combine.c (recog_for_combine): Create a dummy insn with PATTERN pat for recog.

	* combine.c (recog_for_combine): Create a dummy insn with PATTERN
	pat for recog.

	* gcc.dg/20020201-4.c: New test.

From-SVN: r49473

4 files changed, 34 insertions, 8 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 1b6153b..825d95e 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2002-02-04  Jakub Jelinek  <jakub@redhat.com>
+
+	* combine.c (recog_for_combine): Create a dummy insn with PATTERN
+	pat for recog.
+
 2002-02-04  Hartmut Penner  <hpenner@de.ibm.com>
 
         * varasm.c (decode_rtx_const): Allow unspec (symbol_ref) in
diff --git a/gcc/combine.c b/gcc/combine.c
index 47ac3a8..25b4d63 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -9590,7 +9590,7 @@ recog_for_combine (pnewpat, insn, pnotes)
   int num_clobbers_to_add = 0;
   int i;
   rtx notes = 0;
-  rtx old_notes;
+  rtx dummy_insn;
 
   /* If PAT is a PARALLEL, check to see if it contains the CLOBBER
      we use to indicate that something didn't match.  If we find such a
@@ -9601,11 +9601,13 @@ recog_for_combine (pnewpat, insn, pnotes)
 	  && XEXP (XVECEXP (pat, 0, i), 0) == const0_rtx)
 	return -1;
 
-  /* Remove the old notes prior to trying to recognize the new pattern.  */
-  old_notes = REG_NOTES (insn);
-  REG_NOTES (insn) = 0;
+  /* *pnewpat does not have to be actual PATTERN (insn), so make a dummy
+     instruction for pattern recognition.  */
+  dummy_insn = shallow_copy_rtx (insn);
+  PATTERN (dummy_insn) = pat;
+  REG_NOTES (dummy_insn) = 0;
 
-  insn_code_number = recog (pat, insn, &num_clobbers_to_add);
+  insn_code_number = recog (pat, dummy_insn, &num_clobbers_to_add);
 
   /* If it isn't, there is the possibility that we previously had an insn
      that clobbered some register as a side effect, but the combined
@@ -9630,15 +9632,14 @@ recog_for_combine (pnewpat, insn, pnotes)
       if (pos == 1)
 	pat = XVECEXP (pat, 0, 0);
 
-      insn_code_number = recog (pat, insn, &num_clobbers_to_add);
+      PATTERN (dummy_insn) = pat;
+      insn_code_number = recog (pat, dummy_insn, &num_clobbers_to_add);
     }
 
   /* Recognize all noop sets, these will be killed by followup pass.  */
   if (insn_code_number < 0 && GET_CODE (pat) == SET && set_noop_p (pat))
     insn_code_number = NOOP_MOVE_INSN_CODE, num_clobbers_to_add = 0;
 
-  REG_NOTES (insn) = old_notes;
-
   /* If we had any clobbers to add, make a new pattern than contains
      them.  Then check to make sure that all of them are dead.  */
   if (num_clobbers_to_add)
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 8a078a4..fe11a62 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2002-02-04  Jakub Jelinek  <jakub@redhat.com>
+
+	* gcc.dg/20020201-4.c: New test.
+
 2002-02-04  Ben Elliston  <bje@redhat.com>
 
 	* lib/gcc.exp (gcc_init): Check that the need_status_wrapper
diff --git a/gcc/testsuite/gcc.dg/20020201-4.c b/gcc/testsuite/gcc.dg/20020201-4.c
new file mode 100644
index 0000000..3c83fe7
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/20020201-4.c
@@ -0,0 +1,16 @@
+/* This testcase failed because recog_for_combine used to pass a different
+   pattern than contained in insn to recog.  */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fssa -fssa-ccp" } */
+/* { dg-options "-O2 -march=i686 -fssa -fssa-ccp" { target i?86-*-* } } */
+
+extern int bar (char *);
+
+int
+foo (void)
+{
+  char b[512];
+
+  bar (b);
+  return __builtin_strlen (b);
+}