> -----Original Message-----
> From: Richard Biener [mailto:richard.guent...@gmail.com]
> Sent: Friday, September 27, 2013 4:30 PM
> To: Bin Cheng
> Cc: GCC Patches
> Subject: Re: [PATCH]Fix computation of offset in ivopt
>
> On Fri, Sep 27, 2013 at 7:07 AM, bin.cheng <bin.ch...@arm.com> wrote:
> >
> >
> > case INTEGER_CST:
> > //.......
> > *offset = int_cst_value (expr);
> > change to
> > case INTEGER_CST:
> > //.......
> > *offset = sext_hwi (int_cst_value (expr), type);
> >
> > and
> > case MULT_EXPR:
> > //.......
> > *offset = sext_hwi (int_cst_value (expr), type); to
> > case MULT_EXPR:
> > //.......
> > HOST_WIDE_INT xxx = (HOST_WIDE_INT)off0 * int_cst_value (op1);
> > *offset = sext_hwi (xxx, type);
> >
> > Any comments?
>
> The issue is of course that we end up converting offsets to sizetype at
some
> point which makes them all appear unsigned. The fix for this is to simply
> interpret them as signed ... but it's really a mess ;)
>
Hi, this is updated patch which calculates signed offset in strip_offset_1
then sign extend it in strip_offset.
Bootstrap and test on x86_64/x86/arm. Is it OK?
Thanks.
bin
2013-09-30 Bin Cheng <bin.ch...@arm.com>
* tree-ssa-loop-ivopts.c (strip_offset_1): Change parameter type.
Count DECL_FIELD_BIT_OFFSET when computing offset for COMPONENT_REF.
(strip_offset): Sign extend before return.Index: gcc/tree-ssa-loop-ivopts.c
===================================================================
--- gcc/tree-ssa-loop-ivopts.c (revision 202599)
+++ gcc/tree-ssa-loop-ivopts.c (working copy)
@@ -2037,12 +2037,12 @@ find_interesting_uses (struct ivopts_data *data)
static tree
strip_offset_1 (tree expr, bool inside_addr, bool top_compref,
- unsigned HOST_WIDE_INT *offset)
+ HOST_WIDE_INT *offset)
{
tree op0 = NULL_TREE, op1 = NULL_TREE, tmp, step;
enum tree_code code;
tree type, orig_type = TREE_TYPE (expr);
- unsigned HOST_WIDE_INT off0, off1, st;
+ HOST_WIDE_INT off0, off1, st;
tree orig_expr = expr;
STRIP_NOPS (expr);
@@ -2133,19 +2133,26 @@ strip_offset_1 (tree expr, bool inside_addr, bool
break;
case COMPONENT_REF:
- if (!inside_addr)
- return orig_expr;
+ {
+ tree field;
+ HOST_WIDE_INT boffset = 0;
+ if (!inside_addr)
+ return orig_expr;
- tmp = component_ref_field_offset (expr);
- if (top_compref
- && cst_and_fits_in_hwi (tmp))
- {
- /* Strip the component reference completely. */
- op0 = TREE_OPERAND (expr, 0);
- op0 = strip_offset_1 (op0, inside_addr, top_compref, &off0);
- *offset = off0 + int_cst_value (tmp);
- return op0;
- }
+ tmp = component_ref_field_offset (expr);
+ field = TREE_OPERAND (expr, 1);
+ if (top_compref
+ && cst_and_fits_in_hwi (tmp)
+ && cst_and_fits_in_hwi (DECL_FIELD_BIT_OFFSET (field)))
+ {
+ /* Strip the component reference completely. */
+ op0 = TREE_OPERAND (expr, 0);
+ op0 = strip_offset_1 (op0, inside_addr, top_compref, &off0);
+ boffset = int_cst_value (DECL_FIELD_BIT_OFFSET (field));
+ *offset = off0 + int_cst_value (tmp) + boffset / BITS_PER_UNIT;
+ return op0;
+ }
+ }
break;
case ADDR_EXPR:
@@ -2196,7 +2203,16 @@ strip_offset_1 (tree expr, bool inside_addr, bool
static tree
strip_offset (tree expr, unsigned HOST_WIDE_INT *offset)
{
- return strip_offset_1 (expr, false, false, offset);
+ HOST_WIDE_INT off;
+ tree core = strip_offset_1 (expr, false, false, &off);
+
+ /* Sign extend off if expr is in type which has lower precision
+ than HOST_WIDE_INT. */
+ if (TYPE_PRECISION (TREE_TYPE (expr)) <= HOST_BITS_PER_WIDE_INT)
+ off = sext_hwi (off, TYPE_PRECISION (TREE_TYPE (expr)));
+
+ *offset = off;
+ return core;
}
/* Returns variant of TYPE that can be used as base for different uses.
