Bug 197792

Summary:	[B3::ReduceStrength] specializeSelect should update m_root and clear the m_valueForConstant cache
Product:	WebKit	Reporter:	Robin Morisset <rmorisset>
Component:	JavaScriptCore	Assignee:	Robin Morisset <rmorisset>
Status:	RESOLVED DUPLICATE
Severity:	Normal
Priority:	P2
Version:	WebKit Nightly Build
Hardware:	Unspecified
OS:	Unspecified
Bug Depends on:	197265
Bug Blocks:

Description Robin Morisset 2019-05-10 12:59:25 PDT

When I added https://bugs.webkit.org/show_bug.cgi?id=197265 I assumed that which block is the root does not change in the middle of strength reduction.
But specializeSelect can use splitForward, which for some odd reason uses a new block for the first half of the given block (instead of using a new block for the second half, as I expected).
So if the block being split is the root block I must update m_root and erase the m_valueInConstant cache.
Erasing the cache cannot cause wrong results: at most it can make us miss some optimization opportunities in this iteration of the fixpoint.

Comment 1 Robin Morisset 2019-05-10 12:59:39 PDT

rdar://problem/50641659

Comment 2 Robin Morisset 2019-05-10 13:00:45 PDT


*** This bug has been marked as a duplicate of bug 197756 ***