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Bug 230528: sync to latest jsnum.h: Make sure that gcc aliasing optimizations doesn't break mathcode. Fix mathcode on ARM

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r=Pike sr=peterv
This commit is contained in:
sicking%bigfoot.com 2004-01-15 20:36:26 +00:00
parent a213e3d518
commit 9576772580
1 changed files with 43 additions and 4 deletions
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47
extensions/transformiix/source/base/Double.cpp
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@ -59,18 +59,57 @@ fp_except_t allmask = FP_X_INV|FP_X_OFL|FP_X_UFL|FP_X_DZ|FP_X_IMP|FP_X_DNML;
fp_except_t oldmask = fpsetmask(~allmask);
#endif
/*
/**
* Macros to workaround math-bugs bugs in various platforms
*/
#ifdef IS_BIG_ENDIAN
#define TX_DOUBLE_HI32(x) (((PRUint32 *)&(x))[0])
#define TX_DOUBLE_LO32(x) (((PRUint32 *)&(x))[1])
/**
* Stefan Hanske <sh990154@mail.uni-greifswald.de> reports:
* ARM is a little endian architecture but 64 bit double words are stored
* differently: the 32 bit words are in little endian byte order, the two words
* are stored in big endian`s way.
*/
#if defined(__arm) || defined(__arm32__) || defined(_arm26__) || defined(__arm__)
#define CPU_IS_ARM
#endif
#if (__GNUC__ == 2 && __GNUC_MINOR__ > 95) || __GNUC__ > 2
/**
* This version of the macros is safe for the alias optimizations
* that gcc does, but uses gcc-specific extensions.
*/
typedef union txdpun {
PRFloat64 value;
struct {
#if defined(IS_LITTLE_ENDIAN) && !defined(CPU_IS_ARM)
PRUint32 lo, hi;
#else
PRUint32 hi, lo;
#endif
} s;
} txdpun;
#define TX_DOUBLE_HI32(x) (__extension__ ({ txdpun u; u.d = (x); u.s.hi; }))
#define TX_DOUBLE_LO32(x) (__extension__ ({ txdpun u; u.d = (x); u.s.lo; }))
#else // __GNUC__
/* We don't know of any non-gcc compilers that perform alias optimization,
* so this code should work.
*/
#if defined(IS_LITTLE_ENDIAN) && !defined(CPU_IS_ARM)
#define TX_DOUBLE_HI32(x) (((PRUint32 *)&(x))[1])
#define TX_DOUBLE_LO32(x) (((PRUint32 *)&(x))[0])
#else
#define TX_DOUBLE_HI32(x) (((PRUint32 *)&(x))[0])
#define TX_DOUBLE_LO32(x) (((PRUint32 *)&(x))[1])
#endif
#endif // __GNUC__
#define TX_DOUBLE_HI32_SIGNBIT 0x80000000
#define TX_DOUBLE_HI32_EXPMASK 0x7ff00000
#define TX_DOUBLE_HI32_MANTMASK 0x000fffff