From f0d858b6c2793f7bae00e4c5dc2d0f38fc1e30f8 Mon Sep 17 00:00:00 2001 From: Alon Zakai Date: Wed, 11 Oct 2017 10:13:06 -0700 Subject: fix simplify-locals bug where we create a br_if value, which is dangerous if we are moving code out of the br_if's condition - the value executes before (#1213) --- test/passes/simplify-locals.wast | 47 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) (limited to 'test/passes/simplify-locals.wast') diff --git a/test/passes/simplify-locals.wast b/test/passes/simplify-locals.wast index 10fcf1277..842e2b5af 100644 --- a/test/passes/simplify-locals.wast +++ b/test/passes/simplify-locals.wast @@ -940,4 +940,51 @@ (drop (i32.atomic.load (i32.const 1028))) (drop (get_local $x)) ) + (func $br-value-reordering (result i32) + (local $temp i32) + (block $outside + (loop $loop ;; we should exit this loop, hit the unreachable outside + ;; loop logic + (br_if $outside ;; we should not create a block value that adds a value to a br, if the value&condition of the br cannot be reordered, + ;; as the value comes first + (block (result i32) + (br_if $loop + (get_local $temp) ;; false, don't loop + ) + (unreachable) ;; the end + (set_local $temp + (i32.const -1) + ) + (i32.const 0) + ) + ) + ) + (set_local $temp + (i32.const -1) + ) + ) + (unreachable) + ) + (func $br-value-reordering-safe (result i32) + (local $temp i32) + (block $outside + (loop $loop ;; we should exit this loop, hit the unreachable outside + ;; loop logic + (drop (get_local $temp)) ;; different from above - add a use here + (br_if $outside ;; we should not create a block value that adds a value to a br, if the value&condition of the br cannot be reordered, + ;; as the value comes first + (block (result i32) + (set_local $temp ;; the use *is* in the condition, but it's ok, no conflicts + (i32.const -1) + ) + (i32.const 0) + ) + ) + ) + (set_local $temp + (i32.const -1) + ) + ) + (unreachable) + ) ) -- cgit v1.2.3