[v2] MIPS: make mipsisa32 and mipsisa64 link more systematic
Checks
Commit Message
Introduce `static const struct mips_mach_extension mips_mach_32_64[]`
and `mips_mach_extends_32_64 (unsigned long base, unsigned long extension)`,
to make mipsisa32 and mipsisa64 interlink more systemtic.
Normally, the ISA mipsisa64rN has two subset: mipsisa64r(N-1) and
mipsisa32rN. `mips_mach_extensions` can hold only mipsisa64r(N-1),
so we need to introduce a new instruction `mips_mach_32_64`, which holds the pair 32vs64.
Note: R6 is not compatible with pre-R6.
bfd/ChangeLog:
* elfxx-mips.c (mips_mach_extends_p): make mipsisa32 and
mipsisa64 interlink more systematic.
(mips_mach_32_64): new struct added.
(mips_mach_extends_32_64): new function added.
---
bfd/elfxx-mips.c | 40 +++++++++++++++++++++++++++++-----------
1 file changed, 29 insertions(+), 11 deletions(-)
Comments
@Rickard can you help to submit this patch to git?
I have no permission to do so.
YunQiang Su <yunqiang.su@cipunited.com> 于2023年3月2日周四 09:52写道：
>
> Introduce `static const struct mips_mach_extension mips_mach_32_64[]`
> and `mips_mach_extends_32_64 (unsigned long base, unsigned long extension)`,
> to make mipsisa32 and mipsisa64 interlink more systemtic.
>
> Normally, the ISA mipsisa64rN has two subset: mipsisa64r(N-1) and
> mipsisa32rN. `mips_mach_extensions` can hold only mipsisa64r(N-1),
> so we need to introduce a new instruction `mips_mach_32_64`, which holds the pair 32vs64.
>
> Note: R6 is not compatible with pre-R6.
>
> bfd/ChangeLog:
>
> * elfxx-mips.c (mips_mach_extends_p): make mipsisa32 and
> mipsisa64 interlink more systematic.
> (mips_mach_32_64): new struct added.
> (mips_mach_extends_32_64): new function added.
> ---
> bfd/elfxx-mips.c | 40 +++++++++++++++++++++++++++++-----------
> 1 file changed, 29 insertions(+), 11 deletions(-)
>
> diff --git a/bfd/elfxx-mips.c b/bfd/elfxx-mips.c
> index 35bbd86044b..21e6396609b 100644
> --- a/bfd/elfxx-mips.c
> +++ b/bfd/elfxx-mips.c
> @@ -14524,6 +14524,16 @@ struct mips_mach_extension
> unsigned long extension, base;
> };
>
> +/* An array that maps 64-bit architectures to the corresponding 32-bit
> + architectures. */
> +static const struct mips_mach_extension mips_mach_32_64[] =
> +{
> + { bfd_mach_mipsisa64r6, bfd_mach_mipsisa32r6 },
> + { bfd_mach_mipsisa64r5, bfd_mach_mipsisa32r5 },
> + { bfd_mach_mipsisa64r3, bfd_mach_mipsisa32r3 },
> + { bfd_mach_mipsisa64r2, bfd_mach_mipsisa32r2 },
> + { bfd_mach_mipsisa64, bfd_mach_mipsisa32 }
> +};
>
> /* An array describing how BFD machines relate to one another. The entries
> are ordered topologically with MIPS I extensions listed last. */
> @@ -14601,29 +14611,37 @@ static const struct mips_mach_extension mips_mach_extensions[] =
> { bfd_mach_mips3900, bfd_mach_mips3000 }
> };
>
> -/* Return true if bfd machine EXTENSION is an extension of machine BASE. */
> +/* Return true if bfd machine EXTENSION is the same as BASE, or if
> + EXTENSION is the 64-bit equivalent of a 32-bit BASE. */
> +
> +static bool
> +mips_mach_extends_32_64 (unsigned long base, unsigned long extension)
> +{
> + size_t i;
> +
> + if (extension == base)
> + return true;
> +
> + for (i = 0; i < ARRAY_SIZE (mips_mach_64_32); i++)
> + if (extension == mips_mach_32_64[i].extension)
> + return base == mips_mach_32_64[i].base;
> +
> + return false;
> +}
>
> static bool
> mips_mach_extends_p (unsigned long base, unsigned long extension)
> {
> size_t i;
>
> - if (extension == base)
> - return true;
> -
> - if (base == bfd_mach_mipsisa32
> - && mips_mach_extends_p (bfd_mach_mipsisa64, extension))
> - return true;
> -
> - if (base == bfd_mach_mipsisa32r2
> - && mips_mach_extends_p (bfd_mach_mipsisa64r2, extension))
> + if (mips_mach_extends_32_64 (base, extension))
> return true;
>
> for (i = 0; i < ARRAY_SIZE (mips_mach_extensions); i++)
> if (extension == mips_mach_extensions[i].extension)
> {
> extension = mips_mach_extensions[i].base;
> - if (extension == base)
> + if (mips_mach_extends_32_64 (base, extension))
> return true;
> }
>
> --
> 2.30.2
>
ping
YunQiang Su <syq@debian.org> 于2023年3月5日周日 21:38写道：
>
> @Rickard can you help to submit this patch to git?
