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[PATCH 6/7] ios: Utilize buffer reads.
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From: |
Eric Blake |
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Subject: |
[PATCH 6/7] ios: Utilize buffer reads. |
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Date: |
Sat, 29 Feb 2020 05:12:24 -0600 |
Trickier than I expected: To do bulk reads, we have to supply a byte
array instead of our previous uint64_t array, but uint8_t promotes to
int (which sign extends in the wrong places) and triggers undefined
behavior when shifting too far, unless we add lots of casts to
anywhere that shifts by 24 or more bits.
* src/ios.c (ios_read_int_common, ios_read_int, ios_read_uint):
Consolidate reads.
(IOS_READ_INTO_CHARRAY_1BYTE, IOS_READ_INTO_CHARRAY_2BYTES)
(IOS_READ_INTO_CHARRAY_3BYTES, IOS_READ_INTO_CHARRAY_4BYTES)
(IOS_READ_INTO_CHARRAY_5BYTES, IOS_READ_INTO_CHARRAY_6BYTES)
(IOS_READ_INTO_CHARRAY_7BYTES, IOS_READ_INTO_CHARRAY_8BYTES)
(IOS_READ_INTO_CHARRAY_9BYTES): Delete unused macros.
---
ChangeLog | 11 +++
src/ios.c | 288 ++++++++++++++++++++++++------------------------------
2 files changed, 140 insertions(+), 159 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 0077f4b7..c54d4e0d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2020-02-28 Eric Blake <address@hidden>
+
+ ios: Utilize buffer reads.
+ * src/ios.c (ios_read_int_common, ios_read_int, ios_read_uint):
+ Consolidate reads.
+ (IOS_READ_INTO_CHARRAY_1BYTE, IOS_READ_INTO_CHARRAY_2BYTES)
+ (IOS_READ_INTO_CHARRAY_3BYTES, IOS_READ_INTO_CHARRAY_4BYTES)
+ (IOS_READ_INTO_CHARRAY_5BYTES, IOS_READ_INTO_CHARRAY_6BYTES)
+ (IOS_READ_INTO_CHARRAY_7BYTES, IOS_READ_INTO_CHARRAY_8BYTES)
+ (IOS_READ_INTO_CHARRAY_9BYTES): Delete unused macros.
+
2020-02-28 Eric Blake <address@hidden>
ios: Change from getchar to pread device interface.
diff --git a/src/ios.c b/src/ios.c
index 9873dd48..e9cf17ef 100644
--- a/src/ios.c
+++ b/src/ios.c
@@ -49,59 +49,6 @@
return IOS_EIOBJ; \
}
-#define IOS_READ_INTO_CHARRAY_1BYTE(charray, off) \
-{ \
- IOS_GET_C_ERR_CHCK((charray)[0], io, off); \
-}
-
-#define IOS_READ_INTO_CHARRAY_2BYTES(charray, off) \
-{ \
- IOS_READ_INTO_CHARRAY_1BYTE(charray, off); \
- IOS_GET_C_ERR_CHCK((charray)[1], io, (off) + 1); \
-}
-
-#define IOS_READ_INTO_CHARRAY_3BYTES(charray, off) \
-{ \
- IOS_READ_INTO_CHARRAY_2BYTES(charray, off); \
- IOS_GET_C_ERR_CHCK((charray)[2], io, (off) + 2); \
-}
-
-#define IOS_READ_INTO_CHARRAY_4BYTES(charray, off) \
-{ \
- IOS_READ_INTO_CHARRAY_3BYTES(charray, off); \
- IOS_GET_C_ERR_CHCK((charray)[3], io, (off) + 3); \
-}
-
-#define IOS_READ_INTO_CHARRAY_5BYTES(charray, off) \
-{ \
- IOS_READ_INTO_CHARRAY_4BYTES(charray, off); \
- IOS_GET_C_ERR_CHCK((charray)[4], io, (off) + 4); \
-}
-
-#define IOS_READ_INTO_CHARRAY_6BYTES(charray, off) \
-{ \
- IOS_READ_INTO_CHARRAY_5BYTES(charray, off); \
- IOS_GET_C_ERR_CHCK((charray)[5], io, (off) + 5); \
-}
-
-#define IOS_READ_INTO_CHARRAY_7BYTES(charray, off) \
-{ \
- IOS_READ_INTO_CHARRAY_6BYTES(charray, off); \
- IOS_GET_C_ERR_CHCK((charray)[6], io, (off) + 6); \
-}
-
-#define IOS_READ_INTO_CHARRAY_8BYTES(charray, off) \
-{ \
- IOS_READ_INTO_CHARRAY_7BYTES(charray, off); \
- IOS_GET_C_ERR_CHCK((charray)[7], io, (off) + 7); \
-}
-
-#define IOS_READ_INTO_CHARRAY_9BYTES(charray, off) \
-{ \
- IOS_READ_INTO_CHARRAY_8BYTES(charray, off); \
- IOS_GET_C_ERR_CHCK((charray)[8], io, (off) + 8); \
-}
-
/* The following struct implements an instance of an IO space.
`ID' is an unique integer identifying the IO space.
@@ -357,7 +304,7 @@ ios_read_int_common (ios io, ios_off offset, int flags,
uint64_t *value)
{
/* 64 bits might span at most 9 bytes. */
- uint64_t c[9] = {0, 0, 0, 0, 0, 0, 0, 0, 0};
+ uint8_t c[9] = {0, 0, 0, 0, 0, 0, 0, 0, 0};
/* Number of signifcant bits in the first byte. */
int firstbyte_bits = 8 - (offset % 8);
@@ -369,8 +316,9 @@ ios_read_int_common (ios io, ios_off offset, int flags,
int lastbyte_bits = (bits + (offset % 8)) % 8;
lastbyte_bits = lastbyte_bits == 0 ? 8 : lastbyte_bits;
- /* Read the first byte and clear the unused bits. */
- IOS_GET_C_ERR_CHCK(c[0], io, offset / 8);
+ /* Read the bytes and clear the unused bits. */
+ if (io->dev_if->pread (io->dev, c, bytes_minus1 + 1, offset / 8) == IOD_EOF)
+ return IOS_EIOFF;
IOS_CHAR_GET_LSB(&c[0], firstbyte_bits);
switch (bytes_minus1)
@@ -380,7 +328,6 @@ ios_read_int_common (ios io, ios_off offset, int flags,
return IOS_OK;
case 1:
- IOS_READ_INTO_CHARRAY_1BYTE(c+1, offset / 8 + 1);
IOS_CHAR_GET_MSB(&c[1], lastbyte_bits);
if (endian == IOS_ENDIAN_LSB)
{
@@ -411,7 +358,6 @@ ios_read_int_common (ios io, ios_off offset, int flags,
return IOS_OK;
case 2:
- IOS_READ_INTO_CHARRAY_2BYTES(c+1, offset / 8 + 1);
IOS_CHAR_GET_MSB(&c[2], lastbyte_bits);
if (endian == IOS_ENDIAN_LSB)
{
@@ -424,8 +370,9 @@ ios_read_int_common (ios io, ios_off offset, int flags,
/* We have to shift to fill the least significant byte to get
the right bits in the same bytes. */
uint64_t reg;
- reg = (c[0] << (56 + offset % 8)) | (c[1] << (48 + offset % 8))
- | (c[2] << (40 + offset % 8));
+ reg = ((uint64_t) c[0] << (56 + offset % 8))
+ | ((uint64_t) c[1] << (48 + offset % 8))
+ | ((uint64_t) c[2] << (40 + offset % 8));
/* The bits in the most-significant-byte-to-be is aligned to left,
shift it towards right! */
if (bits <= 16)
@@ -448,7 +395,6 @@ ios_read_int_common (ios io, ios_off offset, int flags,
return IOS_OK;
case 3:
- IOS_READ_INTO_CHARRAY_3BYTES(c+1, offset / 8 + 1);
IOS_CHAR_GET_MSB(&c[3], lastbyte_bits);
if (endian == IOS_ENDIAN_LSB)
{
@@ -462,8 +408,10 @@ ios_read_int_common (ios io, ios_off offset, int flags,
/* We have to shift to fill the least significant byte to get
the right bits in the same bytes. */
uint64_t reg;
- reg = (c[0] << (56 + offset % 8)) | (c[1] << (48 + offset % 8))
- | (c[2] << (40 + offset % 8)) | (c[3] << (32 + offset % 8));
+ reg = ((uint64_t) c[0] << (56 + offset % 8))
+ | ((uint64_t) c[1] << (48 + offset % 8))
+ | ((uint64_t) c[2] << (40 + offset % 8))
+ | ((uint64_t) c[3] << (32 + offset % 8));
/* The bits in the most-significant-byte-to-be is aligned to left,
shift it towards right! */
if (bits <= 24)
@@ -486,23 +434,25 @@ ios_read_int_common (ios io, ios_off offset, int flags,
return IOS_OK;
case 4:
- IOS_READ_INTO_CHARRAY_4BYTES(c+1, offset / 8 + 1);
