diff --git a/.cache/clangd/index/XD.c.CF9B5320BE29FE6C.idx b/.cache/clangd/index/XD.c.CF9B5320BE29FE6C.idx
deleted file mode 100644
index 7699412..0000000
Binary files a/.cache/clangd/index/XD.c.CF9B5320BE29FE6C.idx and /dev/null differ
diff --git a/Makefile b/Makefile
index 0027568..66be544 100644
--- a/Makefile
+++ b/Makefile
@@ -2,13 +2,12 @@ include config.mk
 
 # flags and incs
 PKGS = $(GITLIB)
-CFLAGS = -DVERSION=\"$(VERSION)\" -Wall -pedantic -O3 $(GIT) $(ERR) $(EXPLAIN)
+CFLAGS = -DVERSION=\"$(VERSION)\" -Wall -pedantic -O3 $(GIT) $(GITHASH) $(ERR) $(PERF) $(EXPLAIN)
 LIBS = `$(PKG_CONFIG) --libs --cflags $(PKGS)`
 
 all: XD
-XD: XD.o
+XD: XD.o hash.o helpers.o
 	$(CC) *.o $(CFLAGS) $(LIBS) -o $@
-XD.o: XD.c
 
 clean:
 	rm -f XD *.o
diff --git a/XD.1 b/XD.1
index 380bff6..d7a147d 100644
--- a/XD.1
+++ b/XD.1
@@ -12,9 +12,12 @@
 .Sh DESCRIPTION
 .Nm
 Displays information using a smiley face like so: :)
-to interpret it refer to the following tables:
-Displays information using a smiley face.
-to interpret XD's output refer to the following tables (or
+.Nm
+does some special caching to run as fast as possible but there's only so much
+that can be done without relying on an external daemon. Therefore when new
+changes are made in very large repositories it may take a few seconds to
+determine if there are any changes. To interpret XD's output refer to the
+following tables (or
 .Nm
 \fB-e\fR):
 .Ss Eyes
diff --git a/XD.c b/XD.c
index c5af3cd..de8d694 100644
--- a/XD.c
+++ b/XD.c
@@ -1,7 +1,9 @@
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
+#include <errno.h>
 
 #ifdef ERR
 #include <errno.h>
@@ -16,42 +18,11 @@
 #include <git2.h>
 #endif
 
+#include "helpers.h"
+#include "hash.h"
+
 #define P(X) fwrite(X, 1, 1, stdout)
 
-#if defined(ERR) || defined(EXPLAIN)
-void
-l(const char *fmt, ...)
-{
-  va_list ap;
-
-  va_start(ap, fmt);
-  vfprintf(stderr, fmt, ap);
-  va_end(ap);
-
-  if (fmt[0] && fmt[strlen(fmt) - 1] == ':') {
-    fputc(' ', stderr);
-    perror(NULL);
-  } else {
-    fputc('\n', stderr);
-  }
-}
-#endif
-
-#ifdef ERR
-#define L(...) l(__VA_ARGS__)
-#else
-#define L(...)
-#endif
-
-#ifdef EXPLAIN
-static int explain = 0;
-#define E(...) if (explain) {    \
-                 l(__VA_ARGS__); \
-               } else
-#else
-#define E(...)
-#endif
-
 #ifdef GIT
 /**
  * @brief search all parent directories for a git repo
@@ -61,6 +32,7 @@ static int explain = 0;
 char
 *find_git_repo(void)
 {
+  PS();
   char path[PATH_MAX] = ".", fstr[PATH_MAX], *rpath, *res;
   struct stat s;
   FILE *f;
@@ -70,6 +42,7 @@ char
   rpath = realpath(path, NULL);
   if (!rpath) {
     L("realpath: %s", strerror(errno));
+    PE();
     return NULL;
   }
   for (i = c = 0; i < strlen(rpath); i++) {
@@ -86,22 +59,26 @@ char
     /* if there seems to be a git directory return the directory it was found in */
     if (stat(path, &s) == 0) {
       if (S_ISDIR(s.st_mode)) {
+        PE();
         return realpath(path, NULL);
       } else if (S_ISREG(s.st_mode)) {
         /* we do some special magic here to check if we're in a submodule */
         f = fopen(path, "r");
         if (!f) {
           L("fopen: %s", strerror(errno));
+          PE();
           return NULL;
         }
         res = fgets(fstr, PATH_MAX, f);
         fclose(f);
         if (!res) {
           L("fgets: %s", strerror(errno));
+          PE();
           return NULL;
         }
         if (strncmp(fstr, "gitdir: ", strlen("gitdir: ")) == 0) {
           fstr[strlen(fstr) - 1] = '\0';
+          PE();
           return realpath(fstr + strlen("gitdir: "), NULL);
         }
       }
@@ -112,6 +89,7 @@ char
     memset(&path[strlen(path) - 2], 0, 2);
   }
 
