From: Segher Boessenkool <segher@kernel.crashing.org>
To: Michael Meissner <meissner@linux.ibm.com>,
gcc-patches@gcc.gnu.org,
David Edelsohn <dje.gcc@gmail.com>
Subject: Re: [PATCH] V11 patch #3 of 15, Use 'Q' constraint for variable vector extract from memory
Date: Sun, 22 Dec 2019 17:49:00 -0000 [thread overview]
Message-ID: <20191222172451.GC4505@gate.crashing.org> (raw)
In-Reply-To: <20191220234728.GC28993@ibm-toto.the-meissners.org>
Hi!
On Fri, Dec 20, 2019 at 06:47:28PM -0500, Michael Meissner wrote:
> Then I realized that eventaully we will want to generate an X-FORM (register +
> register) address, and it was just simpler to use the 'Q' constraint, and have
> the register allocator put the address into a register.
Yep, good call.
> * config/rs6000/vsx.md (vsx_extract_<mode>_var, VSX_D iterator):
> Use 'Q' for memory constraints because we need to do an X-FORM
> load with the variable index.
> (vsx_extract_v4sf_var): Use 'Q' for memory constraints because we
> need to do an X-FORM load with the variable index.
This comment is a headscratcher -- but you shouldn't say "why" in
changelogs at all, so that is an easy fix ;-)
> (vsx_extract_<mode>_var, VSX_EXTRACT_I iterator):Use 'Q' for
(missing space)
> memory constraints because we need to do an X-FORM load with the
> variable index.
> (vsx_extract_<mode>_<VS_scalar>mode_var): Use 'Q' for memory
> constraints because we need to do an X-FORM load with the variable
> index.
(and more)
> -;; Variable V2DI/V2DF extract
> +;; Variable V2DI/V2DF extract. Use 'Q' for the memory because we will
> +;; ultimately have to convert the address into base + index.
Maybe just don't write anything at all, since it is hard to explain in a
few words? It is clear that "Q" is not a usual constraint, anyway :-)
Okay for trunk like that. Thanks!
Segher
next prev parent reply other threads:[~2019-12-22 17:24 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-20 23:15 PowerPC -mcpu=future patches, V11 Michael Meissner
2019-12-20 23:28 ` [PATCH] V11 patch #1 of 15, Fix bug in vec_extract Michael Meissner
2019-12-22 14:06 ` Segher Boessenkool
2019-12-20 23:47 ` [PATCH] V11 patch #2 of 15, Use prefixed load for vector extract with large offset Michael Meissner
2019-12-22 17:24 ` Segher Boessenkool
2020-01-07 1:41 ` [PATCH, committed] " Michael Meissner
2019-12-20 23:49 ` [PATCH] V11 patch #3 of 15, Use 'Q' constraint for variable vector extract from memory Michael Meissner
2019-12-22 17:49 ` Segher Boessenkool [this message]
2020-01-07 1:43 ` [PATCH, committed] " Michael Meissner
2019-12-20 23:56 ` [PATCH] V11 patch #4 of 15, Update 'Q' constraint documentation Michael Meissner
2019-12-22 20:02 ` Segher Boessenkool
2020-01-07 1:45 ` [PATCH, committed] " Michael Meissner
2019-12-21 0:00 ` [PATCH] V11 patch #5 of 15, Optimize vec_extract of a vector in memory with a PC-relative address Michael Meissner
2019-12-25 6:41 ` Segher Boessenkool
2020-01-06 20:55 ` Michael Meissner
2020-01-06 21:01 ` Michael Meissner
2020-01-07 1:48 ` [PATCH, committed] " Michael Meissner
2019-12-21 0:03 ` [PATCH] V11 patch #6 of 15, Make -mpcrel the default for -mcpu=future on Linux 64-bit Michael Meissner
2019-12-21 0:06 ` [PATCH] V11 patch #7 of 15, Add new target_supports cases for -mcpu=future tests Michael Meissner
2019-12-21 0:11 ` [PATCH] V11 patch #8 of 15, Add new tests for using PADDI and PLI with -mcpu=future Michael Meissner
2019-12-21 0:12 ` [PATCH] V11 patch #9 of 15, Add test to validate generating prefixed memory when the offset is invalid for DS/DQ insns Michael Meissner
2019-12-21 0:22 ` [PATCH] V11 patch #10 of 15, Make sure we don't generate pre-modify prefixed insns with -mcpu=future Michael Meissner
2019-12-21 0:25 ` [PATCH] V11 patch #12 of 15, Add new PC-relative tests for -mcpu=future Michael Meissner
2019-12-21 0:25 ` [PATCH] V11 patch #11 of 15, Add new tests for generating prefixed loads/stores on -mcpu=future with large offsets Michael Meissner
2019-12-21 0:33 ` [PATCH] V11 patch #13 of 15, Add test for -mcpu=future -fstack-protect-strong with large stacks Michael Meissner
2019-12-21 1:23 ` [PATCH] V11 patch #14 of 15, Add tests for vec_extract from memory with PC-relative addrss Michael Meissner
2019-12-21 1:25 ` [PATCH] V11 patch #15 of 15, Add tests for -mcpu=future vec_extract from memory with a large offset Michael Meissner
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