On 1/12/21 9:44 PM, Richard Henderson wrote: > On 1/12/21 8:41 AM, Philippe Mathieu-Daudé wrote: >> Some ISA use a dot in their opcodes. Allow the decodetree >> script to process them. The dot is replaced by an underscore >> in the generated code. > > Given that you then have to remember to use '_' on the C side, what advantage > does this give?
The direct advantage is you can copy/paste the opcode in a PDF viewer without having to edit it :) See i.e. some Loongson opcodes [*]: MULT.G 011100 ..... ..... ..... 00000 010000 @rs_rt_rd DMULT.G 011100 ..... ..... ..... 00000 010001 @rs_rt_rd MULTU.G 011100 ..... ..... ..... 00000 010010 @rs_rt_rd DMULTU.G 011100 ..... ..... ..... 00000 010011 @rs_rt_rd DIV.G 011100 ..... ..... ..... 00000 010100 @rs_rt_rd DDIV.G 011100 ..... ..... ..... 00000 010101 @rs_rt_rd DIVU.G 011100 ..... ..... ..... 00000 010110 @rs_rt_rd DDIVU.G 011100 ..... ..... ..... 00000 010111 @rs_rt_rd MOD.G 011100 ..... ..... ..... 00000 011100 @rs_rt_rd DMOD.G 011100 ..... ..... ..... 00000 011101 @rs_rt_rd MODU.G 011100 ..... ..... ..... 00000 011110 @rs_rt_rd DMODU.G 011100 ..... ..... ..... 00000 011111 @rs_rt_rd The other - remote - advantage I see is when using a disassembler based on decodetree (as AVR does), the opcode displayed also matches the specs. We are not yet there with MIPS, but I have something in progress... [*] https://lists.gnu.org/archive/html/qemu-devel/2021-01/msg02509.html
