.explicit
.text
-.ident "ia64.S, Version 2.0"
+.ident "ia64.S, Version 2.1"
.ident "IA-64 ISA artwork by Andy Polyakov <appro@fy.chalmers.se>"
//
// What does it mean? You might ratiocinate that the original code
// should run just faster... Because sum of latencies is smaller...
// Wrong! Note that getf latency increased. This means that if a loop is
-// scheduled for lower latency (and they are), then it will suffer from
+// scheduled for lower latency (as they were), then it will suffer from
// stall condition and the code will therefore turn anti-scalable, e.g.
// original bn_mul_words spun at 5*n or 2.5 times slower than expected
// on Itanium2! What to do? Reschedule loops for Itanium2? But then
// -Drum=nop.m in command line.
//
+#if defined(_HPUX_SOURCE) && !defined(_LP64)
+#define ADDP addp4
+#else
+#define ADDP add
+#endif
+
#if 1
//
// bn_[add|sub]_words routines.
brp.loop.imp .L_bn_add_words_ctop,.L_bn_add_words_cend-16
}
.body
-{ .mib;
-#if defined(_HPUX_SOURCE) && defined(_ILP32)
- addp4 r14=0,r32 // rp
-#else
- mov r14=r32 // rp
-#endif
+{ .mib; ADDP r14=0,r32 // rp
mov r9=pr };;
-{ .mii;
-#if defined(_HPUX_SOURCE) && defined(_ILP32)
- addp4 r15=0,r33 // ap
-#else
- mov r15=r33 // ap
-#endif
+{ .mii; ADDP r15=0,r33 // ap
mov ar.lc=r10
mov ar.ec=6 }
-{ .mib;
-#if defined(_HPUX_SOURCE) && defined(_ILP32)
- addp4 r16=0,r34 // bp
-#else
- mov r16=r34 // bp
-#endif
+{ .mib; ADDP r16=0,r34 // bp
mov pr.rot=1<<16 };;
.L_bn_add_words_ctop:
brp.loop.imp .L_bn_sub_words_ctop,.L_bn_sub_words_cend-16
}
.body
-{ .mib;
-#if defined(_HPUX_SOURCE) && defined(_ILP32)
- addp4 r14=0,r32 // rp
-#else
- mov r14=r32 // rp
-#endif
+{ .mib; ADDP r14=0,r32 // rp
mov r9=pr };;
-{ .mii;
-#if defined(_HPUX_SOURCE) && defined(_ILP32)
- addp4 r15=0,r33 // ap
-#else
- mov r15=r33 // ap
-#endif
+{ .mii; ADDP r15=0,r33 // ap
mov ar.lc=r10
mov ar.ec=6 }
-{ .mib;
-#if defined(_HPUX_SOURCE) && defined(_ILP32)
- addp4 r16=0,r34 // bp
-#else
- mov r16=r34 // bp
-#endif
+{ .mib; ADDP r16=0,r34 // bp
mov pr.rot=1<<16 };;
.L_bn_sub_words_ctop:
#ifndef XMA_TEMPTATION
-{ .mii;
-#if defined(_HPUX_SOURCE) && defined(_ILP32)
- addp4 r14=0,r32 // rp
- addp4 r15=0,r33 // ap
-#else
- mov r14=r32 // rp
- mov r15=r33 // ap
-#endif
+{ .mmi; ADDP r14=0,r32 // rp
+ ADDP r15=0,r33 // ap
mov ar.lc=r10 }
-{ .mii; mov r40=0 // serves as r35 at first (p27)
+{ .mmi; mov r40=0 // serves as r35 at first (p27)
mov ar.ec=13 };;
// This loop spins in 2*(n+12) ticks. It's scheduled for data in Itanium
.global bn_mul_add_words#
.proc bn_mul_add_words#
.align 64
-//.skip 0 // makes the loop split at 64-byte boundary
+.skip 48 // makes the loop body aligned at 64-byte boundary
bn_mul_add_words:
.prologue
.fframe 0
.save ar.pfs,r2
-{ .mii; alloc r2=ar.pfs,4,12,0,16
- cmp4.le p6,p0=r34,r0 };;
-{ .mfb; mov r8=r0 // return value
-(p6) br.ret.spnt.many b0 };;
-
.save ar.lc,r3
-{ .mii; sub r10=r34,r0,1
- mov r3=ar.lc
- mov r9=pr };;
+ .save pr,r9
+{ .mmi; alloc r2=ar.pfs,4,4,0,8
+ cmp4.le p6,p0=r34,r0
+ mov r3=ar.lc };;
+{ .mib; mov r8=r0 // return value
+ sub r10=r34,r0,1
+(p6) br.ret.spnt.many b0 };;
.body
-{ .mib; setf.sig f8=r35 // w
- mov pr.rot=0x800001<<16
- // ------^----- serves as (p50) at first (p27)
+{ .mib; setf.sig f8=r35 // w
