diff options
| -rw-r--r-- | cgpas.c | 74 | ||||
| -rw-r--r-- | cgptoc.h | 21 | ||||
| -rw-r--r-- | cgpwas.c | 65 |
3 files changed, 160 insertions, 0 deletions
@@ -8,6 +8,7 @@ #include <stdio.h> #include <string.h> #include <ctype.h> +#include <stdlib.h> #include "cgport.h" @@ -539,6 +540,7 @@ static unsigned char real_reg_num [32] = #define as_mtlr(rs) as_mtspr (8,rs) #define as_mtctr(rs) as_mtspr (9,rs) #define as_mtspr(spr,rs) store_instruction ((31<<26)|(reg_num(rs)<<21)|(spr<<16)|(467<<1)); +#define as_mulhw(rd,ra,rb) as_i_dab (rd,ra,rb,75) #define as_mulli(rd,ra,si) as_i_dai (7,rd,ra,si) #define as_mullw(rd,ra,rb) as_i_dab (rd,ra,rb,235) #define as_mullwo_(rd,ra,rb)as_i_dabo_ (rd,ra,rb,235) @@ -1281,6 +1283,54 @@ static void as_mulo_instruction (struct instruction *instruction) as_mullwo_ (r,r,reg); } +/* + From The PowerPC Compiler WriterÕs Guide, + Warren, Henry S., Jr., IBM Research Report RC 18601 [1992]. Changing Division by a + Constant to Multiplication in TwoÕs Complement Arithmetic, (December 21), + Granlund, Torbjorn and Montgomery, Peter L. [1994]. SIGPLAN Notices, 29 (June), 61. +*/ + +struct ms magic (int d) + /* must have 2 <= d <= 231-1 or -231 <= d <= -2 */ +{ + int p; + unsigned int ad, anc, delta, q1, r1, q2, r2, t; + const unsigned int two31 = 2147483648;/* 231 */ + struct ms mag; + + ad = abs(d); + t = two31 + ((unsigned int)d >> 31); + anc = t - 1 - t%ad; /* absolute value of nc */ + p = 31; /* initialize p */ + q1 = two31/anc; /* initialize q1 = 2p/abs(nc) */ + r1 = two31 - q1*anc;/* initialize r1 = rem(2p,abs(nc)) */ + q2 = two31/ad; /* initialize q2 = 2p/abs(d) */ + r2 = two31 - q2*ad; /* initialize r2 = rem(2p,abs(d)) */ + + do { + p = p + 1; + q1 = 2*q1; /* update q1 = 2p/abs(nc) */ + r1 = 2*r1; /* update r1 = rem(2p/abs(nc)) */ + if (r1 >= anc) {/* must be unsigned comparison */ + q1 = q1 + 1; + r1 = r1 - anc; + } + q2 = 2*q2; /* update q2 = 2p/abs(d) */ + r2 = 2*r2; /* update r2 = rem(2p/abs(d)) */ + if (r2 >= ad) { /* must be unsigned comparison */ + q2 = q2 + 1; + r2 = r2 - ad; + } + delta = ad - r2; + } while (q1 < delta || (q1 == delta && r1 == 0)); + + mag.m = q2 + 1; + if (d < 0) mag.m = -mag.m; /* resulting magic number */ + mag.s = p - 32; /* resulting shift */ + + return mag; +} + static void as_div_instruction (struct instruction *instruction) { int reg; @@ -1307,6 +1357,30 @@ static void as_div_instruction (struct instruction *instruction) as_addze (sd_reg,sd_reg); return; + } else if (i>1 || i<-1){ + struct ms ms; + + ms=magic (i); + + sd_reg=instruction->instruction_parameters[1].parameter_data.reg.r; + + as_lis (REGISTER_O0,(ms.m-(WORD)ms.m)>>16); + as_addi (REGISTER_O0,REGISTER_O0,(WORD)ms.m); + as_mulhw (REGISTER_O0,REGISTER_O0,sd_reg); + if (i>=0){ + if (ms.m<0) + as_add (REGISTER_O0,REGISTER_O0,sd_reg); + as_srwi (sd_reg,sd_reg,31); + } else { + if (ms.m>=0) + as_sub (REGISTER_O0,REGISTER_O0,sd_reg); + as_srwi (sd_reg,REGISTER_O0,31); + } + if (ms.s>0) + as_srawi (REGISTER_O0,REGISTER_O0,ms.s); + as_add (sd_reg,sd_reg,REGISTER_O0); + + return; } } diff --git a/cgptoc.h b/cgptoc.h new file mode 100644 index 0000000..dcd0f86 --- /dev/null +++ b/cgptoc.h @@ -0,0 +1,21 @@ + +struct toc_label { + int toc_t_label_number; + struct label * toc_label_label; + int toc_label_offset; + struct toc_label * toc_label_next; + struct toc_label * toc_next; +}; + +extern struct toc_label *toc_labels,**last_toc_next_p; + +extern int make_toc_label (struct label *label,int offset); +extern struct toc_label *new_toc_label (struct label *label,int offset); +extern void initialize_toc (void); + +extern int t_label_number; + +struct ms { int m; int s; }; + +extern struct ms magic (int d); + @@ -2052,6 +2052,71 @@ static void w_as_div_instruction (struct instruction *instruction) w_as_register_newline (sd_reg); return; + } else if (i>1 || i<-1){ + struct ms ms; + + ms=magic (i); + + sd_reg=instruction->instruction_parameters[1].parameter_data.reg.r; + + w_as_opcode ("lis"); + w_as_register_comma (REGISTER_O0); + w_as_immediate ((ms.m-(WORD)ms.m)>>16); + w_as_newline(); + + w_as_opcode ("addi"); + w_as_register_comma (REGISTER_O0); + w_as_register_comma (REGISTER_O0); + w_as_immediate ((WORD)ms.m); + w_as_newline(); + + w_as_opcode ("mulhw"); + w_as_register_comma (REGISTER_O0); + w_as_register_comma (REGISTER_O0); + w_as_register_newline (sd_reg); + + if (i>=0){ + if (ms.m<0){ + w_as_opcode ("add"); + w_as_register_comma (REGISTER_O0); + w_as_register_comma (REGISTER_O0); + w_as_register_newline (sd_reg); + } + + w_as_opcode ("srwi"); + w_as_register_comma (sd_reg); + w_as_register_comma (sd_reg); + w_as_immediate (31); + w_as_newline(); + } else { + if (ms.m>=0){ + w_as_opcode ("sub"); + w_as_register_comma (REGISTER_O0); + w_as_register_comma (REGISTER_O0); + w_as_register_newline (sd_reg); + } + + w_as_opcode ("srwi"); + w_as_register_comma (sd_reg); + w_as_register_comma (REGISTER_O0); + w_as_immediate (31); + w_as_newline(); + } + + if (ms.s>0){ + w_as_opcode ("srawi"); + w_as_register_comma (REGISTER_O0); + w_as_register_comma (REGISTER_O0); + w_as_immediate (ms.s); + w_as_newline(); + } + + w_as_opcode ("add"); + w_as_register_comma (sd_reg); + w_as_register_comma (sd_reg); + w_as_register_newline (REGISTER_O0); + + return; } } |