+  PE();
   return NULL;
 }
 
@@ -123,11 +101,13 @@ char
 git_repository
 *init_git(void)
 {
+  PS();
   char *buf;
   git_repository *repo;
 
   /* check for a repo before loading libgit2 */
   if ((buf = find_git_repo()) == NULL) {
+    PE();
     return NULL;
   }
 
@@ -143,17 +123,20 @@ git_repository
   /* initialize the git library and repository */
   if (git_libgit2_init() < 0) {
     L("Failed to initalize libgit2, proceeding without git functionality enabled.");
+    PE();
     return NULL;
   }
 
   if (git_repository_open(&repo, buf) < 0) {
     L("Failed to open git repo: %s", git_error_last()->message);
     free(buf);
+    PE();
     return NULL;
   }
 
   /* get rid of object containing git repo path and return the repo */
   free(buf);
+  PE();
   return repo;
 }
 
@@ -166,20 +149,24 @@ git_repository
 int
 has_stashes(git_repository *repo)
 {
+  PS();
   git_reference *stash = NULL;
   int e;
 
   e = git_reference_lookup(&stash, repo, "refs/stash");
   if (e == GIT_ENOTFOUND) {
+    PE();
     return 0;
   } else if (e < 0) {
     L("Error looking up stash reference: %s", git_error_last()->message);
+    PE();
     return 0;
   } else {
     e = 1;
   }
 
   git_reference_free(stash);
+  PE();
   return e;
 }
 
@@ -192,27 +179,45 @@ has_stashes(git_repository *repo)
 int
 has_untracked(git_repository *repo)
 {
+  PS();
   git_status_options opts = GIT_STATUS_OPTIONS_INIT;
   git_status_list *list = NULL;
+  repohash *storedhash;
+  uint64_t newhash = generate_hash(repo);
   int r = 0;
 
-  /* FIXME: this is really slow in large git repos :( */
-  opts.show = GIT_STATUS_SHOW_WORKDIR_ONLY;
+  #ifdef GITHASH
+  if ((storedhash = read_hash(repo))
+    && storedhash->hash == newhash) {
+    r = storedhash->changes;
+    free(storedhash);
+    PE();
+    return r;
+  }
+  #endif
+
+  /* if we need to regen the hash then we need to do a hard check on the real
+   * git repository */
+  opts.show = GIT_STATUS_SHOW_INDEX_AND_WORKDIR;
   opts.flags = GIT_STATUS_OPT_INCLUDE_UNTRACKED |
     GIT_STATUS_OPT_RENAMES_HEAD_TO_INDEX |
+    GIT_STATUS_OPT_UPDATE_INDEX |
     GIT_STATUS_OPT_DISABLE_PATHSPEC_MATCH;
 
   if (git_status_list_new(&list, repo, &opts) < 0) {
     L("Error checking for untracked changes: %s", git_error_last()->message);
+    PE();
     return 0;
   }
 
   /* if any changes are found return 1 */
-  if (git_status_list_entrycount(list) > 0) {
-    r = 1;
-  }
+  r = git_status_list_entrycount(list) > 0;
+  #ifdef GITHASH
+  write_hash(repo, (repohash){ .hash = newhash, .changes = r });
+  #endif
 
   git_status_list_free(list);
+  PE();
   return r;
 }
 
@@ -225,6 +230,7 @@ has_untracked(git_repository *repo)
 int
 has_staged(git_repository *repo)
 {
+  PS();
   git_status_entry entry;
   git_status_list *list = NULL;
   git_status_options opts = GIT_STATUS_OPTIONS_INIT;
@@ -235,6 +241,7 @@ has_staged(git_repository *repo)
 
   if (git_status_list_new(&list, repo, &opts) < 0) {
     L("Error checking for staged changes: %s", git_error_last()->message);
+    PE();
     return 0;
   }
 
@@ -253,6 +260,7 @@ has_staged(git_repository *repo)
   }
 
   git_status_list_free(list);
+  PE();
   return r;
 }
 #endif
@@ -260,17 +268,20 @@ has_staged(git_repository *repo)
 inline unsigned
 numcat(unsigned x, unsigned y)
 {
+  PS();
   unsigned pow = 10;
   while(y >= pow) {
     pow *= 10;
   }
 
+  PE();
   return (x * pow) + y;
 }
 
 int
 str_to_int(char *str)
 {
+  PS();
   int res = -1;
   char *c;
 
@@ -282,17 +293,20 @@ str_to_int(char *str)
     }
   }
 
+  PE();
   return res;
 }
 
 int
 main(int argc, char *argv[])
 {
+  PS();
   int code = -1;
 
