diff mbox series

[committed,PR104400] LRA: Modify exclude start hard register calculation for insn alternative

Message ID a04d1464-5532-8af9-2259-91c003cf7992@redhat.com
State New
Headers show
Series [committed,PR104400] LRA: Modify exclude start hard register calculation for insn alternative | expand

Commit Message

Vladimir Makarov Feb. 11, 2022, 3:52 p.m. UTC 
The following patch solves

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104400

The patch was successfully tested and bootstrapped on x86-64 and aarch64.
diff mbox series

Patch

commit 274a4d29421e73c9b40c1641986c6ed904e20184
Author: Vladimir N. Makarov <vmakarov@redhat.com>
Date:   Fri Feb 11 09:52:14 2022 -0500

    [PR104400] LRA: Modify exclude start hard register calculation for insn alternative
    
    v850 target has an interesting insn alternative constraint 'e!r' where e
    denotes even general regs and e is a subset of r.  We cannot just make
    union of exclude start hard registers for e and r and should use only
    exclude start hard registers of r.  The following patch implements this.
    
    gcc/ChangeLog:
    
            PR rtl-optimization/104400
            * lra-constraints.cc (process_alt_operands): Don't make union of
            this_alternative_exclude_start_hard_regs when reg class in insn
            alternative covers other reg classes in the same alternative.
    
    gcc/testsuite/ChangeLog:
    
            PR rtl-optimization/104400
            * gcc.target/v850/pr104400.c: New.
            * gcc.target/v850/v850.exp: New.

diff --git a/gcc/lra-constraints.cc b/gcc/lra-constraints.cc
index 9cee17479ba..fdff9e0720a 100644
--- a/gcc/lra-constraints.cc
+++ b/gcc/lra-constraints.cc
@@ -2498,9 +2498,15 @@  process_alt_operands (int only_alternative)
 		  if (mode == BLKmode)
 		    break;
 		  this_alternative = reg_class_subunion[this_alternative][cl];
+		  if (hard_reg_set_subset_p (this_alternative_set,
+					     reg_class_contents[cl]))
+		    this_alternative_exclude_start_hard_regs
+		      = ira_exclude_class_mode_regs[cl][mode];
+		  else if (!hard_reg_set_subset_p (reg_class_contents[cl],
+						   this_alternative_set))
+		    this_alternative_exclude_start_hard_regs
+		      |= ira_exclude_class_mode_regs[cl][mode];
 		  this_alternative_set |= reg_class_contents[cl];
-		  this_alternative_exclude_start_hard_regs
-		    |= ira_exclude_class_mode_regs[cl][mode];
 		  if (costly_p)
 		    {
 		      this_costly_alternative
diff --git a/gcc/testsuite/gcc.target/v850/pr104400.c b/gcc/testsuite/gcc.target/v850/pr104400.c
new file mode 100644
index 00000000000..5d78a77345c
--- /dev/null
+++ b/gcc/testsuite/gcc.target/v850/pr104400.c
@@ -0,0 +1,8 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -mv850e3v5" } */
+
+double frob (double r)
+{
+    r = -r;
+    return r;
+}
diff --git a/gcc/testsuite/gcc.target/v850/v850.exp b/gcc/testsuite/gcc.target/v850/v850.exp
new file mode 100644
index 00000000000..4e8c745a0b8
--- /dev/null
+++ b/gcc/testsuite/gcc.target/v850/v850.exp
@@ -0,0 +1,41 @@ 
+# Copyright (C) 2022 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+# GCC testsuite that uses the `dg.exp' driver.
+
+# Exit immediately if this isn't an v850 target.
+if ![istarget v850*-*-*] then {
+  return
+}
+
+# Load support procs.
+load_lib gcc-dg.exp
+
+# If a testcase doesn't have special options, use these.
+global DEFAULT_CFLAGS
+if ![info exists DEFAULT_CFLAGS] then {
+    set DEFAULT_CFLAGS " -ansi -pedantic-errors"
+}
+
+# Initialize `dg'.
+dg-init
+
+# Main loop.
+dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/*.\[cS\]]] \
+	"" $DEFAULT_CFLAGS
+
+# All done.
+dg-finish