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
