From c71d553d3e5f6753011338dffe5ba0965e8c739a Mon Sep 17 00:00:00 2001
From: David Malcolm <dmalcolm@redhat.com>
Date: Wed, 13 Apr 2016 15:17:14 -0400
Subject: [PATCH 83/91] FIXME: add -fsingle-pass= option

---
 gcc/rtl/lang.opt                           |  4 +++
 gcc/rtl/rtl-frontend.c                     | 43 +++++++++++++++++++++---------
 gcc/testsuite/rtl.dg/test-loop.cleaned.rtl |  5 ++++
 3 files changed, 39 insertions(+), 13 deletions(-)

diff --git a/gcc/rtl/lang.opt b/gcc/rtl/lang.opt
index 27f9683..54d5aff 100644
--- a/gcc/rtl/lang.opt
+++ b/gcc/rtl/lang.opt
@@ -29,4 +29,8 @@ froundtrip=
 RTL Joined RejectNegative
 FIXME
 
+fsingle-pass=
+RTL Joined RejectNegative
+FIXME
+
 ; This comment is to ensure we retain the blank line above.
diff --git a/gcc/rtl/rtl-frontend.c b/gcc/rtl/rtl-frontend.c
index fc6b11e..1400fa3 100644
--- a/gcc/rtl/rtl-frontend.c
+++ b/gcc/rtl/rtl-frontend.c
@@ -158,6 +158,7 @@ rtl_langhook_init_options_struct (struct gcc_options */*opts*/)
 }
 
 static const char *roundtrip_filename = NULL;
+static const char *single_pass_name = NULL;
 
 static bool
 rtl_langhook_handle_option (
@@ -176,6 +177,10 @@ rtl_langhook_handle_option (
       roundtrip_filename = xstrdup (arg);
       break;
 
+    case OPT_fsingle_pass_:
+      single_pass_name =  xstrdup (arg);
+      break;
+
     default:
       break;
     }
@@ -692,6 +697,27 @@ function_reader::get_insn_by_uid (int uid)
   return m_insns_by_uid.get (uid);
 }
 
+/*  Locate and run PASS_NAME on cfun.  */
+
+static void
+run_one_pass_by_name (const char *pass_name)
+{
+  opt_pass *pass = g->get_passes ()->get_pass_by_name (pass_name);
+  if (!pass)
+    {
+      error ("unrecognized pass: %qs", pass_name);
+      return;
+    }
+
+  pass_init_dump_file (pass);
+  current_function_decl = cfun->decl;
+  pass->execute (cfun);
+  current_function_decl = NULL;
+  if (dump_file)
+    print_rtl_with_bb (dump_file, get_insns (), dump_flags);
+  pass_fini_dump_file (pass);
+}
+
 static void
 rtl_langhook_parse_file (void)
 {
@@ -723,19 +749,10 @@ rtl_langhook_parse_file (void)
 	error ("unable to open %qs for -froundtrip" , roundtrip_filename);
     }
 
-  /*
-    Run just one pass e.g. pass_instantiate_virtual_regs
-    (first after pass_expand). "vregs"
-   */
-  opt_pass *pass = g->get_passes ()->get_pass_by_name ("rtl-vregs");
-  gcc_assert (pass);
-  current_function_decl = cfun->decl;
-  pass->execute (cfun);
-  current_function_decl = NULL;
-
-  FILE *out = fopen ("/tmp/after-pass.rtl", "w");
-  print_rtl_with_bb (out, reader.get_first_insn (), 1024);
-  fclose (out);
+/*  If -fsingle-pass=PASS_NAME was provided, locate and run PASS_NAME
+    on cfun, as created above.  */
+  if (single_pass_name)
+    run_one_pass_by_name (single_pass_name);
 }
 
 static tree
diff --git a/gcc/testsuite/rtl.dg/test-loop.cleaned.rtl b/gcc/testsuite/rtl.dg/test-loop.cleaned.rtl
index 2ea3fdc..221c5b4 100644
--- a/gcc/testsuite/rtl.dg/test-loop.cleaned.rtl
+++ b/gcc/testsuite/rtl.dg/test-loop.cleaned.rtl
@@ -1,3 +1,4 @@
+/* { dg-options "-fsingle-pass=rtl-vregs -fdump-rtl-vregs" } */
 (note 1 0 6 (nil) NOTE_INSN_DELETED)
 (note 6 1 2 2 [bb 2] NOTE_INSN_BASIC_BLOCK)
 (insn 2 6 3 2 (set (mem/c:SI (plus:DI (reg/f:DI 82 virtual-stack-vars)
@@ -73,3 +74,7 @@
      (nil))
 (insn 27 26 0 6 (use (reg/i:SI 0 ax)) ../../src/test-loop.c:7 -1
      (nil))
+
+/* The 9 instances of "virtual-stack-vars" should now all be "frame".  */
+/* { dg-final { scan-rtl-dump-times "frame" 9 "vregs" } }  */
+/* { dog-final { scan-rtl-dump-not "virtual-stack-vars" "vregs" } }  */
-- 
1.8.5.3