PM0214 datasheet(155/245 Pages) STMICROELECTRONICS

155 / 245 page

DocID022708 Rev 4

155/245

PM0214

The STM32 Cortex-M4 instruction set

244

Condition flags

These instructions do not change the flags.

3.10.9

VFNMA, VFNMS

Floating-point Fused Negate Multiply Accumulate and Subtract.

Syntax

VFNMA{cond}.F32 {Sd,} Sn, Sm

VFNMS{cond}.F32 {Sd,} Sn, Sm

where:

•

‘cond’ is an optional condition code, see Conditional execution on page 64.

•

‘Sd’ is the destination register

•

‘Sn, Sm’ are the operand registers.

Operation

The VFNMA instruction:

Negates the first floating-point operand register.

Multiplies the first floating-point operand with second floating-point operand.

Adds the negation of the floating -point destination register to the product

Places the result into the destination register.

The result of the multiply is not rounded before the addition.

The VFNMS instruction:

Multiplies the first floating-point operand with second floating-point operand.

Adds the negation of the floating-point value in the destination register to the product.

Places the result in the destination register.

The result of the multiply is not rounded before the addition.

Restrictions

There are no restrictions.

Condition flags

These instructions do not change the flags.

PM0214 Datasheet(PDF) 155 Page - STMicroelectronics