> I have no permission to do so.
>
> YunQiang Su <yunqiang.su@cipunited.com> 于2023年3月2日周四 09:52写道：
> >
> > Introduce `static const struct mips_mach_extension mips_mach_32_64[]`
> > and `mips_mach_extends_32_64 (unsigned long base, unsigned long extension)`,
> > to make mipsisa32 and mipsisa64 interlink more systemtic.
> >
> > Normally, the ISA mipsisa64rN has two subset: mipsisa64r(N-1) and
> > mipsisa32rN. `mips_mach_extensions` can hold only mipsisa64r(N-1),
> > so we need to introduce a new instruction `mips_mach_32_64`, which holds the pair 32vs64.
> >
> > Note: R6 is not compatible with pre-R6.
> >
> > bfd/ChangeLog:
> >
> > * elfxx-mips.c (mips_mach_extends_p): make mipsisa32 and
> > mipsisa64 interlink more systematic.
> > (mips_mach_32_64): new struct added.
> > (mips_mach_extends_32_64): new function added.
> > ---
> > bfd/elfxx-mips.c | 40 +++++++++++++++++++++++++++++-----------
> > 1 file changed, 29 insertions(+), 11 deletions(-)
> >
> > diff --git a/bfd/elfxx-mips.c b/bfd/elfxx-mips.c
> > index 35bbd86044b..21e6396609b 100644
> > --- a/bfd/elfxx-mips.c
> > +++ b/bfd/elfxx-mips.c
> > @@ -14524,6 +14524,16 @@ struct mips_mach_extension
> > unsigned long extension, base;
> > };
> >
> > +/* An array that maps 64-bit architectures to the corresponding 32-bit
> > + architectures. */
> > +static const struct mips_mach_extension mips_mach_32_64[] =
> > +{
> > + { bfd_mach_mipsisa64r6, bfd_mach_mipsisa32r6 },
> > + { bfd_mach_mipsisa64r5, bfd_mach_mipsisa32r5 },
> > + { bfd_mach_mipsisa64r3, bfd_mach_mipsisa32r3 },
> > + { bfd_mach_mipsisa64r2, bfd_mach_mipsisa32r2 },
> > + { bfd_mach_mipsisa64, bfd_mach_mipsisa32 }
> > +};
> >
> > /* An array describing how BFD machines relate to one another. The entries
> > are ordered topologically with MIPS I extensions listed last. */
> > @@ -14601,29 +14611,37 @@ static const struct mips_mach_extension mips_mach_extensions[] =
> > { bfd_mach_mips3900, bfd_mach_mips3000 }
> > };
> >
> > -/* Return true if bfd machine EXTENSION is an extension of machine BASE. */
> > +/* Return true if bfd machine EXTENSION is the same as BASE, or if
> > + EXTENSION is the 64-bit equivalent of a 32-bit BASE. */
> > +
> > +static bool
> > +mips_mach_extends_32_64 (unsigned long base, unsigned long extension)
> > +{
> > + size_t i;
> > +
> > + if (extension == base)
> > + return true;
> > +
> > + for (i = 0; i < ARRAY_SIZE (mips_mach_64_32); i++)
> > + if (extension == mips_mach_32_64[i].extension)
> > + return base == mips_mach_32_64[i].base;
> > +
> > + return false;
> > +}
> >
> > static bool
> > mips_mach_extends_p (unsigned long base, unsigned long extension)
> > {
> > size_t i;
> >
> > - if (extension == base)
> > - return true;
> > -
> > - if (base == bfd_mach_mipsisa32
> > - && mips_mach_extends_p (bfd_mach_mipsisa64, extension))
> > - return true;
> > -
> > - if (base == bfd_mach_mipsisa32r2
> > - && mips_mach_extends_p (bfd_mach_mipsisa64r2, extension))
> > + if (mips_mach_extends_32_64 (base, extension))
> > return true;
> >
> > for (i = 0; i < ARRAY_SIZE (mips_mach_extensions); i++)
> > if (extension == mips_mach_extensions[i].extension)
> > {
> > extension = mips_mach_extensions[i].base;
> > - if (extension == base)
> > + if (mips_mach_extends_32_64 (base, extension))
> > return true;
> > }
> >
> > --
> > 2.30.2
> >
ping
YunQiang Su <syq@debian.org> 于2023年3月20日周一 09:32写道：
>
> ping
>
> YunQiang Su <syq@debian.org> 于2023年3月5日周日 21:38写道：
> >
> > @Rickard can you help to submit this patch to git?
