ARM Architecture Reference Manual ARMv7-A and ARMv7-R edition

Instruction Details
A8.6.298 VCVT (between double-precision and single-precision)
This instruction does one of the following:
converts the value in a double-precision register to single-precision and writes the result to a
single-precision register
converts the value in a single-precision register to double-precision and writes the result to a
double-precision register.
Encoding T1 / A1 VFPv2, VFPv3 (UNDEFINED in single-precision only variants)
VCVT.F64.F32 ,
VCVT.F32.F64 ,
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
1 1 1 0 1 1 1 0 1 D 1 1 0 1 1 1 Vd 1 0 1 sz 1 1 M 0 Vm
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
cond 1 1 1 0 1 D 1 1 0 1 1 1 Vd 1 0 1 sz 1 1 M 0 Vm
double_to_single = (sz == ‘1’);
d = if double_to_single then UInt(Vd:D) else UInt(D:Vd);
m = if double_to_single then UInt(M:Vm) else UInt(Vm:M);
A8-584 Copyright © 1996-1998, 2000, 2004-2008 ARM Limited. All rights reserved. ARM DDI 0406B