981314 - OdinMonkey: Assertion failure: *thenBlock && *elseOrJoinBlock, at jit/AsmJS.cpp

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, defect)

Description

[Gary Kwong [:gkw] [:nth10sd] (NOT official MoCo now)]

Attachment: stack

(function() {
    "use asm";
    function f() {
        return 0
        if (1) 0
    }
})()

asserts js debug shell on m-c changeset 15df39c10a17 with --ion-parallel-compile=off --no-ion at Assertion failure: *thenBlock && *elseOrJoinBlock, at jit/AsmJS.cpp

My configure flags are:

CC="clang -Qunused-arguments" AR=ar CXX="clang++ -Qunused-arguments" sh ./configure --target=x86_64-apple-darwin12.5.0 --enable-optimize --enable-debug --enable-profiling --enable-gczeal --enable-debug-symbols --enable-methodjit --enable-type-inference --disable-tests --with-ccache --enable-threadsafe <other NSPR options>

=== Tinderbox Build Bisection Results by autoBisect ===

The "good" changeset has the timestamp "20140306070306" and the hash "0f87e8f8446c".
The "bad" changeset has the timestamp "20140306074607" and the hash "6048059d6ea1".

Likely regression window: https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=0f87e8f8446c&tochange=6048059d6ea1

Only bug 919052 is in the regression window - Benjamin, is it a likely regressor?

Comment 1

[Luke Wagner [:luke]]

Oops, I think the assertion is overly conservative since dead code will have null blocks.  Seems like we can keep the assertions by adding FunctionCompiler::inDeadCode() const { return !curBlock_; } and turning the JS_ASSERTs to JS_ASSERT_IF(!f.inDeadCode(), ...);

Comment 2

[Benjamin Bouvier [:bbouvier] (inactive)]

Attachment: Patch + test

Thanks, and nice idea! Also %s/if (!curBlock_)/if (!deadCode()), that makes it clearer in all functions.

Comment 3

[Benjamin Bouvier [:bbouvier] (inactive)]

Attachment: Patch + test

There was actually one more place where we can use inDeadCode().

Comment 4

[Luke Wagner [:luke]]

Comment on attachment 8388577 [details] [diff] [review]
Patch + test

Nice!

Comment 5

[Benjamin Bouvier [:bbouvier] (inactive)]

Thanks!
https://hg.mozilla.org/integration/mozilla-inbound/rev/e271003b1477

Comment 6

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/e271003b1477