diff options
Diffstat (limited to 'src/cmd/9c/mul.c')
| -rw-r--r-- | src/cmd/9c/mul.c | 638 |
1 files changed, 638 insertions, 0 deletions
diff --git a/src/cmd/9c/mul.c b/src/cmd/9c/mul.c new file mode 100644 index 000000000..353376f15 --- /dev/null +++ b/src/cmd/9c/mul.c @@ -0,0 +1,638 @@ +// cmd/9c/mul.c from Vita Nuova. +// +// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved. +// Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net) +// Portions Copyright © 1997-1999 Vita Nuova Limited +// Portions Copyright © 2000-2008 Vita Nuova Holdings Limited (www.vitanuova.com) +// Portions Copyright © 2004,2006 Bruce Ellis +// Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net) +// Revisions Copyright © 2000-2008 Lucent Technologies Inc. and others +// Portions Copyright © 2009 The Go Authors. All rights reserved. +// +// Permission is hereby granted, free of charge, to any person obtaining a copy +// of this software and associated documentation files (the "Software"), to deal +// in the Software without restriction, including without limitation the rights +// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +// copies of the Software, and to permit persons to whom the Software is +// furnished to do so, subject to the following conditions: +// +// The above copyright notice and this permission notice shall be included in +// all copies or substantial portions of the Software. +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +// THE SOFTWARE. + +#include "gc.h" + +/* + * code sequences for multiply by constant. + * [a-l][0-3] + * lsl $(A-'a'),r0,r1 + * [+][0-7] + * add r0,r1,r2 + * [-][0-7] + * sub r0,r1,r2 + */ + +static int multabp; +static int32 mulval; +static char* mulcp; +static int32 valmax; +static int shmax; + +static int docode(char *hp, char *cp, int r0, int r1); +static int gen1(int len); +static int gen2(int len, int32 r1); +static int gen3(int len, int32 r0, int32 r1, int flag); +enum +{ + SR1 = 1<<0, /* r1 has been shifted */ + SR0 = 1<<1, /* r0 has been shifted */ + UR1 = 1<<2, /* r1 has not been used */ + UR0 = 1<<3, /* r0 has not been used */ +}; + +Multab* +mulcon0(Node *n, int32 v) +{ + int a1, a2, g; + Multab *m, *m1; + char hint[10]; + + if(v < 0) + v = -v; + + /* + * look in cache + */ + m = multab; + for(g=0; g<nelem(multab); g++) { + if(m->val == v) { + if(m->code[0] == 0) + return 0; + return m; + } + m++; + } + + /* + * select a spot in cache to overwrite + */ + multabp++; + if(multabp < 0 || multabp >= nelem(multab)) + multabp = 0; + m = multab+multabp; + m->val = v; + mulval = v; + + /* + * look in execption hint table + */ + a1 = 0; + a2 = hintabsize; + for(;;) { + if(a1 >= a2) + goto no; + g = (a2 + a1)/2; + if(v < hintab[g].val) { + a2 = g; + continue; + } + if(v > hintab[g].val) { + a1 = g+1; + continue; + } + break; + } + + if(docode(hintab[g].hint, m->code, 1, 0)) + return m; + print("%L: multiply table failure %ld\n", n->lineno, v); + m->code[0] = 0; + return 0; + +no: + /* + * try to search + */ + hint[0] = 0; + for(g=1; g<=6; g++) { + if(g >= 6 && v >= 65535) + break; + mulcp = hint+g; + *mulcp = 0; + if(gen1(g)) { + if(docode(hint, m->code, 1, 0)) + return m; + print("%L: multiply table failure (g=%d h=%s) %ld\n", + n->lineno, g, hint, v); + break; + } + } + + /* + * try a recur followed by a shift + */ + g = 0; + while(!(v & 1)) { + g++; + v >>= 1; + } + if(g) { + m1 = mulcon0(n, v); + if(m1) { + strcpy(m->code, m1->code); + sprint(strchr(m->code, 0), "%c0", g+'a'); + return m; + } + } + m->code[0] = 0; + return 0; +} + +static int +docode(char *hp, char *cp, int r0, int r1) +{ + int c, i; + + c = *hp++; + *cp = c; + cp += 2; + switch(c) { + default: + c -= 'a'; + if(c < 1 || c >= 30) + break; + for(i=0; i<4; i++) { + switch(i) { + case 0: + if(docode(hp, cp, r0<<c, r1)) + goto out; + break; + case 1: + if(docode(hp, cp, r1<<c, r1)) + goto out; + break; + case 2: + if(docode(hp, cp, r0, r0<<c)) + goto out; + break; + case 3: + if(docode(hp, cp, r0, r1<<c)) + goto out; + break; + } + } + break; + + case '+': + for(i=0; i<8; i++) { + cp[-1] = i+'0'; + switch(i) { + case 1: + if(docode(hp, cp, r0+r1, r1)) + goto out; + break; + case 5: + if(docode(hp, cp, r0, r0+r1)) + goto out; + break; + } + } + break; + + case '-': + for(i=0; i<8; i++) { + cp[-1] = i+'0'; + switch(i) { + case 1: + if(docode(hp, cp, r0-r1, r1)) + goto out; + break; + case 2: + if(docode(hp, cp, r1-r0, r1)) + goto out; + break; + case 5: + if(docode(hp, cp, r0, r0-r1)) + goto out; + break; + case 6: + if(docode(hp, cp, r0, r1-r0)) + goto out; + break; + } + } + break; + + case 0: + if(r0 == mulval) + return 1; + } + return 0; + +out: + cp[-1] = i+'0'; + return 1; +} + +static int +gen1(int len) +{ + int i; + + for(shmax=1; shmax<30; shmax++) { + valmax = 1<<shmax; + if(valmax >= mulval) + break; + } + if(mulval == 1) + return 1; + + len--; + for(i=1; i<=shmax; i++) + if(gen2(len, 1<<i)) { + *--mulcp = 'a'+i; + return 1; + } + return 0; +} + +static int +gen2(int len, int32 r1) +{ + int i; + + if(len <= 0) { + if(r1 == mulval) + return 1; + return 0; + } + + len--; + if(len == 0) + goto calcr0; + + if(gen3(len, r1, r1+1, UR1)) { + i = '+'; + goto out; + } + if(gen3(len, r1-1, r1, UR0)) { + i = '-'; + goto out; + } + if(gen3(len, 1, r1+1, UR1)) { + i = '+'; + goto out; + } + if(gen3(len, 1, r1-1, UR1)) { + i = '-'; + goto out; + } + + return 0; + +calcr0: + if(mulval == r1+1) { + i = '+'; + goto out; + } + if(mulval == r1-1) { + i = '-'; + goto out; + } + return 0; + +out: + *--mulcp = i; + return 1; +} + +static int +gen3(int len, int32 r0, int32 r1, int flag) +{ + int i, f1, f2; + int32 x; + + if(r0 <= 0 || + r0 >= r1 || + r1 > valmax) + return 0; + + len--; + if(len == 0) + goto calcr0; + + if(!