Re: Two days old build breakage on i386.

I fixed the x86 issue and re-commited my work as 4ee4ab01c1d97845aecb7707ad2f9a80933e7a49. On Fri, Jun 27, 2014 at 1:27 PM, Simon Marlow wrote:

On 27/06/2014 12:23, Johan Tibell wrote:

...

On Fri, Jun 27, 2014 at 1:14 PM, Simon Marlow wrote:

...

The problem is that this instruction requires three separate registers, but cmpxchgl already reads and writes %eax leaving only two free registers (%ecx and %edx).

You'll need to arrange to not use the complicated addressing modes with cmpxchg on i386, and keep the number of free regs required <= 2.

Where's the best place to arrange for that? If I switch from using getAmode to computing the address into a temp register in StgCmmPrim will that ensure that the address is simple, or could some optimization replace my temp register computation with a complex address again?

There aren't any optimisations that happen on the instructions after codegen, and if there were, they would have to respect the same rule. So using a register is the right thing, yes.

Cheers, Simon