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authorLinus Torvalds <torvalds@linux-foundation.org>2021-09-19 00:45:48 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-09-19 00:45:48 +0300
commitd4d016caa4b85b9aa98d7ec8c84e928621a614bc (patch)
tree1eef0dcde02bb60b6c8183010b5eab5fc0dd8269 /arch/alpha/lib
parentab41f75ee6a06fa9b947a59c8f9de92370463e40 (diff)
downloadlinux-d4d016caa4b85b9aa98d7ec8c84e928621a614bc.tar.xz
alpha: move __udiv_qrnnd library function to arch/alpha/lib/
We already had the implementation for __udiv_qrnnd (unsigned divide for multi-precision arithmetic) as part of the alpha math emulation code. But you can disable the math emulation code - even if you shouldn't - and then the MPI code that actually wants this functionality (and is needed by various crypto functions) will fail to build. So move the extended-precision divide code to be a regular library function, just like all the regular division code is. That way ie is available regardless of math-emulation. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/alpha/lib')
-rw-r--r--arch/alpha/lib/Makefile1
-rw-r--r--arch/alpha/lib/udiv-qrnnd.S165
2 files changed, 166 insertions, 0 deletions
diff --git a/arch/alpha/lib/Makefile b/arch/alpha/lib/Makefile
index 854d5e79979e..1cc74f7b50ef 100644
--- a/arch/alpha/lib/Makefile
+++ b/arch/alpha/lib/Makefile
@@ -14,6 +14,7 @@ ev6-$(CONFIG_ALPHA_EV6) := ev6-
ev67-$(CONFIG_ALPHA_EV67) := ev67-
lib-y = __divqu.o __remqu.o __divlu.o __remlu.o \
+ udiv-qrnnd.o \
udelay.o \
$(ev6-y)memset.o \
$(ev6-y)memcpy.o \
diff --git a/arch/alpha/lib/udiv-qrnnd.S b/arch/alpha/lib/udiv-qrnnd.S
new file mode 100644
index 000000000000..b887aa5428e5
--- /dev/null
+++ b/arch/alpha/lib/udiv-qrnnd.S
@@ -0,0 +1,165 @@
+ # Alpha 21064 __udiv_qrnnd
+ # Copyright (C) 1992, 1994, 1995, 2000 Free Software Foundation, Inc.
+
+ # This file is part of GCC.
+
+ # The GNU MP Library 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.
+
+ # In addition to the permissions in the GNU General Public License, the
+ # Free Software Foundation gives you unlimited permission to link the
+ # compiled version of this file with other programs, and to distribute
+ # those programs without any restriction coming from the use of this
+ # file. (The General Public License restrictions do apply in other
+ # respects; for example, they cover modification of the file, and
+ # distribution when not linked into another program.)
+
+ # This file 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 Library General Public
+ # License for more details.
+
+ # You should have received a copy of the GNU General Public License
+ # along with GCC; see the file COPYING. If not, write to the
+ # Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ # MA 02111-1307, USA.
+#include <asm/export.h>
+
+ .set noreorder
+ .set noat
+
+ .text
+
+ .globl __udiv_qrnnd
+ .ent __udiv_qrnnd
+__udiv_qrnnd:
+ .frame $30,0,$26,0
+ .prologue 0
+
+#define cnt $2
+#define tmp $3
+#define rem_ptr $16
+#define n1 $17
+#define n0 $18
+#define d $19
+#define qb $20
+#define AT $at
+
+ ldiq cnt,16
+ blt d,$largedivisor
+
+$loop1: cmplt n0,0,tmp
+ addq n1,n1,n1
+ bis n1,tmp,n1
+ addq n0,n0,n0
+ cmpule d,n1,qb
+ subq n1,d,tmp
+ cmovne qb,tmp,n1
+ bis n0,qb,n0
+ cmplt n0,0,tmp
+ addq n1,n1,n1
+ bis n1,tmp,n1
+ addq n0,n0,n0
+ cmpule d,n1,qb
+ subq n1,d,tmp
+ cmovne qb,tmp,n1
+ bis n0,qb,n0
+ cmplt n0,0,tmp
+ addq n1,n1,n1
+ bis n1,tmp,n1
+ addq n0,n0,n0
+ cmpule d,n1,qb
+ subq n1,d,tmp
+ cmovne qb,tmp,n1
+ bis n0,qb,n0
+ cmplt n0,0,tmp
+ addq n1,n1,n1
+ bis n1,tmp,n1
+ addq n0,n0,n0
+ cmpule d,n1,qb
+ subq n1,d,tmp
+ cmovne qb,tmp,n1
+ bis n0,qb,n0
+ subq cnt,1,cnt
+ bgt cnt,$loop1
+ stq n1,0(rem_ptr)
+ bis $31,n0,$0
+ ret $31,($26),1
+
+$largedivisor:
+ and n0,1,$4
+
+ srl n0,1,n0
+ sll n1,63,tmp
+ or tmp,n0,n0
+ srl n1,1,n1
+
+ and d,1,$6
+ srl d,1,$5
+ addq $5,$6,$5
+
+$loop2: cmplt n0,0,tmp
+ addq n1,n1,n1
+ bis n1,tmp,n1
+ addq n0,n0,n0
+ cmpule $5,n1,qb
+ subq n1,$5,tmp
+ cmovne qb,tmp,n1
+ bis n0,qb,n0
+ cmplt n0,0,tmp
+ addq n1,n1,n1
+ bis n1,tmp,n1
+ addq n0,n0,n0
+ cmpule $5,n1,qb
+ subq n1,$5,tmp
+ cmovne qb,tmp,n1
+ bis n0,qb,n0
+ cmplt n0,0,tmp
+ addq n1,n1,n1
+ bis n1,tmp,n1
+ addq n0,n0,n0
+ cmpule $5,n1,qb
+ subq n1,$5,tmp
+ cmovne qb,tmp,n1
+ bis n0,qb,n0
+ cmplt n0,0,tmp
+ addq n1,n1,n1
+ bis n1,tmp,n1
+ addq n0,n0,n0
+ cmpule $5,n1,qb
+ subq n1,$5,tmp
+ cmovne qb,tmp,n1
+ bis n0,qb,n0
+ subq cnt,1,cnt
+ bgt cnt,$loop2
+
+ addq n1,n1,n1
+ addq $4,n1,n1
+ bne $6,$Odd
+ stq n1,0(rem_ptr)
+ bis $31,n0,$0
+ ret $31,($26),1
+
+$Odd:
+ /* q' in n0. r' in n1 */
+ addq n1,n0,n1
+
+ cmpult n1,n0,tmp # tmp := carry from addq
+ subq n1,d,AT
+ addq n0,tmp,n0
+ cmovne tmp,AT,n1
+
+ cmpult n1,d,tmp
+ addq n0,1,AT
+ cmoveq tmp,AT,n0
+ subq n1,d,AT
+ cmoveq tmp,AT,n1
+
+ stq n1,0(rem_ptr)
+ bis $31,n0,$0
+ ret $31,($26),1
+
+ .end __udiv_qrnnd
+EXPORT_SYMBOL(__udiv_qrnnd)