(_HPUX_SOURCE) && !defined(_LP64)
149#define	ADDP	addp4
150#else
151#define	ADDP	add
152#endif
153
154#if 1
155//
156// bn_[add|sub]_words routines.
157//
158// Loops are spinning in 2*(n+5) ticks on Itanuim (provided that the
159// data reside in L1 cache, i.e. 2 ticks away). It's possible to
160// compress the epilogue and get down to 2*n+6, but at the cost of
161// scalability (the neat feature of this implementation is that it
162// shall automagically spin in n+5 on "wider" IA-64 implementations:-)
163// I consider that the epilogue is short enough as it is to trade tiny
164// performance loss on Itanium for scalability.
165//
166// BN_ULONG bn_add_words(BN_ULONG *rp, BN_ULONG *ap, BN_ULONG *bp,int num)
167//
168.global	bn_add_words#
169.proc	bn_add_words#
170.align	64
171.skip	32	// makes the loop body aligned at 64-byte boundary
172bn_add_words:
173	.prologue
174	.fframe	0
175	.save	ar.pfs,r2
176{ .mii;	alloc		r2=ar.pfs,4,12,0,16
177	cmp4.le		p6,p0=r35,r0	};;
178{ .mfb;	mov		r8=r0			// return value
179(p6)	br.ret.spnt.many	b0	};;
180
181	.save	ar.lc,r3
182{ .mib;	sub		r10=r35,r0,1
183	mov		r3=ar.lc
184	brp.loop.imp	.L_bn_add_words_ctop,.L_bn_add_words_cend-16
185					}
186	.body
187{ .mib;	ADDP		r14=0,r32		// rp
188	mov		r9=pr		};;
189{ .mii;	ADDP		r15=0,r33		// ap
190	mov		ar.lc=r10
191	mov		ar.ec=6		}
192{ .mib;	ADDP		r16=0,r34		// bp
193	mov		pr.rot=1<<16	};;
194
195.L_bn_add_words_ctop:
196{ .mii;	(p16)	ld8		r32=[r16],8	  // b=*(bp++)
197	(p18)	add		r39=r37,r34
198	(p19)	cmp.ltu.unc	p56,p0=r40,r38	}
199{ .mfb;	(p0)	nop.m		0x0
200	(p0)	nop.f		0x0
201	(p0)	nop.b		0x0		}
202{ .mii;	(p16)	ld8		r35=[r15],8	  // a=*(ap++)
203	(p58)	cmp.eq.or	p57,p0=-1,r41	  // (p20)
204	(p58)	add		r41=1,r41	} // (p20)
205{ .mfb;	(p21)	st8		[r14]=r42,8	  // *(rp++)=r
206	(p0)	nop.f		0x0
207	br.ctop.sptk	.L_bn_add_words_ctop	};;
208.L_bn_add_words_cend:
209
210{ .mii;
211(p59)	add		r8=1,r8		// return value
212	mov		pr=r9,0x1ffff
213	mov		ar.lc=r3	}
214{ .mbb;	nop.b		0x0
215	br.ret.sptk.many	b0	};;
216.endp	bn_add_words#
217
218//
219// BN_ULONG bn_sub_words(BN_ULONG *rp, BN_ULONG *ap, BN_ULONG *bp,int num)
220//
221.global	bn_sub_words#
222.proc	bn_sub_words#
223.align	64
224.skip	32	// makes the loop body aligned at 64-byte boundary
225bn_sub_words:
226	.prologue
227	.fframe	0
228	.save	ar.pfs,r2
229{ .mii;	alloc		r2=ar.pfs,4,12,0,16
230	cmp4.le		p6,p0=r35,r0	};;
231{ .mfb;	mov		r8=r0			// return value
232(p6)	br.ret.spnt.many	b0	};;
233
234	.save	ar.lc,r3
235{ .mib;	sub		r10=r35,r0,1
236	mov		r3=ar.lc
237	brp.loop.imp	.L_bn_sub_words_ctop,.L_bn_sub_words_cend-16
238					}
239	.body
240{ .mib;	ADDP		r14=0,r32		// rp
241	mov		r9=pr		};;
242{ .mii;	ADDP		r15=0,r33		// ap
243	mov		ar.lc=r10
244	mov		ar.ec=6		}
245{ .mib;	ADDP		r16=0,r34		// bp
246	mov		pr.rot=1<<16	};;
247
248.L_bn_sub_words_ctop:
249{ .mii;	(p16)	ld8		r32=[r16],8	  // b=*(bp++)
250	(p18)	sub		r39=r37,r34
251	(p19)	cmp.gtu.unc	p56,p0=r40,r38	}
252{ .mfb;	(p0)	nop.m		0x0
253	(p0)	nop.f		0x0
254	(p0)	nop.b		0x0		}
255{ .mii;	(p16)	ld8		r35=[r15],8	  // a=*(ap++)
256	(p58)	cmp.eq.or	p57,p0=0,r41	  // (p20)
257	(p58)	add		r41=-1,r41	} // (p20)
258{ .mbb;	(p21)	st8		[r14]=r42,8	  // *(rp++)=r
259	(p0)	nop.b		0x0
260	br.ctop.sptk	.L_bn_sub_words_ctop	};;
261.L_bn_sub_words_cend:
262
263{ .mii;
264(p59)	add		r8=1,r8		// return value
265	mov		pr=r9,0x1ffff
266	mov		ar.lc=r3	}
267{ .mbb;	nop.b		0x0
268	br.ret.sptk.many	b0	};;
269.endp	bn_sub_words#
270#endif
271
272#if 0
273#define XMA_TEMPTATION
274#endif
275
276#if 1
277//
278// BN_ULONG bn_mul_words(BN_ULONG *rp, BN_ULONG *ap, int num, BN_ULONG w)
279//
280.global	bn_mul_words#
281.proc	bn_mul_words#
282.align	64
283.skip	32	// makes the loop body aligned at 64-byte boundary
284bn_mul_words:
285	.prologue
286	.fframe	0
287	.save	ar.pfs,r2
288#ifdef XMA_TEMPTATION
289{ .mfi;	alloc		r2=ar.pfs,4,0,0,0	};;
290#else
291{ .mfi;	alloc		r2=ar.pfs,4,12,0,16	};;
292#endif
293{ .mib;	mov		r8=r0			// return value
294	cmp4.le		p6,p0=r34,r0
295(p6)	br.ret.spnt.many	b0		};;
296
297	.save	ar.lc,r3
298{ .mii;	sub	r10=r34,r0,1
299	mov	r3=ar.lc
300	mov	r9=pr			};;
301
302	.body
303{ .mib;	setf.sig	f8=r35	// w
304	mov		pr.rot=0x800001<<16
305			// ------^----- serves as (p50) at first (p27)
306	brp.loop.imp	.L_bn_mul_words_ctop,.L_bn_mul_words_cend-16
307					}
308
309#ifndef XMA_TEMPTATION
310
311{ .mmi;	ADDP		r14=0,r32	// rp
312	ADDP		r15=0,r33	// ap
313	mov		ar.lc=r10	}
314{ .mmi;	mov		r40=0		// serves as r35 at first (p27)
315	mov		ar.ec=13	};;
316
317// This loop spins in 2*(n+12) ticks. It's scheduled for data in Itanium
318// L2 cache (i.e. 9 ticks away) as floating point load/store instructions
319// bypass L1 cache and L2 latency is actually best-case scenario for
320// ldf8. The loop is not scalable and shall run in 2*(n+12) even on
321// "wider" IA-64 implementations. It's a trade-off here. n+24 loop
322// would give us ~5% in *overall* performance improvement on "wider"
323// IA-64, but would hurt Itanium for about same because of longer
324// epilogue. As it's a matter of few percents in either case I've
325// chosen to trade the scalability for development time (you can see
326// this very instruction sequence in bn_mul_add_words loop which in
327// turn is scalable).
