Re: [RFA][PATCH] Use SCEV conditionally within vr-values and evrp range analysis - V2

[Jeff Law <law@redhat.com>]

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On 11/23/2017 05:49 AM, Richard Biener wrote:
> On Thu, Nov 23, 2017 at 1:16 AM, Jeff Law <law@redhat.com> wrote:
>>
>> Clients of the evrp range analysis may not have initialized the SCEV
>> infrastructure, and in fact my not want to (DOM for example).
>>
>> Yet inside both vr-values.c and gimple-ssa-evrp-analyze.c we have calls
>> into SCEV (that will fault/abort if SCEV is not properly initialized).
>>
>> This patch allows clients of vr-values.c and gimple-ssa-evrp-analyze.c
>> to indicate if they want SCEV analysis.
>>
>> Bootstrapped and regression tested by itself as well as with the DOM
>> patches to use EVRP analysis  (which test the "don't want SCEV path).
>>
>> OK for the trunk?
> 
> There's also scev_initialized_p () which you could conveniently use.
Yea, that worked fine and is (of course) much simpler.

Bootstrapped and regression tested in isolation as well as on top of my
ongoing work to remove jump threading from tree-vrp.c.

OK for the trunk now?

Jeff


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	* gimple-ssa-evrp-analyze.c
	(evrp_range_analyzer::record_ranges_from_phis): Only use SCEV to
	refine ranges if scev_initialized_p returns true.
	* vr-values.c (vr_values::extract_range_from_phi_node): Likewise.

diff --git a/gcc/gimple-ssa-evrp-analyze.c b/gcc/gimple-ssa-evrp-analyze.c
index 68a2cdc..38fb0db 100644
--- a/gcc/gimple-ssa-evrp-analyze.c
+++ b/gcc/gimple-ssa-evrp-analyze.c
@@ -176,7 +176,8 @@ evrp_range_analyzer::record_ranges_from_phis (basic_block bb)
 	     to use VARYING for them.  But we can still resort to
 	     SCEV for loop header PHIs.  */
 	  struct loop *l;
-	  if (interesting
+	  if (scev_initialized_p ()
+	      && interesting
 	      && (l = loop_containing_stmt (phi))
 	      && l->header == gimple_bb (phi))
 	  vr_values.adjust_range_with_scev (&vr_result, l, phi, lhs);
diff --git a/gcc/vr-values.c b/gcc/vr-values.c
index 2d11861..e617556 100644
--- a/gcc/vr-values.c
+++ b/gcc/vr-values.c
@@ -2935,7 +2935,8 @@ scev_check:
      scev_check can be reached from two paths, one is a fall through from above
      "varying" label, the other is direct goto from code block which tries to
      avoid infinite simulation.  */
-  if ((l = loop_containing_stmt (phi))
+  if (scev_initialized_p ()
+      && (l = loop_containing_stmt (phi))
       && l->header == gimple_bb (phi))
     adjust_range_with_scev (vr_result, l, phi, lhs);