Bug 170473

Summary: On ARM64, DFG::SpeculativeJIT::compileArithMod() failed to ensure result is of DataFormatInt32.
Product: WebKit Reporter: Mark Lam <mark.lam>
Component: JavaScriptCoreAssignee: Mark Lam <mark.lam>
Status: RESOLVED FIXED    
Severity: Normal CC: commit-queue, fpizlo, jfbastien, keith_miller, msaboff, saam, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: WebKit Local Build   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
proposed patch. none

Description Mark Lam 2017-04-04 14:50:12 PDT 
In Unchecked mode, when DFG::SpeculativeJIT::compileArithMod() detects that the divisor is 0, it just returns the divisor as the result.  However, the result is expected to be of DataFormatIn32, but the divisor in this case is of DataFormatJSInt32.  The fix is to return an immediate 0 instead.

<rdar://problem/29912391>
Comment 1 Mark Lam 2017-04-04 15:28:36 PDT 
Created attachment 306217 [details]
proposed patch.
Comment 2 Mark Lam 2017-04-04 20:22:20 PDT 
Comment on attachment 306217 [details]
proposed patch.

Thanks for the review.  Landing now.
Comment 3 WebKit Commit Bot 2017-04-04 20:50:10 PDT 
Comment on attachment 306217 [details]
proposed patch.

Clearing flags on attachment: 306217

Committed r214927: <http://trac.webkit.org/changeset/214927>
Comment 4 WebKit Commit Bot 2017-04-04 20:50:12 PDT 
All reviewed patches have been landed.  Closing bug.