IOS_CHAR_GET_MSB(&c[4], lastbyte_bits);
if (endian == IOS_ENDIAN_LSB)
{
if ((offset % 8) == 0)
/* If little endian and the least significant byte is 8 bits aligned,
then we can handle the information byte by byte as we read. */
- *value = (c[4] << (24 + lastbyte_bits)) | (c[3] << 24) | (c[2] << 16)
+ *value = ((uint64_t) c[4] << (24 + lastbyte_bits))
+ | ((uint64_t) c[3] << 24) | (c[2] << 16)
| (c[1] << 8) | c[0];
else
{
/* We have to shift to fill the least significant byte to get
the right bits in the same bytes. */
uint64_t reg;
- reg = (c[0] << (56 + offset % 8)) | (c[1] << (48 + offset % 8))
- | (c[2] << (40 + offset % 8)) | (c[3] << (32 + offset % 8))
- | (c[4] << (24 + offset % 8));
+ reg = ((uint64_t) c[0] << (56 + offset % 8))
+ | ((uint64_t) c[1] << (48 + offset % 8))
+ | ((uint64_t) c[2] << (40 + offset % 8))
+ | ((uint64_t) c[3] << (32 + offset % 8))
+ | ((uint64_t) c[4] << (24 + offset % 8));
/* The bits in the most-significant-byte-to-be is aligned to left,
shift it towards right! */
if (bits <= 32)
@@ -519,30 +469,34 @@ ios_read_int_common (ios io, ios_off offset, int flags,
{
/* We should shift to fill the least significant byte
which is the last 8 bits. */
- *value = (c[0] << (24 + lastbyte_bits)) | (c[1] << (16 + lastbyte_bits))
+ *value = ((uint64_t) c[0] << (24 + lastbyte_bits))
+ | ((uint64_t) c[1] << (16 + lastbyte_bits))
| (c[2] << (8 + lastbyte_bits)) | (c[3] << lastbyte_bits)
| (c[4] >> (8 - lastbyte_bits));
}
return IOS_OK;
case 5:
- IOS_READ_INTO_CHARRAY_5BYTES(c+1, offset / 8 + 1);
IOS_CHAR_GET_MSB(&c[5], lastbyte_bits);
if (endian == IOS_ENDIAN_LSB)
{
if ((offset % 8) == 0)
/* If little endian and the least significant byte is 8 bits aligned,
then we can handle the information byte by byte as we read. */
- *value = (c[5] << (32 + lastbyte_bits)) | (c[4] << 32) | (c[3] << 24)
+ *value = ((uint64_t) c[5] << (32 + lastbyte_bits))
+ | ((uint64_t) c[4] << 32) | ((uint64_t) c[3] << 24)
| (c[2] << 16) | (c[1] << 8) | c[0];
else
{
/* We have to shift to fill the least significant byte to get
the right bits in the same bytes. */
uint64_t reg;
- reg = (c[0] << (56 + offset % 8)) | (c[1] << (48 + offset % 8))
- | (c[2] << (40 + offset % 8)) | (c[3] << (32 + offset % 8))
- | (c[4] << (24 + offset % 8)) | (c[5] << (16 + offset % 8));
+ reg = ((uint64_t) c[0] << (56 + offset % 8))
+ | ((uint64_t) c[1] << (48 + offset % 8))
+ | ((uint64_t) c[2] << (40 + offset % 8))
+ | ((uint64_t) c[3] << (32 + offset % 8))
+ | ((uint64_t) c[4] << (24 + offset % 8))
+ | (c[5] << (16 + offset % 8));
/* The bits in the most-significant-byte-to-be is aligned to left,
shift it towards right! */
if (bits <= 40)
@@ -559,30 +513,36 @@ ios_read_int_common (ios io, ios_off offset, int flags,
{
/* We should shift to fill the least significant byte
which is the last 8 bits. */
