[PATCH] D73891: [RISCV] Support experimental/unratified extensions

[Simon Cook via Phabricator via cfe-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rGdd1ee6dc076f: [RISCV] Support experimental/unratified 
extensions (authored by simoncook).

Changed prior to commit:
  https://reviews.llvm.org/D73891?vs=250770=256369#toc

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D73891/new/

https://reviews.llvm.org/D73891

Files:
  clang/include/clang/Driver/Options.td
  clang/lib/Driver/ToolChains/Arch/RISCV.cpp
  clang/test/Driver/riscv-arch.c

Index: clang/test/Driver/riscv-arch.c
===
--- clang/test/Driver/riscv-arch.c
+++ clang/test/Driver/riscv-arch.c
@@ -264,20 +264,20 @@
 // RV32-IMINOR1: error: invalid arch name 'rv32i2p1', unsupported
 // RV32-IMINOR1: version number 2.1 for extension 'i'
 
-// RUN: %clang -target riscv32-unknown-elf -march=rv32ix2p -### %s \
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ixt2p -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-XMINOR-MISS %s
-// RV32-XMINOR-MISS: error: invalid arch name 'rv32ix2p',
-// RV32-XMINOR-MISS: minor version number missing after 'p' for extension 'x2p'
+// RV32-XMINOR-MISS: error: invalid arch name 'rv32ixt2p',
+// RV32-XMINOR-MISS: minor version number missing after 'p' for extension 'xt'
 
-// RUN: %clang -target riscv32-unknown-elf -march=rv32is2p0 -### %s \
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ist2p0 -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-SMINOR0 %s
-// RV32-SMINOR0: error: invalid arch name 'rv32is2p0',
-// RV32-SMINOR0: unsupported version number 2.0 for extension 's2p0'
+// RV32-SMINOR0: error: invalid arch name 'rv32ist2p0',
+// RV32-SMINOR0: unsupported version number 2.0 for extension 'st'
 
-// RUN: %clang -target riscv32-unknown-elf -march=rv32isx2p1 -### %s \
+// RUN: %clang -target riscv32-unknown-elf -march=rv32isxt2p1 -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-SXMINOR1 %s
-// RV32-SXMINOR1: error: invalid arch name 'rv32isx2p1', unsupported
-// RV32-SXMINOR1: version number 2.1 for extension 'sx2p1'
+// RV32-SXMINOR1: error: invalid arch name 'rv32isxt2p1', unsupported
+// RV32-SXMINOR1: version number 2.1 for extension 'sxt'
 
 // RUN: %clang -target riscv32-unknown-elf -march=rv32ixabc_ -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-XSEP %s
@@ -327,3 +327,36 @@
 // RUN: %clang -target riscv64-unknown-elf -march=rv64i -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV64-TARGET %s
 // RV64-TARGET: "-triple" "riscv64-unknown-unknown-elf"
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-NOFLAG %s
+// RV32-EXPERIMENTAL-NOFLAG: error: invalid arch name 'rv32ib'
+// RV32-EXPERIMENTAL-NOFLAG: requires '-menable-experimental-extensions'
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-NOVERS %s
+// RV32-EXPERIMENTAL-NOVERS: error: invalid arch name 'rv32ib'
+// RV32-EXPERIMENTAL-NOVERS: experimental extension requires explicit version number
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib0p1 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-BADVERS %s
+// RV32-EXPERIMENTAL-BADVERS: error: invalid arch name 'rv32ib0p1'
+// RV32-EXPERIMENTAL-BADVERS: unsupported version number 0.1 for experimental extension
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib0p92 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-GOODVERS %s
+// RV32-EXPERIMENTAL-GOODVERS: "-target-feature" "+experimental-b"
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32izbb -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-ZBB-NOFLAG %s
+// RV32-EXPERIMENTAL-ZBB-NOFLAG: error: invalid arch name 'rv32izbb'
+// RV32-EXPERIMENTAL-ZBB-NOFLAG: requires '-menable-experimental-extensions'
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32izbb0p92 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-ZBB %s
+// RV32-EXPERIMENTAL-ZBB: "-target-feature" "+experimental-zbb"
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32izbb0p92_zbp0p92 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-ZBB-ZBP %s
+// RV32-EXPERIMENTAL-ZBB-ZBP: "-target-feature" "+experimental-zbb"
+// RV32-EXPERIMENTAL-ZBB-ZBP: "-target-feature" "+experimental-zbp"
Index: clang/lib/Driver/ToolChains/Arch/RISCV.cpp
===
--- clang/lib/Driver/ToolChains/Arch/RISCV.cpp
+++ clang/lib/Driver/ToolChains/Arch/RISCV.cpp
@@ -22,6 

[PATCH] D73891: [RISCV] Support experimental/unratified extensions

[Alex Bradbury via Phabricator via cfe-commits]

asb added a comment.

