Re: [PATCH] libgccjit: Improve doc and comments regarding type casts

[Andrea Corallo <andrea.corallo@arm.com>]

Andrea Corallo <andrea.corallo@arm.com> writes:

> Hi Alex,
>
> Looking at the code I believe all these casts are meant to be supported
> (read your intuition was correct).
>
> Also IMO source of confusion is that the doc is mentioning 'int' and
> 'float' but I believe would be better to have like 'integral' and
> 'floating-point' to clearly disambiguates with respect to the C
> types.
>
> AFAIU the set of supported casts should be like:
>
>      integral       <-> integral
>      floating-point <-> floating-point
>      integral       <-> floating-point
>      integral       <-> bool
>      P*             <-> Q*   for pointer types P and Q.
>
> I'd propose to install the following patch to make doc and comments
> homogeneous at documenting what do we accept, and I guess we should just
> consider bugs if some of these conversions is not handled correctly or
> leads to ICE.
>
> Bests
>
>   Andrea
>
> gcc/jit/ChangeLog
>
> 2020-07-21  Andrea Corallo  <andrea.corallo@arm.com>
>
> 	* docs/_build/texinfo/libgccjit.texi (Type-coercion): Improve doc
> 	on allowed type casting.
> 	* docs/topics/expressions.rst (gccjit::context::new_cast)
> 	(gcc_jit_context_new_cast): Likewise.
> 	* libgccjit.c: Improve comment on allowed type casting.
> 	* libgccjit.h: Likewise
>
> From 914b9e86808c947d4bb2b06c6960fd8031125f67 Mon Sep 17 00:00:00 2001
> From: Andrea Corallo <andrea.corallo@arm.com>
> Date: Tue, 21 Jul 2020 20:12:23 +0200
> Subject: [PATCH] libgccjit: improve documentation on type conversions
>
> gcc/jit/ChangeLog
>
> 2020-07-21  Andrea Corallo  <andrea.corallo@arm.com>
>
> 	* docs/_build/texinfo/libgccjit.texi (Type-coercion): Improve doc
> 	on allowed type casting.
> 	* docs/topics/expressions.rst (gccjit::context::new_cast)
> 	(gcc_jit_context_new_cast): Likewise.
> 	* libgccjit.c: Improve comment on allowed type casting.
> 	* libgccjit.h: Likewise
> ---
>  gcc/jit/docs/_build/texinfo/libgccjit.texi | 30 +++++++++++++++-------
>  gcc/jit/docs/topics/expressions.rst        |  8 +++---
>  gcc/jit/libgccjit.c                        |  8 +++---
>  gcc/jit/libgccjit.h                        |  7 +++--
>  4 files changed, 36 insertions(+), 17 deletions(-)
>
> diff --git a/gcc/jit/docs/_build/texinfo/libgccjit.texi b/gcc/jit/docs/_build/texinfo/libgccjit.texi
> index 1e14be010426..b170f24d1bb1 100644
> --- a/gcc/jit/docs/_build/texinfo/libgccjit.texi
> +++ b/gcc/jit/docs/_build/texinfo/libgccjit.texi
> @@ -6685,13 +6685,19 @@ Currently only a limited set of conversions are possible:
>  @itemize *
>  
>  @item 
> -int <-> float
> +integral       <-> integral
>  
>  @item 
> -int <-> bool
> +floating-point <-> floating-point
>  
>  @item 
> -P*  <-> Q*, for pointer types P and Q
> +integral       <-> floating-point
> +
> +@item 
> +integral       <-> bool
> +
> +@item 
> +P*             <-> Q*   for pointer types P and Q
>  @end itemize
>  @end quotation
>  @end deffn
> @@ -12964,14 +12970,20 @@ Currently only a limited set of conversions are possible:
>  
>  @itemize *
>  
> -@item 
> -int <-> float
> +@item
> +integral       <-> integral
>  
> -@item 
> -int <-> bool
> +@item
> +floating-point <-> floating-point
>  
> -@item 
> -P*  <-> Q*, for pointer types P and Q
> +@item
> +integral       <-> floating-point
> +
> +@item
> +integral       <-> bool
> +
> +@item
> +P*             <-> Q*, for pointer types P and Q
>  @end itemize
>  @end quotation
>  @end deffn
> diff --git a/gcc/jit/docs/topics/expressions.rst b/gcc/jit/docs/topics/expressions.rst
> index d783ceea51a8..051cee5db211 100644
> --- a/gcc/jit/docs/topics/expressions.rst
> +++ b/gcc/jit/docs/topics/expressions.rst
> @@ -504,9 +504,11 @@ Type-coercion
>  
>     Currently only a limited set of conversions are possible:
>  
> -     * int <-> float
> -     * int <-> bool
> -     * P*  <-> Q*, for pointer types P and Q
> +     * integral       <-> integral
> +     * floating-point <-> floating-point
> +     * integral       <-> floating-point
> +     * integral       <-> bool
> +     * P*             <-> Q*   for pointer types P and Q
>  
>  Lvalues
>  -------
> diff --git a/gcc/jit/libgccjit.c b/gcc/jit/libgccjit.c
> index 3d04f6db3aff..403233d5577a 100644
> --- a/gcc/jit/libgccjit.c
> +++ b/gcc/jit/libgccjit.c
> @@ -1629,9 +1629,11 @@ gcc_jit_context_new_call_through_ptr (gcc_jit_context *ctxt,
>  
>     We only permit these kinds of cast:
>  
> -     int <-> float
> -     int <-> bool
> -     P*  <-> Q*   for pointer types P and Q.  */
> +     integral       <-> integral
> +     floating-point <-> floating-point
> +     integral       <-> floating-point
> +     integral       <-> bool
> +     P*             <-> Q*   for pointer types P and Q.  */
>  
>  static bool
>  is_valid_cast (gcc::jit::recording::type *src_type,
> diff --git a/gcc/jit/libgccjit.h b/gcc/jit/libgccjit.h
> index 1c5a12e9c015..228befa896d7 100644
> --- a/gcc/jit/libgccjit.h
> +++ b/gcc/jit/libgccjit.h
> @@ -996,8 +996,11 @@ gcc_jit_context_new_call_through_ptr (gcc_jit_context *ctxt,
>  /* Type-coercion.
>  
>     Currently only a limited set of conversions are possible:
> -     int <-> float
> -     int <-> bool  */
> +     integral       <-> integral
> +     floating-point <-> floating-point
> +     integral       <-> floating-point
> +     integral       <-> bool
> +     P*             <-> Q*   for pointer types P and Q.  */
>  extern gcc_jit_rvalue *
>  gcc_jit_context_new_cast (gcc_jit_context *ctxt,
>  			  gcc_jit_location *loc,

Ping

Thanks
  Andrea