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Unformatted text preview: single-precision (4-byte) values, corresponding to C data type float; double-precision (8-byte) values, corresponding to C data type double; and extended-precision (10-byte) values. G CC uses the data type long double to refer to extended-precision ﬂoating-point values. It also stores them as 12byte quantities to improve memory system performance, as will be discussed later. Although the ANSI C standard includes long double as a data type, they are implemented for most combinations of compiler and machine using the same 8-byte format as ordinary double. The support for extended precision is 3.4. ACCESSING INFORMATION
31 %eax %ecx %edx %ebx %esi %edi %esp %ebp %ax %cx %dx %ax %si %di %sp %bp Stack Pointer Frame Pointer 15 %ah %ch %dh %bh 87 %al %cl %dl %bl 0 99 Figure 3.2: Integer Registers. All eight registers can be accessed as either 16 bits (word) or 32 bits (double word). The two low-order bytes of the ﬁrst four registers can be accessed independently. unique to the combination of GCC and IA32. As the table indicates, every operation in GAS has...
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