On Dec 9, 2021, Jeff Law <jeffreya...@gmail.com> wrote:
>> I found a similar pattern of issuing clobbers for multi-word moves, but
>> not when reload_in_progress, in expr.c:emit_move_complex_parts. I don't
>> have a testcase, but I'm tempted to propose '!lra_in_progress &&' for it
>> as well. Can you think of any reason not to?
> The only reason I can think of is we're in stage3 :-) It'd be a lot
> easier to green light that if we could trigger an issue.
I have not found the cycles to try to construct a testcase to trigger
the issue, but before moving on, I have regstrapped this on
x86_64-linux-gnu, so, at least for now, I propose it for the next
release cycle. Ok to install then?
[PR103302] skip multi-part clobber during lra for complex parts too
From: Alexandre Oliva <ol...@adacore.com>
As with the earlier patch, avoid emitting clobbers that we used to
avoid during reload also during LRA, now when moving complex
multi-part values. We don't have a testcase for this one.
for gcc/ChangeLog
PR target/103302
* expr.c (emit_move_complex_parts): Skip clobbers during lra.
---
gcc/expr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/gcc/expr.c b/gcc/expr.c
index 0365625e7b835..30d1735ec29ce 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -3736,7 +3736,7 @@ emit_move_complex_parts (rtx x, rtx y)
/* Show the output dies here. This is necessary for SUBREGs
of pseudos since we cannot track their lifetimes correctly;
hard regs shouldn't appear here except as return values. */
- if (!reload_completed && !reload_in_progress
+ if (!reload_completed && !reload_in_progress && !lra_in_progress
&& REG_P (x) && !reg_overlap_mentioned_p (x, y))
emit_clobber (x);
--
Alexandre Oliva, happy hacker https://FSFLA.org/blogs/lxo/
Free Software Activist GNU Toolchain Engineer
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