> -----Original Message-----
> From: Richard Guenther [mailto:richard.guent...@gmail.com]
> Sent: 03 August 2010 17:22
> To: Bingfeng Mei
> Cc: Alexander Monakov; gcc@gcc.gnu.org
> Subject: Re: Restrict qualifier still not working?
>
> On Tue, Aug 3, 2010 at 6:11 PM, Bingfeng Mei <b...@broadcom.com> wrote:
> > Richard,
> > I applied the patch. The simple example in my previous mail is
> > compiled as expected. However, for a bit more complex example,
> > restrict qualifier still doesn't work as expected. This happens
> > even on trunk compiler so it is not due to some missing patches on
> 4.5.
> >
> > void foo (int * restrict a, int * restrict b, int * restrict c)
> > {
> > int i;
> > for(i = 0; i < 100; i+=4)
> > {
> > a[i] = b[i] * c[i];
> > a[i+1] = b[i+1] * c[i+1];
> > a[i+2] = b[i+2] * c[i+2];
> > a[i+3] = b[i+3] * c[i+3];
> > }
> > }
> >
> > ~/work/install-x86/bin/gcc tst3.c -O2 -S -std=c99 -da -fschedule-
> insns -frename-register
> >
> > .L2:
> > movl (%rdx,%rax), %r10d
> > imull (%rsi,%rax), %r10d
> > movl %r10d, (%rdi,%rax)
> > movl 4(%rdx,%rax), %r9d
> > imull 4(%rsi,%rax), %r9d
> > movl %r9d, 4(%rdi,%rax)
> > movl 8(%rdx,%rax), %r8d
> > imull 8(%rsi,%rax), %r8d
> > movl %r8d, 8(%rdi,%rax)
> > movl 12(%rdx,%rax), %ecx
> > imull 12(%rsi,%rax), %ecx
> > movl %ecx, 12(%rdi,%rax)
> > addq $16, %rax
> > cmpq $400, %rax
> > jne .L2
> > rep
> >
> > This used to compile efficiently on our 4.4 port. Any comments?
>
> It's due to TMR_ORIGINAL being used for MEM_EXPRs during
> expansion (and TMRs not being handled by the alias oracles
> well). I can look at this if you file a bugreport, so I remember.
>
> A patch as simple as
>
> Index: expr.c
> ===================================================================
> --- expr.c (revision 162841)
> +++ expr.c (working copy)
> @@ -8665,7 +8665,7 @@ expand_expr_real_1 (tree exp, rtx target
> set_mem_addr_space (temp, as);
> base = get_base_address (TMR_ORIGINAL (exp));
> if (base
> - && INDIRECT_REF_P (base)
> + && (INDIRECT_REF_P (base) || TREE_CODE (base) == MEM_REF)
> && TMR_BASE (exp)
> && TREE_CODE (TMR_BASE (exp)) == SSA_NAME
> && POINTER_TYPE_P (TREE_TYPE (TMR_BASE (exp))))
>
Thanks, this patch works with trunk x86.
> might help. On the 4.5 branch you need to backport the various
> changes to retain points-to info during IVOPTs (or use -fno-tree-
> ivopts).
Is this gigantic patch you referring to?
2010-07-01 Richard Guenther <rguent...@suse.de>
PR middle-end/42834
PR middle-end/44468
* doc/gimple.texi (is_gimple_mem_ref_addr): Document.
* doc/generic.texi (References to storage): Document MEM_REF.
* tree-pretty-print.c (dump_generic_node): Handle MEM_REF.
(print_call_name): Likewise.
* tree.c (recompute_tree_invariant_for_addr_expr): Handle MEM_REF.
(build_simple_mem_ref_loc): New function.
(mem_ref_offset): Likewise.
* tree.h (build_simple_mem_ref_loc): Declare.
(build_simple_mem_ref): Define.
(mem_ref_offset): Declare.
* fold-const.c: Include tree-flow.h.
(operand_equal_p): Handle MEM_REF.
(build_fold_addr_expr_with_type_loc): Likewise.
(fold_comparison): Likewise.
(fold_unary_loc): Fold
VIEW_CONVERT_EXPR <T1, MEM_REF <T2, ...>> to MEM_REF <T1, ...>.
(fold_binary_loc): Fold MEM[&MEM[p, CST1], CST2] to MEM[p, CST1 + CST2],
fold MEM[&a.b, CST2] to MEM[&a, offsetof (a, b) + CST2].
* tree-ssa-alias.c (ptr_deref_may_alias_decl_p): Handle MEM_REF.
(ptr_deref_may_alias_ref_p_1): Likewise.
(ao_ref_base_alias_set): Properly differentiate base object for
offset and TBAA.
(ao_ref_init_from_ptr_and_size): Use MEM_REF.
(indirect_ref_may_alias_decl_p): Handle MEM_REFs properly.
(indirect_refs_may_alias_p): Likewise.
(refs_may_alias_p_1): Likewise. Remove pointer SSA name def
chasing code.
(ref_maybe_used_by_call_p_1): Handle MEM_REF.
(call_may_clobber_ref_p_1): Likewise.
* dwarf2out.c (loc_list_from_tree): Handle MEM_REF.
>
> Thanks,
> Richard.
