Hi Eliot,
$ grep -r DOUBLE_WORD_ALIGNMENT * Cross/vm/sqMemoryAccess.h:#if defined(DOUBLE_WORD_ALIGNMENT) || defined(DOUBLE_WORD_ORDER) Cross/vm/sqMemoryAccess.h:#else /*!(DOUBLE_WORD_ORDER||DOUBLE_WORD_ALIGNMENT)*/ Cross/plugins/FilePlugin/sqFilePluginBasicPrims.c:#if DOUBLE_WORD_ALIGNMENT Cross/plugins/FilePlugin/sqFilePluginBasicPrims.c:#if DOUBLE_WORD_ALIGNMENT Cross/plugins/FilePlugin/sqFilePluginBasicPrims.c:#if DOUBLE_WORD_ALIGNMENT Cross/plugins/FilePlugin/sqFilePluginBasicPrims.c:#if DOUBLE_WORD_ALIGNMENT iOS/vm/iPhone/config.h:/* #undef DOUBLE_WORD_ALIGNMENT */ Mac OS/vm/config.h:/* #undef DOUBLE_WORD_ALIGNMENT */ unix/vm/config.cmake:TRY_RUN (DOUBLE_WORD_ALIGNMENT tmp ${bld} ${config}/testDoubleWordAlignment.c) unix/vm/config.cmake:CONFIG_DEFINE (DOUBLE_WORD_ALIGNMENT) win32/vm/sqWin32.h:# undef DOUBLE_WORD_ALIGNMENT win32/vm/sqConfig.h:# define DOUBLE_WORD_ALIGNMENT
So it looks like DOUBLE_WORD_ALIGNMENT is used in FilePlugin to handle setting fields in the SQFile data structure. It looks like it is trying to deal with alignment of members of C data structures, which would vary by compiler and platform. It does not look like something that would be related to word size on the object memory, rather it looks like an optimization to handle different compiler conventions in laying out C data structures.
Judging by the name, OBJECTS_32BIT_ALIGNED sounds like it is addressing a different issue? But I do not understand the intent of the change.
Dave
On Wed, Jan 07, 2015 at 04:57:45PM -0500, David T. Lewis wrote:
Hi Eliot,
I'm pretty sure you have access to do the update.
I am away and can't check now, but I'd suggest just do a grep -r through the trunk SVN and make sure nobody is using DOUBLE_WORD_ALIGNMENT. I don't know what it is used for without checking.
The plugin change sounds good, although you might want to call it "re_config" instead of "reconfig" because "reconfig" suggests another meaning ;-)
Dave
Hi David, Hi All,
I need to make some changes to platforms/Cross/plugins, which isshared between the trunk vm and the Cog branch.
- DOUBLE_WORD_ALIGNMENT changes to OBJECTS_32BIT_ALIGNED. In Spur
objects are always 64-bit aligned, even in the 32-bit version, so none of the slow access to avoid unaligned float access is necessary. I've written it like this in platforms/Cross/vm/sqMemoryAccess.h. The changes begin on the #if (SQ_IMAGE64 || SPURVM) line
#if (SQ_VI_BYTES_PER_WORD == 4) # define SQ_IMAGE32 1 #else # define SQ_IMAGE64 1 #endif
#if (SQ_IMAGE64 || SPURVM) # define OBJECTS_32BIT_ALIGNED 0 #else # define OBJECTS_32BIT_ALIGNED 1 #endif
- platforms/Cross/plugins/RePlugin/config.h gets renamed
to platforms/Cross/plugins/RePlugin/reconfig.h to avoid conflicts with the VM's config.h
I'm not sure that I have permission to change trunk. But if I do would it be OK if I made these changes? If not, would you, David, make the change to trunk's platforms/Cross/vm/sqMemoryAccess.h after which I'll check-in the platforms/Cross/plugins changes? -- best, Eliot