Messages in this thread Patch in this message | | | Date | Wed, 23 Nov 2011 20:25:09 +0530 | From | Rabin Vincent <> | Subject | Re: [PATCH 4/4] ARM: add jump label support |
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On Tue, Nov 22, 2011 at 06:50:41PM -0500, Jason Baron wrote: > On Tue, Nov 22, 2011 at 06:39:50PM -0500, Jason Baron wrote: > > Right, for jump labels we have a script at: scripts/gcc-goto.sh, which > > basically just checks if we can compile 'asm goto' without error, so for > > %c, you could probably have some simple 'asm()' that uses %c, and see if > > it compiles. Although, I'm not sure if there's a arch specific dir, for > > such a thing? > > > > thanks, > > > > -Jason > > hmm...actually we could add it to the top level scripts/gcc-goto.sh, > that would be fine, I can take a look at that...
Here's a patch. Atleast on MIPS %c means something else so I had to ifdef it for ARM:
8<---------------------------- From ea211ce77e0ea9c5b8cd32b99bfb24e0140f0068 Mon Sep 17 00:00:00 2001 From: Rabin Vincent <rabin@rab.in> Date: Wed, 23 Nov 2011 20:05:09 +0530 Subject: [PATCH] jump label: detect %c support for ARM
Some versions of ARM GCC don't support the %c specifier fully, but do support asm goto. Since we need the %c to support jump labels on ARM, detect that too in the asm goto detection script to avoid build errors with these versions.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48637
Signed-off-by: Rabin Vincent <rabin@rab.in> --- scripts/gcc-goto.sh | 18 +++++++++++++++++- 1 files changed, 17 insertions(+), 1 deletions(-)
diff --git a/scripts/gcc-goto.sh b/scripts/gcc-goto.sh index 98cffcb..9b744de 100644 --- a/scripts/gcc-goto.sh +++ b/scripts/gcc-goto.sh @@ -2,4 +2,20 @@ # Test for gcc 'asm goto' support # Copyright (C) 2010, Jason Baron <jbaron@redhat.com> -echo "int main(void) { entry: asm goto (\"\"::::entry); return 0; }" | $@ -x c - -c -o /dev/null >/dev/null 2>&1 && echo "y" +cat << "END" | $@ -x c - -c -o /dev/null >/dev/null 2>&1 && echo "y" +int main(void) +{ +#ifdef __arm__ + /* + * Not related to asm goto, but used by jump label + * and broken on some ARM GCC versions (see GCC Bug 48637). + */ + static struct { int dummy; int state; } tp; + asm ("@ %c0" :: "i" (&tp.state)); +#endif + +entry: + asm goto ("" :::: entry); + return 0; +} +END -- 1.7.7.3
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