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From: Richard Henderson <richard.henderson@linaro.org>
To: Keith Packard <keithp@keithp.com>, qemu-devel@nongnu.org
Cc: Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [PATCH] tcg: Add 'signed' bit to typecodes
Date: Thu, 17 Feb 2022 08:13:20 +1100	[thread overview]
Message-ID: <6786d609-493a-5ff8-aa75-fcaba0259b2b@linaro.org> (raw)
In-Reply-To: <20220216063945.1986257-1-keithp@keithp.com>

On 2/16/22 17:39, Keith Packard wrote:
> Commit 7319d83a (tcg: Combine dh_is_64bit and dh_is_signed to
> dh_typecode) converted the tcg type system to a 3-bit field from two
> separate 1-bit fields. This subtly lost the 'signed' information from
> the types as it uses the dh_alias macro to reduce the types down to
> basic machine types. However, the dh_alias macro also discards sign
> information, aliasing 's32' to 'i32'.

The signed information is still there, merged with the typecode:

#define dh_typecode_void 0
#define dh_typecode_noreturn 0
#define dh_typecode_i32 2
#define dh_typecode_s32 3
#define dh_typecode_i64 4
#define dh_typecode_s64 5
#define dh_typecode_ptr 6

Note that is_signed is bit 0.

But I can see that dh_alias_s32 hides it -- definitely a bug there.



r~


  reply	other threads:[~2022-02-16 21:14 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-16  6:39 [PATCH] tcg: Add 'signed' bit to typecodes Keith Packard via
2022-02-16 21:13 ` Richard Henderson [this message]
2022-02-16 21:48   ` Keith Packard via

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