[RISCV][MC] Mark Zawrs extension as non-experimental

Support for the unratified 1.0-rc3 specification was introduced in
D133443. The specification has since been ratified (in November 2022
according to the recently ratified extensions list
<https://wiki.riscv.org/display/HOME/Recently+Ratified+Extensions>.

A review of the diff
<riscvarchive/riscv-zawrs@V1.0-rc3...main> of the
1.0-rc3 spec vs the current/ratified document shows no changes to the
instruction encoding or naming. At one point, a note was added
<riscvarchive/riscv-zawrs@e84f424>
indicating Zawrs depends on the Zalrsc extension (not officially
specified, but I believe to be just the LR/SC instructions from the A
extension). The final text ended up as "The instructions in the Zawrs
extension are only useful in conjunction with the LR instructions, which
are provided by the A extension, and which we also expect to be provided
by a narrower Zalrsc extension in the future." I think it's consistent
with this phrasing to not require the A extension for Zawrs, which
matches what was implemented.

No intrinsics are implemented for Zawrs currently, meaning we don't need
to additionally review whether those intrinsics can be considered
finalised and ready for exposure to end users.

Differential Revision: https://reviews.llvm.org/D143507

Author: asb

clang/test/Preprocessor/riscv-target-features.c

@@ -424,11 +424,11 @@
 // RUN: -o - | FileCheck --check-prefix=CHECK-ZICBOP-EXT %s
 // CHECK-ZICBOP-EXT: __riscv_zicbop 1000000{{$}}
 
-// RUN: %clang -target riscv32-unknown-linux-gnu -menable-experimental-extensions \
-// RUN: -march=rv32izawrs1p0 -x c -E -dM %s \
+// RUN: %clang -target riscv32-unknown-linux-gnu \
+// RUN: -march=rv32izawrs -x c -E -dM %s \
 // RUN: -o - | FileCheck --check-prefix=CHECK-ZAWRS-EXT %s
-// RUN: %clang -target riscv64-unknown-linux-gnu -menable-experimental-extensions \
-// RUN: -march=rv64izawrs1p0 -x c -E -dM %s \
+// RUN: %clang -target riscv64-unknown-linux-gnu \
+// RUN: -march=rv64izawrs -x c -E -dM %s \
 // RUN: -o - | FileCheck --check-prefix=CHECK-ZAWRS-EXT %s
 // CHECK-ZAWRS-EXT: __riscv_zawrs 1000000{{$}}
 

llvm/docs/RISCVUsage.rst

@@ -57,6 +57,7 @@ on support follow.
      ``Svnapot``      Assembly Support
      ``Svpbmt``       Supported
      ``V``            Supported
+     ``Zawrs``        Assembly Support
      ``Zba``          Supported
      ``Zbb``          Supported
      ``Zbc``          Supported
@@ -139,9 +140,6 @@ LLVM supports (to various degrees) a number of experimental extensions.  All exp
 
 The primary goal of experimental support is to assist in the process of ratification by providing an existence proof of an implementation, and simplifying efforts to validate the value of a proposed extension against large code bases.  Experimental extensions are expected to either transition to ratified status, or be eventually removed.  The decision on whether to accept an experimental extension is currently done on an entirely case by case basis; if you want to propose one, attending the bi-weekly RISC-V sync-up call is strongly advised.
 
-``experimental-zawrs``
-  LLVM implements the `1.0-rc3 draft specification <https://github.com/riscv/riscv-zawrs/releases/download/V1.0-rc3/Zawrs.pdf>`_.  Note that have been backwards incompatible changes made between release candidates for the 1.0 draft.
-
 ``experimental-zca``
   LLVM implements the `1.0.1 draft specification <https://github.com/riscv/riscv-code-size-reduction/releases/tag/v1.0.1>`_.
 

llvm/docs/ReleaseNotes.rst

@@ -112,6 +112,7 @@ Changes to the RISC-V Backend
 * Adds support for the vendor-defined XTHeadBb (basic bit-manipulation) extension.
 * Adds support for the vendor-defined XTHeadBs (single-bit) extension.
 * Adds support for the vendor-defined XTHeadMac (multiply-accumulate instructions) extension.
+* Support for the now-ratified Zawrs extension is no longer experimental.
 
