JIT: Transform '(cmp & x) | (cmp & y)' to 'cmp & (x | y)'

[BoyBaykiller]

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[BoyBaykiller]

I am having a problem identifying certain cases.
Currently I detect such IR:

[000007] ----------- \--* OR int [000003] ----------- +--* AND int [000001] ----------- | +--* LCL_VAR int V02 arg2 [000002] ----------- | \--* CNS_INT int 256 [000006] ----------- \--* AND int [000004] ----------- +--* LCL_VAR int V02 arg2 (last use) [000005] ----------- \--* CNS_INT int 512 

Which works fine for (flags & 256) | (flags & 512),
but breaks down if I add a operation in front like 1 + (flags & 256) | (flags & 512). Then the IR is:

[000008] ----------- \--* OR int [000004] ----------- +--* ADD int [000000] ----------- | +--* CNS_INT int 1 [000003] ----------- | \--* AND int [000001] ----------- | +--* LCL_VAR int V01 arg1 [000002] ----------- | \--* CNS_INT int 256 [000007] ----------- \--* AND int [000005] ----------- +--* LCL_VAR int V01 arg1 [000006] ----------- \--* CNS_INT int 512 

When adding explicit parentheses like 1 + ((flags & 256) | (flags & 512)) it works again:

[000008] ----------- \--* ADD int [000000] ----------- +--* CNS_INT int 1 [000007] ----------- \--* OR int [000003] ----------- +--* AND int [000001] ----------- | +--* LCL_VAR int V01 arg1 [000002] ----------- | \--* CNS_INT int 256 [000006] ----------- \--* AND int [000004] ----------- +--* LCL_VAR int V01 arg1 [000005] ----------- \--* CNS_INT int 512 

But this shouldn't be needed. It shouldnt get confused by some extra commutative arithmetic like the ADD(1) here. What is the general way to fix this?

[huoyaoyuan]

but breaks down if I add a operation in front like 1 + (flags & 256) | (flags & 512). Then the IR is:

The operator priority of | is lower than +. 1 + (flags & 256) | (flags & 512) means (1 + (flags & 256)) | (flags & 512). Check sharplab.

[EgorBo]

I don't think this is legal - cmp may have side-effect or be a local whose value is changed via x or y