For example: $ echo '0' | ./dist/bin/js --baseline-eager TypeError: null is not an object or null js> 0 2.121995728e-314 js> First, note the TypeError message. Then the value for 0. This doesn't happen without baseline: $ echo '0' | ./dist/bin/js --no-baseline js> 0 0 js> If I print result from EvalAndPrint in gdb, I get this with baseline: $1 = {<js::RootedBase<JS::Value>> = {<js::MutableValueOperations<JS::Rooted<JS::Value> >> = {<js::ValueOperations<JS::Rooted<JS::Value> >> = {<No data fields>}, <No data fields>}, <No data fields>}, stack = 0xadf9d4, prev = 0x0, ptr = {data = {asBits = 4294967169, s = {tag = 0, payload = {i32 = -127, u32 = 4294967169, boo = 4294967169, str = 0xffffff81, sym = 0xffffff81, obj = 0xffffff81, cell = 0xffffff81, ptr = 0xffffff81, why = 4294967169, word = 4294967169, uintptr = 4294967169}}, asDouble = 2.1219957282189353e-314, asPtr = 0x0}}} and this without: $1 = {<js::RootedBase<JS::Value>> = {<js::MutableValueOperations<JS::Rooted<JS::Value> >> = {<js::ValueOperations<JS::Rooted<JS::Value> >> = {<No data fields>}, <No data fields>}, <No data fields>}, stack = 0xadf9d4, prev = 0x0, ptr = {data = { asBits = 18446743528248705024, s = {tag = JSVAL_TAG_INT32, payload = {i32 = 0, u32 = 0, boo = 0, str = 0x0, sym = 0x0, obj = 0x0, cell = 0x0, ptr = 0x0, why = JS_ELEMENTS_HOLE, word = 0, uintptr = 0}}, asDouble = -nan(0xfff8100000000), asPtr = 0xffffff81}}} So I guess baseline is filling JS::Values as if it were little endian.

I tried the obvious thing, changing the offsets in js/src/jit/mips/Architecture-mips.h, but now I'm getting a bug error. I guess there are other things involved.

(In reply to Mike Hommey [:glandium] from comment #1) > bug error bus error.

(In reply to Mike Hommey [:glandium] from comment #1) > I tried the obvious thing, changing the offsets in > js/src/jit/mips/Architecture-mips.h, but now I'm getting a bus error. However, for simple things like numbers, it does solve the problem: $ touch foo.js $ echo '0' | MOZ_SELFHOSTEDJS=foo.js ./dist/bin/js --baseline-eager js> 0 0 js>

My guess is that most problems will go away when I can make this work: $ echo 'Object(1)' | MOZ_SELFHOSTEDJS=foo.js ./dist/bin/js --baseline-eager js> Object(1) (new Number(4.243991519e-314)) js>

Cameron Kaiser recently did a big-endian port to PowerPC for TenFourFox. You might want to talk with him.

Big-endian is currently not supported in MIPS port. I would not expect it to be trivial to make it work. However, you are on the good track. For the current issue, I would look in MacroAssembler-mips.cpp at functions: MacroAssemblerMIPS::ma_ld() MacroAssemblerMIPS::ma_sd()

On the front end I had to do a little hacking in Ion to get around some assertions. (The PowerPC Ion port does pass tests.) As it happens, it was largely based on Branislav's work, though he's right that there were some non-trivial backend changes required. I don't remember all of them because a number were completely rewritten.