From: Vladimir N. Makarov <vmakarov@redhat.com>
Date: Thu, 28 Sep 2023 15:53:51 +0000 (-0400)
Subject: Revert "[RA]: Improve cost calculation of pseudos with equivalences"
X-Git-Tag: basepoints/gcc-15~5827
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8552dcd8e4448c02fe230662093756b75dd94399;p=thirdparty%2Fgcc.git

Revert "[RA]: Improve cost calculation of pseudos with equivalences"

This reverts commit 3c834d85f2ec42c60995c2b678196a06cb744959.

Although the patch improves x86-64 specfp2007, it also results in
performance and code size regression on different targets and
new GCC testsuite failures on tests expecting a specific output.
---

diff --git a/gcc/ira-costs.cc b/gcc/ira-costs.cc
index 8c93ace5094a..d9e700e89473 100644
--- a/gcc/ira-costs.cc
+++ b/gcc/ira-costs.cc
@@ -1947,8 +1947,15 @@ find_costs_and_classes (FILE *dump_file)
 	    }
 	  if (i >= first_moveable_pseudo && i < last_moveable_pseudo)
 	    i_mem_cost = 0;
-	  else
-	    i_mem_cost -= equiv_savings;
+	  else if (equiv_savings < 0)
+	    i_mem_cost = -equiv_savings;
+	  else if (equiv_savings > 0)
+	    {
+	      i_mem_cost = 0;
+	      for (k = cost_classes_ptr->num - 1; k >= 0; k--)
+		i_costs[k] += equiv_savings;
+	    }
+
 	  best_cost = (1 << (HOST_BITS_PER_INT - 2)) - 1;
 	  best = ALL_REGS;
 	  alt_class = NO_REGS;