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From: "phosit at autistici dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/19347] Invariant load not moved out of loop
Date: Wed, 03 Jan 2024 19:14:07 +0000 [thread overview]
Message-ID: <bug-19347-4-lCp3ACahtX@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-19347-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=19347
Phosit <phosit at autistici dot org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |phosit at autistici dot org
--- Comment #9 from Phosit <phosit at autistici dot org> ---
When there are few iterations (likely when it is unroled) there is no
alias-check:
void fill(int* data, int& value)
{
for(unsigned long i{0}; i != 4; ++i)
data[i] = value;
}
--- at -O2 results in:
fill(int*, int&):
movd xmm1, DWORD PTR [rsi]
pshufd xmm0, xmm1, 0xe0
movq QWORD PTR [rdi], xmm0
movd xmm0, DWORD PTR [rsi]
pshufd xmm0, xmm0, 0xe0
movq QWORD PTR [rdi+8], xmm0
ret
---
At -O3 the loop isn't removed and (thus) there is an alias-check.
next parent reply other threads:[~2024-01-03 19:14 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <bug-19347-4@http.gcc.gnu.org/bugzilla/>
2024-01-03 19:14 ` phosit at autistici dot org [this message]
2024-01-03 19:35 ` phosit at autistici dot org
[not found] <bug-19347-9531@http.gcc.gnu.org/bugzilla/>
2005-10-24 0:20 ` pinskia at gcc dot gnu dot org
2009-04-03 12:06 ` rguenth at gcc dot gnu dot org
2005-01-09 10:51 [Bug tree-optimization/19347] New: " irar at il dot ibm dot com
2005-01-09 15:55 ` [Bug tree-optimization/19347] " pinskia at gcc dot gnu dot org
2005-04-11 6:10 ` pinskia at gcc dot gnu dot org
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