From: Stella Lau <laus@fb.com>
Date: Thu, 20 Jul 2017 00:24:09 +0000 (-0700)
Subject: Fix off-by-one in size calculations
X-Git-Tag: v1.3.1^2~12^2~7^2~16
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=13a01ffb27f58d24dae8dc56c1ef75f1743cca27;p=thirdparty%2Fzstd.git

Fix off-by-one in size calculations
---

diff --git a/contrib/long_distance_matching/circular_buffer_table.c b/contrib/long_distance_matching/circular_buffer_table.c
index 9429fbcde..ad7ae9e10 100644
--- a/contrib/long_distance_matching/circular_buffer_table.c
+++ b/contrib/long_distance_matching/circular_buffer_table.c
@@ -11,7 +11,8 @@
 #define HASH_BUCKET_SIZE (1 << (HASH_BUCKET_SIZE_LOG))
 
 // TODO: rename. Number of hash buckets.
-#define LDM_HASHLOG ((LDM_MEMORY_USAGE)-4-HASH_BUCKET_SIZE_LOG)
+// TODO: Link to HASH_ENTRY_SIZE_LOG
+#define LDM_HASHLOG ((LDM_MEMORY_USAGE)-3-(HASH_BUCKET_SIZE_LOG))
 //#define ZSTD_SKIP
 
 struct LDM_hashTable {
diff --git a/contrib/long_distance_matching/ldm.c b/contrib/long_distance_matching/ldm.c
index 6e9addf73..9ffbab48d 100644
--- a/contrib/long_distance_matching/ldm.c
+++ b/contrib/long_distance_matching/ldm.c
@@ -6,12 +6,12 @@
 
 
 #define LDM_HASHTABLESIZE (1 << (LDM_MEMORY_USAGE))
-//#define LDM_HASH_ENTRY_SIZE 4
+#define LDM_HASH_ENTRY_SIZE_LOG 3
 #define LDM_HASHTABLESIZE_U32 ((LDM_HASHTABLESIZE) >> 2)
-#define LDM_HASHTABLESIZE_U64 ((LDM_HASHTABLESIZE) >> 4)
+#define LDM_HASHTABLESIZE_U64 ((LDM_HASHTABLESIZE) >> 3)
 
 // Insert every (HASH_ONLY_EVERY + 1) into the hash table.
-#define HASH_ONLY_EVERY_LOG (LDM_WINDOW_SIZE_LOG-((LDM_MEMORY_USAGE) - 4))
+#define HASH_ONLY_EVERY_LOG (LDM_WINDOW_SIZE_LOG-((LDM_MEMORY_USAGE) - (LDM_HASH_ENTRY_SIZE_LOG)))
 #define HASH_ONLY_EVERY ((1 << HASH_ONLY_EVERY_LOG) - 1)
 
 #define ML_BITS 4
diff --git a/contrib/long_distance_matching/ldm.h b/contrib/long_distance_matching/ldm.h
index 1d5b2f13b..04b6410c2 100644
--- a/contrib/long_distance_matching/ldm.h
+++ b/contrib/long_distance_matching/ldm.h
@@ -13,7 +13,7 @@
 // Defines the size of the hash table.
 // Note that this is not the number of buckets.
 // Currently this should be less than WINDOW_SIZE_LOG + 4?
-#define LDM_MEMORY_USAGE 23
+#define LDM_MEMORY_USAGE 22
 #define HASH_BUCKET_SIZE_LOG 3 // MAX is 4 for now
 
 // Defines the lag in inserting elements into the hash table.
diff --git a/contrib/long_distance_matching/ldm_with_table.c b/contrib/long_distance_matching/ldm_with_table.c
index 5919d588c..813ead6ae 100644
--- a/contrib/long_distance_matching/ldm_with_table.c
+++ b/contrib/long_distance_matching/ldm_with_table.c
@@ -7,17 +7,17 @@
 #include "ldm.h"
 
 #define LDM_HASHTABLESIZE (1 << (LDM_MEMORY_USAGE))
-//#define LDM_HASH_ENTRY_SIZE 4
+#define LDM_HASH_ENTRY_SIZE_LOG 3
 #define LDM_HASHTABLESIZE_U32 ((LDM_HASHTABLESIZE) >> 2)
-#define LDM_HASHTABLESIZE_U64 ((LDM_HASHTABLESIZE) >> 4)
+#define LDM_HASHTABLESIZE_U64 ((LDM_HASHTABLESIZE) >> 3)
 
 // Insert every (HASH_ONLY_EVERY + 1) into the hash table.
-#define HASH_ONLY_EVERY_LOG (LDM_WINDOW_SIZE_LOG-((LDM_MEMORY_USAGE) - 4))
+#define HASH_ONLY_EVERY_LOG (LDM_WINDOW_SIZE_LOG-((LDM_MEMORY_USAGE) - (LDM_HASH_ENTRY_SIZE_LOG)))
 #define HASH_ONLY_EVERY ((1 << HASH_ONLY_EVERY_LOG) - 1)
 
 /* Hash table stuff. */
 #define HASH_BUCKET_SIZE (1 << (HASH_BUCKET_SIZE_LOG))
-#define LDM_HASHLOG ((LDM_MEMORY_USAGE)-4-HASH_BUCKET_SIZE_LOG)
+#define LDM_HASHLOG ((LDM_MEMORY_USAGE)-(LDM_HASH_ENTRY_SIZE_LOG)-(HASH_BUCKET_SIZE_LOG))
 
 #define ML_BITS 4
 #define ML_MASK ((1U<<ML_BITS)-1)