18c2ecf20Sopenharmony_ci/* SPDX-License-Identifier: GPL-2.0 */ 28c2ecf20Sopenharmony_ci#include <linux/linkage.h> 38c2ecf20Sopenharmony_ci 48c2ecf20Sopenharmony_ci/* 58c2ecf20Sopenharmony_ci* Unsigned divide operation. 68c2ecf20Sopenharmony_ci* Input : Divisor in Reg r5 78c2ecf20Sopenharmony_ci* Dividend in Reg r6 88c2ecf20Sopenharmony_ci* Output: Result in Reg r3 98c2ecf20Sopenharmony_ci*/ 108c2ecf20Sopenharmony_ci 118c2ecf20Sopenharmony_ci .text 128c2ecf20Sopenharmony_ci .globl __udivsi3 138c2ecf20Sopenharmony_ci .type __udivsi3, @function 148c2ecf20Sopenharmony_ci .ent __udivsi3 158c2ecf20Sopenharmony_ci 168c2ecf20Sopenharmony_ci__udivsi3: 178c2ecf20Sopenharmony_ci 188c2ecf20Sopenharmony_ci .frame r1, 0, r15 198c2ecf20Sopenharmony_ci 208c2ecf20Sopenharmony_ci addik r1, r1, -12 218c2ecf20Sopenharmony_ci swi r29, r1, 0 228c2ecf20Sopenharmony_ci swi r30, r1, 4 238c2ecf20Sopenharmony_ci swi r31, r1, 8 248c2ecf20Sopenharmony_ci 258c2ecf20Sopenharmony_ci beqi r6, div_by_zero /* div_by_zero /* division error */ 268c2ecf20Sopenharmony_ci beqid r5, result_is_zero /* result is zero */ 278c2ecf20Sopenharmony_ci addik r30, r0, 0 /* clear mod */ 288c2ecf20Sopenharmony_ci addik r29, r0, 32 /* initialize the loop count */ 298c2ecf20Sopenharmony_ci 308c2ecf20Sopenharmony_ci/* check if r6 and r5 are equal - if yes, return 1 */ 318c2ecf20Sopenharmony_ci rsub r18, r5, r6 328c2ecf20Sopenharmony_ci beqid r18, return_here 338c2ecf20Sopenharmony_ci addik r3, r0, 1 348c2ecf20Sopenharmony_ci 358c2ecf20Sopenharmony_ci/* check if (uns)r6 is greater than (uns)r5. in that case, just return 0 */ 368c2ecf20Sopenharmony_ci xor r18, r5, r6 378c2ecf20Sopenharmony_ci bgeid r18, 16 388c2ecf20Sopenharmony_ci add r3, r0, r0 /* we would anyways clear r3 */ 398c2ecf20Sopenharmony_ci blti r6, return_here /* r6[bit 31 = 1] hence is greater */ 408c2ecf20Sopenharmony_ci bri checkr6 418c2ecf20Sopenharmony_ci rsub r18, r6, r5 /* microblazecmp */ 428c2ecf20Sopenharmony_ci blti r18, return_here 438c2ecf20Sopenharmony_ci 448c2ecf20Sopenharmony_ci/* if r6 [bit 31] is set, then return result as 1 */ 458c2ecf20Sopenharmony_cicheckr6: 468c2ecf20Sopenharmony_ci bgti r6, div0 478c2ecf20Sopenharmony_ci brid return_here 488c2ecf20Sopenharmony_ci addik r3, r0, 1 498c2ecf20Sopenharmony_ci 508c2ecf20Sopenharmony_ci/* first part try to find the first '1' in the r5 */ 518c2ecf20Sopenharmony_cidiv0: 528c2ecf20Sopenharmony_ci blti r5, div2 538c2ecf20Sopenharmony_cidiv1: 548c2ecf20Sopenharmony_ci add r5, r5, r5 /* left shift logical r5 */ 558c2ecf20Sopenharmony_ci bgtid r5, div1 568c2ecf20Sopenharmony_ci addik r29, r29, -1 578c2ecf20Sopenharmony_cidiv2: 588c2ecf20Sopenharmony_ci/* left shift logical r5 get the '1' into the carry */ 598c2ecf20Sopenharmony_ci add r5, r5, r5 608c2ecf20Sopenharmony_ci addc r30, r30, r30 /* move that bit into the mod register */ 618c2ecf20Sopenharmony_ci rsub r31, r6, r30 /* try to subtract (r30 a r6) */ 628c2ecf20Sopenharmony_ci blti r31, mod_too_small 638c2ecf20Sopenharmony_ci/* move the r31 to mod since the result was positive */ 648c2ecf20Sopenharmony_ci or r30, r0, r31 658c2ecf20Sopenharmony_ci addik r3, r3, 1 668c2ecf20Sopenharmony_cimod_too_small: 678c2ecf20Sopenharmony_ci addik r29, r29, -1 688c2ecf20Sopenharmony_ci beqi r29, loop_end 698c2ecf20Sopenharmony_ci add r3, r3, r3 /* shift in the '1' into div */ 708c2ecf20Sopenharmony_ci bri div2 /* div2 */ 718c2ecf20Sopenharmony_ciloop_end: 728c2ecf20Sopenharmony_ci bri return_here 738c2ecf20Sopenharmony_cidiv_by_zero: 748c2ecf20Sopenharmony_ciresult_is_zero: 758c2ecf20Sopenharmony_ci or r3, r0, r0 /* set result to 0 */ 768c2ecf20Sopenharmony_cireturn_here: 778c2ecf20Sopenharmony_ci/* restore values of csrs and that of r3 and the divisor and the dividend */ 788c2ecf20Sopenharmony_ci lwi r29, r1, 0 798c2ecf20Sopenharmony_ci lwi r30, r1, 4 808c2ecf20Sopenharmony_ci lwi r31, r1, 8 818c2ecf20Sopenharmony_ci rtsd r15, 8 828c2ecf20Sopenharmony_ci addik r1, r1, 12 838c2ecf20Sopenharmony_ci 848c2ecf20Sopenharmony_ci.size __udivsi3, . - __udivsi3 858c2ecf20Sopenharmony_ci.end __udivsi3 86