diff options
| author | Aurelien Jacquiot <a-jacquiot@ti.com> | 2011-10-04 11:15:51 -0400 |
|---|---|---|
| committer | Mark Salter <msalter@redhat.com> | 2011-10-06 19:48:23 -0400 |
| commit | 09831ca73443bd819ad7993db5409b19c899ba33 (patch) | |
| tree | 4558fb0a5e0e1fcd8582be2155cd9c7498e429db /arch/c6x/lib/mpyll.S | |
| parent | a7f626c1948ab6178d2338831c5ffea7385e9f7f (diff) | |
C6X: library code
Original port to early 2.6 kernel using TI COFF toolchain.
Brought up to date by Mark Salter <msalter@redhat.com>
Signed-off-by: Aurelien Jacquiot <a-jacquiot@ti.com>
Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/c6x/lib/mpyll.S')
| -rw-r--r-- | arch/c6x/lib/mpyll.S | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/arch/c6x/lib/mpyll.S b/arch/c6x/lib/mpyll.S new file mode 100644 index 000000000000..f1034418b4db --- /dev/null +++ b/arch/c6x/lib/mpyll.S @@ -0,0 +1,49 @@ +;; Copyright (C) 2010 Texas Instruments Incorporated +;; Contributed by Mark Salter <msalter@redhat.com>. +;; +;; This program is free software; you can redistribute it and/or modify +;; it under the terms of the GNU General Public License as published by +;; the Free Software Foundation; either version 2 of the License, or +;; (at your option) any later version. +;; +;; This program is distributed in the hope that it will be useful, +;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;; GNU General Public License for more details. +;; +;; You should have received a copy of the GNU General Public License +;; along with this program; if not, write to the Free Software +;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + +#include <linux/linkage.h> + + ;; uint64_t __c6xabi_mpyll(uint64_t x, uint64_t y) + ;; + ;; 64x64 multiply + ;; First compute partial results using 32-bit parts of x and y: + ;; + ;; b63 b32 b31 b0 + ;; ----------------------------- + ;; | 1 | 0 | + ;; ----------------------------- + ;; + ;; P0 = X0*Y0 + ;; P1 = X0*Y1 + X1*Y0 + ;; P2 = X1*Y1 + ;; + ;; result = (P2 << 64) + (P1 << 32) + P0 + ;; + ;; Since the result is also 64-bit, we can skip the P2 term. + + .text +ENTRY(__c6xabi_mpyll) + mpy32u .m1x A4,B4,A1:A0 ; X0*Y0 + b .s2 B3 + || mpy32u .m2x B5,A4,B1:B0 ; X0*Y1 (don't need upper 32-bits) + || mpy32u .m1x A5,B4,A3:A2 ; X1*Y0 (don't need upper 32-bits) + nop + nop + mv .s1 A0,A4 + add .l1x A2,B0,A5 + add .s1 A1,A5,A5 +ENDPROC(__c6xabi_mpyll) |