Messages in this thread | | | Date | Thu, 4 Dec 2014 09:40:24 -0800 | From | David Daney <> | Subject | Re: [PATCH 2/3] MIPS: Add full ISA emulator. |
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On 12/04/2014 03:49 AM, Maciej W. Rozycki wrote: > On Wed, 3 Dec 2014, David Daney wrote: > >>> but it doesn't support customized instructions, >> >> GCC will never put these in the delay slot of a FPU branch, so it is not >> needed. >> >>> multiple ASEs, >> >> Same as above. But any instructions that are deemed necessary can easily be >> added. > > GAS will happily schedule any instruction into a branch delay slot as > long as the instruction is not architecturally forbidden there (e.g. > ERET), there is no data dependency with the branch that would affect the > result produced and the instruction is not an explicit exception trap > operation (BREAK, SYSCALL, TEQ, etc.). For some reason, unknown to me all > MT ASE instructions are disallowed too. Anything else -- free to go in! > > Of course instructions can be scheduled into branch delay slots manually > too, in handcoded assembly, and that has to continue working. >
It is not difficult to also emulate the trapping instructions. In order to move forward, I will implement the trapping instructions in my emulator for the next patch.
Thanks, David Daney
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