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Luca Benini <lbenini@csr.unibo.it> writes: > Andreas Jaeger wrote: >> That has nothing to do with this - on x86-64, we use the 387 unit for >> long doubles, > ... 387 can at most support 80 bits floating point value during > > From amd manuals 24592: > x87 instructions operate on data in three floating-point > formats--32-bit single-precision, 64-bit double-precision, and > 80-bit double-extended-precision (sometimes called extended > precision)--as well as integer, and 80-bit packed-BCD fo > > > on one of my x86_64 server: > sizeof(float) == 4 (32 bit) > sizeof(double) == 8 (64 bit) > sizeof(long double) == 16 (128 bit) > > is your fp bigger? ;-) Read the AMD64 ABI - we use the 80 double-extended precision for long double which is an x87 data type - just align it to 128 bits, Andreas -- Andreas Jaeger, aj@suse.de, http://www.suse.de/~aj SUSE Linux Products GmbH, Maxfeldstr. 5, 90409 NÃrnberg, Germany GPG fingerprint = 93A3 365E CE47 B889 DF7F FED1 389A 563C C272 A126
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