rtl.h (REG_EH_REGION): Update comment to indicate a value of -1 indicates no throw and no nonlocal gotos.

Tue Apr 27 19:50:25 EDT 1999  Andrew MacLeod  <amacleod@cygnus.com>
	* rtl.h (REG_EH_REGION): Update comment to indicate a value of -1
	indicates no throw and no nonlocal gotos.
	* optabs.c (emit_libcall_block): Emit REG_EH_REGION with a value
	of -1 instead of 0 to indicate a nonlocal goto won't happen either.
	* flow.c (count_basic_blocks, find_basic_blocks_1): Ignore libcall
	blocks, look for REG_EH_REGION note exclusively.
	(make_edges): Check for REG_EH_REGION > 0 for specified handlers.

From-SVN: r26680

1 files changed, 5 insertions, 3 deletions

diff --git a/gcc/rtl.h b/gcc/rtl.h
index 964a8ab..8eba5ea 100644
--- a/gcc/rtl.h
+++ b/gcc/rtl.h
@@ -343,12 +343,14 @@ typedef struct rtvec_def{
    but are too complex for DWARF to interpret what they imply.  The attached
    rtx is used instead of intuition.  */
 /*   REG_EH_REGION is used to indicate what exception region an INSN
-   belongs in. This can be used to indicate what region a call may throw
-   to. a REGION of 0 indicates that a call cannot throw at all.
+   belongs in.  This can be used to indicate what region a call may throw
+   to.  A REGION of 0 indicates that a call cannot throw at all.
+   A REGION  of -1 indicates that it cannot throw, nor will it execute
+   a non-local goto.
      REG_EH_RETHROW is used to indicate what that a call is actually a
    call to rethrow, and specifies which region the rethrow is targetting.
    This provides a way to generate the non standard flow edges required 
-   for a rethrow. */
+   for a rethrow.  */
    
 
 #define REG_NOTES(INSN)	((INSN)->fld[6].rtx)