   /* print version information */
   if (argc > 1 && strcmp(argv[1], "-v") == 0) {
     printf("XD [number] %s\n", VERSION);
+    PE();
     return 0;
   #ifdef EXPLAIN
   } else if (argc > 1 && strcmp(argv[1], "-e") == 0) {
@@ -344,6 +358,7 @@ main(int argc, char *argv[])
     code = str_to_int(argv[argc - 1]);
     if (code < 0) {
       L("Return code, %d, not valid", code);
+      PE();
       exit(1);
     }
   }
@@ -377,5 +392,6 @@ main(int argc, char *argv[])
     P("|"); /* no code info */
   }
 
+  PE();
   return code;
 }
diff --git a/config.mk b/config.mk
index b7f4032..2614a75 100644
--- a/config.mk
+++ b/config.mk
@@ -1,4 +1,4 @@
-VERSION = `git describe --tags --abbrev=0`
+VERSION := `git describe --tags --dirty`
 
 PKG_CONFIG = pkg-config
 
@@ -7,15 +7,21 @@ PREFIX = /usr/local
 MANDIR = $(PREFIX)/share/man
 
 GIT =
+GITHASH =
 GITLIB =
 # comment to disable git support
 GIT = -DGIT
+GITHASH = -DGITHASH
 GITLIB = libgit2
 
 ERR =
 # uncomment to enable errors
 # ERR = -DERR
 
+PERF =
+# uncomment to enable performance logging
+# PERF = -DPERF
+
 EXPLAIN =
 # comment to disable explinations
 EXPLAIN = -DEXPLAIN
@@ -24,15 +30,25 @@ EXPLAIN = -DEXPLAIN
 ifneq ($(GIT),)
 	VERSION := $(VERSION)"\\nlibgit2 "`$(PKG_CONFIG) --modversion $(GITLIB)`
 endif
-ifeq ($(ERR),)
-	VERSION := $(VERSION)"\\nerrors disabled"
+ifeq ($(GITHASH),)
+	VERSION := $(VERSION)"\\ngit hashing disabled"
 else
-	VERSION := $(VERSION)"\\nerrors enabled"
+	VERSION := $(VERSION)"\\ngit hashing enabled"
 endif
 ifeq ($(EXPLAIN),)
 	VERSION := $(VERSION)"\\nexplinations disabled"
 else
 	VERSION := $(VERSION)"\\nexplinations enabled"
 endif
+ifeq ($(ERR),)
+	VERSION := $(VERSION)"\\nerrors disabled"
+else
+	VERSION := $(VERSION)"\\nerrors enabled"
+endif
+ifeq ($(PERF),)
+	VERSION := $(VERSION)"\\nperformance logging disabled"
+else
+	VERSION := $(VERSION)"\\nperformance logging enabled"
+endif
 
