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FMUL
Multiplies the destination operand by the source operand. The result is stored in the destination operand.
The table after the description covers what the source and destinations can be.
| source | destination(s) |
|---|---|
| reg | reg |
| memory | reg |
| reg | memory |
DO NOT support LOCK
The instruction is available in 64-bit mode and compatibility mode. It operates on the x87 floating-point stack. If the destination is not specified (implicit), the instruction uses the top of the stack (ST(0)).
When using FMUL with a memory operand, the operand MUST be a valid floating-point format (f32 or f64). Using an incorrect data size for the memory operand WILL result in a general protection exception (#GP).
Precision and rounding control are governed by the x87 control word. Results that cannot be represented exactly in the destination format WILL trigger #P. Results that exceed the representable range of the floating-point format WILL trigger #O, and results that are too small WILL trigger #U. Denormalized operands WILL trigger #D.