Overlapping opcodes for certain order of instructions not detected

[rob-sch]

If you define a R-Type instruction with the same opcode and funct3 fields as a previously defined I-Type instruction, the parse-opcode script will not recognise the overlapping.

Example opcodes file (named opcodes-fail), that produces the error:

foo1  rd rs1 imm12            14..12=0 6..2=2 1..0=3
bar1  rd rs1 rs2     31..25=1 14..12=0 6..2=2 1..0=3

bar0  rd rs1 rs2     31..25=1 14..12=1 6..2=2 1..0=3
foo0  rd rs1 imm12            14..12=1 6..2=2 1..0=3

Shell command:

 cat opcodes-fail | ./parse-opcodes -c

Output:

foo0 and bar0 overlap