Should p-code in SLEIGH files favor decompilation or emulation?

[thixotropist]

When generating SLEIGH code for new instructions, should the pcode (semantics) be appropriate for the decompilation window or RTL emulation fidelity?

If decompilation, then:

• there should be no explicit pcode testing for or handling of exceptions - don't include explicit checks for floating point NaN inputs, divide by zero, memory access or alignment errors, or unimplemented or privileged instructions.
• the generated pcode should assume normal C implicit (automatic) type conversion and not include explicit pcode conversions.
• optionally add Ghidra hooks to an external qemu or other RTL emulator with full support for exception generation.

If emulation, then:

• add a design document showing which types of hardware exceptions should be handled in SLEIGH and which ignored
• add qemu-like microarchitecture settings to match the target processor