bool rules, constant condition, switch pull in beneath

egraphs-good / eggcc

MIT License

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bool rules, constant condition, switch pull in beneath #229

Closed ajpal closed 9 months ago

ajpal commented 10 months ago

1. !(a or b) ==> !a and !b
2. !(a and b) ==> !a or !b
3. !! a ==> a
4. if true A B ==> A
5. if false A B ==> B
6. (if E then S1 else S2); S3 ==> if E then S1;S3 else S2;S3

yihozhang commented 9 months ago

Note: This PR does seem to handle cases like

var x = 0;
if b {
  x = 1;
} else {
  x = -1;
}
return f(x)

whose corresponding IR form is

f(if b then 1 else -1)

since there are no side effects. So this PR actually implements a different optimization than the switch pull in beneath from the milestone encoding?