328.L_bn_mul_words_ctop:
329{ .mfi;	(p25)	getf.sig	r36=f52			// low
330	(p21)	xmpy.lu		f48=f37,f8
331	(p28)	cmp.ltu		p54,p50=r41,r39	}
332{ .mfi;	(p16)	ldf8		f32=[r15],8
333	(p21)	xmpy.hu		f40=f37,f8
334	(p0)	nop.i		0x0		};;
335{ .mii;	(p25)	getf.sig	r32=f44			// high
336	.pred.rel	"mutex",p50,p54
337	(p50)	add		r40=r38,r35		// (p27)
338	(p54)	add		r40=r38,r35,1	}	// (p27)
339{ .mfb;	(p28)	st8		[r14]=r41,8
340	(p0)	nop.f		0x0
341	br.ctop.sptk	.L_bn_mul_words_ctop	};;
342.L_bn_mul_words_cend:
343
344{ .mii;	nop.m		0x0
345.pred.rel	"mutex",p51,p55
346(p51)	add		r8=r36,r0
347(p55)	add		r8=r36,r0,1	}
348{ .mfb;	nop.m	0x0
349	nop.f	0x0
350	nop.b	0x0			}
351
352#else	// XMA_TEMPTATION
353
354	setf.sig	f37=r0	// serves as carry at (p18) tick
355	mov		ar.lc=r10
356	mov		ar.ec=5;;
357
358// Most of you examining this code very likely wonder why in the name
359// of Intel the following loop is commented out? Indeed, it looks so
360// neat that you find it hard to believe that it's something wrong
361// with it, right? The catch is that every iteration depends on the
362// result from previous one and the latter isn't available instantly.
363// The loop therefore spins at the latency of xma minus 1, or in other
364// words at 6*(n+4) ticks:-( Compare to the "production" loop above
365// that runs in 2*(n+11) where the low latency problem is worked around
366// by moving the dependency to one-tick latent interger ALU. Note that
367// "distance" between ldf8 and xma is not latency of ldf8, but the
368// *difference* between xma and ldf8 latencies.
369.L_bn_mul_words_ctop:
370{ .mfi;	(p16)	ldf8		f32=[r33],8
371	(p18)	xma.hu		f38=f34,f8,f39	}
372{ .mfb;	(p20)	stf8		[r32]=f37,8
373	(p18)	xma.lu		f35=f34,f8,f39
374	br.ctop.sptk	.L_bn_mul_words_ctop	};;
375.L_bn_mul_words_cend:
376
377	getf.sig	r8=f41		// the return value
378
379#endif	// XMA_TEMPTATION
380
381{ .mii;	nop.m		0x0
382	mov		pr=r9,0x1ffff
383	mov		ar.lc=r3	}
384{ .mfb;	rum		1<<5		// clear um.mfh
385	nop.f		0x0
386	br.ret.sptk.many	b0	};;
387.endp	bn_mul_words#
388#endif
389
390#if 1
391//
392// BN_ULONG bn_mul_add_words(BN_ULONG *rp, BN_ULONG *ap, int num, BN_ULONG w)
393//
394.global	bn_mul_add_words#
395.proc	bn_mul_add_words#
396.align	64
397.skip	48	// makes the loop body aligned at 64-byte boundary
398bn_mul_add_words:
399	.prologue
400	.fframe	0
401	.save	ar.pfs,r2
402	.save	ar.lc,r3
403	.save	pr,r9
404{ .mmi;	alloc		r2=ar.pfs,4,4,0,8
405	cmp4.le		p6,p0=r34,r0
406	mov		r3=ar.lc	};;
407{ .mib;	mov		r8=r0		// return value
408	sub		r10=r34,r0,1
409(p6)	br.ret.spnt.many	b0	};;
410
411	.body
412{ .mib;	setf.sig	f8=r35		// w
413	mov		r9=pr
414	brp.loop.imp	.L_bn_mul_add_words_ctop,.L_bn_mul_add_words_cend-16
415					}
416{ .mmi;	ADDP		r14=0,r32	// rp
417	ADDP		r15=0,r33	// ap
418	mov		ar.lc=r10	}
419{ .mii;	ADDP		r16=0,r32	// rp copy
420	mov		pr.rot=0x2001<<16
421			// ------^----- serves as (p40) at first (p27)
422	mov		ar.ec=11	};;
423
424// This loop spins in 3*(n+10) ticks on Itanium and in 2*(n+10) on
425// Itanium 2. Yes, unlike previous versions it scales:-) Previous
426// version was peforming *all* additions in IALU and was starving
427// for those even on Itanium 2. In this version one addition is
428// moved to FPU and is folded with multiplication. This is at cost
429// of propogating the result from previous call to this subroutine
430// to L2 cache... In other words negligible even for shorter keys.
431// *Overall* performance improvement [over previous version] varies
432// from 11 to 22 percent depending on key length.
433.L_bn_mul_add_words_ctop:
434.pred.rel	"mutex",p40,p42
435{ .mfi;	(p23)	getf.sig	r36=f45			// low
436	(p20)	xma.lu		f42=f36,f8,f50		// low
437	(p40)	add		r39=r39,r35	}	// (p27)
438{ .mfi;	(p16)	ldf8		f32=[r15],8		// *(ap++)
439	(p20)	xma.hu		f36=f36,f8,f50		// high
440	(p42)	add		r39=r39,r35,1	};;	// (p27)
441{ .mmi;	(p24)	getf.sig	r32=f40			// high
442	(p16)	ldf8		f46=[r16],8		// *(rp1++)
443	(p40)	cmp.ltu		p41,p39=r39,r35	}	// (p27)
444{ .mib;	(p26)	st8		[r14]=r39,8		// *(rp2++)
445	(p42)	cmp.leu		p41,p39=r39,r35		// (p27)
446	br.ctop.sptk	.L_bn_mul_add_words_ctop};;
447.L_bn_mul_add_words_cend:
448
449{ .mmi;	.pred.rel	"mutex",p40,p42
450(p40)	add		r8=r35,r0
451(p42)	add		r8=r35,r0,1
452	mov		pr=r9,0x1ffff	}
453{ .mib;	rum		1<<5		// clear um.mfh
454	mov		ar.lc=r3
455	br.ret.sptk.many	b0	};;
456.endp	bn_mul_add_words#
457#endif
458
459#if 1
460//
461// void bn_sqr_words(BN_ULONG *rp, BN_ULONG *ap, int num)
462//
463.global	bn_sqr_words#
464.proc	bn_sqr_words#
465.align	64
466.skip	32	// makes the loop body aligned at 64-byte boundary
467bn_sqr_words:
468	.prologue
469	.fframe	0
470	.save	ar.pfs,r2
471{ .mii;	alloc		r2=ar.pfs,3,0,0,0
472	sxt4		r34=r34		};;
473{ .mii;	cmp.le		p6,p0=r34,r0
474	mov		r8=r0		}	// return value
475{ .mfb;	ADDP		r32=0,r32
476	nop.f		0x0
477(p6)	br.ret.spnt.many	b0	};;
478
479	.save	ar.lc,r3
480{ .mii;	sub	r10=r34,r0,1
481	mov	r3=ar.lc
482	mov	r9=pr			};;
483
484	.body
485{ .mib;	ADDP		r33=0,r33
486	mov		pr.rot=1<<16
487	brp.loop.imp	.L_bn_sqr_words_ctop,.L_bn_sqr_words_cend-16
488					}
489{ .mii;	add		r34=8,r32
490	mov		ar.lc=r10
491	mov		ar.ec=18	};;
492
493// 2*(n+17) on Itanium, (n+17) on "wider" IA-64 implementations. It's
494// possible to compress the epilogue (I'm getting tired to write this
495// comment over and over) and get down to 2*n+16 at the cost of
496// scalability. The decision will very likely be reconsidered after the
497// benchmark program is profiled. I.e. if perfomance gain on Itanium
498// will appear larger than loss on "wider" IA-64, then the loop should
499// be explicitely split and the epilogue compressed.
500.L_bn_sqr_words_ctop:
501{ .mfi;	(p16)	ldf8		f32=[r33],8
502	(p25)	xmpy.lu		f42=f41,f41
503	(p0)	nop.i		0x0		}
504{ .mib;	(p33)	stf8		[r32]=f50,16
505	(p0)	nop.i		0x0
506	(p0)	nop.b		0x0		}
507{ .mfi;	(p0)	nop.m		0x0
508	(p25)	xmpy.hu		f52=f41,f41
509	(p0)	nop.i		0x0		}
510{ .mib;	(p33)	stf8		[r34]=f60,16
511	(p0)	nop.i		0x0
512	br.ctop.sptk	.L_bn_sqr_words_ctop	};;
513.L_bn_sqr_words_cend:
514
515{ .mii;	nop.m		0x0
516	mov		pr=r9,0x1ffff
517	mov		ar.lc=r3	}
518{ .mfb;	rum		1<<5		// clear um.mfh
519	nop.f		0x0
520	br.ret.sptk.many	b0	};;
521.endp	bn_sqr_words#
522#endif
523
524#if 1
525// Apparently we win nothing by implementing special bn_sqr_comba8.