(flag & UR1)) { + f1 = UR1|SR1; + for(i=1; i<=shmax; i++) { + x = r0<<i; + if(x > valmax) + break; + if(gen3(len, r0, x, f1)) { + i += 'a'; + goto out; + } + } + } + + if(!(flag & UR0)) { + f1 = UR1|SR1; + for(i=1; i<=shmax; i++) { + x = r1<<i; + if(x > valmax) + break; + if(gen3(len, r1, x, f1)) { + i += 'a'; + goto out; + } + } + } + + if(!(flag & SR1)) { + f1 = UR1|SR1|(flag&UR0); + for(i=1; i<=shmax; i++) { + x = r1<<i; + if(x > valmax) + break; + if(gen3(len, r0, x, f1)) { + i += 'a'; + goto out; + } + } + } + + if(!(flag & SR0)) { + f1 = UR0|SR0|(flag&(SR1|UR1)); + + f2 = UR1|SR1; + if(flag & UR1) + f2 |= UR0; + if(flag & SR1) + f2 |= SR0; + + for(i=1; i<=shmax; i++) { + x = r0<<i; + if(x > valmax) + break; + if(x > r1) { + if(gen3(len, r1, x, f2)) { + i += 'a'; + goto out; + } + } else + if(gen3(len, x, r1, f1)) { + i += 'a'; + goto out; + } + } + } + + x = r1+r0; + if(gen3(len, r0, x, UR1)) { + i = '+'; + goto out; + } + + if(gen3(len, r1, x, UR1)) { + i = '+'; + goto out; + } + + x = r1-r0; + if(gen3(len, x, r1, UR0)) { + i = '-'; + goto out; + } + + if(x > r0) { + if(gen3(len, r0, x, UR1)) { + i = '-'; + goto out; + } + } else + if(gen3(len, x, r0, UR0)) { + i = '-'; + goto out; + } + + return 0; + +calcr0: + f1 = flag & (UR0|UR1); + if(f1 == UR1) { + for(i=1; i<=shmax; i++) { + x = r1<<i; + if(x >= mulval) { + if(x == mulval) { + i += 'a'; + goto out; + } + break; + } + } + } + + if(mulval == r1+r0) { + i = '+'; + goto out; + } + if(mulval == r1-r0) { + i = '-'; + goto out; + } + + return 0; + +out: + *--mulcp = i; + return 1; +} + +/* + * hint table has numbers that + * the search algorithm fails on. + * <1000: + * all numbers + * <5000: + * ÷ by 5 + * <10000: + * ÷ by 50 + * <65536: + * ÷ by 250 + */ +Hintab hintab[] = +{ + 683, "b++d+e+", + 687, "b+e++e-", + 691, "b++d+e+", + 731, "b++d+e+", + 811, "b++d+i+", + 821, "b++e+e+", + 843, "b+d++e+", + 851, "b+f-+e-", + 853, "b++e+e+", + 877, "c++++g-", + 933, "b+c++g-", + 981, "c-+e-d+", + 1375, "b+c+b+h-", + 1675, "d+b++h+", + 2425, "c++f-e+", + 2675, "c+d++f-", + 2750, "b+d-b+h-", + 2775, "c-+g-e-", + 3125, "b++e+g+", + 3275, "b+c+g+e+", + 3350, "c++++i+", + 3475, "c-+e-f-", + 3525, "c-+d+g-", + 3625, "c-+e-j+", + 3675, "b+d+d+e+", + 3725, "b+d-+h+", + 3925, "b+d+f-d-", + 4275, "b+g++e+", + 4325, "b+h-+d+", + 4425, "b+b+g-j-", + 4525, "b+d-d+f+", + 4675, "c++d-g+", + 4775, "b+d+b+g-", + 4825, "c+c-+i-", + 4850, "c++++i-", + 4925, "b++e-g-", + 4975, "c+f++e-", + 5500, "b+g-c+d+", + 