[gcc r14-8274] RISC-V: Add the Zihpm and Zicntr extensions

[Kito Cheng <kito@gcc.gnu.org>]

https://gcc.gnu.org/g:730a801f950e7817696067906cf40d590688387a

commit r14-8274-g730a801f950e7817696067906cf40d590688387a
Author: Palmer Dabbelt <palmer@rivosinc.com>
Date:   Tue Nov 8 19:00:36 2022 -0800

    RISC-V: Add the Zihpm and Zicntr extensions
    
    These extensions were recently frozen [1].  As per Andrew's post [2]
    we're meant to ignore these in software, this just adds them to the list
    of allowed extensions and otherwise ignores them.  I added these under
    SPEC_CLASS_NONE even though the PDF lists them as 20190614 because it
    seems pointless to add another spec class just to accept two extensions
    we then ignore.
    
    1: https://groups.google.com/a/groups.riscv.org/g/isa-dev/c/HZGoqP1eyps/m/GTNKRLJoAQAJ
    2: https://groups.google.com/a/groups.riscv.org/g/sw-dev/c/QKjQhChrq9Q/m/7gqdkctgAgAJ
    
    gcc/ChangeLog
    
            * common/config/riscv/riscv-common.cc: Add Zihpm and Zicnttr
            extensions.

Diff:
---
 gcc/common/config/riscv/riscv-common.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/gcc/common/config/riscv/riscv-common.cc b/gcc/common/config/riscv/riscv-common.cc
index 958a6925a6d..4da7f37303b 100644
--- a/gcc/common/config/riscv/riscv-common.cc
+++ b/gcc/common/config/riscv/riscv-common.cc
@@ -279,6 +279,9 @@ static const struct riscv_ext_version riscv_ext_version_table[] =
   {"zicbom",ISA_SPEC_CLASS_NONE, 1, 0},
   {"zicbop",ISA_SPEC_CLASS_NONE, 1, 0},
 
+  {"zicntr", ISA_SPEC_CLASS_NONE, 2, 0},
+  {"zihpm",  ISA_SPEC_CLASS_NONE, 2, 0},
+
   {"zk",    ISA_SPEC_CLASS_NONE, 1, 0},
   {"zkn",   ISA_SPEC_CLASS_NONE, 1, 0},
   {"zks",   ISA_SPEC_CLASS_NONE, 1, 0},