+ mov r9=pr
brp.loop.imp .L_bn_mul_add_words_ctop,.L_bn_mul_add_words_cend-16
}
-{ .mii;
-#if defined(_HPUX_SOURCE) && defined(_ILP32)
- addp4 r14=0,r32 // rp
- addp4 r15=0,r33 // ap
-#else
- mov r14=r32 // rp
- mov r15=r33 // ap
-#endif
+{ .mmi; ADDP r14=0,r32 // rp
+ ADDP r15=0,r33 // ap
mov ar.lc=r10 }
-{ .mii; mov r40=0 // serves as r35 at first (p27)
-#if defined(_HPUX_SOURCE) && defined(_ILP32)
- addp4 r18=0,r32 // rp copy
-#else
- mov r18=r32 // rp copy
-#endif
- mov ar.ec=15 };;
-
-// This loop spins in 3*(n+14) ticks on Itanium and should spin in
-// 2*(n+14) on "wider" IA-64 implementations (to be verified with new
-// µ-architecture manuals as they become available). As usual it's
-// possible to compress the epilogue, down to 10 in this case, at the
-// cost of scalability. Compressed (and therefore non-scalable) loop
-// running at 3*(n+11) would buy you ~10% on Itanium but take ~35%
-// from "wider" IA-64 so let it be scalable! Special attention was
-// paid for having the loop body split at 64-byte boundary. ld8 is
-// scheduled for L1 cache as the data is more than likely there.
-// Indeed, bn_mul_words has put it there a moment ago:-)
+{ .mii; ADDP r16=0,r32 // rp copy
+ mov pr.rot=0x2001<<16
+ // ------^----- serves as (p40) at first (p27)
+ mov ar.ec=11 };;
+
+// This loop spins in 3*(n+10) ticks on Itanium and in 2*(n+10) on
+// Itanium 2. Yes, unlike previous versions it scales:-) Previous
+// version was peforming *all* additions in IALU and was starving
+// for those even on Itanium 2. In this version one addition is
+// moved to FPU and is folded with multiplication. This is at cost
+// of propogating the result from previous call to this subroutine
+// to L2 cache... In other words negligible even for shorter keys.
+// *Overall* performance improvement [over previous version] varies
+// from 11 to 22 percent depending on key length.
.L_bn_mul_add_words_ctop:
-{ .mfi; (p25) getf.sig r36=f52 // low
- (p21) xmpy.lu f48=f37,f8
- (p28) cmp.ltu p54,p50=r41,r39 }
-{ .mfi; (p16) ldf8 f32=[r15],8
- (p21) xmpy.hu f40=f37,f8
- (p28) add r45=r45,r41 };;
-{ .mii; (p25) getf.sig r32=f44 // high
- .pred.rel "mutex",p50,p54
- (p50) add r40=r38,r35 // (p27)
- (p54) add r40=r38,r35,1 } // (p27)
-{ .mfb; (p28) cmp.ltu.unc p60,p0=r45,r41
- (p0) nop.f 0x0
- (p0) nop.b 0x0 }
-{ .mii; (p27) ld8 r44=[r18],8
- (p62) cmp.eq.or p61,p0=-1,r46
- (p62) add r46=1,r46 }
-{ .mfb; (p30) st8 [r14]=r47,8
- (p0) nop.f 0x0
+.pred.rel "mutex",p40,p42
+{ .mfi; (p23) getf.sig r36=f45 // low
+ (p20) xma.lu f42=f36,f8,f50 // low
+ (p40) add r39=r39,r35 } // (p27)
+{ .mfi; (p16) ldf8 f32=[r15],8 // *(ap++)
+ (p20) xma.hu f36=f36,f8,f50 // high
+ (p42) add r39=r39,r35,1 };; // (p27)
+{ .mmi; (p24) getf.sig r32=f40 // high
+ (p16) ldf8 f46=[r16],8 // *(rp1++)
+ (p40) cmp.ltu p41,p39=r39,r35 } // (p27)
+{ .mib; (p26) st8 [r14]=r39,8 // *(rp2++)
+ (p42) cmp.leu p41,p39=r39,r35 // (p27)
br.ctop.sptk .L_bn_mul_add_words_ctop};;
.L_bn_mul_add_words_cend:
-{ .mii; nop.m 0x0
-.pred.rel "mutex",p53,p57
-(p53) add r8=r38,r0
-(p57) add r8=r38,r0,1 }
-{ .mfb; nop.m 0x0
- nop.f 0x0
- nop.b 0x0 };;
-{ .mii;
-(p63) add r8=1,r8
- mov pr=r9,0x1ffff
- mov ar.lc=r3 }
-{ .mfb; rum 1<<5 // clear um.mfh
- nop.f 0x0