> > I have no permission to do so.
> >
> > YunQiang Su <yunqiang.su@cipunited.com> 于2023年3月2日周四 09:52写道：
> > >
> > > Introduce `static const struct mips_mach_extension mips_mach_32_64[]`
> > > and `mips_mach_extends_32_64 (unsigned long base, unsigned long extension)`,
> > > to make mipsisa32 and mipsisa64 interlink more systemtic.
> > >
> > > Normally, the ISA mipsisa64rN has two subset: mipsisa64r(N-1) and
> > > mipsisa32rN. `mips_mach_extensions` can hold only mipsisa64r(N-1),
> > > so we need to introduce a new instruction `mips_mach_32_64`, which holds the pair 32vs64.
> > >
> > > Note: R6 is not compatible with pre-R6.
> > >
> > > bfd/ChangeLog:
> > >
> > > * elfxx-mips.c (mips_mach_extends_p): make mipsisa32 and
> > > mipsisa64 interlink more systematic.
> > > (mips_mach_32_64): new struct added.
> > > (mips_mach_extends_32_64): new function added.
> > > ---
> > > bfd/elfxx-mips.c | 40 +++++++++++++++++++++++++++++-----------
> > > 1 file changed, 29 insertions(+), 11 deletions(-)
> > >
> > > diff --git a/bfd/elfxx-mips.c b/bfd/elfxx-mips.c
> > > index 35bbd86044b..21e6396609b 100644
> > > --- a/bfd/elfxx-mips.c
> > > +++ b/bfd/elfxx-mips.c
> > > @@ -14524,6 +14524,16 @@ struct mips_mach_extension
> > > unsigned long extension, base;
> > > };
> > >
> > > +/* An array that maps 64-bit architectures to the corresponding 32-bit
> > > + architectures. */
> > > +static const struct mips_mach_extension mips_mach_32_64[] =
> > > +{
> > > + { bfd_mach_mipsisa64r6, bfd_mach_mipsisa32r6 },
> > > + { bfd_mach_mipsisa64r5, bfd_mach_mipsisa32r5 },
> > > + { bfd_mach_mipsisa64r3, bfd_mach_mipsisa32r3 },
> > > + { bfd_mach_mipsisa64r2, bfd_mach_mipsisa32r2 },
> > > + { bfd_mach_mipsisa64, bfd_mach_mipsisa32 }
> > > +};
> > >
> > > /* An array describing how BFD machines relate to one another. The entries
> > > are ordered topologically with MIPS I extensions listed last. */
> > > @@ -14601,29 +14611,37 @@ static const struct mips_mach_extension mips_mach_extensions[] =
> > > { bfd_mach_mips3900, bfd_mach_mips3000 }
> > > };
> > >
> > > -/* Return true if bfd machine EXTENSION is an extension of machine BASE. */
> > > +/* Return true if bfd machine EXTENSION is the same as BASE, or if
> > > + EXTENSION is the 64-bit equivalent of a 32-bit BASE. */
> > > +
> > > +static bool
> > > +mips_mach_extends_32_64 (unsigned long base, unsigned long extension)
> > > +{
> > > + size_t i;
> > > +
> > > + if (extension == base)
> > > + return true;
> > > +
> > > + for (i = 0; i < ARRAY_SIZE (mips_mach_64_32); i++)
> > > + if (extension == mips_mach_32_64[i].extension)
> > > + return base == mips_mach_32_64[i].base;
> > > +
> > > + return false;
> > > +}
> > >
> > > static bool
> > > mips_mach_extends_p (unsigned long base, unsigned long extension)
> > > {
> > > size_t i;
> > >
> > > - if (extension == base)
> > > - return true;
> > > -
> > > - if (base == bfd_mach_mipsisa32
> > > - && mips_mach_extends_p (bfd_mach_mipsisa64, extension))
> > > - return true;
