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[base] Clean up signedness in arithmetic functions.

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This makes the code more readable and reduces compiler warnings.

* src/base/ftcalc.c (FT_MulDiv, FT_MulDiv_No_Round, FT_MulFix,
FT_DivFix): Convert input parameters to unsigned, do the
computation, then convert the result back to signed.
(ft_corner_orientation): Fix casts.
2.6.5
Werner Lemberg 10 years ago
parent 92359bd885
commit 6d7d636b46
2 changed files with 179 additions and 115 deletions
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  1. 11
      ChangeLog
  2. 283
      src/base/ftcalc.c

11
ChangeLog
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@ -1,3 +1,14 @@
2015-02-15 Werner Lemberg <wl@gnu.org>
[base] Clean up signedness in arithmetic functions.
This makes the code more readable and reduces compiler warnings.
* src/base/ftcalc.c (FT_MulDiv, FT_MulDiv_No_Round, FT_MulFix,
FT_DivFix): Convert input parameters to unsigned, do the
computation, then convert the result back to signed.
(ft_corner_orientation): Fix casts.
2015-02-07 Werner Lemberg <wl@gnu.org>
[sfnt] Fix Savannah bug #44184.

283
src/base/ftcalc.c
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@ -173,52 +173,66 @@
/* documentation is in freetype.h */
FT_EXPORT_DEF( FT_Long )
FT_MulDiv( FT_Long a,
FT_Long b,
FT_Long c )
FT_MulDiv( FT_Long a_,
FT_Long b_,
FT_Long c_ )
{
FT_Int s = 1;
FT_Long d;
FT_Int s = 1;
FT_UInt64 a, b, c, d;
FT_Long d_;
FT_MOVE_SIGN( a, s );
FT_MOVE_SIGN( b, s );
FT_MOVE_SIGN( c, s );
FT_MOVE_SIGN( a_, s );
FT_MOVE_SIGN( b_, s );
FT_MOVE_SIGN( c_, s );
d = (FT_Long)( c > 0 ? ( (FT_Int64)a * b + ( c >> 1 ) ) / c
: 0x7FFFFFFFL );
a = (FT_UInt64)a_;
b = (FT_UInt64)b_;
c = (FT_UInt64)c_;
return s < 0 ? -d : d;
d = c > 0 ? ( a * b + ( c >> 1 ) ) / c
: 0x7FFFFFFFUL;
d_ = (FT_Long)d;
return s < 0 ? -d_ : d_;
}
/* documentation is in ftcalc.h */
FT_BASE_DEF( FT_Long )
FT_MulDiv_No_Round( FT_Long a,
FT_Long b,
FT_Long c )
FT_MulDiv_No_Round( FT_Long a_,
FT_Long b_,
FT_Long c_ )
{
FT_Int s = 1;
FT_Long d;
FT_Int s = 1;
FT_UInt64 a, b, c, d;
FT_Long d_;
FT_MOVE_SIGN( a_, s );
FT_MOVE_SIGN( b_, s );
FT_MOVE_SIGN( c_, s );
FT_MOVE_SIGN( a, s );
FT_MOVE_SIGN( b, s );
FT_MOVE_SIGN( c, s );
a = (FT_UInt64)a_;
b = (FT_UInt64)b_;
c = (FT_UInt64)c_;
d = (FT_Long)( c > 0 ? (FT_Int64)a * b / c
: 0x7FFFFFFFL );
d = c > 0 ? a * b / c
: 0x7FFFFFFFUL;
return s < 0 ? -d : d;
d_ = (FT_Long)d;
return s < 0 ? -d_ : d_;
}
/* documentation is in freetype.h */
FT_EXPORT_DEF( FT_Long )
FT_MulFix( FT_Long a,
FT_Long b )
FT_MulFix( FT_Long a_,
FT_Long b_ )
{
#ifdef FT_MULFIX_ASSEMBLER
@ -226,16 +240,22 @@
#else
FT_Int s = 1;
FT_Long c;
FT_Int s = 1;
FT_UInt64 a, b, c;
FT_Long c_;
FT_MOVE_SIGN( a_, s );
FT_MOVE_SIGN( b_, s );
a = (FT_UInt64)a_;
b = (FT_UInt64)b_;
FT_MOVE_SIGN( a, s );
FT_MOVE_SIGN( b, s );
c = ( a * b + 0x8000UL ) >> 16;
c = (FT_Long)( ( (FT_Int64)a * b + 0x8000L ) >> 16 );
c_ = (FT_Long)c;
return s < 0 ? -c : c;
return s < 0 ? -c_ : c_;
#endif /* FT_MULFIX_ASSEMBLER */
