Bug 69821 – Switch RegisterSizedBoolean/dfgConvertJSValueToInt32 return type to size_t

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Gavin Barraclough]

Operations returning types Z (int32_t) and B (RegisterSizedBoolean - implemented as an intptr_t) are indistinguishable on 32-bit Linux, preventing the DFG JIT from building.

dfgConvertJSValueToInt32 would be better returning a value known to be register sized, for JSVALUE64 (we currently zero-extend in JIT code, potentially introducing an unnecessary mov), so by switching all associated operations to return a size_t we can fix the type problem on Linux & make it a small tweak that removes an unnecessary instruction.

[Gavin Barraclough]

Created attachment 110482 [details]
The patch

[WebKit Review Bot]

Attachment 110482 [details] did not pass style-queue:

Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'Source/JavaScriptCore/ChangeLog', u'Source..." exit_code: 1

Source/JavaScriptCore/dfg/DFGOperations.h:79:  DFG_OPERATION is incorrectly named. Don't use underscores in your identifier names.  [readability/naming] [4]
Source/JavaScriptCore/dfg/DFGOperations.h:80:  DFG_OPERATION is incorrectly named. Don't use underscores in your identifier names.  [readability/naming] [4]
Total errors found: 2 in 11 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Filip Pizlo]

Comment on attachment 110482 [details]
The patch

Wouldn't it be better to use uintptr_t instead of size_t?  size_t implies that you're describing the size of something in memory.  uintptr_t implies any unsigned pointer-sized word for holding any kind of integer or pointer, and doesn't imply any meaning (unlike size_t).  It might be less confusing in this case, since these operations are pretty much never returning the size of things.

[Filip Pizlo]

Comment on attachment 110482 [details]
The patch

Eh, r=me to fix the build.  Your call if you want size_t or uintptr_t.

[WebKit Review Bot]

Comment on attachment 110482 [details]
The patch

Clearing flags on attachment: 110482

Committed r97153: <http://trac.webkit.org/changeset/97153>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.