> > > -
> > > - if (base == bfd_mach_mipsisa32r2
> > > - && mips_mach_extends_p (bfd_mach_mipsisa64r2, extension))
> > > + if (mips_mach_extends_32_64 (base, extension))
> > > return true;
> > >
> > > for (i = 0; i < ARRAY_SIZE (mips_mach_extensions); i++)
> > > if (extension == mips_mach_extensions[i].extension)
> > > {
> > > extension = mips_mach_extensions[i].base;
> > > - if (extension == base)
> > > + if (mips_mach_extends_32_64 (base, extension))
> > > return true;
> > > }
> > >
> > > --
> > > 2.30.2
> > >
YunQiang Su <yunqiang.su@cipunited.com> writes:
> Introduce `static const struct mips_mach_extension mips_mach_32_64[]`
> and `mips_mach_extends_32_64 (unsigned long base, unsigned long extension)`,
> to make mipsisa32 and mipsisa64 interlink more systemtic.
>
> Normally, the ISA mipsisa64rN has two subset: mipsisa64r(N-1) and
> mipsisa32rN. `mips_mach_extensions` can hold only mipsisa64r(N-1),
> so we need to introduce a new instruction `mips_mach_32_64`, which holds the pair 32vs64.
>
> Note: R6 is not compatible with pre-R6.
>
> bfd/ChangeLog:
>
> * elfxx-mips.c (mips_mach_extends_p): make mipsisa32 and
> mipsisa64 interlink more systematic.
> (mips_mach_32_64): new struct added.
> (mips_mach_extends_32_64): new function added.
Sorry for the delay in pushing this. Could you check whether it's
the right version though? When I build locally I get:
> ---
> bfd/elfxx-mips.c | 40 +++++++++++++++++++++++++++++-----------
> 1 file changed, 29 insertions(+), 11 deletions(-)
>
> diff --git a/bfd/elfxx-mips.c b/bfd/elfxx-mips.c
> index 35bbd86044b..21e6396609b 100644
> --- a/bfd/elfxx-mips.c
> +++ b/bfd/elfxx-mips.c
> @@ -14524,6 +14524,16 @@ struct mips_mach_extension
> unsigned long extension, base;
> };
>
> +/* An array that maps 64-bit architectures to the corresponding 32-bit
> + architectures. */
> +static const struct mips_mach_extension mips_mach_32_64[] =
> +{
> + { bfd_mach_mipsisa64r6, bfd_mach_mipsisa32r6 },
> + { bfd_mach_mipsisa64r5, bfd_mach_mipsisa32r5 },
> + { bfd_mach_mipsisa64r3, bfd_mach_mipsisa32r3 },
> + { bfd_mach_mipsisa64r2, bfd_mach_mipsisa32r2 },
> + { bfd_mach_mipsisa64, bfd_mach_mipsisa32 }
> +};
>
> /* An array describing how BFD machines relate to one another. The entries
> are ordered topologically with MIPS I extensions listed last. */
> @@ -14601,29 +14611,37 @@ static const struct mips_mach_extension mips_mach_extensions[] =
> { bfd_mach_mips3900, bfd_mach_mips3000 }
> };
>
> -/* Return true if bfd machine EXTENSION is an extension of machine BASE. */
> +/* Return true if bfd machine EXTENSION is the same as BASE, or if
> + EXTENSION is the 64-bit equivalent of a 32-bit BASE. */
> +
> +static bool
> +mips_mach_extends_32_64 (unsigned long base, unsigned long extension)
> +{
> + size_t i;
> +
> + if (extension == base)
> + return true;
> +
> + for (i = 0; i < ARRAY_SIZE (mips_mach_64_32); i++)
error: ‘mips_mach_64_32’ undeclared (first use in this function); did you mean ‘mips_mach_32_64’?