+{ .mmi; .pred.rel "mutex",p40,p42
+(p40) add r8=r35,r0
+(p42) add r8=r35,r0,1
+ mov pr=r9,0x1ffff }
+{ .mib; rum 1<<5 // clear um.mfh
+ mov ar.lc=r3
br.ret.sptk.many b0 };;
.endp bn_mul_add_words#
#endif
sxt4 r34=r34 };;
{ .mii; cmp.le p6,p0=r34,r0
mov r8=r0 } // return value
-{ .mfb; nop.f 0x0
+{ .mfb; ADDP r32=0,r32
+ nop.f 0x0
(p6) br.ret.spnt.many b0 };;
.save ar.lc,r3
mov r9=pr };;
.body
-#if defined(_HPUX_SOURCE) && defined(_ILP32)
-{ .mii; addp4 r32=0,r32
- addp4 r33=0,r33 };;
-#endif
-{ .mib;
+{ .mib; ADDP r33=0,r33
mov pr.rot=1<<16
brp.loop.imp .L_bn_sqr_words_ctop,.L_bn_sqr_words_cend-16
}
.prologue
.fframe 0
.save ar.pfs,r2
-#if defined(_HPUX_SOURCE) && defined(_ILP32)
+#if defined(_HPUX_SOURCE) && !defined(_LP64)
{ .mii; alloc r2=ar.pfs,2,1,0,0
addp4 r33=0,r33
addp4 r32=0,r32 };;
// clause in Itanium µ-architecture manual? Comments are welcomed and
// highly appreciated.
//
+// On Itanium 2 it takes ~190 ticks. This is because of stalls on
+// result from getf.sig. I do nothing about it at this point for
+// reasons depicted below.
+//
// However! It should be noted that even 160 ticks is darn good result
// as it's over 10 (yes, ten, spelled as t-e-n) times faster than the
// C version (compiled with gcc with inline assembler). I really
.prologue
.fframe 0
.save ar.pfs,r2
-#if defined(_HPUX_SOURCE) && defined(_ILP32)
+#if defined(_HPUX_SOURCE) && !defined(_LP64)
{ .mii; alloc r2=ar.pfs,3,0,0,0
addp4 r33=0,r33
addp4 r34=0,r34 };;
.prologue
.fframe 0
.save ar.pfs,r2
-#if defined(_HPUX_SOURCE) && defined(_ILP32)
+#if defined(_HPUX_SOURCE) && !defined(_LP64)
{ .mii; alloc r2=ar.pfs,2,1,0,0
addp4 r32=0,r32
addp4 r33=0,r33 };;
.prologue
.fframe 0
.save ar.pfs,r2
-#if defined(_HPUX_SOURCE) && defined(_ILP32)
+#if defined(_HPUX_SOURCE) && !defined(_LP64)
{ .mii; alloc r2=ar.pfs,3,0,0,0
addp4 r33=0,r33
addp4 r34=0,r34 };;
#define I r21
#if 0
-// Some preprocessors (most notably HP-UX) apper to be allergic to
-// macros enclosed to parenthesis as these three will be.
+// Some preprocessors (most notably HP-UX) appear to be allergic to
+// macros enclosed to parenthesis [as these three were].
#define cont p16
#define break p0 // p20
#define equ p24
// output: f8 = (int)(a/b)
// clobbered: f8,f9,f10,f11,pred
pred=p15
-// This procedure is essentially Intel code and therefore is
-// copyrighted to Intel Corporation (I suppose...). It's sligtly
-// modified for specific needs.
+// One can argue that this snippet is copyrighted to Intel
+// Corporation, as it's essentially identical to one of those
+// found in "Divide, Square Root and Remainder" section at
+// http://www.intel.com/software/products/opensource/libraries/num.htm.
+// Yes, I admit that the referred code was used as template,
+// but after I realized that there hardly is any other instruction
+// sequence which would perform this operation. I mean I figure that
+// any independent attempt to implement high-performance division
+// will result in code virtually identical to the Intel code. It
+// should be noted though that below division kernel is 1 cycle
+// faster than Intel one (note commented splits:-), not to mention
+// original prologue (rather lack of one) and epilogue.
.align 32
.skip 16
.L_udiv64_32_b6: