WebSVN – planix.SVN – Blame – /os/branches/feature_posix/sys/src/libc/sparc/muldivrt.s

Rev	Author	Line No.	Line
2	-	1	`/*`
		2	`* ulong`
		3	`* _udiv(ulong num, ulong den)`
		4	`* {`
		5	`* int i;`
		6	`* ulong quo;`
		7	`*`
		8	`* if(den == 0)`
		9	`* (ulong)-1 = 0;`
		10	`* quo = num;`
		11	`* if(quo > 1<<(32-1))`
		12	`* quo = 1<<(32-1);`
		13	`* for(i=0; den<quo; i++)`
		14	`* den <<= 1;`
		15	`* quo = 0;`
		16	`* for(; i>=0; i--) {`
		17	`* quo <<= 1;`
		18	`* if(num >= den) {`
		19	`* num -= den;`
		20	`* quo \|= 1;`
		21	`* }`
		22	`* den >>= 1;`
		23	`* }`
		24	`* return quo::num;`
		25	`* }`
		26	`*/`
		27
		28	`#define NOPROF 1`
		29
		30	`/*`
		31	`* calling sequence:`
		32	`* num: 4(R1)`
		33	`* den: 8(R1)`
		34	`* returns`
		35	`* quo: 4(R1)`
		36	`* rem: 8(R1)`
		37	`*/`
		38	`TEXT _udivmod(SB), NOPROF, $-4`
		39
		40	`MOVW $(1<<31), R11`
		41	`MOVW 4(R1), R13 /* numerator */`
		42	`MOVW 8(R1), R10 /* denominator */`
		43	`CMP R10, R0`
		44	`BNE udm20`
		45	`MOVW R0, -1(R0) /* fault -- divide by zero */`
		46	`udm20:`
		47	`MOVW R13, R12`
		48	`CMP R13, R11`
		49	`BLEU udm34`
		50	`MOVW R11, R12`
		51	`udm34:`
		52	`MOVW R0, R11`
		53	`udm38:`
		54	`CMP R10, R12`
		55	`BCC udm54`
		56	`SLL $1, R10`
		57	`ADD $1, R11`
		58	`BA udm38`
		59	`udm54:`
		60	`MOVW R0, R12`
		61	`udm58:`
		62	`CMP R11, R0`
		63	`BL udm8c`
		64	`SLL $1, R12`
		65	`CMP R13, R10`
		66	`BCS udm7c`
		67	`SUB R10, R13`
		68	`OR $1, R12`
		69	`udm7c:`
		70	`SRL $1, R10`
		71	`SUB $1, R11`
		72	`BA udm58`
		73	`udm8c:`
		74	`MOVW R12, 4(R1) /* quotent */`
		75	`MOVW R13, 8(R1) /* remainder */`
		76	`JMPL 8(R15)`
		77
		78	`/*`
		79	`* save working registers`
		80	`* and bring in num/den parameters`
		81	`*/`
		82	`TEXT _unsarg(SB), NOPROF, $-4`
		83	`MOVW R10, 12(R1)`
		84	`MOVW R11, 16(R1)`
		85	`MOVW R12, 20(R1)`
		86	`MOVW R13, 24(R1)`
		87
		88	`MOVW R14, 4(R1)`
		89	`MOVW 32(R1), R14`
		90	`MOVW R14, 8(R1)`
		91
		92	`JMPL 8(R15)`
		93
		94	`/*`
		95	`* save working registers`
		96	`* and bring in absolute value`
		97	`* of num/den parameters`
		98	`*/`
		99	`TEXT _absarg(SB), NOPROF, $-4`
		100	`MOVW R10, 12(R1)`
		101	`MOVW R11, 16(R1)`
		102	`MOVW R12, 20(R1)`
		103	`MOVW R13, 24(R1)`
		104
		105	`MOVW R14, 28(R1)`
		106	`CMP R14, R0`
		107	`BGE ab1`
		108	`SUB R14, R0, R14`
		109	`ab1:`
		110	`MOVW R14, 4(R1) /* numerator */`
		111
		112	`MOVW 32(R1), R14`
		113	`CMP R14, R0`
		114	`BGE ab2`
		115	`SUB R14, R0, R14`
		116	`ab2:`
		117	`MOVW R14, 8(R1) /* denominator */`
		118	`JMPL 8(R15)`
		119
		120	`/*`
		121	`* restore registers and`
		122	`* return to original caller`
		123	`* answer is in R14`
		124	`*/`
		125	`TEXT _retarg(SB), NOPROF, $-4`
		126	`MOVW 12(R1), R10`
		127	`MOVW 16(R1), R11`
		128	`MOVW 20(R1), R12`
		129	`MOVW 24(R1), R13`
		130	`MOVW 0(R1), R15`
		131
		132	`ADD $28, R1`
		133	`JMP 8(R15) /* back to main sequence */`
		134
		135	`/*`
		136	`* calling sequence`
		137	`* num: R14`
		138	`* den: 8(R1)`
		139	`* returns`
		140	`* quo: R14`
		141	`*/`
		142	`TEXT _div(SB), NOPROF, $-4`
		143	`SUB $28, R1 /* 4 reg save, 2 parameters, link */`
		144	`MOVW R15, 0(R1)`
		145
		146	`JMPL _absarg(SB)`
		147	`JMPL _udivmod(SB)`
		148	`MOVW 4(R1), R14`
		149
		150	`MOVW 28(R1), R10 /* clean up the sign */`
		151	`MOVW 32(R1), R11`
		152	`XORCC R11, R10, R0`
		153	`BGE div1`
		154	`SUB R14, R0, R14`
		155	`div1:`
		156
		157	`JMPL _retarg(SB)`
		158	`JMP 8(R15) /* not executed */`
		159
		160	`/*`
		161	`* calling sequence`
		162	`* num: R14`
		163	`* den: 8(R1)`
		164	`* returns`
		165	`* quo: R14`
		166	`*/`
		167	`TEXT _divl(SB), NOPROF, $-4`
		168	`SUB $((4+2+1)4), R1 / 4 reg save, 2 parameters, link */`
		169	`MOVW R15, 0(R1)`
		170
		171	`JMPL _unsarg(SB)`
		172	`JMPL _udivmod(SB)`
		173	`MOVW 4(R1), R14`
		174
		175	`JMPL _retarg(SB)`
		176	`JMP 8(R15) /* not executed */`
		177
		178	`/*`
		179	`* calling sequence`
		180	`* num: R14`
		181	`* den: 8(R1)`
		182	`* returns`
		183	`* rem: R14`
		184	`*/`
		185	`TEXT _mod(SB), NOPROF, $-4`
		186	`SUB $28, R1 /* 4 reg save, 2 parameters, link */`
		187
		188	`MOVW R15, 0(R1)`
		189	`JMPL _absarg(SB)`
		190	`JMPL _udivmod(SB)`
		191	`MOVW 8(R1), R14`
		192
		193	`MOVW 28(R1), R10 /* clean up the sign */`
		194	`CMP R10, R0`
		195	`BGE mod1`
		196	`SUB R14, R0, R14`
		197	`mod1:`
		198
		199	`JMPL _retarg(SB)`
		200	`JMP 8(R15) /* not executed */`
		201
		202	`/*`
		203	`* calling sequence`
		204	`* num: R14`
		205	`* den: 8(R1)`
		206	`* returns`
		207	`* rem: R14`
		208	`*/`
		209	`TEXT _modl(SB), NOPROF, $-4`
		210	`SUB $28, R1 /* 4 reg save, 2 parameters, link */`
		211
		212
		213	`MOVW R15, 0(R1)`
		214	`JMPL _unsarg(SB)`
		215	`JMPL _udivmod(SB)`
		216	`MOVW 8(R1), R14`
		217
		218	`JMPL _retarg(SB)`
		219	`JMP 8(R15) /* not executed */`
		220
		221	`/*`
		222	`* special calling sequence:`
		223	`* arg1 in R14`
		224	`* arg2 in 4(R1), will save R9`
		225	`* nothing in 0(R1), will save R8`
		226	`* result in R14`
		227	`*/`