6700, "d+b++i+", + 9700, "d++++j-", + 11000, "b+f-c-h-", + 11750, "b+d+g+j-", + 12500, "b+c+e-k+", + 13250, "b+d+e-f+", + 13750, "b+h-c-d+", + 14250, "b+g-c+e-", + 14500, "c+f+j-d-", + 14750, "d-g--f+", + 16750, "b+e-d-n+", + 17750, "c+h-b+e+", + 18250, "d+b+h-d+", + 18750, "b+g-++f+", + 19250, "b+e+b+h+", + 19750, "b++h--f-", + 20250, "b+e-l-c+", + 20750, "c++bi+e-", + 21250, "b+i+l+c+", + 22000, "b+e+d-g-", + 22250, "b+d-h+k-", + 22750, "b+d-e-g+", + 23250, "b+c+h+e-", + 23500, "b+g-c-g-", + 23750, "b+g-b+h-", + 24250, "c++g+m-", + 24750, "b+e+e+j-", + 25000, "b++dh+g+", + 25250, "b+e+d-g-", + 25750, "b+e+b+j+", + 26250, "b+h+c+e+", + 26500, "b+h+c+g+", + 26750, "b+d+e+g-", + 27250, "b+e+e+f+", + 27500, "c-i-c-d+", + 27750, "b+bd++j+", + 28250, "d-d-++i-", + 28500, "c+c-h-e-", + 29000, "b+g-d-f+", + 29500, "c+h+++e-", + 29750, "b+g+f-c+", + 30250, "b+f-g-c+", + 33500, "c-f-d-n+", + 33750, "b+d-b+j-", + 34250, "c+e+++i+", + 35250, "e+b+d+k+", + 35500, "c+e+d-g-", + 35750, "c+i-++e+", + 36250, "b+bh-d+e+", + 36500, "c+c-h-e-", + 36750, "d+e--i+", + 37250, "b+g+g+b+", + 37500, "b+h-b+f+", + 37750, "c+be++j-", + 38500, "b+e+b+i+", + 38750, "d+i-b+d+", + 39250, "b+g-l-+d+", + 39500, "b+g-c+g-", + 39750, "b+bh-c+f-", + 40250, "b+bf+d+g-", + 40500, "b+g-c+g+", + 40750, "c+b+i-e+", + 41250, "d++bf+h+", + 41500, "b+j+c+d-", + 41750, "c+f+b+h-", + 42500, "c+h++g+", + 42750, "b+g+d-f-", + 43250, "b+l-e+d-", + 43750, "c+bd+h+f-", + 44000, "b+f+g-d-", + 44250, "b+d-g--f+", + 44500, "c+e+c+h+", + 44750, "b+e+d-h-", + 45250, "b++g+j-g+", + 45500, "c+d+e-g+", + 45750, "b+d-h-e-", + 46250, "c+bd++j+", + 46500, "b+d-c-j-", + 46750, "e-e-b+g-", + 47000, "b+c+d-j-", + 47250, "b+e+e-g-", + 47500, "b+g-c-h-", + 47750, "b+f-c+h-", + 48250, "d--h+n-", + 48500, "b+c-g+m-", + 48750, "b+e+e-g+", + 49500, "c-f+e+j-", + 49750, "c+c+g++f-", + 50000, "b+e+e+k+", + 50250, "b++i++g+", + 50500, "c+g+f-i+", + 50750, "b+e+d+k-", + 51500, "b+i+c-f+", + 51750, "b+bd+g-e-", + 52250, "b+d+g-j+", + 52500, "c+c+f+g+", + 52750, "b+c+e+i+", + 53000, "b+i+c+g+", + 53500, "c+g+g-n+", + 53750, "b+j+d-c+", + 54250, "b+d-g-j-", + 54500, "c-f+e+f+", + 54750, "b+f-+c+g+", + 55000, "b+g-d-g-", + 55250, "b+e+e+g+", + 55500, "b+cd++j+", + 55750, "b+bh-d-f-", + 56250, "c+d-b+j-", + 56500, "c+d+c+i+", + 56750, "b+e+d++h-", + 57000, "b+d+g-f+", + 57250, "b+f-m+d-", + 57750, "b+i+c+e-", + 58000, "b+e+d+h+", + 58250, "c+b+g+g+", + 58750, "d-e-j--e+", + 59000, "d-i-+e+", + 59250, "e--h-m+", + 59500, "c+c-h+f-", + 59750, "b+bh-e+i-", + 60250, "b+bh-e-e-", + 60500, "c+c-g-g-", + 60750, "b+e-l-e-", + 61250, "b+g-g-c+", + 61750, "b+g-c+g+", + 62250, "f--+c-i-", + 62750, "e+f--+g+", + 64750, "b+f+d+p-", +}; +int hintabsize = nelem(hintab); |