[PATCH 9/9] cse.c selftests

[David Malcolm <dmalcolm at redhat dot com>]

This patch uses rtl_dump_test to start building out a test suite
for cse.

I attempted to create a reproducer for PR 71779; however I'm not yet
able to replicate the bogus cse reported there via the test case.

gcc/ChangeLog:
	* cse.c: Include selftest.h and selftest-rtl.h.
	(selftest::test_simple_cse): New function.
	(selftest::test_pr71779): New function.
	(selftest::cse_c_tests): New function.
	* selftest-run-tests.c (selftest::run_tests): Call
	selftest::cse_c_tests.
	* selftest.h (selftest::cse_c_tests): New decl.
---
 gcc/cse.c                | 109 +++++++++++++++++++++++++++++++++++++++++++++++
 gcc/selftest-run-tests.c |   1 +
 gcc/selftest.h           |   1 +
 3 files changed, 111 insertions(+)

diff --git a/gcc/cse.c b/gcc/cse.c
index 0bfd7ff..f4f06fe 100644
--- a/gcc/cse.c
+++ b/gcc/cse.c
@@ -41,6 +41,8 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-pass.h"
 #include "dbgcnt.h"
 #include "rtl-iter.h"
+#include "selftest.h"
+#include "selftest-rtl.h"
 
 #ifndef LOAD_EXTEND_OP
 #define LOAD_EXTEND_OP(M) UNKNOWN
@@ -7773,3 +7775,110 @@ make_pass_cse_after_global_opts (gcc::context *ctxt)
 {
   return new pass_cse_after_global_opts (ctxt);
 }
+
+#if CHECKING_P
+
+namespace selftest {
+
+/* Selftests for CSE.  */
+
+/* Simple test of eliminating a redundant (reg + 1) computation
+   i.e. that:
+     r101 = r100 + 1;
+     r102 = r100 + 1; <<< common subexpression
+     *r103 = r101 * r102;
+   can be CSE-ed to:
+     r101 = r100 + 1;
+     r102 = r101; <<< replaced
+     *r103 = r101 * r102;
+   by cse_main.  */
+
+static void
+test_simple_cse ()
+{
+  /* Only run this tests for i386.  */
+#ifndef I386_OPTS_H
+  return;
+#endif
+
+  const char *input_dump
+    = (/* "r101 = r100 + 1;" */
+       "(insn 1 0 2 2 (set (reg:SI 101)\n"
+       "                   (plus:SI (reg:SI 100)\n"
+       "                            (const_int 1 [0x1]))) -1 (nil))\n"
+       /* "r102 = r100 + 1;" */
+       "(insn 2 1 3 2 (set (reg:SI 102)\n"
+       "                   (plus:SI (reg:SI 100)\n"
+       "                            (const_int 1 [0x1]))) -1 (nil))\n"
+       /* "*r103 = r101 * r102;" */
+       "(insn 3 2 0 2 (set (mem:SI (reg:SI 103) [1 i+0 S4 A32])\n"
+       "                   (mult:SI (reg:SI 101) (reg:SI 102))) -1 (nil))\n"
+       );
+  rtl_dump_test t (input_dump, 100);
+  dataflow_test df_test;
+
+  int tem;
+  tem = cse_main (get_insns (), max_reg_num ());
+  ASSERT_EQ (0, tem);
+
+  /* Verify that insn 2's SET_SRC has been replaced with
+     the SET_DEST of insn 1.  */
+  ASSERT_EQ (SET_DEST (PATTERN (get_insn_by_uid (1))),
+	     SET_SRC (PATTERN (get_insn_by_uid (2))));
+}
+
+/* Towards a regression test for PR 71779.  */
+
+static void
+test_pr71779 ()
+{
+  /* Only run this tests for target==aarch64.  */
+#ifndef GCC_AARCH64_H
+  return;
+#endif
+
+  /* Dump taken from comment 2 of PR 71779, of
+     "...the relevant memory access coming out of expand"
+     with basic block IDs added, and prev/next insns set to
+     0 at ends.  */
+  const char *input_dump
+    = (";; MEM[(struct isl_obj *)&obj1] = &isl_obj_map_vtable;\n"
+       "(insn 1045 0 1046 2 (set (reg:SI 480)\n"
+       "        (high:SI (symbol_ref:SI (\"isl_obj_map_vtable\") [flags 0xc0] <var_decl 0x7fa0363ea240 isl_obj_map_vtable>))) y.c:12702 -1\n"
+       "     (nil))\n"
+       "(insn 1046 1045 1047 2 (set (reg/f:SI 479)\n"
+       "        (lo_sum:SI (reg:SI 480)\n"
+       "            (symbol_ref:SI (\"isl_obj_map_vtable\") [flags 0xc0] <var_decl 0x7fa0363ea240 isl_obj_map_vtable>))) y.c:12702 -1\n"
+       "     (expr_list:REG_EQUAL (symbol_ref:SI (\"isl_obj_map_vtable\") [flags 0xc0] <var_decl 0x7fa0363ea240 isl_obj_map_vtable>)\n"
+       "        (nil)))\n"
+       "(insn 1047 1046 1048 2 (set (reg:DI 481)\n"
+       "        (subreg:DI (reg/f:SI 479) 0)) y.c:12702 -1\n"
+       "     (nil))\n"
+       "(insn 1048 1047 1049 2 (set (zero_extract:DI (reg/v:DI 191 [ obj1D.17368 ])\n"
+       "            (const_int 32 [0x20])\n"
+       "            (const_int 0 [0]))\n"
+       "        (reg:DI 481)) y.c:12702 -1\n"
+       "     (nil))\n"
+       /* Extra insn, to avoid all of the above from being deleted by DCE.  */
+       "(insn 1049 1048 0 2 (set (mem:DI (reg:DI 191) [1 i+0 S4 A32])\n"
+       "                         (const_int 1 [0x1])) -1 (nil))\n");
+
+  rtl_dump_test t (input_dump);
+  dataflow_test df_test;
+
+  int tem;
+  tem = cse_main (get_insns (), max_reg_num ());
+  ASSERT_EQ (0, tem);
+}
+
+/* Run all of the selftests within this file.  */
+
+void
+cse_c_tests ()
+{
+  test_simple_cse ();
+  test_pr71779 ();
+}
+
+} // namespace selftest
+#endif /* CHECKING_P */
diff --git a/gcc/selftest-run-tests.c b/gcc/selftest-run-tests.c
index 015572c..5fdfb42 100644
--- a/gcc/selftest-run-tests.c
+++ b/gcc/selftest-run-tests.c
@@ -65,6 +65,7 @@ selftest::run_tests ()
   rtl_tests_c_tests ();
   read_rtl_function_c_tests ();
   df_core_c_tests ();
+  cse_c_tests ();
 
   /* Higher-level tests, or for components that other selftests don't
      rely on.  */
diff --git a/gcc/selftest.h b/gcc/selftest.h
index 6ad6c88..c0dc862 100644
--- a/gcc/selftest.h
+++ b/gcc/selftest.h
@@ -191,6 +191,7 @@ extern void forcibly_ggc_collect ();
    alphabetical order.  */
 extern void bitmap_c_tests ();
 extern void combine_c_tests ();
+extern void cse_c_tests ();
 extern void df_core_c_tests ();
 extern void diagnostic_c_tests ();
 extern void diagnostic_show_locus_c_tests ();
-- 
1.8.5.3