526// Yes, it is possible to reduce the number of multiplications by
527// almost factor of two, but then the amount of additions would
528// increase by factor of two (as we would have to perform those
529// otherwise performed by xma ourselves). Normally we would trade
530// anyway as multiplications are way more expensive, but not this
531// time... Multiplication kernel is fully pipelined and as we drain
532// one 128-bit multiplication result per clock cycle multiplications
533// are effectively as inexpensive as additions. Special implementation
534// might become of interest for "wider" IA-64 implementation as you'll
535// be able to get through the multiplication phase faster (there won't
536// be any stall issues as discussed in the commentary section below and
537// you therefore will be able to employ all 4 FP units)... But these
538// Itanium days it's simply too hard to justify the effort so I just
539// drop down to bn_mul_comba8 code:-)
540//
541// void bn_sqr_comba8(BN_ULONG *r, BN_ULONG *a)
542//
543.global	bn_sqr_comba8#
544.proc	bn_sqr_comba8#
545.align	64
546bn_sqr_comba8:
547	.prologue
548	.fframe	0
549	.save	ar.pfs,r2
550#if defined(_HPUX_SOURCE) && !defined(_LP64)
551{ .mii;	alloc	r2=ar.pfs,2,1,0,0
552	addp4	r33=0,r33
553	addp4	r32=0,r32		};;
554{ .mii;
555#else
556{ .mii;	alloc	r2=ar.pfs,2,1,0,0
557#endif
558	mov	r34=r33
559	add	r14=8,r33		};;
560	.body
561{ .mii;	add	r17=8,r34
562	add	r15=16,r33
563	add	r18=16,r34		}
564{ .mfb;	add	r16=24,r33
565	br	.L_cheat_entry_point8	};;
566.endp	bn_sqr_comba8#
567#endif
568
569#if 1
570// I've estimated this routine to run in ~120 ticks, but in reality
571// (i.e. according to ar.itc) it takes ~160 ticks. Are those extra
572// cycles consumed for instructions fetch? Or did I misinterpret some
573// clause in Itanium �-architecture manual? Comments are welcomed and
574// highly appreciated.
575//
576// On Itanium 2 it takes ~190 ticks. This is because of stalls on
577// result from getf.sig. I do nothing about it at this point for
578// reasons depicted below.
579//
580// However! It should be noted that even 160 ticks is darn good result
581// as it's over 10 (yes, ten, spelled as t-e-n) times faster than the
582// C version (compiled with gcc with inline assembler). I really
583// kicked compiler's butt here, didn't I? Yeah! This brings us to the
584// following statement. It's damn shame that this routine isn't called
585// very often nowadays! According to the profiler most CPU time is
586// consumed by bn_mul_add_words called from BN_from_montgomery. In
587// order to estimate what we're missing, I've compared the performance
588// of this routine against "traditional" implementation, i.e. against
589// following routine:
590//
591// void bn_mul_comba8(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b)
592// {	r[ 8]=bn_mul_words(    &(r[0]),a,8,b[0]);
593//	r[ 9]=bn_mul_add_words(&(r[1]),a,8,b[1]);
594//	r[10]=bn_mul_add_words(&(r[2]),a,8,b[2]);
595//	r[11]=bn_mul_add_words(&(r[3]),a,8,b[3]);
596//	r[12]=bn_mul_add_words(&(r[4]),a,8,b[4]);
597//	r[13]=bn_mul_add_words(&(r[5]),a,8,b[5]);
598//	r[14]=bn_mul_add_words(&(r[6]),a,8,b[6]);
599//	r[15]=bn_mul_add_words(&(r[7]),a,8,b[7]);
600// }
601//
602// The one below is over 8 times faster than the one above:-( Even
603// more reasons to "combafy" bn_mul_add_mont...
604//
605// And yes, this routine really made me wish there were an optimizing
606// assembler! It also feels like it deserves a dedication.
607//
608//	To my wife for being there and to my kids...
609//
610// void bn_mul_comba8(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b)
611//
612#define	carry1	r14
613#define	carry2	r15
614#define	carry3	r34
615.global	bn_mul_comba8#
616.proc	bn_mul_comba8#
617.align	64
618bn_mul_comba8:
619	.prologue
620	.fframe	0
621	.save	ar.pfs,r2
622#if defined(_HPUX_SOURCE) && !defined(_LP64)
623{ .mii;	alloc	r2=ar.pfs,3,0,0,0
624	addp4	r33=0,r33
625	addp4	r34=0,r34		};;
626{ .mii;	addp4	r32=0,r32
627#else
628{ .mii;	alloc   r2=ar.pfs,3,0,0,0
629#endif
630	add	r14=8,r33
631	add	r17=8,r34		}
632	.body
633{ .mii;	add	r15=16,r33
634	add	r18=16,r34
635	add	r16=24,r33		}
636.L_cheat_entry_point8:
637{ .mmi;	add	r19=24,r34
638
639	ldf8	f32=[r33],32		};;
640
641{ .mmi;	ldf8	f120=[r34],32
642	ldf8	f121=[r17],32		}
643{ .mmi;	ldf8	f122=[r18],32
644	ldf8	f123=[r19],32		};;
645{ .mmi;	ldf8	f124=[r34]
646	ldf8	f125=[r17]		}
647{ .mmi;	ldf8	f126=[r18]
648	ldf8	f127=[r19]		}
649
650{ .mmi;	ldf8	f33=[r14],32
651	ldf8	f34=[r15],32		}
652{ .mmi;	ldf8	f35=[r16],32;;
653	ldf8	f36=[r33]		}
654{ .mmi;	ldf8	f37=[r14]
655	ldf8	f38=[r15]		}
656{ .mfi;	ldf8	f39=[r16]
657// -------\ Entering multiplier's heaven /-------
658// ------------\                    /------------
659// -----------------\          /-----------------
660// ----------------------\/----------------------
661		xma.hu	f41=f32,f120,f0		}
662{ .mfi;		xma.lu	f40=f32,f120,f0		};; // (*)
663{ .mfi;		xma.hu	f51=f32,f121,f0		}
664{ .mfi;		xma.lu	f50=f32,f121,f0		};;
665{ .mfi;		xma.hu	f61=f32,f122,f0		}
666{ .mfi;		xma.lu	f60=f32,f122,f0		};;
667{ .mfi;		xma.hu	f71=f32,f123,f0		}
668{ .mfi;		xma.lu	f70=f32,f123,f0		};;
669{ .mfi;		xma.hu	f81=f32,f124,f0		}
670{ .mfi;		xma.lu	f80=f32,f124,f0		};;
671{ .mfi;		xma.hu	f91=f32,f125,f0		}
672{ .mfi;		xma.lu	f90=f32,f125,f0		};;
673{ .mfi;		xma.hu	f101=f32,f126,f0	}
674{ .mfi;		xma.lu	f100=f32,f126,f0	};;
675{ .mfi;		xma.hu	f111=f32,f127,f0	}
676{ .mfi;		xma.lu	f110=f32,f127,f0	};;//
677// (*)	You can argue that splitting at every second bundle would
678//	prevent "wider" IA-64 implementations from achieving the peak
679//	performance. Well, not really... The catch is that if you
680//	intend to keep 4 FP units busy by splitting at every fourth
681//	bundle and thus perform these 16 multiplications in 4 ticks,
682//	the first bundle *below* would stall because the result from
683//	the first xma bundle *above* won't be available for another 3
684//	ticks (if not more, being an optimist, I assume that "wider"
685//	implementation will have same latency:-). This stall will hold
686//	you back and the performance would be as if every second bundle
687//	were split *anyway*...
