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Diffstat (limited to 'arch/c6x/lib/divu.S')
-rw-r--r-- | arch/c6x/lib/divu.S | 86 |
1 files changed, 0 insertions, 86 deletions
diff --git a/arch/c6x/lib/divu.S b/arch/c6x/lib/divu.S deleted file mode 100644 index f0f6082944c2..000000000000 --- a/arch/c6x/lib/divu.S +++ /dev/null @@ -1,86 +0,0 @@ -;; SPDX-License-Identifier: GPL-2.0-or-later -;; Copyright 2010 Free Software Foundation, Inc. -;; Contributed by Bernd Schmidt <bernds@codesourcery.com>. -;; - -#include <linux/linkage.h> - - ;; ABI considerations for the divide functions - ;; The following registers are call-used: - ;; __c6xabi_divi A0,A1,A2,A4,A6,B0,B1,B2,B4,B5 - ;; __c6xabi_divu A0,A1,A2,A4,A6,B0,B1,B2,B4 - ;; __c6xabi_remi A1,A2,A4,A5,A6,B0,B1,B2,B4 - ;; __c6xabi_remu A1,A4,A5,A7,B0,B1,B2,B4 - ;; - ;; In our implementation, divu and remu are leaf functions, - ;; while both divi and remi call into divu. - ;; A0 is not clobbered by any of the functions. - ;; divu does not clobber B2 either, which is taken advantage of - ;; in remi. - ;; divi uses B5 to hold the original return address during - ;; the call to divu. - ;; remi uses B2 and A5 to hold the input values during the - ;; call to divu. It stores B3 in on the stack. - - .text -ENTRY(__c6xabi_divu) - ;; We use a series of up to 31 subc instructions. First, we find - ;; out how many leading zero bits there are in the divisor. This - ;; gives us both a shift count for aligning (shifting) the divisor - ;; to the, and the number of times we have to execute subc. - - ;; At the end, we have both the remainder and most of the quotient - ;; in A4. The top bit of the quotient is computed first and is - ;; placed in A2. - - ;; Return immediately if the dividend is zero. - mv .s2x A4, B1 - [B1] lmbd .l2 1, B4, B1 -|| [!B1] b .s2 B3 ; RETURN A -|| [!B1] mvk .d2 1, B4 - mv .l1x B1, A6 -|| shl .s2 B4, B1, B4 - - ;; The loop performs a maximum of 28 steps, so we do the - ;; first 3 here. - cmpltu .l1x A4, B4, A2 - [!A2] sub .l1x A4, B4, A4 -|| shru .s2 B4, 1, B4 -|| xor .s1 1, A2, A2 - - shl .s1 A2, 31, A2 -|| [B1] subc .l1x A4,B4,A4 -|| [B1] add .s2 -1, B1, B1 - [B1] subc .l1x A4,B4,A4 -|| [B1] add .s2 -1, B1, B1 - - ;; RETURN A may happen here (note: must happen before the next branch) -_divu_loop: - cmpgt .l2 B1, 7, B0 -|| [B1] subc .l1x A4,B4,A4 -|| [B1] add .s2 -1, B1, B1 - [B1] subc .l1x A4,B4,A4 -|| [B1] add .s2 -1, B1, B1 -|| [B0] b .s1 _divu_loop - [B1] subc .l1x A4,B4,A4 -|| [B1] add .s2 -1, B1, B1 - [B1] subc .l1x A4,B4,A4 -|| [B1] add .s2 -1, B1, B1 - [B1] subc .l1x A4,B4,A4 -|| [B1] add .s2 -1, B1, B1 - [B1] subc .l1x A4,B4,A4 -|| [B1] add .s2 -1, B1, B1 - [B1] subc .l1x A4,B4,A4 -|| [B1] add .s2 -1, B1, B1 - ;; loop backwards branch happens here - - ret .s2 B3 -|| mvk .s1 32, A1 - sub .l1 A1, A6, A6 - shl .s1 A4, A6, A4 - shru .s1 A4, 1, A4 -|| sub .l1 A6, 1, A6 - or .l1 A2, A4, A4 - shru .s1 A4, A6, A4 - nop -ENDPROC(__c6xabi_divu) |