Bug 117951 – [3.4/ICE] Vector code that crashes w/ -O -mmmx

• Status: RESOLVED FIXED
• Product: Gentoo Linux

[Description Joël 2006-01-05 15:19:58 UTC]

The following code, when compiled on x86 with "-O2 -mmmx" will crash gcc 3.4.5:

int main()
{
        union { __attribute__ ((mode(V8QI))) v; int i; } a, b;
        a.v = __builtin_ia32_punpcklbw(a.v, b.v);
        printf("%x", a.i);
}


Thanks,

Jo

[Comment 1 Joël 2006-01-05 15:19:58 UTC]

The following code, when compiled on x86 with "-O2 -mmmx" will crash gcc 3.4.5:

int main()
{
        union { __attribute__ ((mode(V8QI))) v; int i; } a, b;
        a.v = __builtin_ia32_punpcklbw(a.v, b.v);
        printf("%x", a.i);
}


Thanks,

Joël

[Comment 2 Joël 2006-01-05 15:20:46 UTC]

The error is:
"internal compiler error: in simplify_binary_operation, at simplify-rtx.c:2012"

[Comment 3 Mark Loeser (RETIRED) 2006-01-05 15:24:38 UTC]

Confirmed.  This does work on >=gcc-4 as far as I can tell though, so getting a fix upstream may be difficult.  I'll see if I can find the fix and backport it.

[Comment 4 Mark Loeser (RETIRED) 2006-01-29 10:50:03 UTC]

Fixed in gcc-4.0.  I'd rather not incorporate patches unless they are absolutely needed.