From bb1a6d92989a50df13b1a21085c86625089c9e53 Mon Sep 17 00:00:00 2001 From: Richard Sandiford Date: Wed, 15 Jun 2022 11:12:51 +0100 Subject: [PATCH] aarch64: Revert bogus fix for PR105254 In f2ebf2d98efe0ac2314b58cf474f44cb8ebd5244 I'd forced the chosen unroll factor to be a factor of the VF, in order to work around an exact_div ICE in PR105254. This was completely bogus -- clearly I didn't look in enough detail at why we ended up with an unrolled VF that wasn't a multiple of the UF. Kewen has since fixed the bug properly for PR105940, so this patch reverts my earlier attempt. Sorry for the stupidity. gcc/ PR tree-optimization/105254 PR tree-optimization/105940 Revert: * config/aarch64/aarch64.cc (aarch64_vector_costs::determine_suggested_unroll_factor): Take a loop_vec_info as argument. Restrict the unroll factor to values that divide the VF. (aarch64_vector_costs::finish_cost): Update call accordingly. gcc/testsuite/ * gcc.target/aarch64/sve/cost_model_14.c: New test. (cherry picked from commit 2636660b6f35423e0cfbf53bfad5c5fed6ae6471) --- gcc/config/aarch64/aarch64.cc | 12 ++++-------- .../gcc.target/aarch64/sve/cost_model_14.c | 13 +++++++++++++ 2 files changed, 17 insertions(+), 8 deletions(-) create mode 100644 gcc/testsuite/gcc.target/aarch64/sve/cost_model_14.c diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc index f4d2a800f39..5c9e7791a12 100644 --- a/gcc/config/aarch64/aarch64.cc +++ b/gcc/config/aarch64/aarch64.cc @@ -15637,7 +15637,7 @@ private: unsigned int adjust_body_cost (loop_vec_info, const aarch64_vector_costs *, unsigned int); bool prefer_unrolled_loop () const; - unsigned int determine_suggested_unroll_factor (loop_vec_info); + unsigned int determine_suggested_unroll_factor (); /* True if we have performed one-time initialization based on the vec_info. */ @@ -16746,8 +16746,7 @@ adjust_body_cost_sve (const aarch64_vec_op_count *ops, } unsigned int -aarch64_vector_costs:: -determine_suggested_unroll_factor (loop_vec_info loop_vinfo) +aarch64_vector_costs::determine_suggested_unroll_factor () { bool sve = m_vec_flags & VEC_ANY_SVE; /* If we are trying to unroll an Advanced SIMD main loop that contains @@ -16761,7 +16760,6 @@ determine_suggested_unroll_factor (loop_vec_info loop_vinfo) return 1; unsigned int max_unroll_factor = 1; - auto vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo); for (auto vec_ops : m_ops) { aarch64_simd_vec_issue_info const *vec_issue @@ -16770,8 +16768,7 @@ determine_suggested_unroll_factor (loop_vec_info loop_vinfo) return 1; /* Limit unroll factor to a value adjustable by the user, the default value is 4. */ - unsigned int unroll_factor = MIN (aarch64_vect_unroll_limit, - (int) known_alignment (vf)); + unsigned int unroll_factor = aarch64_vect_unroll_limit; unsigned int factor = vec_ops.reduction_latency > 1 ? vec_ops.reduction_latency : 1; unsigned int temp; @@ -16949,8 +16946,7 @@ aarch64_vector_costs::finish_cost (const vector_costs *uncast_scalar_costs) { m_costs[vect_body] = adjust_body_cost (loop_vinfo, scalar_costs, m_costs[vect_body]); - m_suggested_unroll_factor - = determine_suggested_unroll_factor (loop_vinfo); + m_suggested_unroll_factor = determine_suggested_unroll_factor (); } /* Apply the heuristic described above m_stp_sequence_cost. Prefer diff --git a/gcc/testsuite/gcc.target/aarch64/sve/cost_model_14.c b/gcc/testsuite/gcc.target/aarch64/sve/cost_model_14.c new file mode 100644 index 00000000000..b65826b0889 --- /dev/null +++ b/gcc/testsuite/gcc.target/aarch64/sve/cost_model_14.c @@ -0,0 +1,13 @@ +/* { dg-options "-O3 -mtune=neoverse-v1" } */ + +#include + +uint64_t f2(uint64_t *ptr, int n) { + uint64_t res = 0; + for (int i = 0; i < n; ++i) + res += ptr[i]; + return res; +} + +/* { dg-final { scan-assembler-times {\tld1d\tz[0-9]+\.d,} 5 } } */ +/* { dg-final { scan-assembler-times {\tadd\tz[0-9]+\.d,} 8 } } */