[Bug target/106187] armhf: Miscompilation at O2 level (O0 / O1 are working)

["mathieu.malaterre at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106187

--- Comment #8 from Mathieu Malaterre <mathieu.malaterre at gmail dot com> ---
(In reply to Jan Wassenberg from comment #7)
> The easiest way to reduce the amount of code in the binary is to comment out
> from mul_test.cc all the HWY_EXPORT_AND_TEST_P except the one with
> TestAllMulEven.
> 
> The actual miscompilation is probably happening within ops/emu128-inl.h.
> 
> You can further reduce instantiations by replacing
> ForFloatTypes(ForPartialVectors<TestMulAdd>());
> with
> TestMulAdd()(float(), FixedTag<float, 4>());
> 
> That gets us down to a fairly minimal single TU (mul_test.cc).

Bingo !

Program received signal SIGABRT, Aborted.
0xb6cafe86 in ?? () from /lib/arm-linux-gnueabihf/libc.so.6
(gdb) bt
#0  0xb6cafe86 in ?? () from /lib/arm-linux-gnueabihf/libc.so.6
#1  0xb6cbf0e4 in raise () from /lib/arm-linux-gnueabihf/libc.so.6
#2  0xb6cafa16 in abort () from /lib/arm-linux-gnueabihf/libc.so.6
#3  0x00416a2c in hwy::Abort (file=file@entry=0x43acf8
"/home/malat/highway/hwy/tests/mul_test.cc", line=line@entry=308,
format=0x43b6ec "%s, %sx%llu lane %llu mismatch: expected '%s', got '%s'.\n")
    at /home/malat/highway/hwy/targets.cc:322
#4  0x00416cbc in hwy::detail::PrintMismatchAndAbort (info=...,
expected_ptr=expected_ptr@entry=0x0, actual_ptr=0x467580,
actual_ptr@entry=0x43acf8, target_name=target_name@entry=0x43ad24 "Emu128",
    filename=0x43acf8 "/home/malat/highway/hwy/tests/mul_test.cc",
filename@entry=0xb6ff3010 "", line=line@entry=308, lane=0,
num_lanes=num_lanes@entry=4) at /home/malat/highway/hwy/tests/test_util.cc:90
#5  0x00416d54 in hwy::detail::AssertArrayEqual (info=...,
expected_void=expected_void@entry=0x467500,
actual_void=actual_void@entry=0x467580, N=N@entry=4, target_name=0x43ad24
"Emu128",
    filename=0x43acf8 "/home/malat/highway/hwy/tests/mul_test.cc", line=308) at
/home/malat/highway/hwy/tests/test_util.cc:113
#6  0x004108ae in hwy::N_EMU128::AssertVecEqual<hwy::N_EMU128::Simd<float, 4u,
0>, float, hwy::N_EMU128::Vec128<float, 4u> > (line=308, filename=0x43acf8
"/home/malat/highway/hwy/tests/mul_test.cc",
    actual=..., expected=0x467500, d=...) at
/home/malat/highway/hwy/tests/test_util-inl.h:51
#7  hwy::N_EMU128::TestMulAdd::operator()<float, hwy::N_EMU128::Simd<float, 4u,
0> > (d=..., this=<optimized out>) at
/home/malat/highway/hwy/tests/mul_test.cc:308
#8  0x0043a114 in void
testing::internal::HandleExceptionsInMethodIfSupported<testing::Test,
void>(testing::Test*, void (testing::Test::*)(), char const*) ()