🚀 go-pugleaf

In article <0YrsEMy00V4GQ=CJZw@andrew.cmu.edu> jk3k+@andrew.cmu.edu (Joe Keane) writes:
| The IBM RT manual says (rather verbosely IMHO):
| 
| Certain instructions are not allowed to be the subject of a branch with execute
| instruction.  Since the branch with execute instructions change the normal
| sequential execution of instructions, the subject instructions cannot be an
| instruction that also changes the instruction sequencing; otherwise the
| processor may be put in an unpredictable state.  Thus, all branches, jumps,
| traps, Load Program Status, Supervisor Call, and Wait instructions cannot be
| subject instructions.  The system processor provides hardware that detects
| these illegal instructions and causes a program check interrupt if any of these
| instructions occur as the subject of a branch with execute instruction.

Thanks for the information -- I didn't have my RT arch. manual with me to look it
up.   Does anyone else know of other processors with such restrictions?


	-- Tim Olson
	Advanced Micro Devices
	(tim@amd.com)