https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70584
Bug ID: 70584
Summary: constexpr variables cannot be used as intrinsic
arguments where an immediate is expected
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: daniel.gutson at tallertechnologies dot com
Target Milestone: ---
Created attachment 38216
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38216&action=edit
test case
The following code causes gcc to complain that the last argument should be an
8-bit immediate value:
#include <wmmintrin.h>
int main()
{
__m128i r;
constexpr auto index = 1;
r = _mm_aeskeygenassist_si128(r, index);
}
This fails with -O0 but not with -O3.
The arguments to reproduce the issue are:
g++ -std=c++14 -msse -msse2 -maes -O0 tst.cpp -o tst
I attached the code anyway.
FWIW, this works in clang both for -O0 and for -O3. I think that constexpr
variables should be valid immediate arguments.
This bug affects the development of template metaprograms.
If there is agreement that this should be fixed, feel free to assign this to
andres.tirabos...@tallertechnologies.com .