688{ .mfi;	getf.sig	r16=f40
689		xma.hu	f42=f33,f120,f41
690	add		r33=8,r32		}
691{ .mfi;		xma.lu	f41=f33,f120,f41	};;
692{ .mfi;	getf.sig	r24=f50
693		xma.hu	f52=f33,f121,f51	}
694{ .mfi;		xma.lu	f51=f33,f121,f51	};;
695{ .mfi;	st8		[r32]=r16,16
696		xma.hu	f62=f33,f122,f61	}
697{ .mfi;		xma.lu	f61=f33,f122,f61	};;
698{ .mfi;		xma.hu	f72=f33,f123,f71	}
699{ .mfi;		xma.lu	f71=f33,f123,f71	};;
700{ .mfi;		xma.hu	f82=f33,f124,f81	}
701{ .mfi;		xma.lu	f81=f33,f124,f81	};;
702{ .mfi;		xma.hu	f92=f33,f125,f91	}
703{ .mfi;		xma.lu	f91=f33,f125,f91	};;
704{ .mfi;		xma.hu	f102=f33,f126,f101	}
705{ .mfi;		xma.lu	f101=f33,f126,f101	};;
706{ .mfi;		xma.hu	f112=f33,f127,f111	}
707{ .mfi;		xma.lu	f111=f33,f127,f111	};;//
708//-------------------------------------------------//
709{ .mfi;	getf.sig	r25=f41
710		xma.hu	f43=f34,f120,f42	}
711{ .mfi;		xma.lu	f42=f34,f120,f42	};;
712{ .mfi;	getf.sig	r16=f60
713		xma.hu	f53=f34,f121,f52	}
714{ .mfi;		xma.lu	f52=f34,f121,f52	};;
715{ .mfi;	getf.sig	r17=f51
716		xma.hu	f63=f34,f122,f62
717	add		r25=r25,r24		}
718{ .mfi;		xma.lu	f62=f34,f122,f62
719	mov		carry1=0		};;
720{ .mfi;	cmp.ltu		p6,p0=r25,r24
721		xma.hu	f73=f34,f123,f72	}
722{ .mfi;		xma.lu	f72=f34,f123,f72	};;
723{ .mfi;	st8		[r33]=r25,16
724		xma.hu	f83=f34,f124,f82
725(p6)	add		carry1=1,carry1		}
726{ .mfi;		xma.lu	f82=f34,f124,f82	};;
727{ .mfi;		xma.hu	f93=f34,f125,f92	}
728{ .mfi;		xma.lu	f92=f34,f125,f92	};;
729{ .mfi;		xma.hu	f103=f34,f126,f102	}
730{ .mfi;		xma.lu	f102=f34,f126,f102	};;
731{ .mfi;		xma.hu	f113=f34,f127,f112	}
732{ .mfi;		xma.lu	f112=f34,f127,f112	};;//
733//-------------------------------------------------//
734{ .mfi;	getf.sig	r18=f42
735		xma.hu	f44=f35,f120,f43
736	add		r17=r17,r16		}
737{ .mfi;		xma.lu	f43=f35,f120,f43	};;
738{ .mfi;	getf.sig	r24=f70
739		xma.hu	f54=f35,f121,f53	}
740{ .mfi;	mov		carry2=0
741		xma.lu	f53=f35,f121,f53	};;
742{ .mfi;	getf.sig	r25=f61
743		xma.hu	f64=f35,f122,f63
744	cmp.ltu		p7,p0=r17,r16		}
745{ .mfi;	add		r18=r18,r17
746		xma.lu	f63=f35,f122,f63	};;
747{ .mfi;	getf.sig	r26=f52
748		xma.hu	f74=f35,f123,f73
749(p7)	add		carry2=1,carry2		}
750{ .mfi;	cmp.ltu		p7,p0=r18,r17
751		xma.lu	f73=f35,f123,f73
752	add		r18=r18,carry1		};;
753{ .mfi;
754		xma.hu	f84=f35,f124,f83
755(p7)	add		carry2=1,carry2		}
756{ .mfi;	cmp.ltu		p7,p0=r18,carry1
757		xma.lu	f83=f35,f124,f83	};;
758{ .mfi;	st8		[r32]=r18,16
759		xma.hu	f94=f35,f125,f93
760(p7)	add		carry2=1,carry2		}
761{ .mfi;		xma.lu	f93=f35,f125,f93	};;
762{ .mfi;		xma.hu	f104=f35,f126,f103	}
763{ .mfi;		xma.lu	f103=f35,f126,f103	};;
764{ .mfi;		xma.hu	f114=f35,f127,f113	}
765{ .mfi;	mov		carry1=0
766		xma.lu	f113=f35,f127,f113
767	add		r25=r25,r24		};;//
768//-------------------------------------------------//
769{ .mfi;	getf.sig	r27=f43
770		xma.hu	f45=f36,f120,f44
771	cmp.ltu		p6,p0=r25,r24		}
772{ .mfi;		xma.lu	f44=f36,f120,f44
773	add		r26=r26,r25		};;
774{ .mfi;	getf.sig	r16=f80
775		xma.hu	f55=f36,f121,f54
776(p6)	add		carry1=1,carry1		}
777{ .mfi;		xma.lu	f54=f36,f121,f54	};;
778{ .mfi;	getf.sig	r17=f71
779		xma.hu	f65=f36,f122,f64
780	cmp.ltu		p6,p0=r26,r25		}
781{ .mfi;		xma.lu	f64=f36,f122,f64
782	add		r27=r27,r26		};;
783{ .mfi;	getf.sig	r18=f62
784		xma.hu	f75=f36,f123,f74
785(p6)	add		carry1=1,carry1		}
786{ .mfi;	cmp.ltu		p6,p0=r27,r26
787		xma.lu	f74=f36,f123,f74
788	add		r27=r27,carry2		};;
789{ .mfi;	getf.sig	r19=f53
790		xma.hu	f85=f36,f124,f84
791(p6)	add		carry1=1,carry1		}
792{ .mfi;		xma.lu	f84=f36,f124,f84
793	cmp.ltu		p6,p0=r27,carry2	};;
794{ .mfi;	st8		[r33]=r27,16
795		xma.hu	f95=f36,f125,f94
796(p6)	add		carry1=1,carry1		}
797{ .mfi;		xma.lu	f94=f36,f125,f94	};;
798{ .mfi;		xma.hu	f105=f36,f126,f104	}
799{ .mfi;	mov		carry2=0
800		xma.lu	f104=f36,f126,f104
801	add		r17=r17,r16		};;
802{ .mfi;		xma.hu	f115=f36,f127,f114
803	cmp.ltu		p7,p0=r17,r16		}
804{ .mfi;		xma.lu	f114=f36,f127,f114
805	add		r18=r18,r17		};;//
806//-------------------------------------------------//
807{ .mfi;	getf.sig	r20=f44
808		xma.hu	f46=f37,f120,f45
809(p7)	add		carry2=1,carry2		}
810{ .mfi;	cmp.ltu		p7,p0=r18,r17
811		xma.lu	f45=f37,f120,f45
812	add		r19=r19,r18		};;
813{ .mfi;	getf.sig	r24=f90
814		xma.hu	f56=f37,f121,f55	}
815{ .mfi;		xma.lu	f55=f37,f121,f55	};;
816{ .mfi;	getf.sig	r25=f81
817		xma.hu	f66=f37,f122,f65
818(p7)	add		carry2=1,carry2		}
819{ .mfi;	cmp.ltu		p7,p0=r19,r18
820		xma.lu	f65=f37,f122,f65
821	add		r20=r20,r19		};;
822{ .mfi;	getf.sig	r26=f72
823		xma.hu	f76=f37,f123,f75
824(p7)	add		carry2=1,carry2		}
825{ .mfi;	cmp.ltu		p7,p0=r20,r19
826		xma.lu	f75=f37,f123,f75
827	add		r20=r20,carry1		};;
828{ .mfi;	getf.sig	r27=f63
829		xma.hu	f86=f37,f124,f85
830(p7)	add		carry2=1,carry2		}
831{ .mfi;		xma.lu	f85=f37,f124,f85
832	cmp.ltu		p7,p0=r20,carry1	};;
833{ .mfi;	getf.sig	r28=f54
834		xma.hu	f96=f37,f125,f95
835(p7)	add		carry2=1,carry2		}
836{ .mfi;	st8		[r32]=r20,16
837		xma.lu	f95=f37,f125,f95	};;
838{ .mfi;		xma.hu	f106=f37,f126,f105	}
839{ .mfi;	mov		carry1=0
840		xma.lu	f105=f37,f126,f105
841	add		r25=r25,r24		};;
842{ .mfi;		xma.hu	f116=f37,f127,f115
