From: Jakub Jelinek <jakub@redhat.com>
Date: Wed, 6 Sep 2023 15:49:44 +0000 (+0200)
Subject: _BitInt profile fixes [PR102989]
X-Git-Tag: basepoints/gcc-15~6382
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3ad9948b3e716885ce66bdf1c8e053880a843a2b;p=thirdparty%2Fgcc.git

_BitInt profile fixes [PR102989]

On Thu, Aug 24, 2023 at 03:14:32PM +0200, Jan Hubicka via Gcc-patches wrote:
> this patch extends verifier to check that all probabilities and counts are
> initialized if profile is supposed to be present.  This is a bit complicated
> by the posibility that we inline !flag_guess_branch_probability function
> into function with profile defined and in this case we need to stop
> verification.  For this reason I added flag to cfg structure tracking this.

This patch broke a couple of _BitInt tests (in the admittedly still
uncommitted series - still waiting for review of the C FE bits).

Here is a minimal patch to make it work again, though I'm not sure
if in the if_then_else and if_then_if_then_else cases I shouldn't scale
count of the other bbs as well.  if_then method creates
if (COND) new_bb1;
in a middle of some pre-existing bb (with PROB that COND is true), if_then_else
if (COND) new_bb1; else new_bb2;
and if_then_if_then_else
if (COND1) { if (COND2) new_bb2; else new_bb1; }
with PROB1 and PROB2 probabilities that COND1 and COND2 are true.
The lowering happens shortly after IPA.

2023-09-06  Jakub Jelinek  <jakub@redhat.com>

	PR c/102989
	* gimple-lower-bitint.cc (bitint_large_huge::if_then_else,
	bitint_large_huge::if_then_if_then_else): Use make_single_succ_edge
	rather than make_edge, initialize bb->count.
---

diff --git a/gcc/gimple-lower-bitint.cc b/gcc/gimple-lower-bitint.cc
index 3906c00bf3fa..dceaec779c82 100644
--- a/gcc/gimple-lower-bitint.cc
+++ b/gcc/gimple-lower-bitint.cc
@@ -683,9 +683,10 @@ bitint_large_huge::if_then_else (gimple *cond, profile_probability prob,
   e1->flags = EDGE_FALSE_VALUE;
   e3->probability = prob;
   e1->probability = prob.invert ();
+  bb->count = e1->src->count.apply_probability (prob);
   set_immediate_dominator (CDI_DOMINATORS, bb, e1->src);
   set_immediate_dominator (CDI_DOMINATORS, e2->dest, e1->src);
-  edge_true = make_edge (bb, e2->dest, EDGE_FALLTHRU);
+  edge_true = make_single_succ_edge (bb, e2->dest, EDGE_FALLTHRU);
   edge_false = e2;
   m_gsi = gsi_after_labels (bb);
 }
@@ -741,7 +742,8 @@ bitint_large_huge::if_then_if_then_else (gimple *cond1, gimple *cond2,
   e4->probability = prob2;
   e2->flags = EDGE_FALSE_VALUE;
   e2->probability = prob2.invert ();
-  e4 = make_edge (bb, e3->dest, EDGE_FALLTHRU);
+  bb->count = e2->src->count.apply_probability (prob2);
+  e4 = make_single_succ_edge (bb, e3->dest, EDGE_FALLTHRU);
   e2 = find_edge (e2->dest, e3->dest);
   edge_true_true = e4;
   edge_true_false = e2;