This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: RFA: LM32: Fix building libgcc
- From: nick clifton <nickc at redhat dot com>
- To: Sébastien Bourdeauducq <sebastien dot bourdeauducq at lekernel dot net>
- Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Wed, 22 Aug 2012 08:17:04 +0100
- Subject: Re: RFA: LM32: Fix building libgcc
- References: <87has1stsj.fsf@redhat.com> <50324F29.1090300@lekernel.net>
Hi Sébastien,
After applying your patch, I get an assertion failure in
emit_return_into_block, at function.c:5600 when trying to compile
anything (line is "gcc_assert (ANY_RETURN_P (pat));").
Any ideas?
Doh - I should have checked further. The problem is the return_internal
pattern. emit_return_into_block() expects that in a return insn that
contains more than one piece of RTL, the first piece of RTL will be
(return). This is not (currently) true for the lm23.
Fixing that let the build proceed as far as truncdfsf2.c in libgcc,
This then fails with a return insn that does not match the return
pattern. This turns out to be because the "return" pattern should
really be an expander that will work when conditions are not being
tested. The simplest way to fix this was to create an expander and
rename "return" to "basic_return".
Next there is seg-fault building ffssi2 in newlib. I do not have a fix
for this one yet, but at least libgcc builds now.
OK to apply ?
Cheers
Nick
gcc/ChangeLog
2012-08-21 Nick Clifton <nickc@redhat.com>
* config/lm32/lm32.md (return_internal): Place the (return) as the
first element in the vector.
(return): Changed into an expander.
(basic_return): Renamed version of previous return pattern.
Index: gcc/config/lm32/lm32.md
===================================================================
--- gcc/config/lm32/lm32.md (revision 190564)
+++ gcc/config/lm32/lm32.md (working copy)
@@ -629,16 +629,22 @@
)
(define_insn "return_internal"
- [(use (match_operand:SI 0 "register_operand" "r"))
- (return)]
+ [(return)
+ (use (match_operand:SI 0 "register_operand" "r"))]
""
"b %0"
[(set_attr "type" "uibranch")]
)
-(define_insn "return"
+(define_expand "return"
[(return)]
"lm32_can_use_return ()"
+ "lm32_expand_epilogue (); DONE;"
+)
+
+(define_insn "basic_return"
+ [(return)]
+ "lm32_can_use_return ()"
"ret"
[(set_attr "type" "uibranch")]
)