Re: [Qemu-devel] RISC-V: insn32.decode: Confusing encodings

2019-08-07 Thread Richard Henderson
On 8/6/19 5:48 AM, Maxim Blinov wrote: > slli 00 ... 001 . 0010011 @sh > srli 00 ... 101 . 0010011 @sh > srai 01 ... 101 . 0010011 @sh > > First question: Why does the %sh10 field exist? There are no 10-bit > shamt fields

[Qemu-devel] RISC-V: insn32.decode: Confusing encodings

2019-08-06 Thread Maxim Blinov
Hi all, I've been going through the insn32.decode file, and found some confusing inconsistencies with the ISA spec that I don't understand. I hope some of you can clarify. There is a field defined called "%sh10" as follows: %sh1020:10 Which is used in the "@sh" format as follows: @sh ..