- *value = (c[0] << (32 + lastbyte_bits)) | (c[1] << (24 + lastbyte_bits))
- | (c[2] << (16 + lastbyte_bits)) | (c[3] << (8 +
lastbyte_bits))
+ *value = ((uint64_t) c[0] << (32 + lastbyte_bits))
+ | ((uint64_t) c[1] << (24 + lastbyte_bits))
+ | ((uint64_t) c[2] << (16 + lastbyte_bits))
+ | (c[3] << (8 + lastbyte_bits))
| (c[4] << lastbyte_bits) | (c[5] >> (8 - lastbyte_bits));
}
return IOS_OK;
case 6:
- IOS_READ_INTO_CHARRAY_6BYTES(c+1, offset / 8 + 1);
IOS_CHAR_GET_MSB(&c[6], lastbyte_bits);
if (endian == IOS_ENDIAN_LSB)
{
if ((offset % 8) == 0)
/* If little endian and the least significant byte is 8 bits aligned,
then we can handle the information byte by byte as we read. */
- *value = (c[6] << (40 + lastbyte_bits)) | (c[5] << 40) | (c[4] << 32)
- | (c[3] << 24) | (c[2] << 16) | (c[1] << 8) | c[0];
+ *value = ((uint64_t) c[6] << (40 + lastbyte_bits))
+ | ((uint64_t) c[5] << 40) | ((uint64_t) c[4] << 32)
+ | ((uint64_t) c[3] << 24) | (c[2] << 16) | (c[1] << 8)
+ | c[0];
else
{
/* We have to shift to fill the least significant byte to get
the right bits in the same bytes. */
uint64_t reg;
- reg = (c[0] << (56 + offset % 8)) | (c[1] << (48 + offset % 8))
- | (c[2] << (40 + offset % 8)) | (c[3] << (32 + offset % 8))
- | (c[4] << (24 + offset % 8)) | (c[5] << (16 + offset % 8))
+ reg = ((uint64_t) c[0] << (56 + offset % 8))
+ | ((uint64_t) c[1] << (48 + offset % 8))
+ | ((uint64_t) c[2] << (40 + offset % 8))
+ | ((uint64_t) c[3] << (32 + offset % 8))
+ | ((uint64_t) c[4] << (24 + offset % 8))
+ | (c[5] << (16 + offset % 8))
| (c[6] << (8 + offset % 8));
/* The bits in the most-significant-byte-to-be is aligned to left,
shift it towards right! */
@@ -600,32 +560,37 @@ ios_read_int_common (ios io, ios_off offset, int flags,
{
/* We should shift to fill the least significant byte
which is the last 8 bits. */
- *value = (c[0] << (40 + lastbyte_bits)) | (c[1] << (32 + lastbyte_bits))
- | (c[2] << (24 + lastbyte_bits)) | (c[3] << (16 +
lastbyte_bits))
+ *value = ((uint64_t) c[0] << (40 + lastbyte_bits))
+ | ((uint64_t) c[1] << (32 + lastbyte_bits))
+ | ((uint64_t) c[2] << (24 + lastbyte_bits))
+ | ((uint64_t) c[3] << (16 + lastbyte_bits))
| (c[4] << (8 + lastbyte_bits)) | (c[5] << lastbyte_bits)
| (c[6] >> (8 - lastbyte_bits));
}
return IOS_OK;
case 7:
- IOS_READ_INTO_CHARRAY_7BYTES(c+1, offset / 8 + 1);
IOS_CHAR_GET_MSB(&c[7], lastbyte_bits);
if (endian == IOS_ENDIAN_LSB)
{
if ((offset % 8) == 0)
/* If little endian and the least significant byte is 8 bits aligned,
then we can handle the information byte by byte as we read. */
- *value = (c[7] << (48 + lastbyte_bits)) | (c[6] << 48) | (c[5] << 40)
- | (c[4] << 32) | (c[3] << 24) | (c[2] << 16) | (c[1] << 8)
- | c[0];
+ *value = ((uint64_t) c[7] << (48 + lastbyte_bits))
+ | ((uint64_t) c[6] << 48) | ((uint64_t) c[5] << 40)
