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@ -1,4 +1,4 @@ |
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@c Copyright 1991, 1992, 1993, 1994, 1995, 1997, 2001 |
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@c Copyright 1991, 1992, 1993, 1994, 1995, 1997, 2001, 2004 |
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@c Free Software Foundation, Inc. |
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@c This is part of the GAS manual. |
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@c For copying conditions, see the file as.texinfo. |
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@ -164,9 +164,23 @@ Immediate data |
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@cindex floating point, SH (@sc{ieee}) |
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@cindex SH floating point (@sc{ieee}) |
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The SH family has no hardware floating point, but the @code{.float} |
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directive generates @sc{ieee} floating-point numbers for compatibility |
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with other development tools. |
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SH2E, SH3E and SH4 groups have on-chip floating-point unit (FPU). Other |
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SH groups can use @code{.float} directive to generate @sc{ieee} |
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floating-point numbers. |
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SH2E and SH3E support single-precision floating point calculations as |
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well as entirely PCAPI compatible emulation of double-precision |
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floating point calculations. SH2E and SH3E instructions are a subset of |
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the floating point calculations conforming to the IEEE754 standard. |
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In addition to single-precision and double-precision floating-point |
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operation capability, the on-chip FPU of SH4 has a 128-bit graphic |
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engine that enables 32-bit floating-point data to be processed 128 |
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bits at a time. It also supports 4 * 4 array operations and inner |
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product operations. Also, a superscalar architecture is employed that |
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enables simultaneous execution of two instructions (including FPU |
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instructions), providing performance of up to twice that of |
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conventional architectures at the same frequency. |
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@node SH Directives |
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@section SH Machine Directives |
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