Out of curiosity I decided to try compiling TFF 17.0.2 on Intel Tiger. It seems Cameron did quite a good job of keeping PPC-specific things #ifdef'd out, so the changes required were very small for the most part. It runs very well, with the Intel-specific optimizations from the main tree intact. It's slightly slower than mainline FF on newer OS X. For example, Sunspider ran in 343ms on 10.8 and 383ms on TFF/10.4 on my late '07 MBP.

In case anyone's interested, here are the notes I kept. Sorry, no patch--it was my first time using Mercurial. There's probably other stuff I missed (OpenGL stuff, maybe?) but it worked and was quite stable. With the hard work already done it took less than half an hour if you exclude the time spent compiling it.

-- patch 110055

nsprpub/pr/src/md/unix/os_Darwin.s -- remove ppc asm stuff

nsprpub/pr/src/md/unix/pratom.h -- remove references to stuff we took out of os_Darwin.s

-- patch 110013, 110018

write_vmx vs. write_sse2

xpcom/string/public/nsUTF8Utils.h -- remove two add'l MOZILLA_MAY_SUPPORT_SSE2 ifdefs vs. mainline FF's version

-- patch 109972

toolkit/crashreporter/client/crashreporter_osx.mm -- add CPU_TYPE_X86

toolkit/mozapps/update/updater -- "" ""

xpcom/threads/nsProcessCommon.cpp -- "" ""

-- patch 110058

gfx/thebes/gfxMacPlatformFontList.mm -- change if(0) to if(1) to revert big-endian changes

-- not associated with any patch

gfx/ycbcr/yuv_row_posix.cpp -- change .global to .globl, remove .type, add _ prefix to SSE ASM functions

dom/plugins/base/nsNPAPIPlugin.cpp -- change GLint to long in GMA9XXGraphics()

toolkit/xre/nsSigHandlers.cpp -- fpehandler() doesn't compile

to fix:

#include

#include

#include

remove __ from all names

use fp_control_t and fp_status_t