It looks like the previous patch had the same thing (sorry for not
noticing). Obviously it's a simple fix, but it would be good to have
some reassurance that the patch has been tested beyond my crude sanity
checks.
Thanks,
Richard
> + if (extension == mips_mach_32_64[i].extension)
> + return base == mips_mach_32_64[i].base;
> +
> + return false;
> +}
>
> static bool
> mips_mach_extends_p (unsigned long base, unsigned long extension)
> {
> size_t i;
>
> - if (extension == base)
> - return true;
> -
> - if (base == bfd_mach_mipsisa32
> - && mips_mach_extends_p (bfd_mach_mipsisa64, extension))
> - return true;
> -
> - if (base == bfd_mach_mipsisa32r2
> - && mips_mach_extends_p (bfd_mach_mipsisa64r2, extension))
> + if (mips_mach_extends_32_64 (base, extension))
> return true;
>
> for (i = 0; i < ARRAY_SIZE (mips_mach_extensions); i++)
> if (extension == mips_mach_extensions[i].extension)
> {
> extension = mips_mach_extensions[i].base;
> - if (extension == base)
> + if (mips_mach_extends_32_64 (base, extension))
> return true;
> }
Richard Sandiford <richard.sandiford@arm.com> 于2023年4月3日周一 22:03写道：
>
> YunQiang Su <yunqiang.su@cipunited.com> writes:
> > Introduce `static const struct mips_mach_extension mips_mach_32_64[]`
> > and `mips_mach_extends_32_64 (unsigned long base, unsigned long extension)`,
> > to make mipsisa32 and mipsisa64 interlink more systemtic.
> >
> > Normally, the ISA mipsisa64rN has two subset: mipsisa64r(N-1) and
> > mipsisa32rN. `mips_mach_extensions` can hold only mipsisa64r(N-1),
> > so we need to introduce a new instruction `mips_mach_32_64`, which holds the pair 32vs64.
> >
> > Note: R6 is not compatible with pre-R6.
> >
> > bfd/ChangeLog:
> >
> > * elfxx-mips.c (mips_mach_extends_p): make mipsisa32 and
> > mipsisa64 interlink more systematic.
> > (mips_mach_32_64): new struct added.
> > (mips_mach_extends_32_64): new function added.
>
> Sorry for the delay in pushing this. Could you check whether it's
> the right version though? When I build locally I get:
>
> > ---
> > bfd/elfxx-mips.c | 40 +++++++++++++++++++++++++++++-----------
> > 1 file changed, 29 insertions(+), 11 deletions(-)
> >
> > diff --git a/bfd/elfxx-mips.c b/bfd/elfxx-mips.c
> > index 35bbd86044b..21e6396609b 100644
> > --- a/bfd/elfxx-mips.c
> > +++ b/bfd/elfxx-mips.c
> > @@ -14524,6 +14524,16 @@ struct mips_mach_extension
> > unsigned long extension, base;
> > };
> >
> > +/* An array that maps 64-bit architectures to the corresponding 32-bit
> > + architectures. */
> > +static const struct mips_mach_extension mips_mach_32_64[] =
> > +{
> > + { bfd_mach_mipsisa64r6, bfd_mach_mipsisa32r6 },
> > + { bfd_mach_mipsisa64r5, bfd_mach_mipsisa32r5 },
> > + { bfd_mach_mipsisa64r3, bfd_mach_mipsisa32r3 },
> > + { bfd_mach_mipsisa64r2, bfd_mach_mipsisa32r2 },
> > + { bfd_mach_mipsisa64, bfd_mach_mipsisa32 }
> > +};
> >
> > /* An array describing how BFD machines relate to one another. The entries
> > are ordered topologically with MIPS I extensions listed last. */
> > @@ -14601,29 +14611,37 @@ static const struct mips_mach_extension mips_mach_extensions[] =
> > { bfd_mach_mips3900, bfd_mach_mips3000 }
> > };
> >
> > -/* Return true if bfd machine EXTENSION is an extension of machine BASE. */
> > +/* Return true if bfd machine EXTENSION is the same as BASE, or if
> > + EXTENSION is the 64-bit equivalent of a 32-bit BASE. */
> > +
> > +static bool
> > +mips_mach_extends_32_64 (unsigned long base, unsigned long extension)
> > +{
> > + size_t i;
> > +
> > + if (extension == base)
> > + return true;
> > +
> > + for (i = 0; i < ARRAY_SIZE (mips_mach_64_32); i++)
>
> error: ‘mips_mach_64_32’ undeclared (first use in this function); did you mean ‘mips_mach_32_64’?
