5.7.14. FMRX, FMXR, and FMSTAT

Transfer contents between an ARM register and a VFP system register.

Syntax

FMRX{cond} Rd, VFPsysreg
FMXR{cond} VFPsysreg, Rd
FMSTAT{cond}

where:

cond

is an optional condition code (see VFP and condition codes).

VFPsysreg

is the VFP system register, usually FPSCR, FPSID, or FPEXC (see Floating-point registers).

Rd

is the ARM register.

Usage

The FMRX instruction transfers the contents of VFPsysreg into Rd.

The FMXR instruction transfers the contents of Rd into VFPsysreg.

The FMSTAT instruction is a synonym for FMRX r15, FPSCR. It transfers the floating-point condition flags to the corresponding flags in the ARM CPSR (see VFP and condition codes).

Note

These instructions stall the ARM until all current VFP operations complete.

Exceptions

These instructions do not produce any exceptions.

Examples

    FMSTAT
    FMSTATNE
    FMXR        FPSCR, r2
    FMRX        r3, FPSID
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