+ | ((uint64_t) c[4] << 32) | ((uint64_t) c[3] << 24)
+ | (c[2] << 16) | (c[1] << 8) | c[0];
else
{
/* We have to shift to fill the least significant byte to get
the right bits in the same bytes. */
uint64_t reg;
- reg = (c[0] << (56 + offset % 8)) | (c[1] << (48 + offset % 8))
- | (c[2] << (40 + offset % 8)) | (c[3] << (32 + offset % 8))
- | (c[4] << (24 + offset % 8)) | (c[5] << (16 + offset % 8))
+ reg = ((uint64_t) c[0] << (56 + offset % 8))
+ | ((uint64_t) c[1] << (48 + offset % 8))
+ | ((uint64_t) c[2] << (40 + offset % 8))
+ | ((uint64_t) c[3] << (32 + offset % 8))
+ | ((uint64_t) c[4] << (24 + offset % 8))
+ | (c[5] << (16 + offset % 8))
| (c[6] << (8 + offset % 8)) | (c[7] << offset % 8);
/* The bits in the most-significant-byte-to-be is aligned to left,
shift it towards right! */
@@ -643,24 +608,29 @@ ios_read_int_common (ios io, ios_off offset, int flags,
{
/* We should shift to fill the least significant byte
which is the last 8 bits. */
- *value = (c[0] << (48 + lastbyte_bits)) | (c[1] << (40 + lastbyte_bits))
- | (c[2] << (32 + lastbyte_bits)) | (c[3] << (24 +
lastbyte_bits))
- | (c[4] << (16 + lastbyte_bits)) | (c[5] << (8 +
lastbyte_bits))
+ *value = ((uint64_t) c[0] << (48 + lastbyte_bits))
+ | ((uint64_t) c[1] << (40 + lastbyte_bits))
+ | ((uint64_t) c[2] << (32 + lastbyte_bits))
+ | ((uint64_t) c[3] << (24 + lastbyte_bits))
+ | ((uint64_t) c[4] << (16 + lastbyte_bits))
+ | (c[5] << (8 + lastbyte_bits))
| (c[6] << lastbyte_bits) | (c[7] >> (8 - lastbyte_bits));
}
return IOS_OK;
case 8:
- IOS_READ_INTO_CHARRAY_8BYTES(c+1, offset / 8 + 1);
IOS_CHAR_GET_MSB(&c[8], lastbyte_bits);
if (endian == IOS_ENDIAN_LSB)
{
/* We have to shift to fill the least significant byte to get
the right bits in the same bytes. */
uint64_t reg;
- reg = (c[0] << (56 + offset % 8)) | (c[1] << (48 + offset % 8))
- | (c[2] << (40 + offset % 8)) | (c[3] << (32 + offset % 8))
- | (c[4] << (24 + offset % 8)) | (c[5] << (16 + offset % 8))
+ reg = ((uint64_t) c[0] << (56 + offset % 8))
+ | ((uint64_t) c[1] << (48 + offset % 8))
+ | ((uint64_t) c[2] << (40 + offset % 8))
+ | ((uint64_t) c[3] << (32 + offset % 8))
+ | ((uint64_t) c[4] << (24 + offset % 8))
+ | (c[5] << (16 + offset % 8))
| (c[6] << (8 + offset % 8)) | (c[7] << offset % 8)
| (c[8] >> firstbyte_bits);
/* The bits in the most-significant-byte-to-be is aligned to left,
@@ -674,9 +644,12 @@ ios_read_int_common (ios io, ios_off offset, int flags,
{
/* We should shift to fill the least significant byte
which is the last 8 bits. */
- *value = (c[0] << (56 + lastbyte_bits)) | (c[1] << (48 + lastbyte_bits))
- | (c[2] << (40 + lastbyte_bits)) | (c[3] << (32 +
lastbyte_bits))
- | (c[4] << (24 + lastbyte_bits)) | (c[5] << (16 +
lastbyte_bits))
+ *value = ((uint64_t) c[0] << (56 + lastbyte_bits))
+ | ((uint64_t) c[1] << (48 + lastbyte_bits))
