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authorRaymond Lu <songyulu@hdfgroup.org>2004-03-19 19:55:42 (GMT)
committerRaymond Lu <songyulu@hdfgroup.org>2004-03-19 19:55:42 (GMT)
commit7fb0362eeda413222426613058a51282d25d0235 (patch)
treee7f8b8fdf45f79aa88fe1eba429fb2bc1732d2a9
parente45e85190bf33ce8f49e4b919cab6fa60d4ff967 (diff)
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[svn-r8266] Purpose: Internal function change
Description: The algorithm of H5T_bit_neg wasn't general enough. Solution: Changed it to handle arbitory starting position and size in a bit sequence. Platforms tested: h5committest.
-rw-r--r--src/H5Tbit.c71
-rw-r--r--src/H5Tconv.c1
-rw-r--r--src/H5Tpkg.h1
3 files changed, 68 insertions, 5 deletions
diff --git a/src/H5Tbit.c b/src/H5Tbit.c
index d5fbdcb..b2908b1 100644
--- a/src/H5Tbit.c
+++ b/src/H5Tbit.c
@@ -579,7 +579,7 @@ H5T_bit_dec(uint8_t *buf, size_t start, size_t size)
assert(size);
/* The first partial byte */
- if ((size+start)/8 > idx) { /*bit sequence doesn't end in the same byte as starts*/
+ if ((size+start-1)/8 > idx) { /*bit sequence doesn't end in the same byte as starts*/
/* Example: a sequence like 11000100 and start = 3. We substract 00001000 from
* it and get 10111100. If a sequence is 00000111, we do right shift for START
* bits and get 00000000. So we need to borrow from higher byte when we substract
@@ -589,6 +589,7 @@ H5T_bit_dec(uint8_t *buf, size_t start, size_t size)
borrow = 1;
buf[idx] -= 1 << pos;
idx++;
+ size -= (8 - pos);
} else { /* bit sequence ends in the same byte as starts */
/* Example: a sequence like 11000100 and start=3, size=3. We substract 00001000
* and get 10111100. A bit is borrowed from 6th bit(buf[idx]>>6=00000010, tmp>>6=00000011,
@@ -613,7 +614,7 @@ H5T_bit_dec(uint8_t *buf, size_t start, size_t size)
size -= 8;
}
- /* The last byte */
+ /* The last partial byte */
if (borrow && size>0) {
/* Similar to the first byte case, where sequence ends in the same byte as starts */
tmp = buf[idx];
@@ -628,7 +629,7 @@ done:
/*-------------------------------------------------------------------------
- * Function: H5T_bit_neg
+ * Function: H5T_bit_neg2
*
* Purpose: Bit-negate buffer.
* At this moment, START is always 0 and SIZE is always a
@@ -647,7 +648,7 @@ done:
*-------------------------------------------------------------------------
*/
void
-H5T_bit_neg(uint8_t *buf, size_t start, size_t size)
+H5T_bit_neg2(uint8_t *buf, size_t start, size_t size)
{
size_t i;
@@ -658,3 +659,65 @@ H5T_bit_neg(uint8_t *buf, size_t start, size_t size)
for(i=0; i<size/8; i++)
buf[i] = ~(buf[i]);
}
+
+
+/*-------------------------------------------------------------------------
+ * Function: H5T_bit_neg
+ *
+ * Purpose: negate part of a bit sequence. The bit
+ * field starts with bit position START and is SIZE bits long.
+ *
+ * Return: void
+ *
+ * Programmer: Raymond Lu
+ * March 19, 2004
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+void
+H5T_bit_neg(uint8_t *buf, size_t start, size_t size)
+{
+ size_t idx = start / 8;
+ size_t pos = start % 8;
+ uint8_t tmp;
+
+ /* Use FUNC_ENTER_NOAPI_NOINIT_NOFUNC here to avoid performance issues */
+ FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5T_bit_neg);
+
+ assert(buf);
+ assert(size);
+
+ /* The first partial byte */
+ tmp = buf[idx];
+ tmp = ~tmp;
+
+ /* Simply copy the negated bit field back to the original byte */
+ if((size+start-1)/8 > idx) { /*bit sequence doesn't end in the same byte as starts*/
+ H5T_bit_copy (&(buf[idx]), pos, &tmp, pos, (8-pos));
+ idx++;
+ size -= (8 - pos);
+ } else { /* bit sequence ends in the same byte as starts */
+ H5T_bit_copy (&(buf[idx]), pos, &tmp, pos, size);
+ goto done;
+ }
+
+ /* The middle bytes */
+ while (size>=8) {
+ buf[idx] = ~(buf[idx]);
+ idx++;
+ size -= 8;
+ }
+
+ /* The last partial byte */
+ if (size>0) {
+ /* Similar to the first byte case, where sequence ends in the same byte as starts */
+ tmp = buf[idx];
+ tmp = ~tmp;
+ H5T_bit_copy (&(buf[idx]), 0, &tmp, 0, size);
+ }
+
+done:
+ FUNC_LEAVE_NOAPI_VOID
+}
diff --git a/src/H5Tconv.c b/src/H5Tconv.c
index bb66141..fde424c 100644
--- a/src/H5Tconv.c
+++ b/src/H5Tconv.c
@@ -8607,7 +8607,6 @@ H5T_conv_f_i (hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, hsize_t nelmts,
*/
if(sign) {
H5T_bit_dec(int_buf, 0, 8*buf_size);
-
H5T_bit_neg(int_buf, 0, 8*buf_size);
}
diff --git a/src/H5Tpkg.h b/src/H5Tpkg.h
index 70a4f56..3f8e10d 100644
--- a/src/H5Tpkg.h
+++ b/src/H5Tpkg.h
@@ -1081,6 +1081,7 @@ H5_DLL ssize_t H5T_bit_find(uint8_t *buf, size_t offset, size_t size,
H5_DLL htri_t H5T_bit_inc(uint8_t *buf, size_t start, size_t size);
H5_DLL htri_t H5T_bit_dec(uint8_t *buf, size_t start, size_t size);
H5_DLL void H5T_bit_neg(uint8_t *buf, size_t start, size_t size);
+H5_DLL void H5T_bit_neg2(uint8_t *buf, size_t start, size_t size);
/* VL functions */
H5_DLL H5T_t * H5T_vlen_create(const H5T_t *base);