[PATCH] Add missing edge probability in simd_clone_adjust

[Tom de Vries <Tom_deVries at mentor dot com>]

[ 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  <tom@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;
     }