I've approved D65649  now, so I think this one 
can land as soon as that one does.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D73891/new/

https://reviews.llvm.org/D73891



___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D73891: [RISCV] Support experimental/unratified extensions

[Alex Bradbury via Phabricator via cfe-commits]

asb accepted this revision.
asb added a comment.

LGTM, thanks Simon!


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D73891/new/

https://reviews.llvm.org/D73891



___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D73891: [RISCV] Support experimental/unratified extensions

[Sam Elliott via Phabricator via cfe-commits]

lenary accepted this revision.
lenary added a comment.

I'm happy with the approach here.

At some point we should put version numbers into the target features, but I 
think that can wait until we know how to cope with how the `G` extension 
expands into its other extensions (this has some open questions in general). 
This suggestion does not, in my mind, block this patch, as including 
`experimental-` in the target feature names does make it clear which features 
are experimental today.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D73891/new/

https://reviews.llvm.org/D73891



___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D73891: [RISCV] Support experimental/unratified extensions

[Lewis Revill via Phabricator via cfe-commits]

lewis-revill accepted this revision.
lewis-revill added a comment.
This revision is now accepted and ready to land.

Thanks, this is looking in good shape now. As long as everyone agrees on this 
scheme I think the implementation is good to go (pending the bitmanip extension 
support).


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D73891/new/

https://reviews.llvm.org/D73891



___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D73891: [RISCV] Support experimental/unratified extensions

[Simon Cook via Phabricator via cfe-commits]

simoncook updated this revision to Diff 250770.
simoncook added a comment.

- Update to match latest dependencies
- Handle adding "experimental-" to SubtargetFeatures for experimental features


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D73891/new/

https://reviews.llvm.org/D73891

Files:
  clang/include/clang/Driver/Options.td
  clang/lib/Driver/ToolChains/Arch/RISCV.cpp
  clang/test/Driver/riscv-arch.c

Index: clang/test/Driver/riscv-arch.c
===
--- clang/test/Driver/riscv-arch.c
+++ clang/test/Driver/riscv-arch.c
@@ -264,20 +264,20 @@
 // RV32-IMINOR1: error: invalid arch name 'rv32i2p1', unsupported
 // RV32-IMINOR1: version number 2.1 for extension 'i'
 
-// RUN: %clang -target riscv32-unknown-elf -march=rv32ix2p -### %s \
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ixt2p -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-XMINOR-MISS %s
-// RV32-XMINOR-MISS: error: invalid arch name 'rv32ix2p',
-// RV32-XMINOR-MISS: minor version number missing after 'p' for extension 'x2p'
+// RV32-XMINOR-MISS: error: invalid arch name 'rv32ixt2p',
+// RV32-XMINOR-MISS: minor version number missing after 'p' for extension 'xt'
 
-// RUN: %clang -target riscv32-unknown-elf -march=rv32is2p0 -### %s \
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ist2p0 -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-SMINOR0 %s
-// RV32-SMINOR0: error: invalid arch name 'rv32is2p0',
-// RV32-SMINOR0: unsupported version number 2.0 for extension 's2p0'
+// RV32-SMINOR0: error: invalid arch name 'rv32ist2p0',
+// RV32-SMINOR0: unsupported version number 2.0 for extension 'st'
 
-// RUN: %clang -target riscv32-unknown-elf -march=rv32isx2p1 -### %s \
+// RUN: %clang -target riscv32-unknown-elf -march=rv32isxt2p1 -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-SXMINOR1 %s
-// RV32-SXMINOR1: error: invalid arch name 'rv32isx2p1', unsupported
-// RV32-SXMINOR1: version number 2.1 for extension 'sx2p1'
+// RV32-SXMINOR1: error: invalid arch name 'rv32isxt2p1', unsupported
+// RV32-SXMINOR1: version number 2.1 for extension 'sxt'
 
 // RUN: %clang -target riscv32-unknown-elf -march=rv32ixabc_ -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-XSEP %s
@@ -327,3 +327,36 @@
 // RUN: %clang -target riscv64-unknown-elf -march=rv64i -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV64-TARGET %s
 // RV64-TARGET: "-triple" "riscv64-unknown-unknown-elf"
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-NOFLAG %s
+// RV32-EXPERIMENTAL-NOFLAG: error: invalid arch name 'rv32ib'
+// RV32-EXPERIMENTAL-NOFLAG: requires '-menable-experimental-extensions'
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-NOVERS %s
+// RV32-EXPERIMENTAL-NOVERS: error: invalid arch name 'rv32ib'
+// RV32-EXPERIMENTAL-NOVERS: experimental extension requires explicit version number
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib0p1 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-BADVERS %s
+// RV32-EXPERIMENTAL-BADVERS: error: invalid arch name 'rv32ib0p1'
+// RV32-EXPERIMENTAL-BADVERS: unsupported version number 0.1 for experimental extension
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib0p92 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-GOODVERS %s
+// RV32-EXPERIMENTAL-GOODVERS: "-target-feature" "+experimental-b"
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32izbb -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-ZBB-NOFLAG %s
+// RV32-EXPERIMENTAL-ZBB-NOFLAG: error: invalid arch name 'rv32izbb'
+// RV32-EXPERIMENTAL-ZBB-NOFLAG: requires '-menable-experimental-extensions'
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32izbb0p92 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-ZBB %s
+// RV32-EXPERIMENTAL-ZBB: "-target-feature" "+experimental-zbb"
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32izbb0p92_zbp0p92 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-ZBB-ZBP %s
+// RV32-EXPERIMENTAL-ZBB-ZBP: "-target-feature" "+experimental-zbb"
+// RV32-EXPERIMENTAL-ZBB-ZBP: "-target-feature" "+experimental-zbp"
Index: clang/lib/Driver/ToolChains/Arch/RISCV.cpp
===
--- clang/lib/Driver/ToolChains/Arch/RISCV.cpp
+++ clang/lib/Driver/ToolChains/Arch/RISCV.cpp
@@ -22,6 +22,14 @@
 using namespace clang;
 using namespace llvm::opt;
 
