[PATCH 2/4] zstd: use U16 data type for rankPos

[Maninder Singh]

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@xxxxxxxxxxx>
Signed-off-by: Vaneet Narang <v.narang@xxxxxxxxxxx>
---
 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