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-rw-r--r--src/H5detect.c215
1 files changed, 121 insertions, 94 deletions
diff --git a/src/H5detect.c b/src/H5detect.c
index caed569..be661ea 100644
--- a/src/H5detect.c
+++ b/src/H5detect.c
@@ -118,10 +118,12 @@ static volatile int nd_g = 0, na_g = 0;
static void print_results(int nd, detected_t *d, int na, malign_t *m);
static void iprint(detected_t *);
-static int byte_cmp(int, const void *, const void *);
-static int bit_cmp(int, int *, volatile void *, volatile void *);
+static int byte_cmp(int, const void *, const void *, const unsigned char *);
+static int bit_cmp(int, int *, volatile void *, volatile void *,
+ const unsigned char *);
static void fix_order(int, int, int *, const char **);
-static int imp_bit(int, int *, volatile void *, volatile void *);
+static int imp_bit(int, int *, volatile void *, volatile void *,
+ const unsigned char *);
static unsigned long find_bias(int, int, int *, void *);
static void precision (detected_t*);
static void print_header(void);
@@ -298,71 +300,88 @@ precision (detected_t *d)
*
*-------------------------------------------------------------------------
*/
-#define DETECT_F(TYPE,VAR,INFO) { \
- volatile TYPE _v1, _v2, _v3; \
- unsigned char _buf1[sizeof(TYPE)], _buf3[sizeof(TYPE)]; \
- int _i, _j, _last = (-1); \
- char *_mesg; \
- \
- HDmemset(&INFO, 0, sizeof(INFO)); \
- INFO.varname = #VAR; \
- INFO.size = sizeof(TYPE); \
- \
- /* Completely initialize temporary variables, in case the bits used in */ \
- /* the type take less space than the number of bits used to store the type */ \
- HDmemset(&_v3, 0, sizeof(TYPE)); \
- HDmemset(&_v2, 0, sizeof(TYPE)); \
- HDmemset(&_v1, 0, sizeof(TYPE)); \
- \
- /* Byte Order */ \
- for(_i = 0, _v1 = 0.0, _v2 = 1.0; _i < (int)sizeof(TYPE); _i++) { \
- _v3 = _v1; \
- _v1 += _v2; \
- _v2 /= 256.0; \
- HDmemcpy(_buf1, (const void *)&_v1, sizeof(TYPE)); \
- HDmemcpy(_buf3, (const void *)&_v3, sizeof(TYPE)); \
- _j = byte_cmp(sizeof(TYPE), &_buf3, &_buf1); \
- if(_j >= 0) { \
- INFO.perm[_i] = _j; \
- _last = _i; \
- } \
- } \
- fix_order(sizeof(TYPE), _last, INFO.perm, (const char**)&_mesg); \
+#define DETECT_F(TYPE,VAR,INFO) { \
+ volatile TYPE _v1, _v2, _v3; \
+ unsigned char _buf1[sizeof(TYPE)], _buf3[sizeof(TYPE)]; \
+ unsigned char _pad_mask[sizeof(TYPE)]; \
+ unsigned char _byte_mask; \
+ int _i, _j, _last = (-1); \
+ char *_mesg; \
\
- if(!HDstrcmp(_mesg, "VAX")) \
- INFO.is_vax = TRUE; \
- \
- /* Implicit mantissa bit */ \
- _v1 = 0.5; \
- _v2 = 1.0; \
- INFO.imp = imp_bit (sizeof(TYPE), INFO.perm, &_v1, &_v2); \
- \
- /* Sign bit */ \
- _v1 = 1.0; \
- _v2 = -1.0; \
- INFO.sign = bit_cmp (sizeof(TYPE), INFO.perm, &_v1, &_v2); \
- \
- /* Mantissa */ \
- INFO.mpos = 0; \
- \
- _v1 = 1.0; \
- _v2 = 1.5; \
- INFO.msize = bit_cmp (sizeof(TYPE), INFO.perm, &_v1, &_v2); \
- INFO.msize += 1 + (INFO.imp?0:1) - INFO.mpos; \
- \
- /* Exponent */ \
- INFO.epos = INFO.mpos + INFO.msize; \
- \
