# Documentation

Lean.Compiler.IR.ExpandResetReuse

@[inline]

Mapping from variable to projections

Equations
@[inline]
Equations
• One or more equations did not get rendered due to their size.

Create a mapping from variables to projections. This function assumes variable ids have been normalized

Equations

Return true iff x is consumed in all branches of the current block. Here consumption means the block contains a dec x or reuse x ....

@[inline]
Equations

Auxiliary function for eraseProjIncFor

Try to erase inc instructions on projections of y occurring in the tail of bs. Return the updated bs and a bit mask specifying which incs have been removed.

Equations

Replace reuse x ctor ... with ctor ..., and remoce dec x

replace

x := reset y; b


with

inc z_1; ...; inc z_i; dec y; b'


where z_i's are the variables in mask, and b' is b where we removed dec x and replaced reuse x ctor_i ... with ctor_i ....

Equations
• One or more equations did not get rendered due to their size.
@[inline]
Equations
Equations
Equations
• One or more equations did not get rendered due to their size.

Given set x[i] := y, return true iff y := proj[i] x

Equations
• One or more equations did not get rendered due to their size.

Given uset x[i] := y, return true iff y := uproj[i] x

Equations

Given sset x[n, i] := y, return true iff y := sproj[n, i] x

Equations

Remove unnecessary set/uset/sset operations

replace

x := reset y; b


with

let f_i_1 := proj[i_1] y;
...
let f_i_k := proj[i_k] y;
b'


where i_js are the field indexes that the code did not touch immediately before the reset. That is mask[j] == none. b' is b where y dec x is replaced with del y, and z := reuse x ctor_i ws; F is replaced with set x i ws[i] operations, and we replace z with x in F

Equations
Equations
• One or more equations did not get rendered due to their size.
Equations
• One or more equations did not get rendered due to their size.

(Try to) expand reset and reuse instructions.

Equations