On Mon, 1 Jul 2024, Tamar Christina wrote:
> Hi All,
>
> The current implementation of constant_multiple_of is doing a more limited
> version of aff_combination_constant_multiple_p.
>
> The only non-debug usage of constant_multiple_of will proceed with the values
> as affine trees. There is scope for further optimization here, namely I
> believe
> that if constant_multiple_of returns the aff_tree after the conversion then
> get_computation_aff_1 can use it instead of manually creating the aff_tree.
>
> However I think it makes sense to first commit this smaller change and then
> incrementally change things.
>
> Bootstrapped Regtested on aarch64-none-linux-gnu,
> x86_64-pc-linux-gnu -m32, -m64 and no issues.
>
> Ok for master?
OK.
Thanks,
Richard.
> Thanks,
> Tamar
>
> gcc/ChangeLog:
>
> PR tree-optimization/114932
> * tree-ssa-loop-ivopts.cc (constant_multiple_of): Use
> aff_combination_constant_multiple_p instead.
>
> ---
> diff --git a/gcc/tree-ssa-loop-ivopts.cc b/gcc/tree-ssa-loop-ivopts.cc
> index
> 7cae5bdefea3648ddde238a357af527a934a569e..c3218a3e8eedbb8d0a7f14c01eeb069cb6024c29
> 100644
> --- a/gcc/tree-ssa-loop-ivopts.cc
> +++ b/gcc/tree-ssa-loop-ivopts.cc
> @@ -2146,65 +2146,15 @@ idx_record_use (tree base, tree *idx,
> static bool
> constant_multiple_of (tree top, tree bot, widest_int *mul)
> {
> - tree mby;
> - enum tree_code code;
> - unsigned precision = TYPE_PRECISION (TREE_TYPE (top));
> - widest_int res, p0, p1;
> -
> - STRIP_NOPS (top);
> - STRIP_NOPS (bot);
> -
> - if (operand_equal_p (top, bot, 0))
> - {
> - *mul = 1;
> - return true;
> - }
> -
> - code = TREE_CODE (top);
> - switch (code)
> - {
> - case MULT_EXPR:
> - mby = TREE_OPERAND (top, 1);
> - if (TREE_CODE (mby) != INTEGER_CST)
> - return false;
> -
> - if (!constant_multiple_of (TREE_OPERAND (top, 0), bot, &res))
> - return false;
> -
> - *mul = wi::sext (res * wi::to_widest (mby), precision);
> - return true;
> -
> - case PLUS_EXPR:
> - case MINUS_EXPR:
> - if (!constant_multiple_of (TREE_OPERAND (top, 0), bot, &p0)
> - || !constant_multiple_of (TREE_OPERAND (top, 1), bot, &p1))
> - return false;
> -
> - if (code == MINUS_EXPR)
> - p1 = -p1;
> - *mul = wi::sext (p0 + p1, precision);
> - return true;
> -
> - case INTEGER_CST:
> - if (TREE_CODE (bot) != INTEGER_CST)
> - return false;
> -
> - p0 = widest_int::from (wi::to_wide (top), SIGNED);
> - p1 = widest_int::from (wi::to_wide (bot), SIGNED);
> - if (p1 == 0)
> - return false;
> - *mul = wi::sext (wi::divmod_trunc (p0, p1, SIGNED, &res), precision);
> - return res == 0;
> -
> - default:
> - if (POLY_INT_CST_P (top)
> - && POLY_INT_CST_P (bot)
> - && constant_multiple_p (wi::to_poly_widest (top),
> - wi::to_poly_widest (bot), mul))
> - return true;
> + aff_tree aff_top, aff_bot;
> + tree_to_aff_combination (top, TREE_TYPE (top), &aff_top);
> + tree_to_aff_combination (bot, TREE_TYPE (bot), &aff_bot);
> + poly_widest_int poly_mul;
> + if (aff_combination_constant_multiple_p (&aff_top, &aff_bot, &poly_mul)
> + && poly_mul.is_constant (mul))
> + return true;
>
> - return false;
> - }
> + return false;
> }
>
> /* Return true if memory reference REF with step STEP may be unaligned. */
>
>
>
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)