 CC = cc
diff --git a/hash.c b/hash.c
new file mode 100644
index 0000000..5403d50
--- /dev/null
+++ b/hash.c
@@ -0,0 +1,152 @@
+#include <git2/repository.h>
+#include <git2/types.h>
+#include <linux/limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <stdint.h>
+
+#include "hash.h"
+#include "helpers.h"
+
+#ifdef GITHASH
+static uint64_t
+murmur64(uint64_t k)
+{
+  PS();
+  k ^= k >> 33;
+  k *= 0xff51afd7ed558ccdLLU;
+  k ^= k >> 33;
+  k *= 0xc4ceb9fe1a85ec53LLU;
+  k ^= k >> 33;
+
+  PE();
+  return k;
+}
+
+uint64_t
+generate_hash(git_repository *repo)
+{
+  PS();
+  struct stat dir, index;
+  char path[PATH_MAX] = { 0 };
+
+  const char *gitpath = git_repository_path(repo);
+  if (strlen(gitpath) + strlen("/..") > PATH_MAX - 1) {
+    L("strlen: %s", strerror(errno));
+    PE();
+    return -1;
+  }
+
+  strcat(path, gitpath);
+  if (stat(path, &index) < 0) {
+    PE();
+    return -1;
+  }
+  strcat(path, "/..");
+  if (stat(path, &dir) < 0) {
+    PE();
+    return -1;
+  }
+  PE();
+  return murmur64(dir.st_mtim.tv_nsec ^ index.st_mtim.tv_nsec);
+}
+
+repohash
+*read_hash(git_repository *repo)
+{
+  PS();
+  FILE *f;
+  uint64_t data;
+  uint8_t changes;
+  repohash *hash = malloc(sizeof(repohash));
+  char path[PATH_MAX] = { 0 };
+
+  const char *gitpath = git_repository_path(repo);
+  if (strlen(gitpath) + strlen(XD_HASH_PATH) > PATH_MAX - 1) {
+    L("strlen: %s", strerror(errno));
+    PE();
+    return NULL;
+  }
+  strcat(path, gitpath);
+  strcat(path, XD_HASH_PATH);
+
+  f = fopen(path, "r");
+  if (!f) {
+    L("fopen: %s", strerror(errno));
+    PE();
+    return NULL;
+  }
+
+  if (fread(&data, sizeof(uint64_t), 1, f) != 1) {
+    L("fread: %s", strerror(errno));
+    PE();
+    return NULL;
+  }
+
+  if (fseek(f, sizeof(uint64_t), SEEK_SET) < 0) {
+    L("fseek: %s", strerror(errno));
+    PE();
+    return NULL;
+  }
+
+  if (fread(&changes, sizeof(uint8_t), 1, f) != 1) {
+    L("fread: %s", strerror(errno));
+    PE();
+    return NULL;
+  }
+  fclose(f);
+
+  hash->hash = data;
+  hash->changes = changes;
+  PE();
+  return hash;
+}
+
+int
+write_hash(git_repository *repo, repohash hash)
+{
+  PS();
+  FILE *f;
+  char path[PATH_MAX] = { 0 };
+
+  const char *gitpath = git_repository_path(repo);
+  if (strlen(gitpath) + strlen(XD_HASH_PATH) > PATH_MAX - 1) {
+    L("strlen: %s", strerror(errno));
+    PE();
+    return 1;
+  }
+  strcat(path, gitpath);
+  strcat(path, XD_HASH_PATH);
+
+  f = fopen(path, "wb");
+  if (!f) {
+    L("fopen: %s", strerror(errno));
+    PE();
+    return 1;
+  }
+
+  if (fwrite(&hash.hash, sizeof(uint64_t), 1, f) != 1) {
+    L("fwrite: %s", strerror(errno));
+    PE();
+    return 1;
+  }
+
+  if (fseek(f, sizeof(uint64_t), SEEK_SET) < 0) {
+    L("fseek: %s", strerror(errno));
+    PE();
+    return 1;
+  }
+
+  if (fwrite(&hash.changes, sizeof(uint8_t), 1, f) != 1) {
+    L("fwrite: %s", strerror(errno));
+    PE();
+    return 1;
+  }
+
+  fclose(f);
+  PE();
+  return 0;
+}
+#endif
diff --git a/hash.h b/hash.h
new file mode 100644
index 0000000..a78cd99
--- /dev/null
+++ b/hash.h
@@ -0,0 +1,37 @@
+#pragma once
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <git2/repository.h>
+
+#ifdef GIT
+typedef struct {
+  uint64_t hash;
+  bool changes;
+} repohash;
+
+#define XD_HASH_PATH "/XDhash"
+/**
+ * @brief generate a hash from the repository state
+ *
+ * @param repo the git repository
+ * @return the hash
+ */
+uint64_t generate_hash(git_repository *repo);
+
+/**
+ * @brief read the hash from the git repo
+ *
+ * @param repo the git repository
+ * @return the hash
+ */
+repohash *read_hash(git_repository *repo);
+
+/**
+ * @brief write a new hash to the repository
+ *
+ * @param repo the repository
+ * @param hash the hash to write
+ */
+int write_hash(git_repository *repo, repohash hash);
+#endif
diff --git a/helpers.c b/helpers.c
new file mode 100644
index 0000000..e3ef987
--- /dev/null
+++ b/helpers.c
@@ -0,0 +1,28 @@
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "helpers.h"
+
+#ifdef EXPLAIN
+int explain = 0;
+#endif
+
+#if defined(ERR) || defined(EXPLAIN)
+void
+l(const char *fmt, ...)
+{
+  va_list ap;
+
+  va_start(ap, fmt);
+  vfprintf(stderr, fmt, ap);
+  va_end(ap);
+
+  if (fmt[0] && fmt[strlen(fmt) - 1] == ':') {
+    fputc(' ', stderr);
+    perror(NULL);
+  } else {
+    fputc('\n', stderr);
+  }
+}
+#endif
diff --git a/helpers.h b/helpers.h
new file mode 100644
index 0000000..b106667
--- /dev/null
+++ b/helpers.h
@@ -0,0 +1,28 @@
+#pragma once
+
+#if defined(ERR) || defined(EXPLAIN)
+void l(const char *fmt, ...);
+#endif
+
+#ifdef ERR
+#define L(...) l(__VA_ARGS__)
+#else
+#define L(...)
+#endif
+
+#ifdef EXPLAIN
+extern int explain;
+#define E(...) if (explain) {    \
+                 l(__VA_ARGS__); \
+               } else
+#else
+#define E(...)
+#endif
+
+#ifdef PERF
+#define PS() long __start = clock()
+#define PE() l("%s: %fs", __func__, ((double) (clock() - __start)) / CLOCKS_PER_SEC)
+#else
+#define PS()
+#define PE()
+#endif