On Wed, Sep 14, 2022 at 3:25 AM liuhongt via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> In vectorizable_nonlinear_induction, r13-2503-gc13223b790bbc5 prevent
> variable peeling by
> only checking LOOP_VINFO_MASK_SKIP_NITERS (loop_vinfo). But when
> "!vect_use_loop_mask_for_alignment_p (loop_vinfo) &&
> LOOP_VINFO_PEELING_FOR_ALIGNMENT (loop_vinfo) < 0", vectorizer will
> still do variable peeling for epilog, and it hits gcc_assert in
> vect_peel_nonlinear_iv_init.
>
>
> Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}.
> The patch also fix ICE of the testcase in the PR for ia64-linux-gnu(verified
> by cross-compile).
>
> Ok for trunk?
OK.
Thanks,
Richard.
> gcc/ChangeLog:
>
> PR tree-optimization/106905
> * tree-vect-loop.cc (vectorizable_nonlinear_induction): Return
> false when !vect_use_loop_mask_for_alignment_p (loop_vinfo) &&
> LOOP_VINFO_PEELING_FOR_ALIGNMENT (loop_vinfo) < 0.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/i386/pr106905.c: New test.
> * gcc.target/ia64/pr106905.c: New test.
> ---
> gcc/testsuite/gcc.target/i386/pr106905.c | 14 ++++++++++++++
> gcc/testsuite/gcc.target/ia64/pr106905.c | 20 ++++++++++++++++++++
> gcc/tree-vect-loop.cc | 6 ++++--
> 3 files changed, 38 insertions(+), 2 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/i386/pr106905.c
> create mode 100644 gcc/testsuite/gcc.target/ia64/pr106905.c
>
> diff --git a/gcc/testsuite/gcc.target/i386/pr106905.c
> b/gcc/testsuite/gcc.target/i386/pr106905.c
> new file mode 100644
> index 00000000000..a190a1c84e6
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr106905.c
> @@ -0,0 +1,14 @@
> +/* { dg-do compile } */
> +/* { dg-options "-march=silvermont -O2 -fvect-cost-model=dynamic" } */
> +
> +void
> +foo_mul_peel (int *a, int b)
> +{
> + int i;
> +
> + for (i = 0; i < 7; ++i)
> + {
> + b *= 2;
> + a[i] = b;
> + }
> +}
> diff --git a/gcc/testsuite/gcc.target/ia64/pr106905.c
> b/gcc/testsuite/gcc.target/ia64/pr106905.c
> new file mode 100644
> index 00000000000..1b9656e1203
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/ia64/pr106905.c
> @@ -0,0 +1,20 @@
> +/* { dg-do compile } */
> +/* { dg-options "-std=c99 -O3 -fPIC" } */
> +long ZDICT_fillNoise_p, ZDICT_trainFromBuffer_legacy_result;
> +unsigned ZDICT_fillNoise_acc;
> +int ZDICT_totalSampleSize_nbFiles;
> +static void ZDICT_fillNoise(void *buffer, long length) {
> + unsigned prime2 = 9;
> + for (ZDICT_fillNoise_p = 0; ZDICT_fillNoise_p < length;
> ZDICT_fillNoise_p++)
> + ZDICT_fillNoise_acc *= ((char *)buffer)[ZDICT_fillNoise_p] = prime2;
> +}
> +long ZDICT_trainFromBuffer_legacy() {
> + void *newBuff;
> + long total = 0;
> + for (; ZDICT_totalSampleSize_nbFiles;)
> + total += 0;
> + long sBuffSize = total;
> + newBuff = 0;
> + ZDICT_fillNoise(newBuff + sBuffSize, 32);
> + return ZDICT_trainFromBuffer_legacy_result;
> +}
> diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
> index 8f88f1755be..9c434b66c5b 100644
> --- a/gcc/tree-vect-loop.cc
> +++ b/gcc/tree-vect-loop.cc
> @@ -8646,8 +8646,10 @@ vectorizable_nonlinear_induction (loop_vec_info
> loop_vinfo,
> /* Also doens't support peel for neg when niter is variable.
> ??? generate something like niter_expr & 1 ? init_expr : -init_expr? */
> niters_skip = LOOP_VINFO_MASK_SKIP_NITERS (loop_vinfo);
> - if (niters_skip != NULL_TREE
> - && TREE_CODE (niters_skip) != INTEGER_CST)
> + if ((niters_skip != NULL_TREE
> + && TREE_CODE (niters_skip) != INTEGER_CST)
> + || (!vect_use_loop_mask_for_alignment_p (loop_vinfo)
> + && LOOP_VINFO_PEELING_FOR_ALIGNMENT (loop_vinfo) < 0))
> {
> if (dump_enabled_p ())
> dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
> --
> 2.27.0
>
