The testcase no longer fails on the 4.8 branch and trunk, committed there so we do not regress.
Richard. 2013-04-03 Richard Biener <rguent...@suse.de> PR tree-optimization/56407 * gcc.dg/torture/pr56407.c: New testcase. Index: gcc/testsuite/gcc.dg/torture/pr56407.c =================================================================== --- gcc/testsuite/gcc.dg/torture/pr56407.c (revision 0) +++ gcc/testsuite/gcc.dg/torture/pr56407.c (working copy) @@ -0,0 +1,48 @@ +/* { dg-do run } */ + +extern void abort(void); +extern int rand(void); + +static void copy(int *r,int *a,int na) +{ + int i; + for( i = 0 ; i < na ; i++ ) + r[i] = a[i]; +} + +static void foo(int *a,int na) +{ + int i; + for( i = 0 ; i < na ; i++ ) + a[i] = rand(); +} + +static int cmp(int *a,int *b,int n) +{ + int i; + for( i = 0 ; i < n ; i++ ) + if ( a[i] != b[i] ) + return -1; + return 0; +} + +void __attribute__((noinline,noclone)) +test(int sz,int comm) +{ + int j,n; + int v[64],w[64]; + for( j = 1 ; j <= sz ; j++ ) + { + n = (2 * j - 1) * (2 * j - 1); + foo(w,n); + copy(v,w,n); + if ( comm ) + if ( cmp(v,w,n) ) abort (); + } +} + +int main() +{ + test(2,1); + return 0; +}