843	cmp.ltu		p6,p0=r25,r24		}
844{ .mfi;		xma.lu	f115=f37,f127,f115
845	add		r26=r26,r25		};;//
846//-------------------------------------------------//
847{ .mfi;	getf.sig	r29=f45
848		xma.hu	f47=f38,f120,f46
849(p6)	add		carry1=1,carry1		}
850{ .mfi;	cmp.ltu		p6,p0=r26,r25
851		xma.lu	f46=f38,f120,f46
852	add		r27=r27,r26		};;
853{ .mfi;	getf.sig	r16=f100
854		xma.hu	f57=f38,f121,f56
855(p6)	add		carry1=1,carry1		}
856{ .mfi;	cmp.ltu		p6,p0=r27,r26
857		xma.lu	f56=f38,f121,f56
858	add		r28=r28,r27		};;
859{ .mfi;	getf.sig	r17=f91
860		xma.hu	f67=f38,f122,f66
861(p6)	add		carry1=1,carry1		}
862{ .mfi;	cmp.ltu		p6,p0=r28,r27
863		xma.lu	f66=f38,f122,f66
864	add		r29=r29,r28		};;
865{ .mfi;	getf.sig	r18=f82
866		xma.hu	f77=f38,f123,f76
867(p6)	add		carry1=1,carry1		}
868{ .mfi;	cmp.ltu		p6,p0=r29,r28
869		xma.lu	f76=f38,f123,f76
870	add		r29=r29,carry2		};;
871{ .mfi;	getf.sig	r19=f73
872		xma.hu	f87=f38,f124,f86
873(p6)	add		carry1=1,carry1		}
874{ .mfi;		xma.lu	f86=f38,f124,f86
875	cmp.ltu		p6,p0=r29,carry2	};;
876{ .mfi;	getf.sig	r20=f64
877		xma.hu	f97=f38,f125,f96
878(p6)	add		carry1=1,carry1		}
879{ .mfi;	st8		[r33]=r29,16
880		xma.lu	f96=f38,f125,f96	};;
881{ .mfi;	getf.sig	r21=f55
882		xma.hu	f107=f38,f126,f106	}
883{ .mfi;	mov		carry2=0
884		xma.lu	f106=f38,f126,f106
885	add		r17=r17,r16		};;
886{ .mfi;		xma.hu	f117=f38,f127,f116
887	cmp.ltu		p7,p0=r17,r16		}
888{ .mfi;		xma.lu	f116=f38,f127,f116
889	add		r18=r18,r17		};;//
890//-------------------------------------------------//
891{ .mfi;	getf.sig	r22=f46
892		xma.hu	f48=f39,f120,f47
893(p7)	add		carry2=1,carry2		}
894{ .mfi;	cmp.ltu		p7,p0=r18,r17
895		xma.lu	f47=f39,f120,f47
896	add		r19=r19,r18		};;
897{ .mfi;	getf.sig	r24=f110
898		xma.hu	f58=f39,f121,f57
899(p7)	add		carry2=1,carry2		}
900{ .mfi;	cmp.ltu		p7,p0=r19,r18
901		xma.lu	f57=f39,f121,f57
902	add		r20=r20,r19		};;
903{ .mfi;	getf.sig	r25=f101
904		xma.hu	f68=f39,f122,f67
905(p7)	add		carry2=1,carry2		}
906{ .mfi;	cmp.ltu		p7,p0=r20,r19
907		xma.lu	f67=f39,f122,f67
908	add		r21=r21,r20		};;
909{ .mfi;	getf.sig	r26=f92
910		xma.hu	f78=f39,f123,f77
911(p7)	add		carry2=1,carry2		}
912{ .mfi;	cmp.ltu		p7,p0=r21,r20
913		xma.lu	f77=f39,f123,f77
914	add		r22=r22,r21		};;
915{ .mfi;	getf.sig	r27=f83
916		xma.hu	f88=f39,f124,f87
917(p7)	add		carry2=1,carry2		}
918{ .mfi;	cmp.ltu		p7,p0=r22,r21
919		xma.lu	f87=f39,f124,f87
920	add		r22=r22,carry1		};;
921{ .mfi;	getf.sig	r28=f74
922		xma.hu	f98=f39,f125,f97
923(p7)	add		carry2=1,carry2		}
924{ .mfi;		xma.lu	f97=f39,f125,f97
925	cmp.ltu		p7,p0=r22,carry1	};;
926{ .mfi;	getf.sig	r29=f65
927		xma.hu	f108=f39,f126,f107
928(p7)	add		carry2=1,carry2		}
929{ .mfi;	st8		[r32]=r22,16
930		xma.lu	f107=f39,f126,f107	};;
931{ .mfi;	getf.sig	r30=f56
932		xma.hu	f118=f39,f127,f117	}
933{ .mfi;		xma.lu	f117=f39,f127,f117	};;//
934//-------------------------------------------------//
935// Leaving muliplier's heaven... Quite a ride, huh?
936
937{ .mii;	getf.sig	r31=f47
938	add		r25=r25,r24
939	mov		carry1=0		};;
940{ .mii;		getf.sig	r16=f111
941	cmp.ltu		p6,p0=r25,r24
942	add		r26=r26,r25		};;
943{ .mfb;		getf.sig	r17=f102	}
944{ .mii;
945(p6)	add		carry1=1,carry1
946	cmp.ltu		p6,p0=r26,r25
947	add		r27=r27,r26		};;
948{ .mfb;	nop.m	0x0				}
949{ .mii;
950(p6)	add		carry1=1,carry1
951	cmp.ltu		p6,p0=r27,r26
952	add		r28=r28,r27		};;
953{ .mii;		getf.sig	r18=f93
954		add		r17=r17,r16
955		mov		carry3=0	}
956{ .mii;
957(p6)	add		carry1=1,carry1
958	cmp.ltu		p6,p0=r28,r27
959	add		r29=r29,r28		};;
960{ .mii;		getf.sig	r19=f84
961		cmp.ltu		p7,p0=r17,r16	}
962{ .mii;
963(p6)	add		carry1=1,carry1
964	cmp.ltu		p6,p0=r29,r28
965	add		r30=r30,r29		};;
966{ .mii;		getf.sig	r20=f75
967		add		r18=r18,r17	}
968{ .mii;
969(p6)	add		carry1=1,carry1
970	cmp.ltu		p6,p0=r30,r29
971	add		r31=r31,r30		};;
972{ .mfb;		getf.sig	r21=f66		}
973{ .mii;	(p7)	add		carry3=1,carry3
974		cmp.ltu		p7,p0=r18,r17
975		add		r19=r19,r18	}
976{ .mfb;	nop.m	0x0				}
977{ .mii;
978(p6)	add		carry1=1,carry1
979	cmp.ltu		p6,p0=r31,r30
980	add		r31=r31,carry2		};;
981{ .mfb;		getf.sig	r22=f57		}
982{ .mii;	(p7)	add		carry3=1,carry3
983		cmp.ltu		p7,p0=r19,r18
984		add		r20=r20,r19	}
985{ .mfb;	nop.m	0x0				}
986{ .mii;
987(p6)	add		carry1=1,carry1
988	cmp.ltu		p6,p0=r31,carry2	};;
989{ .mfb;		getf.sig	r23=f48		}
990{ .mii;	(p7)	add		carry3=1,carry3
991		cmp.ltu		p7,p0=r20,r19
992		add		r21=r21,r20	}
993{ .mii;
994(p6)	add		carry1=1,carry1		}
995{ .mfb;	st8		[r33]=r31,16		};;
996
997{ .mfb;	getf.sig	r24=f112		}
998{ .mii;	(p7)	add		carry3=1,carry3
999		cmp.ltu		p7,p0=r21,r20
1000		add		r22=r22,r21	};;
1001{ .mfb;	getf.sig	r25=f103		}
1002{ .mii;	(p7)	add		carry3=1,carry3
1003		cmp.ltu		p7,p0=r22,r21
1004		add		r23=r23,r22	};;
1005{ .mfb;	getf.sig	r26=f94			}
1006{ .mii;	(p7)	add		carry3=1,carry3
1007		cmp.ltu		p7,p0=r23,r22
1008		add		r23=r23,carry1	};;
1009{ .mfb;	getf.sig	r27=f85			}
1010{ .mii;	(p7)	add		carry3=1,carry3
1011		cmp.ltu		p7,p8=r23,carry1};;
1012{ .mii;	getf.sig	r28=f76
1013	add		r25=r25,r24
1014	mov		carry1=0		}
1015{ .mii;		st8		[r32]=r23,16
1016	(p7)	add		carry2=1,carry3
1017	(p8)	add		carry2=0,carry3	};;
1018
1019{ .mfb;	nop.m	0x0				}
1020{ .mii;	getf.sig	r29=f67
1021	cmp.ltu		p6,p0=r25,r24
1022	add		r26=r26,r25		};;
1023{ .mfb;	getf.sig	r30=f58			}
1024{ .mii;
1025(p6)	add		carry1=1,carry1
1026	cmp.ltu		p6,p0=r26,r25
1027	add		r27=r27,r26		};;
1028{ .mfb;		getf.sig	r16=f113	}
1029{ .mii;
1030(p6)	add		carry1=1,carry1
1031	cmp.ltu		p6,p0=r27,r26
1032	add		r28=r28,r27		};;
1033{ .mfb;		getf.sig	r17=f104	}
1034{ .mii;
1035(p6)	add		carry1=1,carry1
1036	cmp.ltu		p6,p0=r28,r27
1037	add		r29=r29,r28		};;
1038{ .mfb;		getf.sig	r18=f95		}
1039{ .mii;
1040(p6)	add		carry1=1,carry1
1041	cmp.ltu		p6,p0=r29,r28
1042	add		r30=r30,r29		};;
1043{ .mii;		getf.sig	r19=f86
1044		add		r17=r17,r16
1045		mov		carry3=0	}
1046{ .mii;
1047(p6)	add		carry1=1,carry1
1048	cmp.ltu		p6,p0=r30,r29
1049	add		r30=r30,carry2		};;
1050{ .mii;		getf.sig	r20=f77
1051		cmp.ltu		p7,p0=r17,r16
1052		add		r18=r18,r17	}
1053{ .mii;
1054(p6)	add		carry1=1,carry1
1055	cmp.ltu		p6,p0=r30,carry2	};;
1056{ .mfb;		getf.sig	r21=f68		}
1057{ .mii;	st8		[r33]=r30,16
1058(p6)	add		carry1=1,carry1		};;
1059
1060{ .mfb;	getf.sig	r24=f114		}
1061{ .mii;	(p7)	add		carry3=1,carry3
1062		cmp.ltu		p7,p0=r18,r17
1063		add		r19=r19,r18	};;
1064{ .mfb;	getf.sig	r25=f105		}
1065{ .mii;	(p7)	add		carry3=1,carry3
1066		cmp.ltu		p7,p0=r19,r18
1067		add		r20=r20,r19	};;
1068{ .mfb;	getf.sig	r26=f96			}
1069{ .mii;	(p7)	add		carry3=1,carry3
1070		cmp.ltu		p7,p0=r20,r19
1071		add		r21=r21,r20	};;
1072{ .mfb;	getf.sig	r27=f87			}
1073{ .mii;	(p7)	add		carry3=1,carry3
1074		cmp.ltu		p7,p0=r21,r20
1075		add		r21=r21,carry1	};;
1076{ .mib;	getf.sig	r28=f78
1077	add		r25=r25,r24		}
1078{ .mib;	(p7)	add		carry3=1,carry3
1079		cmp.ltu		p7,p8=r21,carry1};;
1080{ .mii;		st8		[r32]=r21,16
1081	(p7)	add		carry2=1,carry3
1082	(p8)	add		carry2=0,carry3	}
1083
1084{ .mii;	mov		carry1=0
1085	cmp.ltu		p6,p0=r25,r24
1086	add		r26=r26,r25		};;
1087{ .mfb;		getf.sig	r16=f115	}
1088{ .mii;
1089(p6)	add		carry1=1,carry1
1090	cmp.ltu		p6,p0=r26,r25
1091	add		r27=r27,r26		};;
1092{ .mfb;		getf.sig	r17=f106	}
1093{ .mii;
1094(p6)	add		carry1=1,carry1
1095	cmp.ltu		p6,p0=r27,r26
1096	add		r28=r28,r27		};;
1097{ .mfb;		getf.sig	r18=f97		}
1098{ .mii;
1099(p6)	add		carry1=1,carry1
1100	cmp.ltu		p6,p0=r28,r27
1101	add		r28=r28,carry2		};;
1102{ .mib;		getf.sig	r19=f88
1103		add		r17=r17,r16	}
1104{ .mib;
1105(p6)	add		carry1=1,carry1
1106	cmp.ltu		p6,p0=r28,carry2	};;
1107{ .mii;	st8		[r33]=r28,16
1108(p6)	add		carry1=1,carry1		}
1109
1110{ .mii;		mov		carry2=0
1111		cmp.ltu		p7,p0=r17,r16
1112		add		r18=r18,r17	};;
1113{ .mfb;	getf.sig	r24=f116		}
1114{ .mii;	(p7)	add		carry2=1,carry2
1115		cmp.ltu		p7,p0=r18,r17
1116		add		r19=r19,r18	};;
1117{ .mfb;	getf.sig	r25=f107		}
1118{ .mii;	(p7)	add		carry2=1,carry2
1119		cmp.ltu		p7,p0=r19,r18
1120		add		r19=r19,carry1	};;
1121{ .mfb;	getf.sig	r26=f98			}
1122{ .mii;	(p7)	add		carry2=1,carry2
1123		cmp.ltu		p7,p0=r19,carry1};;
1124{ .mii;		st8		[r32]=r19,16
1125	(p7)	add		carry2=1,carry2	}
1126
1127{ .mfb;	add		r25=r25,r24		};;
1128
1129{ .mfb;		getf.sig	r16=f117	}
1130{ .mii;	mov		carry1=0
1131	cmp.ltu		p6,p0=r25,r24
1132	add		r26=r26,r25		};;
1133{ .mfb;		getf.sig	r17=f108	}
1134{ .mii;
1135(p6)	add		carry1=1,carry1
1136	cmp.ltu		p6,p0=r26,r25
1137	add		r26=r26,carry2		};;
1138{ .mfb;	nop.m	0x0				}
1139{ .mii;
1140(p6)	add		carry1=1,carry1
1141	cmp.ltu		p6,p0=r26,carry2	};;
1142{ .mii;	st8		[r33]=r26,16
1143(p6)	add		carry1=1,carry1		}
1144
1145{ .mfb;		add		r17=r17,r16	};;
1146{ .mfb;	getf.sig	r24=f118		}
1147{ .mii;		mov		carry2=0
1148		cmp.ltu		p7,p0=r17,r16
1149		add		r17=r17,carry1	};;
1150{ .mii;	(p7)	add		carry2=1,carry2
1151		cmp.ltu		p7,p0=r17,carry1};;
1152{ .mii;		st8		[r32]=r17
1153	(p7)	add		carry2=1,carry2	};;
1154{ .mfb;	add		r24=r24,carry2		};;
1155{ .mib;	st8		[r33]=r24		}
1156
1157{ .mib;	rum		1<<5		// clear um.mfh
1158	br.ret.sptk.many	b0	};;
1159.endp	bn_mul_comba8#
1160#undef	carry3
1161#undef	carry2
1162#undef	carry1
1163#endif
1164
1165#if 1
1166// It's possible to make it faster (see comment to bn_sqr_comba8), but
1167// I reckon it doesn't worth the effort. Basically because the routine
1168// (actually both of them) practically never called... So I just play
1169// same trick as with bn_sqr_comba8.
1170//
1171// void bn_sqr_comba4(BN_ULONG *r, BN_ULONG *a)
1172//
1173.global	bn_sqr_comba4#
1174.proc	bn_sqr_comba4#
1175.align	64
1176bn_sqr_comba4:
1177	.prologue
1178	.fframe	0
1179	.save	ar.pfs,r2
1180#if defined(_HPUX_SOURCE) && !defined(_LP64)
1181{ .mii;	alloc   r2=ar.pfs,2,1,0,0
1182	addp4	r32=0,r32
1183	addp4	r33=0,r33		};;
1184{ .mii;
1185#else
1186{ .mii;	alloc	r2=ar.pfs,2,1,0,0
1187#endif
1188	mov	r34=r33
1189	add	r14=8,r33		};;
1190	.body
1191{ .mii;	add	r17=8,r34
1192	add	r15=16,r33
1193	add	r18=16,r34		}
1194{ .mfb;	add	r16=24,r33
1195	br	.L_cheat_entry_point4	};;
1196.endp	bn_sqr_comba4#
1197#endif
1198
1199#if 1
1200// Runs in ~115 cycles and ~4.5 times faster than C. Well, whatever...
