1 files changed, 114 insertions, 0 deletions
diff --git a/src/erasure-code/jerasure/gf-complete/tools/gf_add.c b/src/erasure-code/jerasure/gf-complete/tools/gf_add.c
new file mode 100644
index 000000000..28cc12c1c
--- /dev/null
+++ b/src/erasure-code/jerasure/gf-complete/tools/gf_add.c
@@ -0,0 +1,114 @@
+/*
+ * GF-Complete: A Comprehensive Open Source Library for Galois Field Arithmetic
+ * James S. Plank, Ethan L. Miller, Kevin M. Greenan,
+ * Benjamin A. Arnold, John A. Burnum, Adam W. Disney, Allen C. McBride.
+ *
+ * gf_add.c
+ *
+ * Adds two numbers in gf_2^w
+ */
+
+#include <stdio.h>
+#include <getopt.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+
+void usage(char *s)
+{
+  fprintf(stderr, "usage: gf_add a b w - does addition of a and b in GF(2^w)\n");
+  fprintf(stderr, "       If w has an h on the end, treat a, b and the sum as hexadecimal (no 0x required)\n");
+  fprintf(stderr, "\n");
+  fprintf(stderr, "       legal w are: 1-32, 64 and 128\n");
+  fprintf(stderr, "       128 is hex only (i.e. '128' will be an error - do '128h')\n");
+
+  if (s != NULL) fprintf(stderr, "%s", s);
+  exit(1);
+}
+
+int read_128(char *s, uint64_t *v)
+{
+  int l, t;
+  char save;
+
+  l = strlen(s);
+  if (l > 32) return 0;
+
+  if (l > 16) {
+    if (sscanf(s + (l-16), "%llx", (long long unsigned int *) &(v[1])) == 0) return 0;
+    save = s[l-16];
+    s[l-16] = '\0';
+    t = sscanf(s, "%llx", (long long unsigned int *) &(v[0]));
+    s[l-16] = save;
+    return t;
+  } else {
+    v[0] = 0;
+    return sscanf(s, "%llx", (long long unsigned int *)&(v[1]));
+  }
+  return 1;
+}
+
+void print_128(uint64_t *v) 
+{
+  if (v[0] > 0) {
+    printf("%llx", (long long unsigned int) v[0]);
+    printf("%016llx", (long long unsigned int) v[1]);
+  } else {
+    printf("%llx", (long long unsigned int) v[1]);
+  }
+  printf("\n");
+}
+
+
+int main(int argc, char **argv)
+{
+  int hex, w;
+  uint32_t a, b, c, top;
+  uint64_t a64, b64, c64;
+  uint64_t a128[2], b128[2], c128[2];
+  char *format;
+
+  if (argc != 4) usage(NULL);
+  if (sscanf(argv[3], "%d", &w) == 0) usage("Bad w\n");
+
+  if (w <= 0 || (w > 32 && w != 64 && w != 128)) usage("Bad w");
+
+  hex = (strchr(argv[3], 'h') != NULL);
+
+  if (!hex && w == 128) usage(NULL);
+ 
+  if (w <= 32) {
+    format = (hex) ? "%x" : "%u";
+    if (sscanf(argv[1], format, &a) == 0) usage("Bad a\n");
+    if (sscanf(argv[2], format, &b) == 0) usage("Bad b\n");
+
+    if (w < 32) {
+      top = (w == 31) ? 0x80000000 : (1 << w);
+      if (w != 32 && a >= top) usage("a is too large\n");
+      if (w != 32 && b >= top) usage("b is too large\n");
+    }
+  
+    c = a ^ b;
+    printf(format, c);
+    printf("\n");
+
+  } else if (w == 64) {
+    format = (hex) ? "%llx" : "%llu";
+    if (sscanf(argv[1], format, &a64) == 0) usage("Bad a\n");
+    if (sscanf(argv[2], format, &b64) == 0) usage("Bad b\n");
+    c64 = a64 ^ b64;
+
+    printf(format, c64);
+    printf("\n");
+
+  } else if (w == 128) {
+
+    if (read_128(argv[1], a128) == 0) usage("Bad a\n");
+    if (read_128(argv[2], b128) == 0) usage("Bad b\n");
+    c128[0] = a128[0] ^ b128[0];
+    c128[1] = a128[1] ^ b128[1];
+
+    print_128(c128);
+  }
+  exit(0);
+}