- INFO.esize = INFO.sign - INFO.epos; \
- \
- _v1 = 1.0; \
- INFO.bias = find_bias (INFO.epos, INFO.esize, INFO.perm, &_v1); \
- precision (&(INFO)); \
- ALIGNMENT(TYPE, INFO); \
- if(!HDstrcmp(INFO.varname, "FLOAT") || !HDstrcmp(INFO.varname, "DOUBLE") || \
- !HDstrcmp(INFO.varname, "LDOUBLE")) { \
- COMP_ALIGNMENT(TYPE,INFO.comp_align); \
- } \
+ HDmemset(&INFO, 0, sizeof(INFO)); \
+ INFO.varname = #VAR; \
+ INFO.size = sizeof(TYPE); \
+ \
+ /* Initialize padding mask */ \
+ HDmemset(_pad_mask, 0, sizeof(_pad_mask)); \
+ \
+ /* Padding bits. Set a variable to 4.0, then flip each bit and see if \
+ * the modified variable is equal ("==") to the original. Build a \
+ * padding bitmask to indicate which bits in the type are padding (i.e. \
+ * have no effect on the value and should be ignored by subsequent \
+ * steps). This is necessary because padding bits can change arbitrarily \
+ * and interfere with detection of the various properties below unless we \
+ * know to ignore them. */ \
+ _v1 = 4.0; \
+ HDmemcpy(_buf1, (const void *)&_v1, sizeof(TYPE)); \
+ for(_i = 0; _i < (int)sizeof(TYPE); _i++) \
+ for(_byte_mask = (unsigned char)1; _byte_mask; _byte_mask <<= 1) { \
+ _buf1[_i] ^= _byte_mask; \
+ HDmemcpy((void *)&_v2, (const void *)_buf1, sizeof(TYPE)); \
+ if(_v1 != _v2) \
+ _pad_mask[_i] |= _byte_mask; \
+ _buf1[_i] ^= _byte_mask; \
+ } /* enf for */ \
+ \
+ /* Byte Order */ \
+ for(_i = 0, _v1 = 0.0, _v2 = 1.0; _i < (int)sizeof(TYPE); _i++) { \
+ _v3 = _v1; \
+ _v1 += _v2; \
+ _v2 /= 256.0; \
+ HDmemcpy(_buf1, (const void *)&_v1, sizeof(TYPE)); \
+ HDmemcpy(_buf3, (const void *)&_v3, sizeof(TYPE)); \
+ _j = byte_cmp(sizeof(TYPE), _buf3, _buf1, _pad_mask); \
+ if(_j >= 0) { \
+ INFO.perm[_i] = _j; \
+ _last = _i; \
+ } \
+ } \
+ fix_order(sizeof(TYPE), _last, INFO.perm, (const char**)&_mesg); \
+ \
+ if(!HDstrcmp(_mesg, "VAX")) \
+ INFO.is_vax = TRUE; \
+ \
+ /* Implicit mantissa bit */ \
+ _v1 = 0.5; \
+ _v2 = 1.0; \
+ INFO.imp = imp_bit (sizeof(TYPE), INFO.perm, &_v1, &_v2, _pad_mask); \
+ \
+ /* Sign bit */ \
+ _v1 = 1.0; \
+ _v2 = -1.0; \
+ INFO.sign = bit_cmp (sizeof(TYPE), INFO.perm, &_v1, &_v2, _pad_mask); \
+ \
+ /* Mantissa */ \
+ INFO.mpos = 0; \
+ \
+ _v1 = 1.0; \
+ _v2 = 1.5; \
+ INFO.msize = bit_cmp (sizeof(TYPE), INFO.perm, &_v1, &_v2, _pad_mask); \
+ INFO.msize += 1 + (INFO.imp?0:1) - INFO.mpos; \
+ \
+ /* Exponent */ \
+ INFO.epos = INFO.mpos + INFO.msize; \
+ \
+ INFO.esize = INFO.sign - INFO.epos; \
+ \
+ _v1 = 1.0; \
+ INFO.bias = find_bias (INFO.epos, INFO.esize, INFO.perm, &_v1); \
+ precision (&(INFO)); \
+ ALIGNMENT(TYPE, INFO); \
+ if(!HDstrcmp(INFO.varname, "FLOAT") || !HDstrcmp(INFO.varname, "DOUBLE") || \
+ !HDstrcmp(INFO.varname, "LDOUBLE")) { \
+ COMP_ALIGNMENT(TYPE,INFO.comp_align); \
+ } \
}
@@ -887,7 +906,8 @@ iprint(detected_t *d)
*
* Purpose: Compares two chunks of memory A and B and returns the
* byte index into those arrays of the first byte that
- * differs between A and B.
