18c2ecf20Sopenharmony_ci/* SPDX-License-Identifier: GPL-2.0 */ 28c2ecf20Sopenharmony_ci#include <linux/linkage.h> 38c2ecf20Sopenharmony_ci 48c2ecf20Sopenharmony_ci/* 58c2ecf20Sopenharmony_ci * Unsigned modulo operation for 32 bit integers. 68c2ecf20Sopenharmony_ci * Input : op1 in Reg r5 78c2ecf20Sopenharmony_ci * op2 in Reg r6 88c2ecf20Sopenharmony_ci * Output: op1 mod op2 in Reg r3 98c2ecf20Sopenharmony_ci */ 108c2ecf20Sopenharmony_ci 118c2ecf20Sopenharmony_ci .text 128c2ecf20Sopenharmony_ci .globl __umodsi3 138c2ecf20Sopenharmony_ci .type __umodsi3, @function 148c2ecf20Sopenharmony_ci .ent __umodsi3 158c2ecf20Sopenharmony_ci 168c2ecf20Sopenharmony_ci__umodsi3: 178c2ecf20Sopenharmony_ci .frame r1, 0, r15 188c2ecf20Sopenharmony_ci 198c2ecf20Sopenharmony_ci addik r1, r1, -12 208c2ecf20Sopenharmony_ci swi r29, r1, 0 218c2ecf20Sopenharmony_ci swi r30, r1, 4 228c2ecf20Sopenharmony_ci swi r31, r1, 8 238c2ecf20Sopenharmony_ci 248c2ecf20Sopenharmony_ci beqi r6, div_by_zero /* div_by_zero - division error */ 258c2ecf20Sopenharmony_ci beqid r5, result_is_zero /* result is zero */ 268c2ecf20Sopenharmony_ci addik r3, r0, 0 /* clear div */ 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 0 */ 318c2ecf20Sopenharmony_ci rsub r18, r5, r6 328c2ecf20Sopenharmony_ci beqi r18, return_here 338c2ecf20Sopenharmony_ci 348c2ecf20Sopenharmony_ci/* check if (uns)r6 is greater than (uns)r5. in that case, just return r5 */ 358c2ecf20Sopenharmony_ci xor r18, r5, r6 368c2ecf20Sopenharmony_ci bgeid r18, 16 378c2ecf20Sopenharmony_ci addik r3, r5, 0 388c2ecf20Sopenharmony_ci blti r6, return_here 398c2ecf20Sopenharmony_ci bri $lcheckr6 408c2ecf20Sopenharmony_ci rsub r18, r5, r6 /* microblazecmp */ 418c2ecf20Sopenharmony_ci bgti r18, return_here 428c2ecf20Sopenharmony_ci 438c2ecf20Sopenharmony_ci/* if r6 [bit 31] is set, then return result as r5-r6 */ 448c2ecf20Sopenharmony_ci$lcheckr6: 458c2ecf20Sopenharmony_ci bgtid r6, div0 468c2ecf20Sopenharmony_ci addik r3, r0, 0 478c2ecf20Sopenharmony_ci addik r18, r0, 0x7fffffff 488c2ecf20Sopenharmony_ci and r5, r5, r18 498c2ecf20Sopenharmony_ci and r6, r6, r18 508c2ecf20Sopenharmony_ci brid return_here 518c2ecf20Sopenharmony_ci rsub r3, r6, r5 528c2ecf20Sopenharmony_ci/* first part: try to find the first '1' in the r5 */ 538c2ecf20Sopenharmony_cidiv0: 548c2ecf20Sopenharmony_ci blti r5, div2 558c2ecf20Sopenharmony_cidiv1: 568c2ecf20Sopenharmony_ci add r5, r5, r5 /* left shift logical r5 */ 578c2ecf20Sopenharmony_ci bgeid r5, div1 588c2ecf20Sopenharmony_ci addik r29, r29, -1 598c2ecf20Sopenharmony_cidiv2: 608c2ecf20Sopenharmony_ci /* left shift logical r5 get the '1' into the carry */ 618c2ecf20Sopenharmony_ci add r5, r5, r5 628c2ecf20Sopenharmony_ci addc r3, r3, r3 /* move that bit into the mod register */ 638c2ecf20Sopenharmony_ci rsub r31, r6, r3 /* try to subtract (r3 a r6) */ 648c2ecf20Sopenharmony_ci blti r31, mod_too_small 658c2ecf20Sopenharmony_ci /* move the r31 to mod since the result was positive */ 668c2ecf20Sopenharmony_ci or r3, r0, r31 678c2ecf20Sopenharmony_ci addik r30, r30, 1 688c2ecf20Sopenharmony_cimod_too_small: 698c2ecf20Sopenharmony_ci addik r29, r29, -1 708c2ecf20Sopenharmony_ci beqi r29, loop_end 718c2ecf20Sopenharmony_ci add r30, r30, r30 /* shift in the '1' into div */ 728c2ecf20Sopenharmony_ci bri div2 /* div2 */ 738c2ecf20Sopenharmony_ciloop_end: 748c2ecf20Sopenharmony_ci bri return_here 758c2ecf20Sopenharmony_cidiv_by_zero: 768c2ecf20Sopenharmony_ciresult_is_zero: 778c2ecf20Sopenharmony_ci or r3, r0, r0 /* set result to 0 */ 788c2ecf20Sopenharmony_cireturn_here: 798c2ecf20Sopenharmony_ci/* restore values of csrs and that of r3 and the divisor and the dividend */ 808c2ecf20Sopenharmony_ci lwi r29, r1, 0 818c2ecf20Sopenharmony_ci lwi r30, r1, 4 828c2ecf20Sopenharmony_ci lwi r31, r1, 8 838c2ecf20Sopenharmony_ci rtsd r15, 8 848c2ecf20Sopenharmony_ci addik r1, r1, 12 858c2ecf20Sopenharmony_ci 868c2ecf20Sopenharmony_ci.size __umodsi3, . - __umodsi3 878c2ecf20Sopenharmony_ci.end __umodsi3 88