[Bug c++/59071] New: sse2 intrinsics and constant expressions

[vermaelen.wouter at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59071

            Bug ID: 59071
           Summary: sse2 intrinsics and constant expressions
           Product: gcc
           Version: 4.8.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: vermaelen.wouter at gmail dot com

gcc-4.8.2 with -O0 rejects the following code. With -O1 it works fine. Gcc-4.6,
4.7 and clang also work fine. I *believe* the stuff below is a constant
expression, so it should compile (even without optimizations enabled).

-------

#include "emmintrin.h"

template<int N> __m128i foo(__m128i x) {
    return _mm_slli_si128(x, sizeof(__m128i) - N);
}

void bar(__m128i x) { foo<4>(x); }

--------

> g++ test.cc
In file included from test.cc:1:0:
test.cc: In function ‘__m128i foo(__m128i) [with int N = 4; __m128i =
__vector(2) long long int]’:
test.cc:4:9: error: the last argument must be an 8-bit immediate
  return _mm_slli_si128(x, sizeof(__m128i) - N);