On Sat, 05 Feb 2022 00:14:26 PST (-0800), gcc-patches@gcc.gnu.org wrote:
Thanks, LGTM :)
On Sat, Feb 5, 2022 at 7:56 AM Maciej W. Rozycki <ma...@embecosm.com> wrote:
We have recently updated the default for the `-misa-spec=' option, yet
we still have not documented it nor its `--with-isa-spec=' counterpart
in the GCC manuals. Fix that.
gcc/
* doc/install.texi (Configuration): Document `--with-isa-spec='
RISC-V option.
* doc/invoke.texi (Option Summary): List `-misa-spec=' RISC-V
option.
(RISC-V Options): Document it.
---
> Thanks. I have a version of this floating around somewhere. I probably
forgot
> to post it and it's generally inferior to yours, so this LGTM.
Thank you for your review.
> The only thing I'd point out is that this specifically controls the version of
> the Unprivileged (formally called user) specification, as there are many
RISC-V
> specifications and it can be a bit ambiguous what folks mean when they just
say
> "specification". Not sure exactly what the right wording is there, maybe
> "version of the RISC-V Unprivileged (formerly user-level) ISA specification"?
Good point. I have updated the text to your suggested wording, which is
also what I would use if I were to propose it (modulo capitalisation). I
will commit the change as included here shortly then unless I hear an
objection.
I wasn't sure about the capitalization either, but that's how it is on
the website. It's in a regular-looking sentence, not a title where I'd
expect the extra capital, so I guess the whole spec name is a proper
noun?
I don't really care either way, just chiming in as I don't see this on
trunk. The original message sounded to me like you intended on
committing it, but just in case I misunderstood and you're waiting for
me
Reviewed-by: Palmer Dabbelt <pal...@rivosinc.com>
Acked-by: Palmer Dabbelt <pal...@rivosinc.com>
Thanks!
Maciej
Changes from v1:
- Clarify it is the Unprivileged (formerly User-Level) ISA specification
the options concerned refer to.
- Fix a typo `-misa-spec' vs `-misa-spec=' in ChangeLog.
---
gcc/doc/install.texi | 14 ++++++++++++++
gcc/doc/invoke.texi | 17 +++++++++++++++++
2 files changed, 31 insertions(+)
gcc-riscv-misa-doc.diff
Index: gcc/gcc/doc/install.texi
===================================================================
--- gcc.orig/gcc/doc/install.texi
+++ gcc/gcc/doc/install.texi
@@ -1599,6 +1599,20 @@ On certain targets this option sets the
size as a power of two in bytes. On AArch64 @var{size} is required to be
either
12 (4KB) or 16 (64KB).
+@item --with-isa-spec=@var{ISA-spec-string}
+On RISC-V targets specify the default version of the RISC-V Unprivileged
+(formerly User-Level) ISA specification to produce code conforming to.
+The possibilities for @var{ISA-spec-string} are:
+@table @code
+@item 2.2
+Produce code conforming to version 2.2.
+@item 20190608
+Produce code conforming to version 20190608.
+@item 20191213
+Produce code conforming to version 20191213.
+@end table
+In the absence of this configuration option the default version is 20191213.
+
@item --enable-__cxa_atexit
Define if you want to use __cxa_atexit, rather than atexit, to
register C++ destructors for local statics and global objects.
Index: gcc/gcc/doc/invoke.texi
===================================================================
--- gcc.orig/gcc/doc/invoke.texi
+++ gcc/gcc/doc/invoke.texi
@@ -1184,6 +1184,7 @@ See RS/6000 and PowerPC Options.
-mabi=@var{ABI-string} @gol
-mfdiv -mno-fdiv @gol
-mdiv -mno-div @gol
+-misa-spec=@var{ISA-spec-string} @gol
-march=@var{ISA-string} @gol
-mtune=@var{processor-string} @gol
-mpreferred-stack-boundary=@var{num} @gol
@@ -27632,6 +27633,22 @@ Do or don't use hardware instructions fo
M extension. The default is to use them if the specified architecture has
these instructions.
+@item -misa-spec=@var{ISA-spec-string}
+@opindex misa-spec
+Specify the version of the RISC-V Unprivileged (formerly User-Level)
+ISA specification to produce code conforming to. The possibilities
+for @var{ISA-spec-string} are:
+@table @code
+@item 2.2
+Produce code conforming to version 2.2.
+@item 20190608
+Produce code conforming to version 20190608.
+@item 20191213
+Produce code conforming to version 20191213.
+@end table
+The default is @option{-misa-spec=20191213} unless GCC has been configured
+with @option{--with-isa-spec=} specifying a different default version.
+
@item -march=@var{ISA-string}
@opindex march
Generate code for given RISC-V ISA (e.g.@: @samp{rv64im}). ISA strings must be
