Question about Trigger Match Control Type6 CSR's "match" field function

[micreven]

Hi All,

I have a question about the mc6 trigger CSR's match field.

When I read the "match" field function, I think the compare formula should be like below if I config match=5.
"results=((compare_value[63:32]&tdata2[63:32])==(tdata2[31:0]))"

But the SPIKE code shows the tdata2[31:0] also ANDed with tdata[63:32], which seems mismatch with SPEC（Because I think the SPEC doesn't say the tdata2[31:0] should ANDed with tdata2[63:32]）

the SPIKE code copied below，from https://github.com/riscv-software-src/riscv-isa-sim/blob/master/riscv/triggers.cc

the same question is also existed for match=4、5、12、13.

Could anyone help me explain the SPEC description ?

Best regards，
Micreven

[pdonahue-ventana]

You're right. The Spike code looks wrong. It seems like it should be something like ((value >> (xlen/2)) & mask) == (tdata2 & ((1<<(xlen/2))-1).

If I want to match when value[1:0]=3 then I need to program tdata2=0x0000000300000003 where [31:2] must be 0 according to the spec. If I have non-zero in [31:2] like 0x00000003DEADBEEF then the trigger cannot possibly match. The Spike bug was probably never caught because nobody programmed the trigger in this way that made it impossible to match.

[micreven]

Got it.
Thanks a lot.