Segfault when handling __m128i

Question

Hi,
the below code segfaults when compiled with -m32, but runs fine when built with -m64 or when built with gcc regardless of the 32/64 bits.
A slight shift of the cast makes the segfault go away (below).
Is it a bug in CC or is there something else in it?
(this is with 12.3beta and 12.1)
TIA for any hints
failing code:
<pre>
#include <cstdlib>
#ifdef __SUNPRO_CC
#include <sys/emmintrin.h>
#else
#include <xmmintrin.h>
#endif
int main(int argc, char** argv) {
const unsigned char s1[16] = {0U,1U,2U,3U,4U,5U,6U,7U,8U,9U,10U,11U,12U,13U,14U,15U};
const unsigned char *s2 = s1;
int x = 0;
__m128i top = mmloadu_si128((__m128i*)((const unsigned int *)(s2)+x));
return 0;
</pre>
non-failing code:
<pre>
#include <cstdlib>
#ifdef __SUNPRO_CC
#include <sys/emmintrin.h>
#else
#include <xmmintrin.h>
#endif
int main(int argc, char** argv) {
const unsigned char s1[16] = {0U,1U,2U,3U,4U,5U,6U,7U,8U,9U,10U,11U,12U,13U,14U,15U};
const unsigned char *s2 = s1;
int x = 0;
__m128i* qqq = (__m128i*)((const unsigned int *)(s2)+x);
__m128i top = mmloadu_si128(qqq);
return 0;
</pre>

Answer 1

Take a look at the bug I have filed in the middle of Nov 2011. Under some conditions the Oracle C++ compilers won't even compile SSE2 code.
*2011-11-14 15:42:54.85 EMAIL SENT BY* ****
From: *** ****
Subject: Re: (Incident Review ID: 2127676) C++ compiler crash when compiling SSE2 code.
Hi Konstantin, we have verified this bug against our latest build and it is no longer reproducible.
Report
<font face="courier">
    category : compiler
 subcategory : ube
     release : spica
        type : bug
    synopsis : C++ compiler crash when compiling SSE2 code.
      sdn id :
    hardware : x86
          os : solaris_10
      bug id : 0
date created : Mon Nov 14 04:19:23 MST 2011
   date eval : Mon Nov 14 15:42:59 MST 2011
</font>
ADDITIONAL OS VERSION INFORMATION :
uname -a: SunOS jabba 5.11 snv_130 i86pc i386 i86pc
This is a "SXCE snv_130 X86 (14 Dec 2009)" system running 32-bit kernel.
EXTRA RELEVANT SYSTEM CONFIGURATION :
$ CC -V
CC: Sun C++ 5.12 SunOS_i386 Spica 2011/07/21
A DESCRIPTION OF THE PROBLEM :
Compiling this peace of code results in compiler crash if optimization level is not zero:
#include <emmintrin.h>
class A {
public:
    ~A() {};
    char *data();
static A
foo(const short *src) {
    A a;
    char *dst = a.data();
    __m128i chunk = _mm_loadu_si128((__m128i*)src);
    const __m128i rv = _mm_packus_epi16(chunk, chunk);
    _mm_storeu_si128((__m128i*)dst, rv);
    return a;
A
bar() {
    short u[3];
    return foo(u);
}| $ CC -xO1 -c -xarch=sse2 -o t.o t.C
|  
| assertion failed in function unzip() @ fall_thru.c:521
| assert(nd_not_null_(start_label))
|  
| CC: ube failed for t.C
Compiling very similar peace of code results in compiler crash in ir2hf:
#include <emmintrin.h>
class A {
public:
    ~A() {};
    char *data();
static A
foo(const short *src) {
    A a;
    __m128i chunk = _mm_loadu_si128((__m128i*)src);
    const __m128i rv = _mm_packus_epi16(chunk, chunk);
    _mm_storeu_si128((__m128i*)a.data(), rv);
    return a;
A
bar() {
    short u[3];
    return foo(u);
}| $ CC -xO1 -c -xarch=sse2 -o t.o t.C
| CC: Fatal error in /opt/SUNWspro/prod/bin/ir2hf
| CC: Status 139
I nominate this bug as regression, because "Sun Studio Express 2009/03" compiles this code flawlessly.
With that, I shall strongly emphasize that SSX0903 is also buggy compiling SSE2 code. Below is the test case to crash SSX0903 C++, and that bug may still present in 12u3b release, but hidden by the front bug. I kindly invite the developers to check this bug too.
Here is a test case to crash SSX0903:
#include <emmintrin.h>
class A {
public:
    char *data();
static A
foo(const short *src) {
    A a;
    char *dst = a.data();
    for ( int i = 0; i < 1; ++ i ) {
        __m128i chunk1 = _mm_loadu_si128((__m128i*)src);
        __m128i chunk2 = _mm_loadu_si128((__m128i*)src);
        const __m128i rv = _mm_packus_epi16(chunk1, chunk2);
        _mm_storeu_si128((__m128i*)dst, rv);
    return a;
A
bar()
    short u[8];
    return foo(u);
}| $ CC -V
| CC: Sun Ceres C++ 5.10 SunOS_i386 2009/03/06
| $ CC -xO2 -c -xarch=sse2 -o t.o t.C
| Assembler: t.C
| "/tmp/ube.10982.6.s", line 63 : Syntax error
| Near line: "{ 14 } movdqa (%xmm0),%xmm1 "
REGRESSION Last worked in version ossx10.06
REPRODUCIBILITY This bug can be reproduced always.