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From: "eric-bugs at omnifarious dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/108361] New: Assembly code that is never called emitted on x86_64
Date: Tue, 10 Jan 2023 14:05:01 +0000 [thread overview]
Message-ID: <bug-108361-4@http.gcc.gnu.org/bugzilla/> (raw)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108361
Bug ID: 108361
Summary: Assembly code that is never called emitted on x86_64
Product: gcc
Version: 12.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: eric-bugs at omnifarious dot org
Target Milestone: ---
Created attachment 54236
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54236&action=edit
Preprocessed C++ code that generates unneeded assembly
The nature of this bug makes a concise test case hard to whittle down to
something minimal...
The attached code generates a whole bunch of assembly that isn't needed. This
assembly references external symbols as well, which creates unnecessary linker
errors.
Clang handles it just fine. :-)
Attached is both the preprocessed C++ code, and the assembly it generates. The
only needed assembly is the code for main and the static data main needs.
_start is defined as a global in a separate file, which is also attached.
The compile command I'm using:
g++ -std=c++20 -march=znver2 -static -O3 -nostartfiles -nostdlib
-I/usr/include/c++/12 -I/home/hopper/src/posixpp/pubincludes -Wl,-e_start
preprocessed.s x86_64_start.s
next reply other threads:[~2023-01-10 14:05 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-10 14:05 eric-bugs at omnifarious dot org [this message]
2023-01-10 14:05 ` [Bug c++/108361] " eric-bugs at omnifarious dot org
2023-01-10 14:06 ` eric-bugs at omnifarious dot org
2023-01-10 18:25 ` pinskia at gcc dot gnu.org
2023-01-10 18:26 ` pinskia at gcc dot gnu.org
2023-01-10 18:30 ` pinskia at gcc dot gnu.org
2023-01-10 19:00 ` eric-bugs at omnifarious dot org
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