Hi Richard,
Many thanks. As promised, here's a clean-up patch that removes the last direct
call to targetm.truly_noop_truncation from the middle-end, allowing this hook
at some point in the future to take modes instead of sizes.
middle-end: Prefer TRULY_NOOP_TRUNCATION_MODES_P over raw target hook.
This patch has been tested with "make bootstrap" and "make -k check" on
x86_64-pc-linux-gnu with no regressions.
2020-07-16 Roger Sayle <ro...@nextmovesoftware.com>
gcc/ChangeLog
* function.c (assign_parm_setup_block): Use the macro
TRULY_NOOP_TRUNCATION_MODES_P instead of calling
targetm.truly_noop_truncation directly.
Ok for mainline?
Thanks again,
Roger
--
-----Original Message-----
From: Richard Biener <richard.guent...@gmail.com>
Sent: 14 July 2020 15:17
To: Roger Sayle <ro...@nextmovesoftware.com>
Cc: GCC Patches <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH] x86: Provide expanders for truncdisi2 and friends.
On Mon, Jul 13, 2020 at 4:50 PM Roger Sayle <ro...@nextmovesoftware.com> wrote:
> > It seems to be improving TARGET_TRULY_NOOP_TRUNCATION documentation might
> > be useful here.
> This is an excellent suggestion. How about the following/attached...
>
> > The only user (after your patch) of this hook is in function.c for the
> > function parameter setup btw.
>
> The targetm.truly_noop_truncation in assign_parm_setup_block is the
> last place that calls this hook directly (with sizes), but the
> majority of uses go via TRULY_NOOP_TRUNCATION_MODES_P as defined in
> machmode.h.
>
> I'll prepare a patch to switch function.c to use
> TRULY_NOOP_TRUNCATION_MODE_P so that we are consistent throughout the
> compiler. In theory, this hook could then be changed to take modes
> instead of (poly_unit64) sizes, but that clean-up might be tricky without
> access to the affected platforms.
>
> Is the above documentation change Ok for mainline?
OK.
Thanks,
Richard.
> Thanks,
> Roger
> --
>
diff --git a/gcc/function.c b/gcc/function.c
index 9eee9b5..cdfcc4b 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -3013,8 +3013,8 @@ assign_parm_setup_block (struct assign_parm_data_all *all,
to the value directly in mode MODE, otherwise we must
start with the register in word_mode and explicitly
convert it. */
- if (targetm.truly_noop_truncation (size * BITS_PER_UNIT,
- BITS_PER_WORD))
+ if (mode == word_mode
+ || TRULY_NOOP_TRUNCATION_MODES_P (mode, word_mode))
reg = gen_rtx_REG (mode, REGNO (entry_parm));
else
{
