Update description of FP behaviour

This commit is contained in:
Nick Clifton 2004-01-02 17:32:12 +00:00
parent 3ab4893121
commit 303e7b798f
2 changed files with 23 additions and 4 deletions

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2004-01-02 Nutan Singh <nutan@kpitcummins.com>
* doc/c-sh.texi: Update description about floating point behavior
of SH family.
2004-01-02 Bernardo Innocenti <bernie@develer.com>
* configure.in: Add m68k-uClinux target.

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@c Copyright 1991, 1992, 1993, 1994, 1995, 1997, 2001
@c Copyright 1991, 1992, 1993, 1994, 1995, 1997, 2001, 2004
@c Free Software Foundation, Inc.
@c This is part of the GAS manual.
@c For copying conditions, see the file as.texinfo.
@ -164,9 +164,23 @@ Immediate data
@cindex floating point, SH (@sc{ieee})
@cindex SH floating point (@sc{ieee})
The SH family has no hardware floating point, but the @code{.float}
directive generates @sc{ieee} floating-point numbers for compatibility
with other development tools.
SH2E, SH3E and SH4 groups have on-chip floating-point unit (FPU). Other
SH groups can use @code{.float} directive to generate @sc{ieee}
floating-point numbers.
SH2E and SH3E support single-precision floating point calculations as
well as entirely PCAPI compatible emulation of double-precision
floating point calculations. SH2E and SH3E instructions are a subset of
the floating point calculations conforming to the IEEE754 standard.
In addition to single-precision and double-precision floating-point
operation capability, the on-chip FPU of SH4 has a 128-bit graphic
engine that enables 32-bit floating-point data to be processed 128
bits at a time. It also supports 4 * 4 array operations and inner
product operations. Also, a superscalar architecture is employed that
enables simultaneous execution of two instructions (including FPU
instructions), providing performance of up to twice that of
conventional architectures at the same frequency.
@node SH Directives
@section SH Machine Directives