| Message ID | 3467344.A8qgcpPzcu@polaris |
|---|---|
| State | New |
| Headers | show |
On Sat, Nov 30, 2013 at 6:24 PM, Eric Botcazou <ebotcazou@adacore.com> wrote: > Hi, > > this test started to fail very recently on 32-bit platforms with 64-bit HWI. > Not sure exactly why, but the issue is straightforward and was latent. > > For the following reference, a call to ao_ref_init_from_ptr_and_size yields: > > (gdb) p debug_generic_expr((tree_node *) 0x7ffff6e01200) > &a[0 ...]{lb: 4294967292 sz: 4} > (gdb) p debug_generic_expr(size) > 20 > (gdb) p dref > $36 = {ref = 0x0, base = 0x7ffff6dfd260, offset = -137438953344, size = 160, > max_size = 160, ref_alias_set = 0, base_alias_set = 0, volatile_p = false} > > The offset is bogus. 'a' is an array with lower bound -4 so {lb: 4294967292 > sz: 4} is actually {lb: -4 sz: 4}. The computation of the offset goes wrong > in get_addr_base_and_unit_offset_1 because it is not done in sizetype. > > Fixed by copying the relevant bits from get_ref_base_and_extent, where the > computation is correctly done in sizetype. > > Tested on x86_64-suse-linux, OK for the mainline? Ok, though the whole function needs double-int-ization ... Thanks, Richard. > > 2013-11-30 Eric Botcazou <ebotcazou@adacore.com> > > * tree-dfa.h (get_addr_base_and_unit_offset_1) <case ARRAY_REF>: Do the > offset computation using the precision of the index type. > > > 2013-11-30 Eric Botcazou <ebotcazou@adacore.com> > > * gnat.dg/opt30.adb: New test. > > > -- > Eric Botcazou
On 11/30/13 10:24, Eric Botcazou wrote: > Hi, > > this test started to fail very recently on 32-bit platforms with 64-bit HWI. > Not sure exactly why, but the issue is straightforward and was latent. > > For the following reference, a call to ao_ref_init_from_ptr_and_size yields: > > (gdb) p debug_generic_expr((tree_node *) 0x7ffff6e01200) > &a[0 ...]{lb: 4294967292 sz: 4} > (gdb) p debug_generic_expr(size) > 20 > (gdb) p dref > $36 = {ref = 0x0, base = 0x7ffff6dfd260, offset = -137438953344, size = 160, > max_size = 160, ref_alias_set = 0, base_alias_set = 0, volatile_p = false} > > The offset is bogus. 'a' is an array with lower bound -4 so {lb: 4294967292 > sz: 4} is actually {lb: -4 sz: 4}. The computation of the offset goes wrong > in get_addr_base_and_unit_offset_1 because it is not done in sizetype. > > Fixed by copying the relevant bits from get_ref_base_and_extent, where the > computation is correctly done in sizetype. > > Tested on x86_64-suse-linux, OK for the mainline? > > > 2013-11-30 Eric Botcazou <ebotcazou@adacore.com> > > * tree-dfa.h (get_addr_base_and_unit_offset_1) <case ARRAY_REF>: Do the > offset computation using the precision of the index type. > > > 2013-11-30 Eric Botcazou <ebotcazou@adacore.com> > > * gnat.dg/opt30.adb: New test. Ok. Thanks, Jeff
Index: tree-dfa.h =================================================================== --- tree-dfa.h (revision 205547) +++ tree-dfa.h (working copy) @@ -102,11 +102,11 @@ get_addr_base_and_unit_offset_1 (tree ex && (unit_size = array_ref_element_size (exp), TREE_CODE (unit_size) == INTEGER_CST)) { - HOST_WIDE_INT hindex = TREE_INT_CST_LOW (index); - - hindex -= TREE_INT_CST_LOW (low_bound); - hindex *= TREE_INT_CST_LOW (unit_size); - byte_offset += hindex; + double_int doffset + = (TREE_INT_CST (index) - TREE_INT_CST (low_bound)) + .sext (TYPE_PRECISION (TREE_TYPE (index))); + doffset *= tree_to_double_int (unit_size); + byte_offset += doffset.to_shwi (); } else return NULL_TREE;
Hi, this test started to fail very recently on 32-bit platforms with 64-bit HWI. Not sure exactly why, but the issue is straightforward and was latent. For the following reference, a call to ao_ref_init_from_ptr_and_size yields: (gdb) p debug_generic_expr((tree_node *) 0x7ffff6e01200) &a[0 ...]{lb: 4294967292 sz: 4} (gdb) p debug_generic_expr(size) 20 (gdb) p dref $36 = {ref = 0x0, base = 0x7ffff6dfd260, offset = -137438953344, size = 160, max_size = 160, ref_alias_set = 0, base_alias_set = 0, volatile_p = false} The offset is bogus. 'a' is an array with lower bound -4 so {lb: 4294967292 sz: 4} is actually {lb: -4 sz: 4}. The computation of the offset goes wrong in get_addr_base_and_unit_offset_1 because it is not done in sizetype. Fixed by copying the relevant bits from get_ref_base_and_extent, where the computation is correctly done in sizetype. Tested on x86_64-suse-linux, OK for the mainline? 2013-11-30 Eric Botcazou <ebotcazou@adacore.com> * tree-dfa.h (get_addr_base_and_unit_offset_1) <case ARRAY_REF>: Do the offset computation using the precision of the index type. 2013-11-30 Eric Botcazou <ebotcazou@adacore.com> * gnat.dg/opt30.adb: New test.