The patch titled
Subject: zstd: use U16 data type for rankPos
has been added to the -mm tree. Its filename is
zstd-use-u16-data-type-for-rankpos.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/zstd-use-u16-data-type-for-rankpos.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/zstd-use-u16-data-type-for-rankpos.patch
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------------------------------------------------------
From: Maninder Singh <maninder1.s@xxxxxxxxxxx>
Subject: zstd: use U16 data type for rankPos
rankPos structure variables value can not be more than 512. So it can
easily be declared as U16 rather than U32.
It will reduce stack usage of HUF_sort from 256 bytes to 128 bytes
original:
e92ddbf0 push {r4, r5, r6, r7, r8, r9, fp, ip, lr, pc}
e24cb004 sub fp, ip, #4
e24ddc01 sub sp, sp, #256 ; 0x100
changed:
e92ddbf0 push {r4, r5, r6, r7, r8, r9, fp, ip, lr, pc}
e24cb004 sub fp, ip, #4
e24dd080 sub sp, sp, #128 ; 0x80
Link: http://lkml.kernel.org/r/1559552526-4317-3-git-send-email-maninder1.s@xxxxxxxxxxx
Signed-off-by: Maninder Singh <maninder1.s@xxxxxxxxxxx>
Signed-off-by: Vaneet Narang <v.narang@xxxxxxxxxxx>
Cc: Amit Sahrawat <a.sahrawat@xxxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: Joe Perches <joe@xxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: <pankaj.m@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/zstd/huf_compress.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/lib/zstd/huf_compress.c~zstd-use-u16-data-type-for-rankpos
+++ a/lib/zstd/huf_compress.c
@@ -382,8 +382,8 @@ static U32 HUF_setMaxHeight(nodeElt *huf
}
typedef struct {
- U32 base;
- U32 curr;
+ U16 base;
+ U16 curr;
} rankPos;
static void HUF_sort(nodeElt *huffNode, const U32 *count, U32 maxSymbolValue)
_
Patches currently in -mm which might be from maninder1.s@xxxxxxxxxxx are
zstd-pass-pointer-rathen-than-structure-to-functions.patch
zstd-use-u16-data-type-for-rankpos.patch
zstd-move-params-structure-to-global-variable-to-reduce-stack-usage.patch
zstd-change-structure-variable-from-int-to-char.patch
