1144005 - IonMonkey: MIPS: Fix encode break instruction

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, defect)

Description

[hev [:hev]]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:36.0) Gecko/20100101 Firefox/36.0
Build ID: 20150305221847

Steps to reproduce:

Breaks between 0 and kMaxWatchpointCode are treated as simple watchpoints, the simulator will run through them and print the registers. In fact, the simulator stoped at break 1. because break instruction encoding error.

break instruction define:
31-26    25-6    5-0
special  code    break
000000           001101

The right code of break shift is 6, isn't RTShift(16).

Comment 1

[hev [:hev]]

Attachment: IonMonkey-MIPS-Fix-encode-break-instruction.patch

Comment 2

[Branislav Rankov [:rankov]]

Comment on attachment 8578442 [details] [diff] [review]
IonMonkey-MIPS-Fix-encode-break-instruction.patch

Review of attachment 8578442 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/jit/mips/Assembler-mips.cpp
@@ +1462,4 @@
>  Assembler::as_break(uint32_t code)
>  {
>      MOZ_ASSERT(code <= MAX_BREAK_CODE);
> +    writeInst(op_special | code << 6 | ff_break);

NIT: Use constant FunctionBits instead of 6.

You can also add a new constant for this. But FunctionBits is also correct choice.

::: js/src/jit/mips/Simulator-mips.cpp
@@ +42,4 @@
>  namespace js {
>  namespace jit {
>  
> +static const Instr kCallRedirInstr = op_special | MAX_BREAK_CODE << 6 | ff_break;

NIT: Same as above.

Comment 3

[hev [:hev]]

Attachment: IonMonkey-MIPS-Fix-encode-braek-instruction.patch

Replace previous patch and review+.

Comment 4

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/c95b819aba41

Comment 5

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/c95b819aba41