On Tue, Feb 14, 2017 at 3:53 PM, Richard Biener <rguent...@suse.de> wrote:
>
> The following patch improves the constant_after_peeling estimate of
> the GIMPLE unroller by not requiring a strictly "simple-iv" but
> an evolution w/o symbols. It also avoids computing any of this for
> ops defined in a subloop of the loop we unroll (that only yields
> garbage). So it makes constant_after_peeling cheaper as well.
>
> It also adjusts the simple-minded CCP to propagate all constants
> (esp. float and vector constants).
>
> Bootstrapped on x86_64-unknown-linux-gnu, testing in progress, queued for
> GCC 8.
Re-bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
> Richard.
>
> 2016-02-14 Richard Biener <rguent...@suse.de>
>
> * tree-ssa-loop-ivcanon.c (constant_after_peeling): Do not require
> sth as strict as a simple_iv but a chrec without symbols and an
> operand defined in the loop we are peeling (and not some subloop).
> (propagate_constants_for_unrolling): Propagate all constants.
>
> * gcc.dg/vect/no-scevccp-outer-13.c: Adjust to prevent unrolling
> of inner loops.
> * gcc.dg/vect/no-scevccp-outer-7.c: Likewise.
> * gcc.dg/vect/vect-104.c: Likewise.
>
> Index: gcc/tree-ssa-loop-ivcanon.c
> ===================================================================
> --- gcc/tree-ssa-loop-ivcanon.c (revision 245417)
> +++ gcc/tree-ssa-loop-ivcanon.c (working copy)
> @@ -157,8 +157,6 @@ struct loop_size
> static bool
> constant_after_peeling (tree op, gimple *stmt, struct loop *loop)
> {
> - affine_iv iv;
> -
> if (is_gimple_min_invariant (op))
> return true;
>
> @@ -188,12 +186,12 @@ constant_after_peeling (tree op, gimple
> return false;
> }
>
> - /* Induction variables are constants. */
> - if (!simple_iv (loop, loop_containing_stmt (stmt), op, &iv, false))
> - return false;
> - if (!is_gimple_min_invariant (iv.base))
> + /* Induction variables are constants when defined in loop. */
> + if (loop_containing_stmt (stmt) != loop)
> return false;
> - if (!is_gimple_min_invariant (iv.step))
> + tree ev = analyze_scalar_evolution (loop, op);
> + if (chrec_contains_undetermined (ev)
> + || chrec_contains_symbols (ev))
> return false;
> return true;
> }
> @@ -1259,7 +1257,7 @@ propagate_constants_for_unrolling (basic
>
> if (! SSA_NAME_OCCURS_IN_ABNORMAL_PHI (result)
> && gimple_phi_num_args (phi) == 1
> - && TREE_CODE (arg) == INTEGER_CST)
> + && CONSTANT_CLASS_P (arg))
> {
> replace_uses_by (result, arg);
> gsi_remove (&gsi, true);
> @@ -1276,7 +1274,7 @@ propagate_constants_for_unrolling (basic
> tree lhs;
>
> if (is_gimple_assign (stmt)
> - && gimple_assign_rhs_code (stmt) == INTEGER_CST
> + && TREE_CODE_CLASS (gimple_assign_rhs_code (stmt)) == tcc_constant
> && (lhs = gimple_assign_lhs (stmt), TREE_CODE (lhs) == SSA_NAME)
> && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
> {
> Index: gcc/testsuite/gcc.dg/vect/no-scevccp-outer-13.c
> ===================================================================
> --- gcc/testsuite/gcc.dg/vect/no-scevccp-outer-13.c (revision 245417)
> +++ gcc/testsuite/gcc.dg/vect/no-scevccp-outer-13.c (working copy)
> @@ -1,4 +1,5 @@
> /* { dg-require-effective-target vect_int } */
> +/* { dg-additional-options "--param max-completely-peel-times=1" } */
>
> #include <stdarg.h>
> #include "tree-vect.h"
> Index: gcc/testsuite/gcc.dg/vect/no-scevccp-outer-7.c
> ===================================================================
> --- gcc/testsuite/gcc.dg/vect/no-scevccp-outer-7.c (revision 245417)
> +++ gcc/testsuite/gcc.dg/vect/no-scevccp-outer-7.c (working copy)
> @@ -1,4 +1,5 @@
> /* { dg-require-effective-target vect_int } */
> +/* { dg-additional-options "--param max-completely-peel-times=1" } */
>
> #include <stdarg.h>
> #include "tree-vect.h"
> Index: gcc/testsuite/gcc.dg/vect/vect-104.c
> ===================================================================
> --- gcc/testsuite/gcc.dg/vect/vect-104.c (revision 245417)
> +++ gcc/testsuite/gcc.dg/vect/vect-104.c (working copy)
> @@ -1,4 +1,5 @@
> /* { dg-require-effective-target vect_int } */
> +/* { dg-additional-options "--param max-completely-peel-times=1" } */
>
> #include <stdlib.h>
> #include <stdarg.h>