+ * differs between A and B. Ignores differences where the
+ * corresponding bit in pad_mask is set to 0.
*
* Return: Success: Index of differing byte.
*
@@ -902,13 +922,16 @@ iprint(detected_t *d)
*-------------------------------------------------------------------------
*/
static int
-byte_cmp(int n, const void *_a, const void *_b)
+byte_cmp(int n, const void *_a, const void *_b, const unsigned char *pad_mask)
{
- int i;
- const unsigned char *a = (const unsigned char *) _a;
- const unsigned char *b = (const unsigned char *) _b;
+ int i;
+ const unsigned char *a = (const unsigned char *) _a;
+ const unsigned char *b = (const unsigned char *) _b;
+
+ for(i = 0; i < n; i++)
+ if((a[i] & pad_mask[i]) != (b[i] & pad_mask[i]))
+ return i;
- for (i = 0; i < n; i++) if (a[i] != b[i]) return i;
return -1;
}
@@ -919,7 +942,8 @@ byte_cmp(int n, const void *_a, const void *_b)
* Purpose: Compares two bit vectors and returns the index for the
* first bit that differs between the two vectors. The
* size of the vector is NBYTES. PERM is a mapping from
- * actual order to little endian.
+ * actual order to little endian. Ignores differences where
+ * the corresponding bit in pad_mask is set to 0.
*
* Return: Success: Index of first differing bit.
*
@@ -934,22 +958,24 @@ byte_cmp(int n, const void *_a, const void *_b)
*-------------------------------------------------------------------------
*/
static int
-bit_cmp(int nbytes, int *perm, volatile void *_a, volatile void *_b)
+bit_cmp(int nbytes, int *perm, volatile void *_a, volatile void *_b,
+ const unsigned char *pad_mask)
{
- int i, j;
- volatile unsigned char *a = (volatile unsigned char *) _a;
- volatile unsigned char *b = (volatile unsigned char *) _b;
- unsigned char aa, bb;
+ int i, j;
+ volatile unsigned char *a = (volatile unsigned char *) _a;
+ volatile unsigned char *b = (volatile unsigned char *) _b;
+ unsigned char aa, bb;
for (i = 0; i < nbytes; i++) {
- HDassert(perm[i] < nbytes);
- if ((aa = a[perm[i]]) != (bb = b[perm[i]])) {
- for (j = 0; j < 8; j++, aa >>= 1, bb >>= 1) {
- if ((aa & 1) != (bb & 1)) return i * 8 + j;
- }
- fprintf(stderr, "INTERNAL ERROR");
- HDabort();
- }
+ HDassert(perm[i] < nbytes);
+ if ((aa = a[perm[i]] & pad_mask[perm[i]])
+ != (bb = b[perm[i]] & pad_mask[perm[i]])) {
+ for (j = 0; j < 8; j++, aa >>= 1, bb >>= 1) {
+ if ((aa & 1) != (bb & 1)) return i * 8 + j;
+ }
+ fprintf(stderr, "INTERNAL ERROR");
+ HDabort();
+ }
}
return -1;
}
@@ -1058,18 +1084,19 @@ fix_order(int n, int last, int *perm, const char **mesg)
*-------------------------------------------------------------------------
*/
static int
-imp_bit(int n, int *perm, volatile void *_a, volatile void *_b)
+imp_bit(int n, int *perm, volatile void *_a, volatile void *_b,
+ const unsigned char *pad_mask)
{
- volatile unsigned char *a = (volatile unsigned char *) _a;
- volatile unsigned char *b = (volatile unsigned char *) _b;
- int changed, major, minor;
- int msmb; /*most significant mantissa bit */
+ volatile unsigned char *a = (volatile unsigned char *) _a;
+ volatile unsigned char *b = (volatile unsigned char *) _b;
+ int changed, major, minor;
+ int msmb; /*most significant mantissa bit */
/*
* Look for the least significant bit that has changed between
- * A and B. This is the least significant bit of the exponent.
+ * A and B. This is the least significant bit of the exponent.
*/
- changed = bit_cmp(n, perm, a, b);
+ changed = bit_cmp(n, perm, a, b, pad_mask);
HDassert(changed >= 0);
/*
generated by cgit v0.12 at 2024-08-23 05:07:19 (GMT)