 Changes to the WebAssembly Backend
 ----------------------------------

llvm/lib/Support/RISCVISAInfo.cpp

@@ -106,6 +106,8 @@ static const RISCVSupportedExtension SupportedExtensions[] = {
     {"zicsr", RISCVExtensionVersion{2, 0}},
     {"zifencei", RISCVExtensionVersion{2, 0}},
 
+    {"zawrs", RISCVExtensionVersion{1, 0}},
+
     {"svnapot", RISCVExtensionVersion{1, 0}},
     {"svpbmt", RISCVExtensionVersion{1, 0}},
     {"svinval", RISCVExtensionVersion{1, 0}},
@@ -128,7 +130,6 @@ static const RISCVSupportedExtension SupportedExperimentalExtensions[] = {
     {"zcf", RISCVExtensionVersion{1, 0}},
     {"zfa", RISCVExtensionVersion{0, 1}},
     {"zvfh", RISCVExtensionVersion{0, 1}},
-    {"zawrs", RISCVExtensionVersion{1, 0}},
     {"ztso", RISCVExtensionVersion{0, 1}},
 };
 

llvm/lib/Target/RISCV/RISCVFeatures.td

@@ -467,9 +467,8 @@ def HasStdExtZtso : Predicate<"Subtarget->hasStdExtZTso()">,
                               AssemblerPredicate<(all_of FeatureStdExtZtso),
                               "'Ztso' (Memory Model - Total Store Order)">;
 
-def FeatureStdExtZawrs
-    : SubtargetFeature<"experimental-zawrs", "HasStdExtZawrs", "true",
-                       "'Zawrs' (Wait on Reservation Set)">;
+def FeatureStdExtZawrs : SubtargetFeature<"zawrs", "HasStdExtZawrs", "true",
+                                          "'Zawrs' (Wait on Reservation Set)">;
 def HasStdExtZawrs : Predicate<"Subtarget->hasStdExtZawrs()">,
                                AssemblerPredicate<(all_of FeatureStdExtZawrs),
                                "'Zawrs' (Wait on Reservation Set)">;

llvm/test/CodeGen/RISCV/attributes.ll

@@ -97,7 +97,7 @@
 ; RUN: llc -mtriple=riscv64 -mattr=+xtheadbs %s -o - | FileCheck --check-prefixes=CHECK,RV64XTHEADBS %s
 ; RUN: llc -mtriple=riscv64 -mattr=+xtheadmac %s -o - | FileCheck --check-prefixes=CHECK,RV64XTHEADMAC %s
 ; RUN: llc -mtriple=riscv64 -mattr=+xtheadvdot %s -o - | FileCheck --check-prefixes=CHECK,RV64XTHEADVDOT %s
-; RUN: llc -mtriple=riscv64 -mattr=+experimental-zawrs %s -o - | FileCheck --check-prefixes=CHECK,RV64ZAWRS %s
+; RUN: llc -mtriple=riscv64 -mattr=+zawrs %s -o - | FileCheck --check-prefixes=CHECK,RV64ZAWRS %s
 ; RUN: llc -mtriple=riscv64 -mattr=+experimental-ztso %s -o - | FileCheck --check-prefixes=CHECK,RV64ZTSO %s
 ; RUN: llc -mtriple=riscv64 -mattr=+experimental-zca %s -o - | FileCheck --check-prefixes=CHECK,RV64ZCA %s
 ; RUN: llc -mtriple=riscv64 -mattr=+experimental-zcb %s -o - | FileCheck --check-prefixes=CHECK,RV64ZCB %s

llvm/test/MC/RISCV/Zawrs-valid.s

@@ -1,12 +1,12 @@
-# RUN: llvm-mc %s -triple=riscv32 -mattr=+experimental-zawrs -riscv-no-aliases -show-encoding \
+# RUN: llvm-mc %s -triple=riscv32 -mattr=+zawrs -riscv-no-aliases -show-encoding \
 # RUN:     | FileCheck -check-prefixes=CHECK-ASM,CHECK-ASM-AND-OBJ %s
-# RUN: llvm-mc %s -triple=riscv64 -mattr=+experimental-zawrs -riscv-no-aliases -show-encoding \
+# RUN: llvm-mc %s -triple=riscv64 -mattr=+zawrs -riscv-no-aliases -show-encoding \
 # RUN:     | FileCheck -check-prefixes=CHECK-ASM,CHECK-ASM-AND-OBJ %s
-# RUN: llvm-mc -filetype=obj -triple=riscv32 -mattr=+experimental-zawrs < %s \
-# RUN:     | llvm-objdump --mattr=+experimental-zawrs -M no-aliases -d -r - \
+# RUN: llvm-mc -filetype=obj -triple=riscv32 -mattr=+zawrs < %s \
+# RUN:     | llvm-objdump --mattr=+zawrs -M no-aliases -d -r - \
 # RUN:     | FileCheck --check-prefix=CHECK-ASM-AND-OBJ %s
-# RUN: llvm-mc -filetype=obj -triple=riscv64 -mattr=+experimental-zawrs < %s \
-# RUN:     | llvm-objdump --mattr=+experimental-zawrs -M no-aliases -d -r - \
+# RUN: llvm-mc -filetype=obj -triple=riscv64 -mattr=+zawrs < %s \
+# RUN:     | llvm-objdump --mattr=+zawrs -M no-aliases -d -r - \
 # RUN:     | FileCheck --check-prefix=CHECK-ASM-AND-OBJ %s
 
 # CHECK-ASM-AND-OBJ: wrs.nto