Discrepancy in codegen for binary operations between master branch and 3.3.0

[hoshiumiarata]

MRuby's master branch is generating the SSEND opcode for binary operations instead of the corresponding opcode when the left-hand side is self.

For example:

self < 5

The master branch generates:

    1 000 LOADI_5       R3      (5)
    1 002 SSEND         R2      :<      n=1

while mruby 3.3.0 generates:

    1 000 LOADSELF      R2      (R0)
    1 002 LOADI_5       R3      (5)
    1 004 LT            R2      R3

Is this intentional?

[matz]

Yes, if the receiver (right side operand for operators) is self, it now generates SSEND. But if you face any issues, I will reconsider.

[hoshiumiarata]

@matz
It is not a major problem, but it seems that SSEND is about 5-10% slower than LOADSELF + binary op for integers (and probably floats). It is not a significant difference, but there are numerous methods in the numeric/integer/float classes that use self + binary operations.