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Refactoring jerry-libc to squeeze out some extra bytes from the code (+fixes) #845

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Merged
merged 1 commit into from
Feb 18, 2016
Merged

Refactoring jerry-libc to squeeze out some extra bytes from the code (+fixes) #845

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33 changes: 7 additions & 26 deletions jerry-libc/jerry-libc-printf.c
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Original file line number Diff line number Diff line change
@@ -1,4 +1,5 @@
/* Copyright 2014-2015 Samsung Electronics Co., Ltd.
/* Copyright 2014-2016 Samsung Electronics Co., Ltd.
* Copyright 2016 University of Szeged
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
Expand Down Expand Up @@ -210,23 +211,13 @@ libc_printf_write_d_i (FILE *stream, /**< stream pointer */
switch (length)
{
case LIBC_PRINTF_ARG_LENGTH_TYPE_NONE:
case LIBC_PRINTF_ARG_LENGTH_TYPE_HH: /* char is promoted to int */
case LIBC_PRINTF_ARG_LENGTH_TYPE_H: /* short int is promoted to int */
{
value = (uintmax_t) va_arg (*args_list_p, int);
break;
}

case LIBC_PRINTF_ARG_LENGTH_TYPE_HH:
{
value = (uintmax_t) va_arg (*args_list_p, int); /* char is promoted to int */
break;
}

case LIBC_PRINTF_ARG_LENGTH_TYPE_H:
{
value = (uintmax_t) va_arg (*args_list_p, int); /* short int is promoted to int */
break;
}

case LIBC_PRINTF_ARG_LENGTH_TYPE_L:
{
value = (uintmax_t) va_arg (*args_list_p, long int);
Expand Down Expand Up @@ -324,23 +315,13 @@ libc_printf_write_u_o_x_X (FILE *stream, /**< stream pointer */
switch (length)
{
case LIBC_PRINTF_ARG_LENGTH_TYPE_NONE:
case LIBC_PRINTF_ARG_LENGTH_TYPE_HH: /* char is promoted to int */
case LIBC_PRINTF_ARG_LENGTH_TYPE_H: /* short int is promoted to int */
{
value = (uintmax_t) va_arg (*args_list_p, unsigned int);
break;
}

case LIBC_PRINTF_ARG_LENGTH_TYPE_HH:
{
value = (uintmax_t) va_arg (*args_list_p, unsigned int); /* char is promoted to int */
break;
}

case LIBC_PRINTF_ARG_LENGTH_TYPE_H:
{
value = (uintmax_t) va_arg (*args_list_p, unsigned int); /* short int is promoted to int */
break;
}

case LIBC_PRINTF_ARG_LENGTH_TYPE_L:
{
value = (uintmax_t) va_arg (*args_list_p, unsigned long int);
Expand Down Expand Up @@ -398,7 +379,7 @@ libc_printf_write_u_o_x_X (FILE *stream, /**< stream pointer */
}
}

uint32_t radix = 10;
uint32_t radix;
const char *alphabet;

switch (specifier)
Expand Down
126 changes: 52 additions & 74 deletions jerry-libc/jerry-libc.c
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Original file line number Diff line number Diff line change
@@ -1,4 +1,5 @@
/* Copyright 2014-2015 Samsung Electronics Co., Ltd.
/* Copyright 2014-2016 Samsung Electronics Co., Ltd.
* Copyright 2016 University of Szeged
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
Expand Down Expand Up @@ -27,7 +28,7 @@
/**
* State of pseudo-random number generator
*/
static unsigned int libc_random_gen_state[4] = { 1455997910, 1999515274, 1234451287, 1949149569 };
static uint32_t libc_random_gen_state[4] = { 1455997910, 1999515274, 1234451287, 1949149569 };

/**
* Standard file descriptors
Expand Down Expand Up @@ -62,9 +63,9 @@ memset (void *s, /**< area to set values in */
size_t n) /**< area size */
{
uint8_t *area_p = (uint8_t *) s;
for (size_t index = 0; index < n; index++)
while (n--)
{
area_p[ index ] = (uint8_t) c;
*area_p++ = (uint8_t) c;
}
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I think the compiler optimize this as well.

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Same as above. Why introduce variables if you can do well without them? This is C, so *p++ is not that much unheard of.

