Re: [PATCH 3/3] score: Add _CPU_Instruction_illegal()

2018-07-20 Thread Gedare Bloom
On Fri, Jul 20, 2018 at 11:46 AM, Sebastian Huber wrote: > - Am 20. Jul 2018 um 16:28 schrieb Gedare Bloom ged...@rtems.org: > >> I want to reiterate my comment that some ISAs have valid instructions >> with an encoding of all zeroes. Off the top of my head, MIPS32 of all >> 0s is the

Re: [PATCH 3/3] score: Add _CPU_Instruction_illegal()

2018-07-20 Thread Sebastian Huber
- Am 20. Jul 2018 um 16:28 schrieb Gedare Bloom ged...@rtems.org: > I want to reiterate my comment that some ISAs have valid instructions > with an encoding of all zeroes. Off the top of my head, MIPS32 of all > 0s is the encoding for sll $0, $0, 0, which is a nop. Yes, I added some special

Re: [PATCH 3/3] score: Add _CPU_Instruction_illegal()

2018-07-20 Thread Gedare Bloom
I want to reiterate my comment that some ISAs have valid instructions with an encoding of all zeroes. Off the top of my head, MIPS32 of all 0s is the encoding for sll $0, $0, 0, which is a nop. I am not too sure about the purpose of the test anymore, as if an illegal instruction exception occurs,

[PATCH 3/3] score: Add _CPU_Instruction_illegal()

2018-07-20 Thread Sebastian Huber
On some architectures/simulators it is difficult to provoke an exception with misaligned or illegal data loads. Use an illegal instruction instead. Update #3433. --- cpukit/score/cpu/arm/include/rtems/score/cpuimpl.h | 5 + cpukit/score/cpu/bfin/include/rtems/score/cpuimpl.h | 5