^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) ;; SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) ;; Copyright 2010 Free Software Foundation, Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) ;; Contributed by Bernd Schmidt <bernds@codesourcery.com>.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) ;;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) #include <linux/linkage.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) ;; ABI considerations for the divide functions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) ;; The following registers are call-used:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) ;; __c6xabi_divi A0,A1,A2,A4,A6,B0,B1,B2,B4,B5
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) ;; __c6xabi_divu A0,A1,A2,A4,A6,B0,B1,B2,B4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) ;; __c6xabi_remi A1,A2,A4,A5,A6,B0,B1,B2,B4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) ;; __c6xabi_remu A1,A4,A5,A7,B0,B1,B2,B4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) ;;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) ;; In our implementation, divu and remu are leaf functions,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) ;; while both divi and remi call into divu.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) ;; A0 is not clobbered by any of the functions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) ;; divu does not clobber B2 either, which is taken advantage of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) ;; in remi.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) ;; divi uses B5 to hold the original return address during
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) ;; the call to divu.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) ;; remi uses B2 and A5 to hold the input values during the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) ;; call to divu. It stores B3 in on the stack.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) .text
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) ENTRY(__c6xabi_divi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) call .s2 __c6xabi_divu
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) || mv .d2 B3, B5
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) || cmpgt .l1 0, A4, A1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) || cmpgt .l2 0, B4, B1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) [A1] neg .l1 A4, A4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) || [B1] neg .l2 B4, B4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) || xor .s1x A1, B1, A1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) [A1] addkpc .s2 _divu_ret, B3, 4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) _divu_ret:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) neg .l1 A4, A4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) || mv .l2 B3,B5
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) || ret .s2 B5
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) nop 5
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) ENDPROC(__c6xabi_divi)