Bug 118148 - fourthTier: JSC's disassembly infrastructure should be able to disassemble the code that LLVM generates
Summary: fourthTier: JSC's disassembly infrastructure should be able to disassemble th...
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: JavaScriptCore (show other bugs)
Version: 528+ (Nightly build)
Hardware: All All
: P2 Normal
Assignee: Filip Pizlo
URL:
Keywords:
Depends on:
Blocks: 112840
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Reported: 2013-06-27 14:17 PDT by Filip Pizlo
Modified: 2013-06-27 15:51 PDT (History)
7 users (show)

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Attachments
the patch (44.18 KB, patch)
2013-06-27 14:23 PDT, Filip Pizlo 		andersca: review+
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Description Filip Pizlo 2013-06-27 14:17:35 PDT 
Oh boy.  UDis86 cannot disassemble the AVX (or whatever it's called) stuff that LLVM generates for floating point.  So the right decision is to switch to the LLVM disassembler, right?  Wrong!!  LLVM's disassembler cannot disassemble the load-from-absolute-address-into-%rax instructions that our JIT generates quite a lot of.

So we should use a combination of the two disassemblers.
Comment 1 Filip Pizlo 2013-06-27 14:23:00 PDT 
Created attachment 205635 [details]
the patch
Comment 2 Filip Pizlo 2013-06-27 15:51:10 PDT 
Landed in http://trac.webkit.org/changeset/152131