Bug 191258 – [JSC][MIPS] JIT support does not work on MIPS R6

• Status: RESOLVED
• Resolution: WONTFIX
• Component: JavaScriptCore

[Adrian Perez]

Created attachment 353853 [details]
Minimal Buildroot configuration to trigger the issue

Currently it is not possible to even build JIT support on MIPS R6
due to the offline assembler using some instructions which have
removed in R6 (like “addi” and “movz”). We would need to generate
slightly different code in this case (e.g. use “seleqz/selnez” in
place of “movz”), and alse make sure that the JIT generates code
accordingly for MIPS R6.

I am attaching a minimal Buildroot configuration which builds
WebKitGTK+ 2.22.3 and causes this issue. It has been tested
with a Git checkout of Buildroot at commit 435613ef29.

---- Error message: ----

[ 52%] Building CXX object Source/JavaScriptCore/CMakeFiles/JavaScriptCore.dir/llint/LowLevelInterpreter.cpp.o
/tmp/ccqrsIMe.s: Assembler messages:
/tmp/ccqrsIMe.s:2841: Error: opcode not supported on this processor: mips32r6 (mips32r6) `movz $v1,$t8,$t7'
/tmp/ccqrsIMe.s:2847: Error: opcode not supported on this processor: mips32r6 (mips32r6) `movz $t2,$t8,$t7'
/tmp/ccqrsIMe.s:2852: Error: opcode not supported on this processor: mips32r6 (mips32r6) `movz $v1,$t7,$t8'
/tmp/ccqrsIMe.s:2887: Error: opcode not supported on this processor: mips32r6 (mips32r6) `movn $v1,$t7,$t8'
/tmp/ccqrsIMe.s:2893: Error: opcode not supported on this processor: mips32r6 (mips32r6) `movn $t2,$t7,$t8'
/tmp/ccqrsIMe.s:2898: Error: opcode not supported on this processor: mips32r6 (mips32r6) `movn $v1,$t8,$t7'
/tmp/ccqrsIMe.s:2961: Error: opcode not supported on this processor: mips32r6 (mips32r6) `movz $v0,$t7,$t8'
/tmp/ccqrsIMe.s:3032: Error: opcode not supported on this processor: mips32r6 (mips32r6) `movn $v0,$t8,$t7'
/tmp/ccqrsIMe.s:3616: Error: opcode not supported on this processor: mips32r6 (mips32r6) `mult $v1,$t3'
/tmp/ccqrsIMe.s:3617: Error: opcode not supported on this processor: mips32r6 (mips32r6) `mflo $t3'
/tmp/ccqrsIMe.s:3618: Error: opcode not supported on this processor: mips32r6 (mips32r6) `mfhi $t8'
/tmp/ccqrsIMe.s:3865: Error: opcode not supported on this processor: mips32r6 (mips32r6) `c.eq.d $f18,$f2'
/tmp/ccqrsIMe.s:3866: Error: opcode not supported on this processor: mips32r6 (mips32r6) `bc1f .L_offlineasm_binaryOpCustomStore__integerOperationAndStore__notInt'
/tmp/ccqrsIMe.s:4403: Error: opcode not supported on this processor: mips32r6 (mips32r6) `movz $v0,$t7,$t8'
/tmp/ccqrsIMe.s:4456: Error: opcode not supported on this processor: mips32r6 (mips32r6) `movz $t3,$t7,$t8'
/tmp/ccqrsIMe.s:4494: Error: opcode not supported on this processor: mips32r6 (mips32r6) `movz $t3,$t7,$t8'
/tmp/ccqrsIMe.s:4520: Error: opcode not supported on this processor: mips32r6 (mips32r6) `movz $v1,$t7,$t8'
/tmp/ccqrsIMe.s:4550: Error: opcode not supported on this processor: mips32r6 (mips32r6) `movz $v0,$t8,$t7'
/tmp/ccqrsIMe.s:4621: Error: opcode not supported on this processor: mips32r6 (mips32r6) `movz $v1,$t7,$t8'
/tmp/ccqrsIMe.s:5352: Error: opcode not supported on this processor: mips32r6 (mips32r6) `c.eq.d $f0,$f0'
/tmp/ccqrsIMe.s:5353: Error: opcode not supported on this processor: mips32r6 (mips32r6) `bc1f .L_offlineasm_opGetByValSlow'
/tmp/ccqrsIMe.s:5585: Error: opcode not supported on this processor: mips32r6 (mips32r6) `c.eq.d $f0,$f0'
/tmp/ccqrsIMe.s:5586: Error: opcode not supported on this processor: mips32r6 (mips32r6) `bc1f .L_offlineasm_putByVal__opPutByValSlow'
/tmp/ccqrsIMe.s:5894: Error: opcode not supported on this processor: mips32r6 (mips32r6) `c.eq.d $f0,$f0'
/tmp/ccqrsIMe.s:5895: Error: opcode not supported on this processor: mips32r6 (mips32r6) `bc1f .L_offlineasm_48_putByVal__opPutByValSlow'
/tmp/ccqrsIMe.s:8216: Error: opcode not supported on this processor: mips32r6 (mips32r6) `movz $v0,$t7,$t8'
/tmp/ccqrsIMe.s:8280: Error: opcode not supported on this processor: mips32r6 (mips32r6) `movn $v0,$t8,$t7'
/tmp/ccqrsIMe.s:8765: Error: opcode not supported on this processor: mips32r6 (mips32r6) `c.olt.d $f0,$f2'
/tmp/ccqrsIMe.s:8766: Error: opcode not supported on this processor: mips32r6 (mips32r6) `bc1t .L_offlineasm_compareJump__jumpTarget'
