From: Andrew Pinski <quic_apinski@quicinc.com>
Date: Thu, 12 Sep 2024 05:10:53 +0000 (-0700)
Subject: Fix factor_out_conditional_operation heuristics for constants
X-Git-Tag: basepoints/gcc-16~5920
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8ed8c342fba682286159f56d0e53a05db95762a0;p=thirdparty%2Fgcc.git

Fix factor_out_conditional_operation heuristics for constants

While working on a different patch, I noticed the heuristics were not
doing the right thing if there was statements before the NOP/PREDICTs.
(LABELS don't have other statements before them).

This fixes that oversight which was added in r15-3334-gceda727dafba6e.

Bootstrapped and tested on x86_64-linux-gnu.

gcc/ChangeLog:

	* tree-ssa-phiopt.cc (factor_out_conditional_operation): Instead
	of just ignorning a NOP/PREDICT, skip over them before checking
	the heuristics.

Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
---

diff --git a/gcc/tree-ssa-phiopt.cc b/gcc/tree-ssa-phiopt.cc
index 5710bc32e61..e5413e40572 100644
--- a/gcc/tree-ssa-phiopt.cc
+++ b/gcc/tree-ssa-phiopt.cc
@@ -332,15 +332,17 @@ factor_out_conditional_operation (edge e0, edge e1, gphi *phi,
 	{
 	  gsi = gsi_for_stmt (arg0_def_stmt);
 	  gsi_prev_nondebug (&gsi);
+	  /* Ignore nops, predicates and labels. */
+	  while (!gsi_end_p (gsi)
+		  && (gimple_code (gsi_stmt (gsi)) == GIMPLE_NOP
+		      || gimple_code (gsi_stmt (gsi)) == GIMPLE_PREDICT
+		      || gimple_code (gsi_stmt (gsi)) == GIMPLE_LABEL))
+	    gsi_prev_nondebug (&gsi);
+
 	  if (!gsi_end_p (gsi))
 	    {
 	      gimple *stmt = gsi_stmt (gsi);
-	      /* Ignore nops, predicates and labels. */
-	      if (gimple_code (stmt) == GIMPLE_NOP
-		  || gimple_code (stmt) == GIMPLE_PREDICT
-		  || gimple_code (stmt) == GIMPLE_LABEL)
-		;
-	      else if (gassign *assign = dyn_cast <gassign *> (stmt))
+	      if (gassign *assign = dyn_cast <gassign *> (stmt))
 		{
 		  tree lhs = gimple_assign_lhs (assign);
 		  enum tree_code ass_code