+ | ((uint64_t) c[2] << (40 + lastbyte_bits))
+ | ((uint64_t) c[3] << (32 + lastbyte_bits))
+ | ((uint64_t) c[4] << (24 + lastbyte_bits))
+ | ((uint64_t) c[5] << (16 + lastbyte_bits))
| (c[6] << (8 + lastbyte_bits)) | (c[7] << lastbyte_bits)
| (c[8] >> (8 - lastbyte_bits));
}
@@ -700,30 +673,28 @@ ios_read_int (ios io, ios_off offset, int flags,
/* Fast track for byte-aligned 8x bits */
if (offset % 8 == 0 && bits % 8 == 0)
{
+ uint8_t c[8];
+ if (io->dev_if->pread (io->dev, c, bits / 8, offset / 8) == IOD_EOF)
+ return IOS_EIOFF;
+
switch (bits) {
case 8:
{
- int8_t c[1] = {0};
- IOS_READ_INTO_CHARRAY_1BYTE(c, offset / 8);
- *value = c[0];
+ *value = (int8_t) c[0];
return IOS_OK;
}
case 16:
{
- int16_t c[2] = {0, 0};
- IOS_READ_INTO_CHARRAY_2BYTES(c, offset / 8);
if (endian == IOS_ENDIAN_LSB)
- *value = (c[1] << 8) | c[0];
+ *value = (int16_t) (c[1] << 8) | c[0];
else
- *value = (c[0] << 8) | c[1];
+ *value = (int16_t) (c[0] << 8) | c[1];
return IOS_OK;
}
case 24:
{
- int64_t c[3] = {0, 0, 0};
- IOS_READ_INTO_CHARRAY_3BYTES(c, offset / 8);
if (endian == IOS_ENDIAN_LSB)
*value = (c[2] << 16) | (c[1] << 8) | c[0];
else
@@ -735,25 +706,21 @@ ios_read_int (ios io, ios_off offset, int flags,
case 32:
{
- int32_t c[4] = {0, 0, 0, 0};
- IOS_READ_INTO_CHARRAY_4BYTES(c, offset / 8);
if (endian == IOS_ENDIAN_LSB)
- *value = (c[3] << 24) | (c[2] << 16) | (c[1] << 8) | c[0];
+ *value = (int32_t) (c[3] << 24) | (c[2] << 16) | (c[1] << 8) | c[0];
else
- *value = (c[0] << 24) | (c[1] << 16) | (c[2] << 8) | c[3];
+ *value = (int32_t) (c[0] << 24) | (c[1] << 16) | (c[2] << 8) | c[3];
return IOS_OK;
}
case 40:
{
- int64_t c[5] = {0, 0, 0, 0, 0};
- IOS_READ_INTO_CHARRAY_5BYTES(c, offset / 8);
if (endian == IOS_ENDIAN_LSB)
- *value = (c[4] << 32) | (c[3] << 24) | (c[2] << 16) | (c[1] << 8)
- | c[0];
+ *value = ((uint64_t) c[4] << 32) | ((uint64_t) c[3] << 24)
+ | (c[2] << 16) | (c[1] << 8) | c[0];
else
- *value = (c[0] << 32) | (c[1] << 24) | (c[2] << 16) | (c[3] << 8)
- | c[4];
+ *value = ((uint64_t) c[0] << 32) | ((uint64_t) c[1] << 24)
+ | (c[2] << 16) | (c[3] << 8) | c[4];
*value <<= 24;
*value >>= 24;
return IOS_OK;
@@ -761,13 +728,13 @@ ios_read_int (ios io, ios_off offset, int flags,
case 48:
{
- int64_t c[6] = {0, 0, 0, 0, 0, 0};
- IOS_READ_INTO_CHARRAY_6BYTES(c, offset / 8);
if (endian == IOS_ENDIAN_LSB)
- *value = (c[5] << 40) | (c[4] << 32) | (c[3] << 24) | (c[2] << 16)
+ *value = ((uint64_t) c[5] << 40) | ((uint64_t) c[4] << 32)
+ | ((uint64_t) c[3] << 24) | (c[2] << 16)
| (c[1] << 8) | c[0];
else
- *value = (c[0] << 40) | (c[1] << 32) | (c[2] << 24) | (c[3] << 16)
+ *value = ((uint64_t) c[0] << 40) | ((uint64_t) c[1] << 32)
+ | ((uint64_t) c[2] << 24) | (c[3] << 16)
| (c[4] << 8) | c[5];
*value <<= 16;
*value >>= 16;
@@ -776,13 +743,13 @@ ios_read_int (ios io, ios_off offset, int flags,
