> From: Anton Johansson <a...@rev.ng>
> Sent: Monday, October 18, 2021 6:23 AM
> To: Taylor Simpson <tsimp...@quicinc.com>; Alessandro Di Federico
> <ale.q...@rev.ng>; qemu-devel@nongnu.org
> Cc: Brian Cain <bc...@quicinc.com>; bab...@rev.ng; ni...@rev.ng;
> richard.hender...@linaro.org; Alessandro Di Federico <a...@rev.ng>
> Subject: Re: [PATCH v6 07/12] target/hexagon: prepare input for the
> idef-parser
>
> On 9/7/21 18:09, Taylor Simpson wrote:
> +#define fADDSAT64(DST, A, B) \
> + __a = fCAST8u(A); \
> + __b = fCAST8u(B); \
> + __sum = __a + __b; \
> + __xor = __a ^ __b; \
> + __mask = fCAST8s(0x8000000000000000ULL); \
> + if (((__a ^ __b) | ~(__a ^ __sum)) & __mask) { \
> + DST = __sum; \
> + } else { \
> + DST = ((__sum & __mask) >> 63) + __mask; \
> + fSET_OVERFLOW(); \
> + }
> There are a bunch of these with pretty complex semantics. Wouldn't it be
> easier to recognize them in the parser and call a hand-written helper?
>
> These macro redefinitions are needed to work with the auto type system in
> idef-parser. We can drop these specializations in the upcoming patchset where
> we parse fHIDE declarations.
> If we still want to resort to helpers here, it's probably better to exclude
> instructions using fADDSAT64 (and similar) directly, and fallback on
> helpers/overrides for those instructions.
Sorry, I wasn't clear. I meant a hand-written function to generate the TCG
code - not a qemu TCG helper.
Thanks,
Taylor
