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From: Maninder Singh <maninder1.s@samsung.com>
To: akpm@linux-foundation.org, herbert@gondor.apana.org.au,
	davem@davemloft.net, keescook@chromium.org,
	gustavo@embeddedor.com
Cc: joe@perches.com, linux-crypto@vger.kernel.org,
	linux-kernel@vger.kernel.org, a.sahrawat@samsung.com,
	pankaj.m@samsung.com, v.narang@samsung.com,
	Maninder Singh <maninder1.s@samsung.com>
Subject: [PATCH 2/4] zstd: use U16 data type for rankPos
Date: Mon,  3 Jun 2019 14:32:04 +0530	[thread overview]
Message-ID: <1559552526-4317-3-git-send-email-maninder1.s@samsung.com> (raw)
In-Reply-To: <1559552526-4317-1-git-send-email-maninder1.s@samsung.com>

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


Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
Signed-off-by: Vaneet Narang <v.narang@samsung.com>
---
 lib/zstd/huf_compress.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/zstd/huf_compress.c b/lib/zstd/huf_compress.c
index e727812..2203124 100644
--- a/lib/zstd/huf_compress.c
+++ b/lib/zstd/huf_compress.c
@@ -382,8 +382,8 @@ static U32 HUF_setMaxHeight(nodeElt *huffNode, U32 lastNonNull, U32 maxNbBits)
 }
 
 typedef struct {
-	U32 base;
-	U32 curr;
+	U16 base;
+	U16 curr;
 } rankPos;
 
 static void HUF_sort(nodeElt *huffNode, const U32 *count, U32 maxSymbolValue)
-- 
2.7.4


  parent reply	other threads:[~2019-06-03  9:07 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20190603090227epcas5p348327061a3facbb9dfcf662bf2bc196e@epcas5p3.samsung.com>
2019-06-03  9:02 ` [PATCH 0/4] zstd: reduce stack usage Maninder Singh
     [not found]   ` <CGME20190603090232epcas5p1630d0584e8a1aa9495edc819605664fc@epcas5p1.samsung.com>
2019-06-03  9:02     ` [PATCH 1/4] zstd: pass pointer rathen than structure to functions Maninder Singh
2019-06-03 21:41       ` Andrew Morton
2019-06-04 22:43       ` Andrew Morton
2019-06-05 11:57         ` David Sterba
2019-06-05 12:32           ` David Sterba
2019-06-05 21:32             ` Andrew Morton
     [not found]       ` <CGME20190603090232epcas5p1630d0584e8a1aa9495edc819605664fc@epcms5p1>
2019-06-04 13:19         ` Vaneet Narang
2019-06-06 14:10         ` Vaneet Narang
2019-06-06 20:14           ` (2) " Nick Terrell
     [not found]   ` <CGME20190603090236epcas5p1bf0733024f7fb52f8129157b11c8f882@epcas5p1.samsung.com>
2019-06-03  9:02     ` Maninder Singh [this message]
     [not found]   ` <CGME20190603090240epcas5p17d0881686df3fa3042d0b2d659e925b3@epcas5p1.samsung.com>
2019-06-03  9:02     ` [PATCH 3/4] zstd: move params structure to global variable to reduce stack usage Maninder Singh
2019-06-03 21:47       ` Andrew Morton
     [not found]   ` <CGME20190603090245epcas5p4a6cdfdb7ef72bfd36472f43bb4e1e0f1@epcas5p4.samsung.com>
2019-06-03  9:02     ` [PATCH 4/4] zstd: change structure variable from int to char Maninder Singh
2019-06-03 21:49   ` [PATCH 0/4] zstd: reduce stack usage Andrew Morton
     [not found]   ` <CGME20190603090227epcas5p348327061a3facbb9dfcf662bf2bc196e@epcms5p3>
2019-06-04 12:06     ` Vaneet Narang

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