#### 11.8.2 `GIMPLE_ASSIGN`

— GIMPLE function: gassign *gimple_build_assign (tree lhs, tree rhs)

> Build a `GIMPLE_ASSIGN` statement. The left-hand side is an lvalue passed in lhs. The right-hand side can be either a unary or binary tree expression. The expression tree rhs will be flattened and its operands assigned to the corresponding operand slots in the new statement. This function is useful when you already have a tree expression that you want to convert into a tuple. However, try to avoid building expression trees for the sole purpose of calling this function. If you already have the operands in separate trees, it is better to use `gimple_build_assign` with `enum tree_code` argument and separate arguments for each operand.

— GIMPLE function: gassign *gimple_build_assign (tree lhs, enum tree_code subcode, tree op1, tree op2, tree op3)

> This function is similar to two operand `gimple_build_assign`, but is used to build a `GIMPLE_ASSIGN` statement when the operands of the right-hand side of the assignment are already split into different operands.

> The left-hand side is an lvalue passed in lhs. Subcode is the `tree_code` for the right-hand side of the assignment. Op1, op2 and op3 are the operands.

— GIMPLE function: gassign *gimple_build_assign (tree lhs, enum tree_code subcode, tree op1, tree op2)

> Like the above 5 operand `gimple_build_assign`, but with the last argument `NULL` - this overload should not be used for `GIMPLE_TERNARY_RHS` assignments.

— GIMPLE function: gassign *gimple_build_assign (tree lhs, enum tree_code subcode, tree op1)

> Like the above 4 operand `gimple_build_assign`, but with the last argument `NULL` - this overload should be used only for `GIMPLE_UNARY_RHS` and `GIMPLE_SINGLE_RHS` assignments.

— GIMPLE function: gimple gimplify_assign (tree dst, tree src, gimple_seq *seq_p)

> Build a new `GIMPLE_ASSIGN` tuple and append it to the end of `*SEQ_P`.

`DST`/`SRC` are the destination and source respectively. You can pass ungimplified trees in `DST` or `SRC`, in which case they will be converted to a gimple operand if necessary.

This function returns the newly created `GIMPLE_ASSIGN` tuple.

— GIMPLE function: enum tree_code gimple_assign_rhs_code (gimple g)

> Return the code of the expression computed on the `RHS` of assignment statement `G`.

— GIMPLE function: enum gimple_rhs_class gimple_assign_rhs_class (gimple g)

> Return the gimple rhs class of the code for the expression computed on the rhs of assignment statement `G`. This will never return `GIMPLE_INVALID_RHS`.

— GIMPLE function: tree gimple_assign_lhs (gimple g)

> Return the `LHS` of assignment statement `G`.

— GIMPLE function: tree * gimple_assign_lhs_ptr (gimple g)

> Return a pointer to the `LHS` of assignment statement `G`.

— GIMPLE function: tree gimple_assign_rhs1 (gimple g)

> Return the first operand on the `RHS` of assignment statement `G`.

— GIMPLE function: tree * gimple_assign_rhs1_ptr (gimple g)

> Return the address of the first operand on the `RHS` of assignment statement `G`.

— GIMPLE function: tree gimple_assign_rhs2 (gimple g)

> Return the second operand on the `RHS` of assignment statement `G`.

— GIMPLE function: tree * gimple_assign_rhs2_ptr (gimple g)

> Return the address of the second operand on the `RHS` of assignment statement `G`.

— GIMPLE function: tree gimple_assign_rhs3 (gimple g)

> Return the third operand on the `RHS` of assignment statement `G`.

— GIMPLE function: tree * gimple_assign_rhs3_ptr (gimple g)

> Return the address of the third operand on the `RHS` of assignment statement `G`.

— GIMPLE function: void gimple_assign_set_lhs (gimple g, tree lhs)

> Set `LHS` to be the `LHS` operand of assignment statement `G`.

— GIMPLE function: void gimple_assign_set_rhs1 (gimple g, tree rhs)

> Set `RHS` to be the first operand on the `RHS` of assignment statement `G`.

— GIMPLE function: void gimple_assign_set_rhs2 (gimple g, tree rhs)

> Set `RHS` to be the second operand on the `RHS` of assignment statement `G`.

— GIMPLE function: void gimple_assign_set_rhs3 (gimple g, tree rhs)

> Set `RHS` to be the third operand on the `RHS` of assignment statement `G`.

— GIMPLE function: bool gimple_assign_cast_p (const_gimple s)

> Return true if `S` is a type-cast assignment.