Steps to repro:
(1) Tools/Scripts/build-jsc --debug --32-bit
(2) Edit run.js to only load base.js and mandreel.js
(2) DYLD_FRAMEWORK_PATH=/Volumes/Data/WebKit-svn-clean/OpenSource/WebKitBuild/Debug/ /Volumes/Data/WebKit-svn-clean/OpenSource/WebKitBuild/Debug/jsc run.js
(3) Observe the following error message:
Exception: Alert called with argument: Check sum mismatch: expected ???, actual 7649662
The issue is due to the 32-bit DFG emitting code that load constants from its CodeBlock's m_constantRegisters vector, and then resizing that vector thereby rendering the addresses in the emitted code state. The fix is to use a dedicated doubles constant pool for the DFG stored in the DFG CommonData.
Created attachment 228094 [details]
Thanks. Landed in r166440: <http://trac.webkit.org/r166440>.