451268 - TM: Double check that its safe to not have a loop check after the unrolled first iteration in a tree call

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Andreas Gal :gal]

js_LoopEdge is triggered before we actually compile the underlying branch opcode, so we never emit code for it on trace. Double check whether thats safe to do.

Comment 1

[Andreas Gal :gal]

The comment above is incorrect. We do trace IFEQ/IFNE first. The resulting guards is simply constant folded in most case. I verified that the guard is emitted if constant folding is impossible, i.e.:

function f(N) {
	for (var i = 0; i < 100; ++i)
		for (var j = 0; j < N; ++j)
			;
}

f(50);

r=shaver