30.6.1.3.1. ARM VCVTR instruction
Example: userland/arch/arm/vcvtr.S
Like ARM VCVT instruction, but the rounding mode is selected by the FPSCR.RMode field.
Selecting rounding mode explicitly per instruction was apparently not possible in ARMv7, but was made possible in AArch32 e.g. with ARMv8 AArch32 VCVTA instruction.
Rounding mode selection is exposed in the ANSI C standard through fesetround.
TODO: is the initial rounding mode specified by the ELF standard? Could not find a reference.