>
> It looks like the previous patch had the same thing (sorry for not
> noticing). Obviously it's a simple fix, but it would be good to have
> some reassurance that the patch has been tested beyond my crude sanity
> checks.
>
Yes, it is a typo.
Sorry for it. I won't happen anymore...
> Thanks,
> Richard
>
> > + if (extension == mips_mach_32_64[i].extension)
> > + return base == mips_mach_32_64[i].base;
> > +
> > + return false;
> > +}
> >
> > static bool
> > mips_mach_extends_p (unsigned long base, unsigned long extension)
> > {
> > size_t i;
> >
> > - if (extension == base)
> > - return true;
> > -
> > - if (base == bfd_mach_mipsisa32
> > - && mips_mach_extends_p (bfd_mach_mipsisa64, extension))
> > - return true;
> > -
> > - if (base == bfd_mach_mipsisa32r2
> > - && mips_mach_extends_p (bfd_mach_mipsisa64r2, extension))
> > + if (mips_mach_extends_32_64 (base, extension))
> > return true;
> >
> > for (i = 0; i < ARRAY_SIZE (mips_mach_extensions); i++)
> > if (extension == mips_mach_extensions[i].extension)
> > {
> > extension = mips_mach_extensions[i].base;
>
>
>
> > - if (extension == base)
> > + if (mips_mach_extends_32_64 (base, extension))
> > return true;
> > }
@@ -14524,6 +14524,16 @@ struct mips_mach_extension
unsigned long extension, base;
};
+/* An array that maps 64-bit architectures to the corresponding 32-bit
+ architectures. */
+static const struct mips_mach_extension mips_mach_32_64[] =
+{
+ { bfd_mach_mipsisa64r6, bfd_mach_mipsisa32r6 },
+ { bfd_mach_mipsisa64r5, bfd_mach_mipsisa32r5 },
+ { bfd_mach_mipsisa64r3, bfd_mach_mipsisa32r3 },
+ { bfd_mach_mipsisa64r2, bfd_mach_mipsisa32r2 },
+ { bfd_mach_mipsisa64, bfd_mach_mipsisa32 }
+};
/* An array describing how BFD machines relate to one another. The entries
are ordered topologically with MIPS I extensions listed last. */
@@ -14601,29 +14611,37 @@ static const struct mips_mach_extension mips_mach_extensions[] =
{ bfd_mach_mips3900, bfd_mach_mips3000 }
};
-/* Return true if bfd machine EXTENSION is an extension of machine BASE. */
+/* Return true if bfd machine EXTENSION is the same as BASE, or if
+ EXTENSION is the 64-bit equivalent of a 32-bit BASE. */
+
+static bool
+mips_mach_extends_32_64 (unsigned long base, unsigned long extension)
+{
+ size_t i;
+
+ if (extension == base)
+ return true;
+
+ for (i = 0; i < ARRAY_SIZE (mips_mach_64_32); i++)
+ if (extension == mips_mach_32_64[i].extension)
+ return base == mips_mach_32_64[i].base;
+
+ return false;
+}
static bool
mips_mach_extends_p (unsigned long base, unsigned long extension)
{
size_t i;
- if (extension == base)
- return true;
-
- if (base == bfd_mach_mipsisa32
- && mips_mach_extends_p (bfd_mach_mipsisa64, extension))
- return true;
-
- if (base == bfd_mach_mipsisa32r2
- && mips_mach_extends_p (bfd_mach_mipsisa64r2, extension))
+ if (mips_mach_extends_32_64 (base, extension))
return true;
for (i = 0; i < ARRAY_SIZE (mips_mach_extensions); i++)
if (extension == mips_mach_extensions[i].extension)
{
extension = mips_mach_extensions[i].base;
- if (extension == base)
+ if (mips_mach_extends_32_64 (base, extension))
return true;
}