c/5680: Trouble extracting SSE values from a union

[tom@womack.net]

>Number:         5680
>Category:       c
>Synopsis:       Trouble extracting SSE values from a union
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Feb 13 02:46:01 PST 2002
>Closed-Date:
>Last-Modified:
>Originator:     Thomas Womack
>Release:        gcc-3.1-20020211
>Organization:
>Environment:
SuSE Linux
>Description:
The short program below

#include <stdio.h>
typedef int m128 __attribute__ ((mode(V4SI)));

typedef union {m128 ti; unsigned int si[4];} m128x;

int main(void)
{
    m128x a;
    m128 w;
    a.si[2] = 1;
    w = a.ti;
}

gives an ICE in expr.c line 2748 -- this is the abort() command when the two sides of an emit_move_insn have incompatible modes.
>How-To-Repeat:
Compile with -march=pentium4
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: