On 09/12/16 14:03, Kyrill Tkachov wrote:
Hi all,
In this ICE GCC reports invalid RTL sharing in the pattern:
(insn 955 954 956 (unspec_volatile [
(const:SI (unspec:SI [
(symbol_ref:SI ("a") [flags 0xe8] <var_decl
0x7fbb0d37cbd0 a>)
(const_int 4 [0x4])
] UNSPEC_TLS))
] VUNSPEC_POOL_4) -1
(nil))
seb.c:116:1: error: shared rtx
(const:SI (unspec:SI [
(symbol_ref:SI ("a") [flags 0xe8] <var_decl 0x7fbb0d37cbd0 a>)
(const_int 4 [0x4])
] UNSPEC_TLS))
This is the consttable_4 pattern emitted by dump_minipool and the shared
rtx that's causing
the problem is the operand to that pattern that comes from the 'value'
field of Mnode.
I'm not very familiar with the exact restrictions on sharing RTL but I
believe the right way
to fix these is to do a copy_rtx of the value we want to use. So this
patch does that when the
pool entries are emitted.
The ICE is quite fragile. See the PR for more details, but I've been
able to reliably reproduce it
on an arm-none-linux-gnueabihf target with -mcpu=arm7tdmi
-mfloat-abi=soft -mfpu=vfp -mthumb and this
patch fixes that there.
Bootstrapped and tested on arm-none-linux-gnueabihf.
Ok for trunk?
Sorry about the time it's taken to review this - I'm way behind on my
gcc-patches mailbox.
Ok.
Thanks,
Ramana
Thanks,
Kyrill
2016-12-09 Kyrylo Tkachov <kyrylo.tkac...@arm.com>
PR target/78694
* config/arm/arm.c (dump_minipool): Copy mp->value before emitting it
in the minipool to avoid invalid RTL sharing.
2016-12-09 Kyrylo Tkachov <kyrylo.tkac...@arm.com>
PR target/78694
* gcc.c-torture/compile/pr78694.c: New test.
