[commons-rng] 01/16: Removed endianness detection and byte reversal.

[ah...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

aherbert pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/commons-rng.git

commit 01ef66dc178d411eeb4a56735a3be20bf6776b9d
Author: aherbert <ah...@apache.org>
AuthorDate: Fri Oct 4 11:20:12 2019 +0100

    Removed endianness detection and byte reversal.
    
    This is done in the java application. Doing it twice results in
    incorrect data.
---
 .../examples-stress/src/main/c/stdin2testu01.c     | 42 ----------------------
 1 file changed, 42 deletions(-)

diff --git a/commons-rng-examples/examples-stress/src/main/c/stdin2testu01.c b/commons-rng-examples/examples-stress/src/main/c/stdin2testu01.c
index b54e375..85192a4 100644
--- a/commons-rng-examples/examples-stress/src/main/c/stdin2testu01.c
+++ b/commons-rng-examples/examples-stress/src/main/c/stdin2testu01.c
@@ -58,16 +58,6 @@ typedef struct {
   uint32_t index;
 } StdinReader_state;
 
-/*
- * Flag used to store if the system is little endian.
- *
- * Note: Java is big endian and the bytes passed on stdin by a
- * Java DataOutputStream will be written most significant first.
- * If the c compiler is little endian for uint32_t the bytes
- * read from stdin must be reversed.
- */
-static int littleEndian = 0;
-
 /* Lookup table for binary representation of bytes. */
 const char *bit_rep[16] = {
     [ 0] = "0000", [ 1] = "0001", [ 2] = "0010", [ 3] = "0011",
@@ -107,31 +97,6 @@ void printInt(uint32_t value)
   printf(" %11u %11d\n", value, (int) value);
 }
 
-/*
- * Determine endianess.
- */
-void detectEndianess() {
-  uint32_t val = 0x01;
-  /*
-   * Use a raw view of the bytes with a char* to determine if
-   * the first byte is unset (big endian) or set (little endian).
-   */
-  char * buff = (char *)&val;
-
-  littleEndian = (buff[0] != 0);
-}
-
-/*
- * Reverse the 4 bytes in an unsigned int, effectively converting from big
- * endian to small or vice versa.
- */
-uint32_t reverseBytes(uint32_t value) {
-  return ((value >> 24) & 0x000000ff) | // move byte 3 to byte 0
-         ((value <<  8) & 0x00ff0000) | // move byte 1 to byte 2
-         ((value >>  8) & 0x0000ff00) | // move byte 2 to byte 1
-         ((value << 24) & 0xff000000);  // byte 0 to byte 3
-}
-
 unsigned long nextInt(void *par,
                       void *sta) {
   static size_t last_read = 0;
@@ -163,11 +128,6 @@ unsigned long nextInt(void *par,
   uint32_t random = state->buffer[state->index];
   ++state->index; /* Next request. */
 
-  if (littleEndian) {
-    /* Convert to machine representation from Java big endian. */
-    random = reverseBytes(random);
-  }
-
   return random;
 }
 
@@ -221,8 +181,6 @@ int main(int argc,
   unif01_Gen *gen = createStdinReader();
   char *spec = argv[1];
 
-  detectEndianess();
-
   if (argc < 2) {
     printf("[ERROR] Specify test suite: '%s', '%s' or '%s'\n", TU_S, TU_C, TU_B);
     exit(1);