Filter
Top Products
Vector Floating-point Programming
6-42 Copyright © 2000, 2001 ARM Limited. All rights reserved. ARM DUI 0068B
6.9.2 VFPASSERT VECTOR
The
VFPASSERT VECTOR
directive informs the assembler that following VFP instructions
are in vector mode. It can also specify the length and stride of the vectors.
Syntax
VFPASSERT VECTOR[<[n[:s]]>]
where:
n
is the vector length, 1-8.
s
is the vector stride, 1-2.
Usage
Use the
VFPASSERT VECTOR
directive to mark the start of a block of instructions where the
VFP mode is
VECTOR
, and to mark changes in the length or stride of vectors.
Place the
VFPASSERT VECTOR
directive immediately after the instruction where the change
occurs. This is usually an
FMXR
instruction, but might be a
BL
instruction.
If a function expects the VFP to be in vector mode on entry, place a
VFPASSERT VECTOR
directive immediately before the first instruction. Such a function would not be ATPCS
conformant. See the Using the Procedure Call Standard chapter in ADS Developer
Guide for further information.
See:
• VFP directives and vector notation on page 6-40
• VFPASSERT SCALAR on page 6-41.
Note
This directive does not generate any code. It is only an assertion by the programmer. The
assembler produces error messages if any such assertions are inconsistent with each
other, or with any vector notation in VFP data processing instructions.