[PATCH] Add missing edge probability in simd_clone_adjust

[Tom de Vries]

[ Re: [PATCH] Verify edge probability consistency in verify_flow_info ]

On 08/02/2017 06:07 PM, Tom de Vries wrote:

I've written this patch to check for the missing probability more consistently. I'm not certain if we can require that the probability should always be set, so I'm just requiring that if it is set on one outgoing edge, it needs to be set on all outgoing edges.

Sofar I've build a c-only x86_64 non-bootstrap compiler and ran dg.exp. The only problem I ran into was in attr-simd{,-2,-4}.c. I've written a tentative patch for that, and will submit it as follow-up.

Jakub,

this patch adds a missing edge probability in simd_clone_adjust.

OK for trunk if bootstrap and reg-test on x86_64 succeeds?

Thanks,
- Tom

Add missing edge probability in simd_clone_adjust

Currently we generate an if with probability set on only one of the two edges:
  <bb 5> [0.00%] [count: INV]:
  _5 = mask.3[iter.6_3];
  if (_5 == 0)
    goto <bb 6>; [INV] [count: INV]
  else
    goto <bb 2>; [100.00%] [count: INV]

Add the missing edge probability:
    goto <bb 6>; [0.00%] [count: INV]

2017-08-02  Tom de Vries  <t...@codesourcery.com>

	* omp-simd-clone.c (simd_clone_adjust): Add missing edge probability.

---
 gcc/omp-simd-clone.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gcc/omp-simd-clone.c b/gcc/omp-simd-clone.c
index a1a563e..5b5d199 100644
--- a/gcc/omp-simd-clone.c
+++ b/gcc/omp-simd-clone.c
@@ -1240,7 +1240,8 @@ simd_clone_adjust (struct cgraph_node *node)
       g = gimple_build_cond (EQ_EXPR, mask, build_zero_cst (TREE_TYPE (mask)),
 			     NULL, NULL);
       gsi_insert_after (&gsi, g, GSI_CONTINUE_LINKING);
-      make_edge (loop->header, incr_bb, EDGE_TRUE_VALUE);
+      edge e = make_edge (loop->header, incr_bb, EDGE_TRUE_VALUE);
+      e->probability = profile_probability::guessed_never ();
       FALLTHRU_EDGE (loop->header)->flags = EDGE_FALSE_VALUE;
     }