Re: DWARF2 exception doesn't work with gcc and gas on MIPS.

["H . J . Lu" <hjl@lucon.org>]

On Thu, Jun 14, 2001 at 10:19:51AM -0700, Richard Henderson wrote:
> 
> I could have sworn there was an exception_receiver pattern on mips
> to handle this, but I don't see it now.  It's relatively easy to fix;
> see TARGET_LD_BUGGY_LDGP is handled on alpha.
> 

Thanks. This patch seems to fix my problem. But I have several
questions:

1. Is the usage of current_frame_info.args_size right?
2. What should be in the place of [(const_int 4)]?
3. Does it need other patterns for similar situations?
4. Is my patch ok?


H.J.
----
2001-06-14  H.J. Lu <hjl@gnu.org>

	* config/mips/mips.md (exception_receiver): New.

--- gcc/config/mips/mips.md.except	Thu Jun 14 10:34:34 2001
+++ gcc/config/mips/mips.md	Thu Jun 14 11:36:31 2001
@@ -10461,3 +10461,21 @@ ld\\t%2,%1-%S1(%2)\;daddu\\t%2,%2,$31\;j
   [(set_attr "type"	"arith")
    (set_attr "mode"	"DI")
    (set_attr "length"	"40")])
+
+;; For o32, the gp register is call clobbered, so it must
+;; be saved & restored around calls by the caller.  If the call
+;; doesn't return normally (nonlocal goto, or an exception is
+;; thrown), then the code at the exception handler label must
+;; restore the gp register.
+(define_insn "exception_receiver"
+  [(const_int 4)]
+  "mips_abi == ABI_32"
+  "*
+{
+  static char ldgp[40];
+  sprintf (ldgp, \"lw\\t$gp,%ld($sp)\", current_frame_info.args_size);
+  return ldgp;
+}"
+  [(set_attr "type"	"load")
+   (set_attr "mode"	"SI")
+   (set_attr "length"	"4")])