}
@ -244,20 +264,26 @@
/* documentation is in freetype.h */
FT_EXPORT_DEF( FT_Long )
FT_DivFix( FT_Long a,
FT_Long b )
FT_DivFix( FT_Long a_,
FT_Long b_ )
{
FT_Int s = 1;
FT_Long q;
FT_Int s = 1;
FT_UInt64 a, b, q;
FT_Long q_;
FT_MOVE_SIGN( a, s );
FT_MOVE_SIGN( b, s );
FT_MOVE_SIGN( a_, s );
FT_MOVE_SIGN( b_, s );
q = (FT_Long)( b > 0 ? ( ( (FT_UInt64)a << 16 ) + ( b >> 1 ) ) / b
: 0x7FFFFFFFL );
a = (FT_UInt64)a_;
b = (FT_UInt64)b_;
return s < 0 ? -q : q;
q = b > 0 ? ( ( a << 16 ) + ( b >> 1 ) ) / b
: 0x7FFFFFFFUL;
q_ = (FT_Long)q;
return s < 0 ? -q_ : q_;
}
@ -401,26 +427,32 @@
/* documentation is in freetype.h */
FT_EXPORT_DEF( FT_Long )
FT_MulDiv( FT_Long a,
FT_Long b,
FT_Long c )
FT_MulDiv( FT_Long a_,
FT_Long b_,
FT_Long c_ )
{
FT_Int s = 1;
FT_Int s = 1;
FT_UInt32 a, b, c;
/* XXX: this function does not allow 64-bit arguments */
if ( a == 0 || b == c )
return a;
FT_MOVE_SIGN( a, s );
FT_MOVE_SIGN( b, s );
FT_MOVE_SIGN( c, s );
if ( a_ == 0 || b_ == c_ )
return a_;
FT_MOVE_SIGN( a_, s );
FT_MOVE_SIGN( b_, s );
FT_MOVE_SIGN( c_, s );
a = (FT_UInt32)a_;
b = (FT_UInt32)b_;
c = (FT_UInt32)c_;
if ( c == 0 )
a = 0x7FFFFFFFL;
a = 0x7FFFFFFFUL;
else if ( (FT_ULong)a + b <= 129894UL - ( c >> 17 ) )
a = ( (FT_ULong)a * b + ( c >> 1 ) ) / c;
else if ( a + b <= 129894UL - ( c >> 17 ) )
a = ( a * b + ( c >> 1 ) ) / c;
else
{
@ -439,30 +471,39 @@
: ft_div64by32( temp.hi, temp.lo, c );
}
return s < 0 ? -a : a;
a_ = (FT_Long)a;
return s < 0 ? -a_ : a_;
}
FT_BASE_DEF( FT_Long )
FT_MulDiv_No_Round( FT_Long a,
FT_Long b,
FT_Long c )
FT_MulDiv_No_Round( FT_Long a_,
FT_Long b_,
FT_Long c_ )
{
FT_Int s = 1;
FT_Int s = 1;
FT_UInt32 a, b, c;
if ( a == 0 || b == c )
return a;
/* XXX: this function does not allow 64-bit arguments */
if ( a_ == 0 || b_ == c_ )
return a_;
FT_MOVE_SIGN( a_, s );
FT_MOVE_SIGN( b_, s );
FT_MOVE_SIGN( c_, s );
FT_MOVE_SIGN( a, s );
FT_MOVE_SIGN( b, s );
FT_MOVE_SIGN( c, s );
a = (FT_UInt32)a_;
b = (FT_UInt32)b_;
c = (FT_UInt32)c_;
if ( c == 0 )
a = 0x7FFFFFFFL;
a = 0x7FFFFFFFUL;
else if ( (FT_ULong)a + b <= 131071UL )
a = (FT_ULong)a * b / c;
else if ( a + b <= 131071UL )
a = a * b / c;
else
{
@ -476,19 +517,21 @@
: ft_div64by32( temp.hi, temp.lo, c );
}
return s < 0 ? -a : a;
a_ = (FT_Long)a;
return s < 0 ? -a_ : a_;
}
/* documentation is in freetype.h */
FT_EXPORT_DEF( FT_Long )
FT_MulFix( FT_Long a,
FT_Long b )
FT_MulFix( FT_Long a_,
FT_Long b_ )
{
#ifdef FT_MULFIX_ASSEMBLER
return FT_MULFIX_ASSEMBLER( a, b );
return FT_MULFIX_ASSEMBLER( a_, b_ );
#elif 0
@ -499,12 +542,12 @@
* the leftmost bits by copying the sign bit, it might be faster.
*/
FT_Long sa, sb;
FT_ULong ua, ub;
FT_Long sa, sb;
FT_UInt32 a, b;
if ( a == 0 || b == 0x10000L )
return a;
if ( a_ == 0 || b_ == 0x10000L )
return a_;
/*
* This is a clever way of converting a signed number `a' into its
@ -524,57 +567,61 @@
* with the value 1 rather than -1. After that, everything else goes
* wrong.
*/
sa = ( a >> ( sizeof ( a ) * 8 - 1 ) );
a = ( a ^ sa ) - sa;
sb = ( b >> ( sizeof ( b ) * 8 - 1 ) );
b = ( b ^ sb ) - sb;