case 56:
{
- int64_t c[7] = {0, 0, 0, 0, 0, 0, 0};
- IOS_READ_INTO_CHARRAY_7BYTES(c, offset / 8);
if (endian == IOS_ENDIAN_LSB)
- *value = (c[6] << 48) | (c[5] << 40) | (c[4] << 32) | (c[3] << 24)
+ *value = ((uint64_t) c[6] << 48) | ((uint64_t) c[5] << 40)
+ | ((uint64_t) c[4] << 32) | ((uint64_t) c[3] << 24)
| (c[2] << 16) | (c[1] << 8) | c[0];
else
- *value = (c[0] << 48) | (c[1] << 40) | (c[2] << 32) | (c[3] << 24)
+ *value = ((uint64_t) c[0] << 48) | ((uint64_t) c[1] << 40)
+ | ((uint64_t) c[2] << 32) | ((uint64_t) c[3] << 24)
| (c[4] << 16) | (c[5] << 8) | c[6];
*value <<= 8;
*value >>= 8;
@@ -791,14 +758,16 @@ ios_read_int (ios io, ios_off offset, int flags,
case 64:
{
- int64_t c[8] = {0, 0, 0, 0, 0, 0, 0, 0};
- IOS_READ_INTO_CHARRAY_8BYTES(c, offset / 8);
if (endian == IOS_ENDIAN_LSB)
- *value = (c[7] << 56) | (c[6] << 48) | (c[5] << 40) | (c[4] << 32)
- | (c[3] << 24) | (c[2] << 16) | (c[1] << 8) | c[0];
+ *value = ((uint64_t) c[7] << 56) | ((uint64_t) c[6] << 48)
+ | ((uint64_t) c[5] << 40) | ((uint64_t) c[4] << 32)
+ | ((uint64_t) c[3] << 24) | (c[2] << 16) | (c[1] << 8)
+ | c[0];
else
- *value = (c[0] << 56) | (c[1] << 48) | (c[2] << 40) | (c[3] << 32)
- | (c[4] << 24) | (c[5] << 16) | (c[6] << 8) | c[7];
+ *value = ((uint64_t) c[0] << 56) | ((uint64_t) c[1] << 48)
+ | ((uint64_t) c[2] << 40) | ((uint64_t) c[3] << 32)
+ | ((uint64_t) c[4] << 24) | (c[5] << 16) | (c[6] << 8)
+ | c[7];
return IOS_OK;
}
}
@@ -825,20 +794,19 @@ ios_read_uint (ios io, ios_off offset, int flags,
/* Apply the IOS bias. */
offset += ios_get_bias (io);
- /* When aligned, 1 to 64 bits can span at most 8 bytes. */
- uint64_t c[8] = {0, 0, 0, 0, 0, 0, 0, 0};
-
/* Fast track for byte-aligned 8x bits */
if (offset % 8 == 0 && bits % 8 == 0)
{
+ uint8_t c[8];
+ if (io->dev_if->pread (io->dev, c, bits / 8, offset / 8) == IOD_EOF)
+ return IOS_EIOFF;
+
switch (bits) {
case 8:
- IOS_READ_INTO_CHARRAY_1BYTE(c, offset / 8);
*value = c[0];
return IOS_OK;
case 16:
- IOS_READ_INTO_CHARRAY_2BYTES(c, offset / 8);
if (endian == IOS_ENDIAN_LSB)
*value = (c[1] << 8) | c[0];
else
@@ -846,7 +814,6 @@ ios_read_uint (ios io, ios_off offset, int flags,
return IOS_OK;
case 24:
- IOS_READ_INTO_CHARRAY_3BYTES(c, offset / 8);
if (endian == IOS_ENDIAN_LSB)
*value = (c[2] << 16) | (c[1] << 8) | c[0];
else
@@ -854,51 +821,54 @@ ios_read_uint (ios io, ios_off offset, int flags,
return IOS_OK;
case 32:
- IOS_READ_INTO_CHARRAY_4BYTES(c, offset / 8);
if (endian == IOS_ENDIAN_LSB)
- *value = (c[3] << 24) | (c[2] << 16) | (c[1] << 8) | c[0];
+ *value = ((uint64_t) c[3] << 24) | (c[2] << 16) | (c[1] << 8) | c[0];
else
- *value = (c[0] << 24) | (c[1] << 16) | (c[2] << 8) | c[3];
+ *value = ((uint64_t) c[0] << 24) | (c[1] << 16) | (c[2] << 8) | c[3];
return IOS_OK;
case 40:
- IOS_READ_INTO_CHARRAY_5BYTES(c, offset / 8);
