From 2c3a56ad15b80efe217db30809f6260d3496b63a Mon Sep 17 00:00:00 2001
From: Jeffrey A Law <law@cygnus.com>
Date: Sat, 27 Dec 1997 23:34:14 +0000
Subject: [PATCH] flow.c (find_basic_blocks): Don't create a new basic block
 for calls in a LIBCALL block.

        * flow.c (find_basic_blocks): Don't create a new basic block
        for calls in a LIBCALL block.

From-SVN: r17247
---
 gcc/ChangeLog |  5 +++++
 gcc/flow.c    | 28 +++++++++++++++++++++++++---
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 898cc852473..05ecb58e73f 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+Sun Dec 28 00:32:16 1997  Jeffrey A Law  (law@cygnus.com)
+
+	* flow.c (find_basic_blocks): Don't create a new basic block
+	for calls in a LIBCALL block.
+
 Sun Dec 28 00:30:24 1997  David Edelsohn  <edelsohn@mhpcc.edu>
 
 	* config/fp-bit.c (L_df_to_sf): Fix typo in last change.
diff --git a/gcc/flow.c b/gcc/flow.c
index 69c7d6b4805..55516b4bdf6 100644
--- a/gcc/flow.c
+++ b/gcc/flow.c
@@ -284,6 +284,7 @@ flow_analysis (f, nregs, file)
   register rtx insn;
   register int i;
   rtx nonlocal_label_list = nonlocal_label_rtx_list ();
+  int in_libcall_block = 0;
 
 #ifdef ELIMINABLE_REGS
   static struct {int from, to; } eliminables[] = ELIMINABLE_REGS;
@@ -312,6 +313,12 @@ flow_analysis (f, nregs, file)
 
     for (insn = f, i = 0; insn; insn = NEXT_INSN (insn))
       {
+
+	/* Track when we are inside in LIBCALL block.  */
+	if (GET_RTX_CLASS (GET_CODE (insn)) == 'i'
+	    && find_reg_note (insn, REG_LIBCALL, NULL_RTX))
+	  in_libcall_block = 1;
+
 	code = GET_CODE (insn);
 	if (INSN_UID (insn) > max_uid_for_flow)
 	  max_uid_for_flow = INSN_UID (insn);
@@ -320,7 +327,7 @@ flow_analysis (f, nregs, file)
 		&& (prev_code == JUMP_INSN
 		    || (prev_code == CALL_INSN
 			&& (nonlocal_label_list != 0 || eh_region)
-			&& ! find_reg_note (insn, REG_RETVAL, NULL_RTX))
+			&& ! in_libcall_block)
 		    || prev_code == BARRIER)))
 	  i++;
 
@@ -333,6 +340,10 @@ flow_analysis (f, nregs, file)
 	  ++eh_region;
 	else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
 	  --eh_region;
+
+	if (GET_RTX_CLASS (GET_CODE (insn)) == 'i'
+	    && find_reg_note (insn, REG_RETVAL, NULL_RTX))
+	  in_libcall_block = 0;
       }
   }
 
@@ -389,6 +400,7 @@ find_basic_blocks (f, nonlocal_label_list)
   rtx x, note, eh_note;
   enum rtx_code prev_code, code;
   int depth, pass;
+  int in_libcall_block = 0;
 
   pass = 1;
   active_eh_handler = (rtx *) alloca ((max_uid_for_flow + 1) * sizeof (rtx));
@@ -412,6 +424,12 @@ find_basic_blocks (f, nonlocal_label_list)
   for (eh_note = NULL_RTX, insn = f, i = -1, prev_code = JUMP_INSN, depth = 1;
        insn; insn = NEXT_INSN (insn))
     {
+
+      /* Track when we are inside in LIBCALL block.  */
+      if (GET_RTX_CLASS (GET_CODE (insn)) == 'i'
+	  && find_reg_note (insn, REG_LIBCALL, NULL_RTX))
+	in_libcall_block = 1;
+
       code = GET_CODE (insn);
       if (code == NOTE)
 	{
@@ -427,7 +445,7 @@ find_basic_blocks (f, nonlocal_label_list)
 		   && (prev_code == JUMP_INSN
 		       || (prev_code == CALL_INSN
 			   && (nonlocal_label_list != 0 || eh_note)
-			   && ! find_reg_note (insn, REG_RETVAL, NULL_RTX))
+			   && ! in_libcall_block)
 		       || prev_code == BARRIER)))
 	{
 	  basic_block_head[++i] = insn;
@@ -485,13 +503,17 @@ find_basic_blocks (f, nonlocal_label_list)
       else if (eh_note
 	       && (asynchronous_exceptions
 		   || (GET_CODE (insn) == CALL_INSN
-		       && ! find_reg_note (insn, REG_RETVAL, NULL_RTX))))
+		       && ! in_libcall_block)))
 	active_eh_handler[INSN_UID (insn)] = XEXP (eh_note, 0);
 
       BLOCK_NUM (insn) = i;
 
       if (code != NOTE)
 	prev_code = code;
+
+      if (GET_RTX_CLASS (GET_CODE (insn)) == 'i'
+	  && find_reg_note (insn, REG_RETVAL, NULL_RTX))
+	in_libcall_block = 0;
     }
 
   /* During the second pass, `n_basic_blocks' is only an upper bound.