18c2ecf20Sopenharmony_ci/* SPDX-License-Identifier: GPL-2.0 */ 28c2ecf20Sopenharmony_ci#include <linux/linkage.h> 38c2ecf20Sopenharmony_ci 48c2ecf20Sopenharmony_ci/* 58c2ecf20Sopenharmony_ci* 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 __modsi3 138c2ecf20Sopenharmony_ci .type __modsi3, @function 148c2ecf20Sopenharmony_ci .ent __modsi3 158c2ecf20Sopenharmony_ci 168c2ecf20Sopenharmony_ci__modsi3: 178c2ecf20Sopenharmony_ci .frame r1, 0, r15 188c2ecf20Sopenharmony_ci 198c2ecf20Sopenharmony_ci addik r1, r1, -16 208c2ecf20Sopenharmony_ci swi r28, r1, 0 218c2ecf20Sopenharmony_ci swi r29, r1, 4 228c2ecf20Sopenharmony_ci swi r30, r1, 8 238c2ecf20Sopenharmony_ci swi r31, r1, 12 248c2ecf20Sopenharmony_ci 258c2ecf20Sopenharmony_ci beqi r6, div_by_zero /* div_by_zero division error */ 268c2ecf20Sopenharmony_ci beqi r5, result_is_zero /* result is zero */ 278c2ecf20Sopenharmony_ci bgeid r5, r5_pos 288c2ecf20Sopenharmony_ci /* get the sign of the result [ depends only on the first arg] */ 298c2ecf20Sopenharmony_ci add r28, r5, r0 308c2ecf20Sopenharmony_ci rsubi r5, r5, 0 /* make r5 positive */ 318c2ecf20Sopenharmony_cir5_pos: 328c2ecf20Sopenharmony_ci bgei r6, r6_pos 338c2ecf20Sopenharmony_ci rsubi r6, r6, 0 /* make r6 positive */ 348c2ecf20Sopenharmony_cir6_pos: 358c2ecf20Sopenharmony_ci addik r3, r0, 0 /* clear mod */ 368c2ecf20Sopenharmony_ci addik r30, r0, 0 /* clear div */ 378c2ecf20Sopenharmony_ci addik r29, r0, 32 /* initialize the loop count */ 388c2ecf20Sopenharmony_ci/* first part try to find the first '1' in the r5 */ 398c2ecf20Sopenharmony_cidiv1: 408c2ecf20Sopenharmony_ci add r5, r5, r5 /* left shift logical r5 */ 418c2ecf20Sopenharmony_ci bgeid r5, div1 428c2ecf20Sopenharmony_ci addik r29, r29, -1 438c2ecf20Sopenharmony_cidiv2: 448c2ecf20Sopenharmony_ci /* left shift logical r5 get the '1' into the carry */ 458c2ecf20Sopenharmony_ci add r5, r5, r5 468c2ecf20Sopenharmony_ci addc r3, r3, r3 /* move that bit into the mod register */ 478c2ecf20Sopenharmony_ci rsub r31, r6, r3 /* try to subtract (r30 a r6) */ 488c2ecf20Sopenharmony_ci blti r31, mod_too_small 498c2ecf20Sopenharmony_ci /* move the r31 to mod since the result was positive */ 508c2ecf20Sopenharmony_ci or r3, r0, r31 518c2ecf20Sopenharmony_ci addik r30, r30, 1 528c2ecf20Sopenharmony_cimod_too_small: 538c2ecf20Sopenharmony_ci addik r29, r29, -1 548c2ecf20Sopenharmony_ci beqi r29, loop_end 558c2ecf20Sopenharmony_ci add r30, r30, r30 /* shift in the '1' into div */ 568c2ecf20Sopenharmony_ci bri div2 /* div2 */ 578c2ecf20Sopenharmony_ciloop_end: 588c2ecf20Sopenharmony_ci bgei r28, return_here 598c2ecf20Sopenharmony_ci brid return_here 608c2ecf20Sopenharmony_ci rsubi r3, r3, 0 /* negate the result */ 618c2ecf20Sopenharmony_cidiv_by_zero: 628c2ecf20Sopenharmony_ciresult_is_zero: 638c2ecf20Sopenharmony_ci or r3, r0, r0 /* set result to 0 [both mod as well as div are 0] */ 648c2ecf20Sopenharmony_cireturn_here: 658c2ecf20Sopenharmony_ci/* restore values of csrs and that of r3 and the divisor and the dividend */ 668c2ecf20Sopenharmony_ci lwi r28, r1, 0 678c2ecf20Sopenharmony_ci lwi r29, r1, 4 688c2ecf20Sopenharmony_ci lwi r30, r1, 8 698c2ecf20Sopenharmony_ci lwi r31, r1, 12 708c2ecf20Sopenharmony_ci rtsd r15, 8 718c2ecf20Sopenharmony_ci addik r1, r1, 16 728c2ecf20Sopenharmony_ci 738c2ecf20Sopenharmony_ci.size __modsi3, . - __modsi3 748c2ecf20Sopenharmony_ci.end __modsi3 75