Re: [Qemu-devel] [PATCH for-1.2] target-ppc: fix altivec instructions

[Peter Maydell]

On 26 August 2012 18:56, Blue Swirl <address@hidden> wrote:
> On Sun, Aug 26, 2012 at 2:14 PM, Aurelien Jarno <address@hidden> wrote:
>> Altivec instructions are not working anymore in PowerPC emulation,
>> following commit d15f74fb, which inverted two registers in the call
>> to helper. Fix that.

> I wonder why TCG debug did not catch this.

Because all of ra, rb, rd and cpu_env are TCGv_ptr. Debug only
catches mismatches between _i32, _i64 and _ptr. It might be
possible to add support for enforcing that you pass a cpu_env
in where your DEF_HELPER_* had an 'env' parameter, but it would
be slightly different from the current checks because you want
to support passing a cpu_env TCGv in where a TCGv_ptr is OK
as well as the places which require exactly a TCGv_env.

-- PMM