cbuild successfully built this on armv7l-natty-cbuild185-ursa4-cortexa9r1.

The build results are available at:
 http://ex.seabright.co.nz/build/gcc-linaro-4.6+bzr106815~irar~change_vector_size_4.6/logs/armv7l-natty-cbuild185-ursa4-cortexa9r1

-PASS: gcc.dg/vect/no-vfa-vect-101.c scan-tree-dump-times vect "can't determine dependence" 1
+XFAIL: gcc.dg/vect/no-vfa-vect-101.c scan-tree-dump-times vect "can't determine dependence" 1
+PASS: gcc.dg/vect/no-vfa-vect-101.c scan-tree-dump-times vect "can't determine dependence" 2
-PASS: gcc.dg/vect/no-vfa-vect-102.c scan-tree-dump-times vect "possible dependence between data-refs" 1
+XFAIL: gcc.dg/vect/no-vfa-vect-102.c scan-tree-dump-times vect "possible dependence between data-refs" 1
+PASS: gcc.dg/vect/no-vfa-vect-102.c scan-tree-dump-times vect "possible dependence between data-refs" 2
-PASS: gcc.dg/vect/no-vfa-vect-102a.c scan-tree-dump-times vect "possible dependence between data-refs" 1
+XFAIL: gcc.dg/vect/no-vfa-vect-102a.c scan-tree-dump-times vect "possible dependence between data-refs" 1
+PASS: gcc.dg/vect/no-vfa-vect-102a.c scan-tree-dump-times vect "possible dependence between data-refs" 2
-PASS: gcc.dg/vect/no-vfa-vect-37.c scan-tree-dump-times vect "can't determine dependence between" 2
+XFAIL: gcc.dg/vect/no-vfa-vect-37.c scan-tree-dump-times vect "can't determine dependence" 2
+PASS: gcc.dg/vect/no-vfa-vect-37.c scan-tree-dump-times vect "can't determine dependence" 4
-PASS: gcc.dg/vect/no-vfa-vect-79.c scan-tree-dump-times vect "can't determine dependence between" 1
+XFAIL: gcc.dg/vect/no-vfa-vect-79.c scan-tree-dump-times vect "can't determine dependence" 1
+PASS: gcc.dg/vect/no-vfa-vect-79.c scan-tree-dump-times vect "can't determine dependence" 2
-PASS: gcc.dg/vect/vect-104.c -flto scan-tree-dump-times vect "possible dependence between data-refs" 1
+XFAIL: gcc.dg/vect/vect-104.c -flto scan-tree-dump-times vect "possible dependence between data-refs" 1
+PASS: gcc.dg/vect/vect-104.c -flto scan-tree-dump-times vect "possible dependence between data-refs" 2
-PASS: gcc.dg/vect/vect-104.c scan-tree-dump-times vect "possible dependence between data-refs" 1
+XFAIL: gcc.dg/vect/vect-104.c scan-tree-dump-times vect "possible dependence between data-refs" 1
+PASS: gcc.dg/vect/vect-104.c scan-tree-dump-times vect "possible dependence between data-refs" 2
-PASS: gcc.dg/vect/vect-outer-1.c -flto scan-tree-dump-times vect "strided access in outer loop" 1
+XFAIL: gcc.dg/vect/vect-outer-1.c -flto scan-tree-dump-times vect "strided access in outer loop" 1
+PASS: gcc.dg/vect/vect-outer-1.c -flto scan-tree-dump-times vect "strided access in outer loop" 2
-PASS: gcc.dg/vect/vect-outer-1.c scan-tree-dump-times vect "strided access in outer loop" 1
+XFAIL: gcc.dg/vect/vect-outer-1.c scan-tree-dump-times vect "strided access in outer loop" 1
+PASS: gcc.dg/vect/vect-outer-1.c scan-tree-dump-times vect "strided access in outer loop" 2
-PASS: gcc.dg/vect/vect-outer-1a.c -flto scan-tree-dump-times vect "strided access in outer loop" 1
+XFAIL: gcc.dg/vect/vect-outer-1a.c -flto scan-tree-dump-times vect "strided access in outer loop" 1
+PASS: gcc.dg/vect/vect-outer-1a.c -flto scan-tree-dump-times vect "strided access in outer loop" 2
-PASS: gcc.dg/vect/vect-outer-1a.c scan-tree-dump-times vect "strided access in outer loop" 1
+XFAIL: gcc.dg/vect/vect-outer-1a.c scan-tree-dump-times vect "strided access in outer loop" 1
+PASS: gcc.dg/vect/vect-outer-1a.c scan-tree-dump-times vect "strided access in outer loop" 2
-PASS: gcc.dg/vect/vect-outer-1b.c -flto scan-tree-dump-times vect "strided access in outer loop" 1
+XFAIL: gcc.dg/vect/vect-outer-1b.c -flto scan-tree-dump-times vect "strided access in outer loop" 1
+PASS: gcc.dg/vect/vect-outer-1b.c -flto scan-tree-dump-times vect "strided access in outer loop" 2
-PASS: gcc.dg/vect/vect-outer-1b.c scan-tree-dump-times vect "strided access in outer loop" 1
+XFAIL: gcc.dg/vect/vect-outer-1b.c scan-tree-dump-times vect "strided access in outer loop" 1
+PASS: gcc.dg/vect/vect-outer-1b.c scan-tree-dump-times vect "strided access in outer loop" 2
-PASS: gcc.dg/vect/vect-outer-2b.c -flto scan-tree-dump-times vect "strided access in outer loop." 1
+XFAIL: gcc.dg/vect/vect-outer-2b.c -flto scan-tree-dump-times vect "strided access in outer loop" 1
+PASS: gcc.dg/vect/vect-outer-2b.c -flto scan-tree-dump-times vect "strided access in outer loop" 2
-PASS: gcc.dg/vect/vect-outer-2b.c scan-tree-dump-times vect "strided access in outer loop." 1
+XFAIL: gcc.dg/vect/vect-outer-2b.c scan-tree-dump-times vect "strided access in outer loop" 1
+PASS: gcc.dg/vect/vect-outer-2b.c scan-tree-dump-times vect "strided access in outer loop" 2
-PASS: gcc.dg/vect/vect-outer-3a.c -flto scan-tree-dump-times vect "step doesn't divide the vector-size" 2
+XFAIL: gcc.dg/vect/vect-outer-3a.c -flto scan-tree-dump-times vect "step doesn't divide the vector-size" 2
+PASS: gcc.dg/vect/vect-outer-3a.c -flto scan-tree-dump-times vect "step doesn't divide the vector-size" 3
-PASS: gcc.dg/vect/vect-outer-3a.c scan-tree-dump-times vect "step doesn't divide the vector-size" 2
+XFAIL: gcc.dg/vect/vect-outer-3a.c scan-tree-dump-times vect "step doesn't divide the vector-size" 2
...and 24 more

The full diff is at:
 http://ex.seabright.co.nz/build/gcc-linaro-4.6+bzr106815~irar~change_vector_size_4.6/logs/armv7l-natty-cbuild185-ursa4-cortexa9r1/testsuite-diff.txt

The full testsuite results are at:
 http://ex.seabright.co.nz/build/gcc-linaro-4.6+bzr106815~irar~change_vector_size_4.6/logs/armv7l-natty-cbuild185-ursa4-cortexa9r1/gcc-testsuite.txt

cbuild-checked: armv7l-natty-cbuild185-ursa4-cortexa9r1