		228	`TEXT _mul+0(SB), NOPROF, $-4`
		229
		230	`/*`
		231	`* exchange stack and registers`
		232	`*/`
		233	`MOVW R8, 0(R1)`
		234	`MOVW 4(R1), R8`
		235	`MOVW R9, 4(R1)`
		236
		237	`CMP R14, R8`
		238	`BLE mul1`
		239	`MOVW R14, R9`
		240	`MOVW R8, R14`
		241	`MOVW R9, R8`
		242	`mul1:`
		243	`MOVW R14, Y`
		244	`ANDNCC $0xFFF, R14, R0`
		245	`BE mul_shortway`
		246	`ANDCC R0, R0, R9 /* zero partial product and clear N and V cond's */`
		247
		248	`/* long multiply */`
		249	`MULSCC R8, R9, R9 /* 0 */`
		250	`MULSCC R8, R9, R9 /* 1 */`
		251	`MULSCC R8, R9, R9 /* 2 */`
		252	`MULSCC R8, R9, R9 /* 3 */`
		253	`MULSCC R8, R9, R9 /* 4 */`
		254	`MULSCC R8, R9, R9 /* 5 */`
		255	`MULSCC R8, R9, R9 /* 6 */`
		256	`MULSCC R8, R9, R9 /* 7 */`
		257	`MULSCC R8, R9, R9 /* 8 */`
		258	`MULSCC R8, R9, R9 /* 9 */`
		259	`MULSCC R8, R9, R9 /* 10 */`
		260	`MULSCC R8, R9, R9 /* 11 */`
		261	`MULSCC R8, R9, R9 /* 12 */`
		262	`MULSCC R8, R9, R9 /* 13 */`
		263	`MULSCC R8, R9, R9 /* 14 */`
		264	`MULSCC R8, R9, R9 /* 15 */`
		265	`MULSCC R8, R9, R9 /* 16 */`
		266	`MULSCC R8, R9, R9 /* 17 */`
		267	`MULSCC R8, R9, R9 /* 18 */`
		268	`MULSCC R8, R9, R9 /* 19 */`
		269	`MULSCC R8, R9, R9 /* 20 */`
		270	`MULSCC R8, R9, R9 /* 21 */`
		271	`MULSCC R8, R9, R9 /* 22 */`
		272	`MULSCC R8, R9, R9 /* 23 */`
		273	`MULSCC R8, R9, R9 /* 24 */`
		274	`MULSCC R8, R9, R9 /* 25 */`
		275	`MULSCC R8, R9, R9 /* 26 */`
		276	`MULSCC R8, R9, R9 /* 27 */`
		277	`MULSCC R8, R9, R9 /* 28 */`
		278	`MULSCC R8, R9, R9 /* 29 */`
		279	`MULSCC R8, R9, R9 /* 30 */`
		280	`MULSCC R8, R9, R9 /* 31 */`
		281	`MULSCC R0, R9, R9 /* 32; shift only */`
		282
		283	`MOVW Y, R14 /* get low part */`
		284	`BA mul_return`
		285
		286	`mul_shortway:`
		287	`ANDCC R0, R0, R9 /* zero partial product and clear N and V cond's */`
		288	`MULSCC R8, R9, R9 /* 0 */`
		289	`MULSCC R8, R9, R9 /* 1 */`
		290	`MULSCC R8, R9, R9 /* 2 */`
		291	`MULSCC R8, R9, R9 /* 3 */`
		292	`MULSCC R8, R9, R9 /* 4 */`
		293	`MULSCC R8, R9, R9 /* 5 */`
		294	`MULSCC R8, R9, R9 /* 6 */`
		295	`MULSCC R8, R9, R9 /* 7 */`
		296	`MULSCC R8, R9, R9 /* 8 */`
		297	`MULSCC R8, R9, R9 /* 9 */`
		298	`MULSCC R8, R9, R9 /* 10 */`
		299	`MULSCC R8, R9, R9 /* 11 */`
		300	`MULSCC R0, R9, R9 /* 12; shift only */`
		301
		302	`MOVW Y, R8`
		303	`SLL $12, R9`
		304	`SRL $20, R8`
		305	`OR R8, R9, R14`
		306
		307	`mul_return:`
		308	`MOVW 0(R1), R8`
		309	`MOVW 4(R1), R9`
		310	`JMP 8(R15)`

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