From: Jeff Law <jeffreyalaw@gmail.com>
To: Manolis Tsamis <manolis.tsamis@vrull.eu>, gcc-patches@gcc.gnu.org
Cc: Richard Biener <richard.guenther@gmail.com>,
Palmer Dabbelt <palmer@rivosinc.com>,
Philipp Tomsich <philipp.tomsich@vrull.eu>,
Kito Cheng <kito.cheng@gmail.com>
Subject: Re: [PATCH 2/2] cprop_hardreg: Enable propagation of the stack pointer if possible.
Date: Thu, 25 May 2023 07:38:10 -0600 [thread overview]
Message-ID: <46d35ebf-b73a-b60d-4e03-35327f1ce80e@gmail.com> (raw)
In-Reply-To: <20230525123550.1072506-3-manolis.tsamis@vrull.eu>
On 5/25/23 06:35, Manolis Tsamis wrote:
> Propagation of the stack pointer in cprop_hardreg is currenty forbidden
> in all cases, due to maybe_mode_change returning NULL. Relax this
> restriction and allow propagation when no mode change is requested.
>
> gcc/ChangeLog:
>
> * regcprop.cc (maybe_mode_change): Enable stack pointer propagation.
I can't see how this can be correct given the stack pointer equality
tests elsewhere in the compiler, particularly the various targets.
The problem is if you change the mode then you end up with multiple REG
expressions that reference the stack pointer.
See rev: d1446456c3fcaa7be628726c9de4a877729490ca and the thread around
the change which introduced this code.
Jeff
next prev parent reply other threads:[~2023-05-25 13:38 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-25 12:35 [PATCH 0/2] RISC-V: New pass to optimize calculation of offsets for memory operations Manolis Tsamis
2023-05-25 12:35 ` [PATCH 1/2] Implementation of new RISCV optimizations pass: fold-mem-offsets Manolis Tsamis
2023-05-25 13:01 ` Richard Biener
2023-05-25 13:25 ` Manolis Tsamis
2023-05-25 13:31 ` Jeff Law
2023-05-25 13:50 ` Richard Biener
2023-05-25 14:02 ` Manolis Tsamis
2023-05-29 23:30 ` Jeff Law
2023-05-31 12:19 ` Manolis Tsamis
2023-05-31 14:00 ` Jeff Law
2023-05-25 14:13 ` Jeff Law
2023-05-25 14:18 ` Philipp Tomsich
2023-06-08 5:37 ` Jeff Law
2023-06-12 7:36 ` Manolis Tsamis
2023-06-12 14:37 ` Jeff Law
2023-06-09 0:57 ` Jeff Law
2023-06-12 7:32 ` Manolis Tsamis
2023-06-12 21:58 ` Jeff Law
2023-06-15 17:34 ` Manolis Tsamis
2023-06-10 15:49 ` Jeff Law
2023-06-12 7:41 ` Manolis Tsamis
2023-06-12 21:36 ` Jeff Law
2023-05-25 12:35 ` [PATCH 2/2] cprop_hardreg: Enable propagation of the stack pointer if possible Manolis Tsamis
2023-05-25 13:38 ` Jeff Law [this message]
2023-05-31 12:15 ` Manolis Tsamis
2023-06-07 22:16 ` Jeff Law
2023-06-07 22:18 ` Jeff Law
2023-06-08 6:15 ` Manolis Tsamis
2023-06-15 20:13 ` Philipp Tomsich
2023-06-19 16:57 ` Thiago Jung Bauermann
2023-06-19 17:07 ` Manolis Tsamis
2023-06-19 23:40 ` Andrew Pinski
2023-06-19 23:48 ` Andrew Pinski
2023-06-20 2:16 ` Jeff Law
2023-06-20 4:52 ` Tamar Christina
2023-06-20 5:00 ` Jeff Law
2023-06-21 23:42 ` Thiago Jung Bauermann
2023-06-22 7:37 ` Richard Biener
2023-06-22 7:58 ` Philipp Tomsich
2023-05-25 13:42 ` [PATCH 0/2] RISC-V: New pass to optimize calculation of offsets for memory operations Jeff Law
2023-05-25 13:57 ` Manolis Tsamis
2023-06-15 15:04 ` Jeff Law
2023-06-15 15:30 ` Manolis Tsamis
2023-06-15 15:56 ` Jeff Law
2023-06-18 18:11 ` Jeff Law
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