sa = ( a_ >> ( sizeof ( a_ ) * 8 - 1 ) );
a = ( a_ ^ sa ) - sa;
sb = ( b_ >> ( sizeof ( b_ ) * 8 - 1 ) );
b = ( b_ ^ sb ) - sb;
ua = (FT_ULong)a;
ub = (FT_ULong)b;
a = (FT_UInt32)a_;
b = (FT_UInt32)b_;
if ( ua + ( ub >> 8 ) <= 8190UL )
ua = ( ua * ub + 0x8000U ) >> 16;
if ( a + ( b >> 8 ) <= 8190UL )
a = ( a * b + 0x8000U ) >> 16;
else
{
FT_ULong al = ua & 0xFFFFU;
FT_UInt32 al = a & 0xFFFFUL;
ua = ( ua >> 16 ) * ub + al * ( ub >> 16 ) +
( ( al * ( ub & 0xFFFFU ) + 0x8000U ) >> 16 );
a = ( a >> 16 ) * b + al * ( b >> 16 ) +
( ( al * ( b & 0xFFFFUL ) + 0x8000UL ) >> 16 );
}
sa ^= sb,
ua = (FT_ULong)(( ua ^ sa ) - sa);
sa ^= sb;
a = ( a ^ sa ) - sa;
return (FT_Long)ua;
return (FT_Long)a;
#else /* 0 */
FT_Int s = 1;
FT_ULong ua, ub;
FT_Int s = 1;
FT_UInt32 a, b;
if ( a == 0 || b == 0x10000L )
return a;
/* XXX: this function does not allow 64-bit arguments */
FT_MOVE_SIGN( a, s );
FT_MOVE_SIGN( b, s );
if ( a_ == 0 || b_ == 0x10000L )
return a_;
ua = (FT_ULong)a;
ub = (FT_ULong)b;
FT_MOVE_SIGN( a_, s );
FT_MOVE_SIGN( b_, s );
if ( ua + ( ub >> 8 ) <= 8190UL )
ua = ( ua * ub + 0x8000UL ) >> 16;
a = (FT_UInt32)a_;
b = (FT_UInt32)b_;
if ( a + ( b >> 8 ) <= 8190UL )
a = ( a * b + 0x8000UL ) >> 16;
else
{
FT_ULong al = ua & 0xFFFFUL;
FT_UInt32 al = a & 0xFFFFUL;
ua = ( ua >> 16 ) * ub + al * ( ub >> 16 ) +
( ( al * ( ub & 0xFFFFUL ) + 0x8000UL ) >> 16 );
a = ( a >> 16 ) * b + al * ( b >> 16 ) +
( ( al * ( b & 0xFFFFUL ) + 0x8000UL ) >> 16 );
}
return s < 0 ? -(FT_Long)ua : (FT_Long)ua;
a_ = (FT_Long)a;
return s < 0 ? -a_ : a_;
#endif /* 0 */
@ -584,27 +631,31 @@
/* documentation is in freetype.h */
FT_EXPORT_DEF( FT_Long )
FT_DivFix( FT_Long a,
FT_Long b )
FT_DivFix( FT_Long a_,
FT_Long b_ )
{
FT_Int s = 1;
FT_Long q;
FT_Int s = 1;
FT_UInt32 a, b, q;
FT_Long q_;
/* XXX: this function does not allow 64-bit arguments */
FT_MOVE_SIGN( a, s );
FT_MOVE_SIGN( b, s );
FT_MOVE_SIGN( a_, s );
FT_MOVE_SIGN( b_, s );
a = (FT_UInt32)a_;
b = (FT_UInt32)b_;
if ( b == 0 )
{
/* check for division by 0 */
q = 0x7FFFFFFFL;
q = 0x7FFFFFFFUL;
}
else if ( a <= 65535L - ( b >> 17 ) )
else if ( a <= 65535UL - ( b >> 17 ) )
{
/* compute result directly */
q = (FT_Long)( ( ( (FT_ULong)a << 16 ) + ( b >> 1 ) ) / b );
q = ( ( a << 16 ) + ( b >> 1 ) ) / b;
}
else
{
@ -618,14 +669,16 @@
temp2.lo = b >> 1;
FT_Add64( &temp, &temp2, &temp );
q = (FT_Long)ft_div64by32( temp.hi, temp.lo, b );
q = ft_div64by32( temp.hi, temp.lo, b );
}
return s < 0 ? -q : q;
q_ = (FT_Long)q;
return s < 0 ? -q_ : q_;
}
#endif /* FT_LONG64 */
#endif /* !FT_LONG64 */
/* documentation is in ftglyph.h */
@ -748,7 +801,7 @@
if ( x > 0 )
{
rem_hi = 0;
rem_lo = x;
rem_lo = (FT_UInt32)x;
count = 24;
do
{
@ -829,8 +882,8 @@
/* XXX: this function does not allow 64-bit arguments */
ft_multo64( (FT_Int32)in_x, (FT_Int32)out_y, &z1 );
ft_multo64( (FT_Int32)in_y, (FT_Int32)out_x, &z2 );
ft_multo64( (FT_UInt32)in_x, (FT_UInt32)out_y, &z1 );
ft_multo64( (FT_UInt32)in_y, (FT_UInt32)out_x, &z2 );
if ( z1.hi > z2.hi )
result = +1;

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