Hi,
We've got a scenario with a combination of old hardware, gcc-8 and
binutils where gcc will ICE during it's selftest. This ICE was exposed
when the builtin processing for better #pragma support was added, where
we no longer skip builtin initialization based on the current mask.
Per the bug report and assorted debug, the ICE occurrs when building
the gcc-8 branch on a 970* based system with an old binutils. (gcc-9 and
newer is OK. binutils 2.34 is reported to allow success).
The attached patch adds a clause to the builtin initialization to skip
initialization of a builtin when the builtin mask is set but the icode
value is zero. The subsequent assert check remains in place.
I've successfully tested this on a yellowdog (970mp) based system.
Mikael has confirmed this allows success on his system.
OK for gcc-8 ?
Thanks,
-Will
2020-07-13 Will Schmidt <[email protected]>
gcc/ChangeLog:
PR target/95952
* gcc/config/rs6000.c (altivec_init_builtins): Add continue clause to
predicate
builtin handling.
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 75d40367a98..18713599d3b 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -18015,10 +18015,24 @@ altivec_init_builtins (void)
if (rs6000_overloaded_builtin_p (d->code))
mode1 = VOIDmode;
else
{
+ /* PR95952: Gracefully skip builtins that do not have the icode
properly
+ set, but do have the builtin mask set. This has occurred in older gcc
+ builds with older binutils support when binutils refuses code
generation
+ for instructions that it does not support. This was exposed by
changes
+ allowing all builtins being initialized for better #pragma support.
*/
+ if (d->icode == CODE_FOR_nothing && d->mask) {
+ HOST_WIDE_INT builtin_mask = rs6000_builtin_mask;
+ if (TARGET_DEBUG_BUILTIN) {
+ fprintf (stderr, "altivec_init_builtins, altivec predicate
builtin %s", d->name);
+ fprintf (stderr, " was skipped. icode:%d, mask: %lx,
builtin_mask: 0x%lx",
+ d->icode, d->mask, builtin_mask);
+ }
+ continue;
+ }
/* Cannot define builtin if the instruction is disabled. */
gcc_assert (d->icode != CODE_FOR_nothing);
mode1 = insn_data[d->icode].operand[1].mode;
}