if (endian == IOS_ENDIAN_LSB)
- *value = (c[4] << 32) | (c[3] << 24) | (c[2] << 16) | (c[1] << 8)
- | c[0];
+ *value = ((uint64_t) c[4] << 32) | ((uint64_t) c[3] << 24)
+ | (c[2] << 16) | (c[1] << 8) | c[0];
else
- *value = (c[0] << 32) | (c[1] << 24) | (c[2] << 16) | (c[3] << 8)
- | c[4];
+ *value = ((uint64_t) c[0] << 32) | ((uint64_t) c[1] << 24)
+ | (c[2] << 16) | (c[3] << 8) | c[4];
return IOS_OK;
case 48:
- IOS_READ_INTO_CHARRAY_6BYTES(c, offset / 8);
if (endian == IOS_ENDIAN_LSB)
- *value = (c[5] << 40) | (c[4] << 32) | (c[3] << 24) | (c[2] << 16)
+ *value = ((uint64_t) c[5] << 40) | ((uint64_t) c[4] << 32)
+ | ((uint64_t) c[3] << 24) | (c[2] << 16)
| (c[1] << 8) | c[0];
else
- *value = (c[0] << 40) | (c[1] << 32) | (c[2] << 24) | (c[3] << 16)
+ *value = ((uint64_t) c[0] << 40) | ((uint64_t) c[1] << 32)
+ | ((uint64_t) c[2] << 24) | (c[3] << 16)
| (c[4] << 8) | c[5];
return IOS_OK;
case 56:
- IOS_READ_INTO_CHARRAY_7BYTES(c, offset / 8);
if (endian == IOS_ENDIAN_LSB)
- *value = (c[6] << 48) | (c[5] << 40) | (c[4] << 32) | (c[3] << 24)
+ *value = ((uint64_t) c[6] << 48) | ((uint64_t) c[5] << 40)
+ | ((uint64_t) c[4] << 32) | ((uint64_t) c[3] << 24)
| (c[2] << 16) | (c[1] << 8) | c[0];
else
- *value = (c[0] << 48) | (c[1] << 40) | (c[2] << 32) | (c[3] << 24)
+ *value = ((uint64_t) c[0] << 48) | ((uint64_t) c[1] << 40)
+ | ((uint64_t) c[2] << 32) | ((uint64_t) c[3] << 24)
| (c[4] << 16) | (c[5] << 8) | c[6];
return IOS_OK;
case 64:
- IOS_READ_INTO_CHARRAY_8BYTES(c, offset / 8);
if (endian == IOS_ENDIAN_LSB)
- *value = (c[7] << 56) | (c[6] << 48) | (c[5] << 40) | (c[4] << 32)
- | (c[3] << 24) | (c[2] << 16) | (c[1] << 8) | c[0];
+ *value = ((uint64_t) c[7] << 56) | ((uint64_t) c[6] << 48)
+ | ((uint64_t) c[5] << 40) | ((uint64_t) c[4] << 32)
+ | ((uint64_t) c[3] << 24) | (c[2] << 16) | (c[1] << 8)
+ | c[0];
else
- *value = (c[0] << 56) | (c[1] << 48) | (c[2] << 40) | (c[3] << 32)
- | (c[4] << 24) | (c[5] << 16) | (c[6] << 8) | c[7];
+ *value = ((uint64_t) c[0] << 56) | ((uint64_t) c[1] << 48)
+ | ((uint64_t) c[2] << 40) | ((uint64_t) c[3] << 32)
+ | ((uint64_t) c[4] << 24) | (c[5] << 16) | (c[6] << 8)
+ | c[7];
return IOS_OK;
}
}
--
2.25.1
- [PATCH 0/7] More efficient I/O, Eric Blake, 2020/02/29
- [PATCH 3/7] ios: Prove we don't need seek., Eric Blake, 2020/02/29
- [PATCH 1/7] ios: Drop Position column from .info ios, Eric Blake, 2020/02/29
- [PATCH 4/7] ios: Drop unused seek/tell callbacks., Eric Blake, 2020/02/29
- [PATCH 5/7] ios: Change from getchar to pread device interface., Eric Blake, 2020/02/29
- [PATCH 7/7] ios: Utilize buffer writes., Eric Blake, 2020/02/29
- [PATCH 6/7] ios: Utilize buffer reads.,
Eric Blake <=
- [PATCH 2/7] ios: Pass offset to low-level macros., Eric Blake, 2020/02/29
- Re: [PATCH 0/7] More efficient I/O, Jose E. Marchesi, 2020/02/29