[Bug 1904259] [NEW] include/qemu/atomic.h:495:5: error: misaligned atomic operation may incur significant performance penalty (Clang 11; Ubuntu 16 i686)

* [Bug 1904259] [NEW] include/qemu/atomic.h:495:5: error: misaligned atomic operation may incur significant performance penalty (Clang 11; Ubuntu 16 i686)
@ 2020-11-14  3:39 Ivan Serdyuk
  2020-11-14  3:45 ` [Bug 1904259] " Ivan Serdyuk
                   ` (4 more replies)
  0 siblings, 5 replies; 6+ messages in thread
From: Ivan Serdyuk @ 2020-11-14  3:39 UTC (permalink / raw)
  To: qemu-devel

Public bug reported:

Hello.
I haven't found any "official" executables, for emulating RISC-V (32bit; 64bit) so I had to compile those myself.

I found that auto-generated build scripts, for Ninja, contained some
warnings interpreted as errors:

oceanfish81@gollvm:~/Desktop/qemu/build$ ninja -j 1
[2/1977] Compiling C object libqemuutil.a.p/util_qsp.c.o
FAILED: libqemuutil.a.p/util_qsp.c.o 
clang-11 -Ilibqemuutil.a.p -I. -I.. -Iqapi -Itrace -Iui -Iui/shader -I/usr/include/glib-2.0 -I/usr/lib/i386-linux-gnu/glib-2.0/include -I/usr/include/gio-unix-2.0/ -Xclang -fcolor-diagnostics -pipe -Wall -Winvalid-pch -Werror -std=gnu99 -O2 -g -m32 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wundef -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common -fwrapv -Wold-style-definition -Wtype-limits -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined -Wno-initializer-overrides -Wno-missing-include-dirs -Wno-shift-negative-value -Wno-string-plus-int -Wno-typedef-redefinition -Wno-tautological-type-limit-compare -Wno-psabi -fstack-protector-strong -isystem /home/oceanfish81/Desktop/qemu/linux-headers -isystem linux-headers -iquote /home/oceanfish81/Desktop/qemu/tcg/i386 -iquote . -iquote /home/oceanfish81/Desktop/qemu -iquote /home/oceanfish81/Desktop/qemu/accel/tcg -iquote /home/oceanfish81/Desktop/qemu/include -iquote /home/oceanfish81/Desktop/qemu/disas/libvixl -pthread -Wno-unused-function -fPIC -MD -MQ libqemuutil.a.p/util_qsp.c.o -MF libqemuutil.a.p/util_qsp.c.o.d -o libqemuutil.a.p/util_qsp.c.o -c ../util/qsp.c
In file included from ../util/qsp.c:62:
In file included from /home/oceanfish81/Desktop/qemu/include/qemu/thread.h:4:
In file included from /home/oceanfish81/Desktop/qemu/include/qemu/processor.h:10:
/home/oceanfish81/Desktop/qemu/include/qemu/atomic.h:495:5: error: misaligned atomic operation may incur significant performance penalty [-Werror,-Watomic-alignment]
    qatomic_set__nocheck(ptr, val);
    ^
/home/oceanfish81/Desktop/qemu/include/qemu/atomic.h:138:5: note: expanded from macro 'qatomic_set__nocheck'
    __atomic_store_n(ptr, i, __ATOMIC_RELAXED)
    ^
/home/oceanfish81/Desktop/qemu/include/qemu/atomic.h:485:12: error: misaligned atomic operation may incur significant performance penalty [-Werror,-Watomic-alignment]
    return qatomic_read__nocheck(ptr);
           ^
/home/oceanfish81/Desktop/qemu/include/qemu/atomic.h:129:5: note: expanded from macro 'qatomic_read__nocheck'
    __atomic_load_n(ptr, __ATOMIC_RELAXED)
    ^
2 errors generated.
ninja: build stopped: subcommand failed.

** Affects: qemu
     Importance: Undecided
         Status: New

** Attachment added: "Attaching my build.ninja file, in case it would be of help"
   https://bugs.launchpad.net/bugs/1904259/+attachment/5434234/+files/build.ninja

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1904259

Title:
  include/qemu/atomic.h:495:5: error: misaligned atomic operation may
  incur significant performance penalty (Clang 11; Ubuntu 16 i686)

Status in QEMU:
  New

Bug description:
  Hello.
  I haven't found any "official" executables, for emulating RISC-V (32bit; 64bit) so I had to compile those myself.

  I found that auto-generated build scripts, for Ninja, contained some
  warnings interpreted as errors:

  oceanfish81@gollvm:~/Desktop/qemu/build$ ninja -j 1
  [2/1977] Compiling C object libqemuutil.a.p/util_qsp.c.o
  FAILED: libqemuutil.a.p/util_qsp.c.o 
  clang-11 -Ilibqemuutil.a.p -I. -I.. -Iqapi -Itrace -Iui -Iui/shader -I/usr/include/glib-2.0 -I/usr/lib/i386-linux-gnu/glib-2.0/include -I/usr/include/gio-unix-2.0/ -Xclang -fcolor-diagnostics -pipe -Wall -Winvalid-pch -Werror -std=gnu99 -O2 -g -m32 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wundef -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common -fwrapv -Wold-style-definition -Wtype-limits -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined -Wno-initializer-overrides -Wno-missing-include-dirs -Wno-shift-negative-value -Wno-string-plus-int -Wno-typedef-redefinition -Wno-tautological-type-limit-compare -Wno-psabi -fstack-protector-strong -isystem /home/oceanfish81/Desktop/qemu/linux-headers -isystem linux-headers -iquote /home/oceanfish81/Desktop/qemu/tcg/i386 -iquote . -iquote /home/oceanfish81/Desktop/qemu -iquote /home/oceanfish81/Desktop/qemu/accel/tcg -iquote /home/oceanfish81/Desktop/qemu/include -iquote /home/oceanfish81/Desktop/qemu/disas/libvixl -pthread -Wno-unused-function -fPIC -MD -MQ libqemuutil.a.p/util_qsp.c.o -MF libqemuutil.a.p/util_qsp.c.o.d -o libqemuutil.a.p/util_qsp.c.o -c ../util/qsp.c
  In file included from ../util/qsp.c:62:
  In file included from /home/oceanfish81/Desktop/qemu/include/qemu/thread.h:4:
  In file included from /home/oceanfish81/Desktop/qemu/include/qemu/processor.h:10:
  /home/oceanfish81/Desktop/qemu/include/qemu/atomic.h:495:5: error: misaligned atomic operation may incur significant performance penalty [-Werror,-Watomic-alignment]
      qatomic_set__nocheck(ptr, val);
      ^
  /home/oceanfish81/Desktop/qemu/include/qemu/atomic.h:138:5: note: expanded from macro 'qatomic_set__nocheck'
      __atomic_store_n(ptr, i, __ATOMIC_RELAXED)
      ^
  /home/oceanfish81/Desktop/qemu/include/qemu/atomic.h:485:12: error: misaligned atomic operation may incur significant performance penalty [-Werror,-Watomic-alignment]
      return qatomic_read__nocheck(ptr);
             ^
  /home/oceanfish81/Desktop/qemu/include/qemu/atomic.h:129:5: note: expanded from macro 'qatomic_read__nocheck'
      __atomic_load_n(ptr, __ATOMIC_RELAXED)
      ^
  2 errors generated.
  ninja: build stopped: subcommand failed.

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1904259/+subscriptions

^ permalink raw reply	[flat|nested] 6+ messages in thread