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Ok, keep this.


return s;
Expand All @@ -74,24 +75,21 @@ memset (void *s, /**< area to set values in */
* memcmp
*
* @return 0, if areas are equal;
* -1, if first area's content is lexicographically less, than second area's content;
* 1, otherwise
* <0, if first area's content is lexicographically less, than second area's content;
* >0, otherwise
*/
int
memcmp (const void *s1, /**< first area */
const void *s2, /**< second area */
size_t n) /**< area size */
{
const uint8_t *area1_p = (uint8_t *) s1, *area2_p = (uint8_t *) s2;
for (size_t index = 0; index < n; index++)
while (n--)
{
if (area1_p[ index ] < area2_p[ index ])
int diff = ((int) *area1_p++) - ((int) *area2_p++);
if (diff)
{
return -1;
}
else if (area1_p[ index ] > area2_p[ index ])
{
return 1;
return diff;
}
}

Expand All @@ -109,9 +107,9 @@ memcpy (void *s1, /**< destination */
uint8_t *area1_p = (uint8_t *) s1;
const uint8_t *area2_p = (const uint8_t *) s2;

for (size_t index = 0; index < n; index++)
while (n--)
{
area1_p[ index ] = area2_p[ index ];
*area1_p++ = *area2_p++;
}

return s1;
Expand All @@ -127,21 +125,27 @@ memmove (void *s1, /**< destination */
const void *s2, /**< source */
size_t n) /**< bytes number */
{
uint8_t *dest_p = (uint8_t *) s1;
const uint8_t *src_p = (const uint8_t *) s2;
uint8_t *dest_p;
const uint8_t *src_p;

if (dest_p < src_p)
if (s1 < s2)
{ /* from begin to end */
for (size_t index = 0; index < n; index++)
dest_p = (uint8_t *) s1;
src_p = (const uint8_t *) s2;

while (n--)
{
dest_p[ index ] = src_p[ index ];
*dest_p++ = *src_p++;
}
}
else if (dest_p > src_p)
else if (s1 > s2)
{ /* from end to begin */
for (size_t index = 1; index <= n; index++)
dest_p = ((uint8_t *) s1) + n - 1;
src_p = ((const uint8_t *) s2) + n - 1;

while (n--)
{
dest_p[ n - index ] = src_p[ n - index ];
*dest_p-- = *src_p--;
}
}

Expand All @@ -156,23 +160,19 @@ CALL_PRAGMA (GCC diagnostic pop)
/** Compare two strings. return an integer less than, equal to, or greater than zero
if s1 is found, respectively, to be less than, to match, or be greater than s2. */
int
strcmp (const char *str1, const char *str2)
strcmp (const char *s1, const char *s2)
{
int s1;
int s2;
do
while (1)
{
s1 = *str1++;
s2 = *str2++;
int c1 = (unsigned char) *s1++;
int c2 = (unsigned char) *s2++;
int diff = c1 - c2;

if (s1 == 0)
if (!c1 || diff)
{
break;
return diff;
}
}
while (s1 == s2);

return (s1 < s2) ? -1 : (s1 > s2 ? 1 : 0);
} /* strcmp */

/** Compare two strings. return an integer less than, equal to, or greater than zero
Expand All @@ -181,38 +181,15 @@ strcmp (const char *str1, const char *str2)
int
strncmp (const char *s1, const char *s2, size_t n)
{
size_t i;

if (n == 0)
while (n--)
{
return 0;
}
int c1 = (unsigned char) *s1++;
int c2 = (unsigned char) *s2++;
int diff = c1 - c2;

if (s1 == NULL)
{
if (s2 != NULL)
if (!c1 || diff)
{
return -1;
}
else
{
return 0;
}
}
if (s2 == NULL)
{
return 1;
}

for (i = 0; i < n; i++)
{
if (s1[i] > s2[i])
{
return 1;
}
else if (s1[i] < s2[i])
{
return -1;
return diff;
}
}

Expand All @@ -225,12 +202,12 @@ strncmp (const char *s1, const char *s2, size_t n)
char * __attr_used___ // FIXME
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Is this FIXME comment valid after your patch?

strncpy (char *dest, const char *src, size_t n)
{
size_t i;

for (i = 0; i < n; i++)
while (n--)
{
dest[i] = src[i];
if (src[i] == '\0')
char c = *src++;
*dest++ = c;

if (!c)
{
break;
}
Expand All @@ -243,10 +220,10 @@ strncpy (char *dest, const char *src, size_t n)
size_t
strlen (const char *s)
{
size_t i;
for (i = 0; s[i]; i++)
size_t i = 0;
while (s[i])
{
;
i++;
}

return i;
Expand All @@ -273,9 +250,7 @@ rand (void)
libc_random_gen_state[3] ^= libc_random_gen_state[3] >> 19;
libc_random_gen_state[3] ^= intermediate;

uint32_t ret = libc_random_gen_state[3] % (RAND_MAX + 1u);

return (int32_t) ret;
return libc_random_gen_state[3] % (RAND_MAX + 1u);
} /* rand */

/**
Expand All @@ -284,5 +259,8 @@ rand (void)
void
srand (unsigned int seed) /**< new seed */
{
libc_random_gen_state[0] =
libc_random_gen_state[1] =
libc_random_gen_state[2] =
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Isn't this increase code size?

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Most probably it is increasing the code size with some bytes. However, I cannot think of a smaller solution for fixing srand. Since that function must reinitialize the whole state of the pseudo-RNG to ensure that always the same sequence is generated from the same seed.

libc_random_gen_state[3] = seed;
} /* srand */