1201//
1202// void bn_mul_comba4(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b)
1203//
1204#define	carry1	r14
1205#define	carry2	r15
1206.global	bn_mul_comba4#
1207.proc	bn_mul_comba4#
1208.align	64
1209bn_mul_comba4:
1210	.prologue
1211	.fframe	0
1212	.save	ar.pfs,r2
1213#if defined(_HPUX_SOURCE) && !defined(_LP64)
1214{ .mii;	alloc   r2=ar.pfs,3,0,0,0
1215	addp4	r33=0,r33
1216	addp4	r34=0,r34		};;
1217{ .mii;	addp4	r32=0,r32
1218#else
1219{ .mii;	alloc	r2=ar.pfs,3,0,0,0
1220#endif
1221	add	r14=8,r33
1222	add	r17=8,r34		}
1223	.body
1224{ .mii;	add	r15=16,r33
1225	add	r18=16,r34
1226	add	r16=24,r33		};;
1227.L_cheat_entry_point4:
1228{ .mmi;	add	r19=24,r34
1229
1230	ldf8	f32=[r33]		}
1231
1232{ .mmi;	ldf8	f120=[r34]
1233	ldf8	f121=[r17]		};;
1234{ .mmi;	ldf8	f122=[r18]
1235	ldf8	f123=[r19]		}
1236
1237{ .mmi;	ldf8	f33=[r14]
1238	ldf8	f34=[r15]		}
1239{ .mfi;	ldf8	f35=[r16]
1240
1241		xma.hu	f41=f32,f120,f0		}
1242{ .mfi;		xma.lu	f40=f32,f120,f0		};;
1243{ .mfi;		xma.hu	f51=f32,f121,f0		}
1244{ .mfi;		xma.lu	f50=f32,f121,f0		};;
1245{ .mfi;		xma.hu	f61=f32,f122,f0		}
1246{ .mfi;		xma.lu	f60=f32,f122,f0		};;
1247{ .mfi;		xma.hu	f71=f32,f123,f0		}
1248{ .mfi;		xma.lu	f70=f32,f123,f0		};;//
1249// Major stall takes place here, and 3 more places below. Result from
1250// first xma is not available for another 3 ticks.
1251{ .mfi;	getf.sig	r16=f40
1252		xma.hu	f42=f33,f120,f41
1253	add		r33=8,r32		}
1254{ .mfi;		xma.lu	f41=f33,f120,f41	};;
1255{ .mfi;	getf.sig	r24=f50
1256		xma.hu	f52=f33,f121,f51	}
1257{ .mfi;		xma.lu	f51=f33,f121,f51	};;
1258{ .mfi;	st8		[r32]=r16,16
1259		xma.hu	f62=f33,f122,f61	}
1260{ .mfi;		xma.lu	f61=f33,f122,f61	};;
1261{ .mfi;		xma.hu	f72=f33,f123,f71	}
1262{ .mfi;		xma.lu	f71=f33,f123,f71	};;//
1263//-------------------------------------------------//
1264{ .mfi;	getf.sig	r25=f41
1265		xma.hu	f43=f34,f120,f42	}
1266{ .mfi;		xma.lu	f42=f34,f120,f42	};;
1267{ .mfi;	getf.sig	r16=f60
1268		xma.hu	f53=f34,f121,f52	}
1269{ .mfi;		xma.lu	f52=f34,f121,f52	};;
1270{ .mfi;	getf.sig	r17=f51
1271		xma.hu	f63=f34,f122,f62
1272	add		r25=r25,r24		}
1273{ .mfi;	mov		carry1=0
1274		xma.lu	f62=f34,f122,f62	};;
1275{ .mfi;	st8		[r33]=r25,16
1276		xma.hu	f73=f34,f123,f72
1277	cmp.ltu		p6,p0=r25,r24		}
1278{ .mfi;		xma.lu	f72=f34,f123,f72	};;//
1279//-------------------------------------------------//
1280{ .mfi;	getf.sig	r18=f42
1281		xma.hu	f44=f35,f120,f43
1282(p6)	add		carry1=1,carry1		}
1283{ .mfi;	add		r17=r17,r16
1284		xma.lu	f43=f35,f120,f43
1285	mov		carry2=0		};;
1286{ .mfi;	getf.sig	r24=f70
1287		xma.hu	f54=f35,f121,f53
1288	cmp.ltu		p7,p0=r17,r16		}
1289{ .mfi;		xma.lu	f53=f35,f121,f53	};;
1290{ .mfi;	getf.sig	r25=f61
1291		xma.hu	f64=f35,f122,f63
1292	add		r18=r18,r17		}
1293{ .mfi;		xma.lu	f63=f35,f122,f63
1294(p7)	add		carry2=1,carry2		};;
1295{ .mfi;	getf.sig	r26=f52
1296		xma.hu	f74=f35,f123,f73
1297	cmp.ltu		p7,p0=r18,r17		}
1298{ .mfi;		xma.lu	f73=f35,f123,f73
1299	add		r18=r18,carry1		};;
1300//-------------------------------------------------//
1301{ .mii;	st8		[r32]=r18,16
1302(p7)	add		carry2=1,carry2
1303	cmp.ltu		p7,p0=r18,carry1	};;
1304
1305{ .mfi;	getf.sig	r27=f43	// last major stall
1306(p7)	add		carry2=1,carry2		};;
1307{ .mii;		getf.sig	r16=f71
1308	add		r25=r25,r24
1309	mov		carry1=0		};;
1310{ .mii;		getf.sig	r17=f62
1311	cmp.ltu		p6,p0=r25,r24
1312	add		r26=r26,r25		};;
1313{ .mii;
1314(p6)	add		carry1=1,carry1
1315	cmp.ltu		p6,p0=r26,r25
1316	add		r27=r27,r26		};;
1317{ .mii;
1318(p6)	add		carry1=1,carry1
1319	cmp.ltu		p6,p0=r27,r26
1320	add		r27=r27,carry2		};;
1321{ .mii;		getf.sig	r18=f53
1322(p6)	add		carry1=1,carry1
1323	cmp.ltu		p6,p0=r27,carry2	};;
1324{ .mfi;	st8		[r33]=r27,16
1325(p6)	add		carry1=1,carry1		}
1326
1327{ .mii;		getf.sig	r19=f44
1328		add		r17=r17,r16
1329		mov		carry2=0	};;
1330{ .mii;	getf.sig	r24=f72
1331		cmp.ltu		p7,p0=r17,r16
1332		add		r18=r18,r17	};;
1333{ .mii;	(p7)	add		carry2=1,carry2
1334		cmp.ltu		p7,p0=r18,r17
1335		add		r19=r19,r18	};;
1336{ .mii;	(p7)	add		carry2=1,carry2
1337		cmp.ltu		p7,p0=r19,r18
1338		add		r19=r19,carry1	};;
1339{ .mii;	getf.sig	r25=f63
1340	(p7)	add		carry2=1,carry2
1341		cmp.ltu		p7,p0=r19,carry1};;
1342{ .mii;		st8		[r32]=r19,16
1343	(p7)	add		carry2=1,carry2	}
1344
1345{ .mii;	getf.sig	r26=f54
1346	add		r25=r25,r24
1347	mov		carry1=0		};;
1348{ .mii;		getf.sig	r16=f73
1349	cmp.ltu		p6,p0=r25,r24
1350	add		r26=r26,r25		};;
1351{ .mii;
1352(p6)	add		carry1=1,carry1
1353	cmp.ltu		p6,p0=r26,r25
1354	add		r26=r26,carry2		};;
1355{ .mii;		getf.sig	r17=f64
1356(p6)	add		carry1=1,carry1
1357	cmp.ltu		p6,p0=r26,carry2	};;
1358{ .mii;	st8		[r33]=r26,16
1359(p6)	add		carry1=1,carry1		}
1360
1361{ .mii;	getf.sig	r24=f74
1362		add		r17=r17,r16
1363		mov		carry2=0	};;
1364{ .mii;		cmp.ltu		p7,p0=r17,r16
1365		add		r17=r17,carry1	};;
1366
1367{ .mii;	(p7)	add		carry2=1,carry2
1368		cmp.ltu		p7,p0=r17,carry1};;
1369{ .mii;		st8		[r32]=r17,16
1370	(p7)	add		carry2=1,carry2	};;
1371
1372{ .mii;	add		r24=r24,carry2		};;
1373{ .mii;	st8		[r33]=r24		}
1374
1375{ .mib;	rum		1<<5		// clear um.mfh
1376	br.ret.sptk.many	b0	};;
1377.endp	bn_mul_comba4#
1378#undef	carry2
1379#undef	carry1
1380#endif
1381
1382#if 1
1383//
1384// BN_ULONG bn_div_words(BN_ULONG h, BN_ULONG l, BN_ULONG d)
1385//
1386// In the nutshell it's a port of my MIPS III/IV implementation.
