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|
;; See bench.js.
(module
;; A chain of three types. Each type has a "next" field, so we can form linked
;; lists.
(type $A (sub (struct (field $next (ref null $A)))))
(type $B (sub $A (struct (field $next (ref null $A)))))
(type $C (sub $B (struct (field $next (ref null $A)))))
(type $func (func (param (ref $A)) (result i32)))
;; Internal helper to iterate over a linked list and call a function on each
;; item, and return the sum of those calls' results.
(func $iter (param $list (ref null $A)) (param $func (ref $func)) (result i32)
(local $sum i32)
(loop $loop
(if
(ref.is_null
(local.get $list)
)
(then
(return
(local.get $sum)
)
)
(else
(local.set $sum
(i32.add
(local.get $sum)
(call_ref $func
(ref.as_non_null
(local.get $list)
)
(local.get $func)
)
)
)
(local.set $list
(struct.get $A $next
(local.get $list)
)
)
(br $loop)
)
)
)
)
;; Using the helper, and depending on inlining to optimize this, lets us
;; write the exports concisely. First, code to compute the length of the list
;; (for comparison purposes).
(func $len (export "len") (param $list (ref $A)) (result i32)
(call $iter
(local.get $list)
;; Add one each time this is called.
(ref.func $one)
)
)
(func $one (param $list (ref $A)) (result i32)
(i32.const 1)
)
;; At each point in the linked list, check if both the current and next item
;; are inputs are $B, using an if to short-circuit when possible.
(func $iff-both (export "iff-both") (param $list (ref $A)) (result i32)
(call $iter
(local.get $list)
(ref.func $do-iff-both)
)
)
(func $do-iff-both (param $list (ref $A)) (result i32)
(if (result i32)
(ref.test (ref $B)
(struct.get $A $next
(local.get $list)
)
)
(then
(ref.test (ref $B)
(local.get $list)
)
)
(else
(i32.const 0)
)
)
)
;; The same computation, but using an and, so both tests always execute.
(func $and (export "and") (param $list (ref $A)) (result i32)
(call $iter
(local.get $list)
(ref.func $do-and)
)
)
(func $do-and (param $list (ref $A)) (result i32)
(i32.and
(ref.test (ref $B)
(struct.get $A $next
(local.get $list)
)
)
(ref.test (ref $B)
(local.get $list)
)
)
)
;; Similar, but return 1 if either test succeeds (using an if).
(func $iff-either (export "iff-either") (param $list (ref $A)) (result i32)
(call $iter
(local.get $list)
(ref.func $do-iff-either)
)
)
(func $do-iff-either (param $list (ref $A)) (result i32)
(if (result i32)
(ref.test (ref $B)
(struct.get $A $next
(local.get $list)
)
)
(then
(i32.const 1)
)
(else
(ref.test (ref $B)
(local.get $list)
)
)
)
)
;; The same computation, but using an or, so both tests always execute.
(func $or (export "or") (param $list (ref $A)) (result i32)
(call $iter
(local.get $list)
(ref.func $do-or)
)
)
(func $do-or (param $list (ref $A)) (result i32)
(i32.or
(ref.test (ref $B)
(struct.get $A $next
(local.get $list)
)
)
(ref.test (ref $B)
(local.get $list)
)
)
)
;; Use a select to do a test of "is next null ? 0 : test curr".
(func $select (export "select") (param $list (ref $A)) (result i32)
(call $iter
(local.get $list)
(ref.func $do-select)
)
)
(func $do-select (param $list (ref $A)) (result i32)
(select
(i32.const 0)
(ref.test (ref $B)
(local.get $list)
)
(ref.is_null
(struct.get $A $next
(local.get $list)
)
)
)
)
;; Use an iff to do the same.
(func $iff-nextor (export "iff-nextor") (param $list (ref $A)) (result i32)
(call $iter
(local.get $list)
(ref.func $do-iff-nextor)
)
)
(func $do-iff-nextor (param $list (ref $A)) (result i32)
(if (result i32)
(ref.is_null
(struct.get $A $next
(local.get $list)
)
)
(then
(i32.const 0)
)
(else
(ref.test (ref $B)
(local.get $list)
)
)
)
)
;; Use an if over three tests: "test if next is B or C depending on if curr is
;; B."
(func $iff-three (export "iff-three") (param $list (ref $A)) (result i32)
(call $iter
(local.get $list)
(ref.func $do-iff-three)
)
)
(func $do-iff-three (param $list (ref $A)) (result i32)
(local $next (ref null $A))
(local.set $next
(struct.get $A $next
(local.get $list)
)
)
(if (result i32)
(ref.test (ref $B)
(local.get $list)
)
(then
(ref.test (ref $C)
(local.get $next)
)
)
(else
(ref.test (ref $B)
(local.get $next)
)
)
)
)
;; Use a select for the same.
(func $select-three (export "select-three") (param $list (ref $A)) (result i32)
(call $iter
(local.get $list)
(ref.func $do-select-three)
)
)
(func $do-select-three (param $list (ref $A)) (result i32)
(local $next (ref null $A))
(local.set $next
(struct.get $A $next
(local.get $list)
)
)
(select
(ref.test (ref $C)
(local.get $next)
)
(ref.test (ref $B)
(local.get $next)
)
(ref.test (ref $B)
(local.get $list)
)
)
)
;; Creation functions.
(func $makeA (export "makeA") (param $next (ref null $A)) (result anyref)
(struct.new $A
(local.get $next)
)
)
(func $makeB (export "makeB") (param $next (ref null $A)) (result anyref)
(struct.new $B
(local.get $next)
)
)
(func $makeC (export "makeC") (param $next (ref null $A)) (result anyref)
;; This function is not used in benchmarks yet, but it keeps the type $C
;; alive, which prevents $B from looking like it could be final, which might
;; allow the optimizer to simplify more than we want.
(struct.new $C
(local.get $next)
)
)
)
|