/tmp/ccqrsIMe.s:8778: Error: opcode not supported on this processor: mips32r6 (mips32r6) `c.olt.d $f0,$f2'
/tmp/ccqrsIMe.s:8779: Error: opcode not supported on this processor: mips32r6 (mips32r6) `bc1t .L_offlineasm_compareJump__jumpTarget'
/tmp/ccqrsIMe.s:8856: Error: opcode not supported on this processor: mips32r6 (mips32r6) `c.olt.d $f0,$f2'
/tmp/ccqrsIMe.s:8857: Error: opcode not supported on this processor: mips32r6 (mips32r6) `bc1f .L_offlineasm_68_compareJump__jumpTarget'
/tmp/ccqrsIMe.s:8869: Error: opcode not supported on this processor: mips32r6 (mips32r6) `c.olt.d $f0,$f2'
/tmp/ccqrsIMe.s:8870: Error: opcode not supported on this processor: mips32r6 (mips32r6) `bc1f .L_offlineasm_68_compareJump__jumpTarget'
/tmp/ccqrsIMe.s:8947: Error: opcode not supported on this processor: mips32r6 (mips32r6) `c.ule.d $f0,$f2'
/tmp/ccqrsIMe.s:8948: Error: opcode not supported on this processor: mips32r6 (mips32r6) `bc1f .L_offlineasm_69_compareJump__jumpTarget'
/tmp/ccqrsIMe.s:8960: Error: opcode not supported on this processor: mips32r6 (mips32r6) `c.ule.d $f0,$f2'
/tmp/ccqrsIMe.s:8961: Error: opcode not supported on this processor: mips32r6 (mips32r6) `bc1f .L_offlineasm_69_compareJump__jumpTarget'
/tmp/ccqrsIMe.s:9038: Error: opcode not supported on this processor: mips32r6 (mips32r6) `c.ule.d $f0,$f2'
/tmp/ccqrsIMe.s:9039: Error: opcode not supported on this processor: mips32r6 (mips32r6) `bc1t .L_offlineasm_70_compareJump__jumpTarget'
/tmp/ccqrsIMe.s:9051: Error: opcode not supported on this processor: mips32r6 (mips32r6) `c.ule.d $f0,$f2'
/tmp/ccqrsIMe.s:9052: Error: opcode not supported on this processor: mips32r6 (mips32r6) `bc1t .L_offlineasm_70_compareJump__jumpTarget'
/tmp/ccqrsIMe.s:9129: Error: opcode not supported on this processor: mips32r6 (mips32r6) `c.ole.d $f0,$f2'
/tmp/ccqrsIMe.s:9130: Error: opcode not supported on this processor: mips32r6 (mips32r6) `bc1t .L_offlineasm_71_compareJump__jumpTarget'
/tmp/ccqrsIMe.s:9142: Error: opcode not supported on this processor: mips32r6 (mips32r6) `c.ole.d $f0,$f2'
/tmp/ccqrsIMe.s:9143: Error: opcode not supported on this processor: mips32r6 (mips32r6) `bc1t .L_offlineasm_71_compareJump__jumpTarget'
/tmp/ccqrsIMe.s:9220: Error: opcode not supported on this processor: mips32r6 (mips32r6) `c.ole.d $f0,$f2'
/tmp/ccqrsIMe.s:9221: Error: opcode not supported on this processor: mips32r6 (mips32r6) `bc1f .L_offlineasm_72_compareJump__jumpTarget'
/tmp/ccqrsIMe.s:9233: Error: opcode not supported on this processor: mips32r6 (mips32r6) `c.ole.d $f0,$f2'
/tmp/ccqrsIMe.s:9234: Error: opcode not supported on this processor: mips32r6 (mips32r6) `bc1f .L_offlineasm_72_compareJump__jumpTarget'
/tmp/ccqrsIMe.s:9311: Error: opcode not supported on this processor: mips32r6 (mips32r6) `c.ult.d $f0,$f2'
/tmp/ccqrsIMe.s:9312: Error: opcode not supported on this processor: mips32r6 (mips32r6) `bc1f .L_offlineasm_73_compareJump__jumpTarget'
/tmp/ccqrsIMe.s:9324: Error: opcode not supported on this processor: mips32r6 (mips32r6) `c.ult.d $f0,$f2'
/tmp/ccqrsIMe.s:9325: Error: opcode not supported on this processor: mips32r6 (mips32r6) `bc1f .L_offlineasm_73_compareJump__jumpTarget'
/tmp/ccqrsIMe.s:9402: Error: opcode not supported on this processor: mips32r6 (mips32r6) `c.ult.d $f0,$f2'
/tmp/ccqrsIMe.s:9403: Error: opcode not supported on this processor: mips32r6 (mips32r6) `bc1t .L_offlineasm_74_compareJump__jumpTarget'
/tmp/ccqrsIMe.s:9415: Error: opcode not supported on this processor: mips32r6 (mips32r6) `c.ult.d $f0,$f2'
/tmp/ccqrsIMe.s:9416: Error: opcode not supported on this processor: mips32r6 (mips32r6) `bc1t .L_offlineasm_74_compareJump__jumpTarget'
/tmp/ccNhC7qP.s: Assembler messages:
/tmp/ccNhC7qP.s:17: Error: opcode not supported on this processor: mips32r6 (mips32r6) `addi $a0,$sp,-8'

[Adrian Perez]

As per bug #267347 we dropped MIPS JIT support in 272866@main and according
to a message to the mailing list [1], the 2.44.x stable series no longer
include MIPS JIT support -- CLoop is to be used on MIPS instead.

---
[1] https://lists.webkit.org/pipermail/webkit-wpe/2023-September/000612.html