1387//
1388#define	AT	r14
1389#define	H	r16
1390#define	HH	r20
1391#define	L	r17
1392#define	D	r18
1393#define	DH	r22
1394#define	I	r21
1395
1396#if 0
1397// Some preprocessors (most notably HP-UX) appear to be allergic to
1398// macros enclosed to parenthesis [as these three were].
1399#define	cont	p16
1400#define	break	p0	// p20
1401#define	equ	p24
1402#else
1403cont=p16
1404break=p0
1405equ=p24
1406#endif
1407
1408.global	abort#
1409.global	bn_div_words#
1410.proc	bn_div_words#
1411.align	64
1412bn_div_words:
1413	.prologue
1414	.fframe	0
1415	.save	ar.pfs,r2
1416	.save	b0,r3
1417{ .mii;	alloc		r2=ar.pfs,3,5,0,8
1418	mov		r3=b0
1419	mov		r10=pr		};;
1420{ .mmb;	cmp.eq		p6,p0=r34,r0
1421	mov		r8=-1
1422(p6)	br.ret.spnt.many	b0	};;
1423
1424	.body
1425{ .mii;	mov		H=r32		// save h
1426	mov		ar.ec=0		// don't rotate at exit
1427	mov		pr.rot=0	}
1428{ .mii;	mov		L=r33		// save l
1429	mov		r36=r0		};;
1430
1431.L_divw_shift:	// -vv- note signed comparison
1432{ .mfi;	(p0)	cmp.lt		p16,p0=r0,r34	// d
1433	(p0)	shladd		r33=r34,1,r0	}
1434{ .mfb;	(p0)	add		r35=1,r36
1435	(p0)	nop.f		0x0
1436(p16)	br.wtop.dpnt		.L_divw_shift	};;
1437
1438{ .mii;	mov		D=r34
1439	shr.u		DH=r34,32
1440	sub		r35=64,r36		};;
1441{ .mii;	setf.sig	f7=DH
1442	shr.u		AT=H,r35
1443	mov		I=r36			};;
1444{ .mib;	cmp.ne		p6,p0=r0,AT
1445	shl		H=H,r36
1446(p6)	br.call.spnt.clr	b0=abort	};;	// overflow, die...
1447
1448{ .mfi;	fcvt.xuf.s1	f7=f7
1449	shr.u		AT=L,r35		};;
1450{ .mii;	shl		L=L,r36
1451	or		H=H,AT			};;
1452
1453{ .mii;	nop.m		0x0
1454	cmp.leu		p6,p0=D,H;;
1455(p6)	sub		H=H,D			}
1456
1457{ .mlx;	setf.sig	f14=D
1458	movl		AT=0xffffffff		};;
1459///////////////////////////////////////////////////////////
1460{ .mii;	setf.sig	f6=H
1461	shr.u		HH=H,32;;
1462	cmp.eq		p6,p7=HH,DH		};;
1463{ .mfb;
1464(p6)	setf.sig	f8=AT
1465(p7)	fcvt.xuf.s1	f6=f6
1466(p7)	br.call.sptk	b6=.L_udiv64_32_b6	};;
1467
1468{ .mfi;	getf.sig	r33=f8				// q
1469	xmpy.lu		f9=f8,f14		}
1470{ .mfi;	xmpy.hu		f10=f8,f14
1471	shrp		H=H,L,32		};;
1472
1473{ .mmi;	getf.sig	r35=f9				// tl
1474	getf.sig	r31=f10			};;	// th
1475
1476.L_divw_1st_iter:
1477{ .mii;	(p0)	add		r32=-1,r33
1478	(p0)	cmp.eq		equ,cont=HH,r31		};;
1479{ .mii;	(p0)	cmp.ltu		p8,p0=r35,D
1480	(p0)	sub		r34=r35,D
1481	(equ)	cmp.leu		break,cont=r35,H	};;
1482{ .mib;	(cont)	cmp.leu		cont,break=HH,r31
1483	(p8)	add		r31=-1,r31
1484(cont)	br.wtop.spnt		.L_divw_1st_iter	};;
1485///////////////////////////////////////////////////////////
1486{ .mii;	sub		H=H,r35
1487	shl		r8=r33,32
1488	shl		L=L,32			};;
1489///////////////////////////////////////////////////////////
1490{ .mii;	setf.sig	f6=H
1491	shr.u		HH=H,32;;
1492	cmp.eq		p6,p7=HH,DH		};;
1493{ .mfb;
1494(p6)	setf.sig	f8=AT
1495(p7)	fcvt.xuf.s1	f6=f6
1496(p7)	br.call.sptk	b6=.L_udiv64_32_b6	};;
1497
1498{ .mfi;	getf.sig	r33=f8				// q
1499	xmpy.lu		f9=f8,f14		}
1500{ .mfi;	xmpy.hu		f10=f8,f14
1501	shrp		H=H,L,32		};;
1502
1503{ .mmi;	getf.sig	r35=f9				// tl
1504	getf.sig	r31=f10			};;	// th
1505
1506.L_divw_2nd_iter:
1507{ .mii;	(p0)	add		r32=-1,r33
1508	(p0)	cmp.eq		equ,cont=HH,r31		};;
1509{ .mii;	(p0)	cmp.ltu		p8,p0=r35,D
1510	(p0)	sub		r34=r35,D
1511	(equ)	cmp.leu		break,cont=r35,H	};;
1512{ .mib;	(cont)	cmp.leu		cont,break=HH,r31
1513	(p8)	add		r31=-1,r31
1514(cont)	br.wtop.spnt		.L_divw_2nd_iter	};;
1515///////////////////////////////////////////////////////////
1516{ .mii;	sub	H=H,r35
1517	or	r8=r8,r33
1518	mov	ar.pfs=r2		};;
1519{ .mii;	shr.u	r9=H,I			// remainder if anybody wants it
1520	mov	pr=r10,0x1ffff		}
1521{ .mfb;	br.ret.sptk.many	b0	};;
1522
1523// Unsigned 64 by 32 (well, by 64 for the moment) bit integer division
1524// procedure.
1525//
1526// inputs:	f6 = (double)a, f7 = (double)b
1527// output:	f8 = (int)(a/b)
1528// clobbered:	f8,f9,f10,f11,pred
1529pred=p15
1530// One can argue that this snippet is copyrighted to Intel
1531// Corporation, as it's essentially identical to one of those
1532// found in "Divide, Square Root and Remainder" section at
1533// http://www.intel.com/software/products/opensource/libraries/num.htm.
1534// Yes, I admit that the referred code was used as template,
1535// but after I realized that there hardly is any other instruction
1536// sequence which would perform this operation. I mean I figure that
1537// any independent attempt to implement high-performance division
1538// will result in code virtually identical to the Intel code. It
1539// should be noted though that below division kernel is 1 cycle
1540// faster than Intel one (note commented splits:-), not to mention
1541// original prologue (rather lack of one) and epilogue.
1542.align	32
1543.skip	16
1544.L_udiv64_32_b6:
1545	frcpa.s1	f8,pred=f6,f7;;		// [0]  y0 = 1 / b
1546
1547(pred)	fnma.s1		f9=f7,f8,f1		// [5]  e0 = 1 - b * y0
1548(pred)	fmpy.s1		f10=f6,f8;;		// [5]  q0 = a * y0
1549(pred)	fmpy.s1		f11=f9,f9		// [10] e1 = e0 * e0
1550(pred)	fma.s1		f10=f9,f10,f10;;	// [10] q1 = q0 + e0 * q0
1551(pred)	fma.s1		f8=f9,f8,f8	//;;	// [15] y1 = y0 + e0 * y0
1552(pred)	fma.s1		f9=f11,f10,f10;;	// [15] q2 = q1 + e1 * q1
1553(pred)	fma.s1		f8=f11,f8,f8	//;;	// [20] y2 = y1 + e1 * y1
1554(pred)	fnma.s1		f10=f7,f9,f6;;		// [20] r2 = a - b * q2
1555(pred)	fma.s1		f8=f10,f8,f9;;		// [25] q3 = q2 + r2 * y2
1556
1557	fcvt.fxu.trunc.s1	f8=f8		// [30] q = trunc(q3)
1558	br.ret.sptk.many	b6;;
1559.endp	bn_div_words#
1560#endif
1561