+namespace {

[PATCH] D73891: [RISCV] Support experimental/unratified extensions

[Simon Cook via Phabricator via cfe-commits]

simoncook updated this revision to Diff 243502.
simoncook added a comment.

Rebase, incorporate changes suggested by Lewis


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D73891/new/

https://reviews.llvm.org/D73891

Files:
  clang/include/clang/Driver/Options.td
  clang/lib/Driver/ToolChains/Arch/RISCV.cpp
  clang/test/Driver/riscv-arch.c

Index: clang/test/Driver/riscv-arch.c
===
--- clang/test/Driver/riscv-arch.c
+++ clang/test/Driver/riscv-arch.c
@@ -264,20 +264,20 @@
 // RV32-IMINOR1: error: invalid arch name 'rv32i2p1', unsupported
 // RV32-IMINOR1: version number 2.1 for extension 'i'
 
-// RUN: %clang -target riscv32-unknown-elf -march=rv32ix2p -### %s \
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ixt2p -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-XMINOR-MISS %s
-// RV32-XMINOR-MISS: error: invalid arch name 'rv32ix2p',
-// RV32-XMINOR-MISS: minor version number missing after 'p' for extension 'x2p'
+// RV32-XMINOR-MISS: error: invalid arch name 'rv32ixt2p',
+// RV32-XMINOR-MISS: minor version number missing after 'p' for extension 'xt'
 
-// RUN: %clang -target riscv32-unknown-elf -march=rv32is2p0 -### %s \
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ist2p0 -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-SMINOR0 %s
-// RV32-SMINOR0: error: invalid arch name 'rv32is2p0',
-// RV32-SMINOR0: unsupported version number 2.0 for extension 's2p0'
+// RV32-SMINOR0: error: invalid arch name 'rv32ist2p0',
+// RV32-SMINOR0: unsupported version number 2.0 for extension 'st'
 
-// RUN: %clang -target riscv32-unknown-elf -march=rv32isx2p1 -### %s \
+// RUN: %clang -target riscv32-unknown-elf -march=rv32isxt2p1 -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-SXMINOR1 %s
-// RV32-SXMINOR1: error: invalid arch name 'rv32isx2p1', unsupported
-// RV32-SXMINOR1: version number 2.1 for extension 'sx2p1'
+// RV32-SXMINOR1: error: invalid arch name 'rv32isxt2p1', unsupported
+// RV32-SXMINOR1: version number 2.1 for extension 'sxt'
 
 // RUN: %clang -target riscv32-unknown-elf -march=rv32ixabc_ -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-XSEP %s
@@ -327,3 +327,36 @@
 // RUN: %clang -target riscv64-unknown-elf -march=rv64i -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV64-TARGET %s
 // RV64-TARGET: "-triple" "riscv64-unknown-unknown-elf"
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-NOFLAG %s
+// RV32-EXPERIMENTAL-NOFLAG: error: invalid arch name 'rv32ib'
+// RV32-EXPERIMENTAL-NOFLAG: requires '-menable-experimental-extensions'
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-NOVERS %s
+// RV32-EXPERIMENTAL-NOVERS: error: invalid arch name 'rv32ib'
+// RV32-EXPERIMENTAL-NOVERS: experimental extension requires explicit version number
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib0p1 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-BADVERS %s
+// RV32-EXPERIMENTAL-BADVERS: error: invalid arch name 'rv32ib0p1'
+// RV32-EXPERIMENTAL-BADVERS: unsupported version number 0.1 for experimental extension
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib0p92 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-GOODVERS %s
+// RV32-EXPERIMENTAL-GOODVERS: "-target-feature" "+b"
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32izbb -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-ZBB-NOFLAG %s
+// RV32-EXPERIMENTAL-ZBB-NOFLAG: error: invalid arch name 'rv32izbb'
+// RV32-EXPERIMENTAL-ZBB-NOFLAG: requires '-menable-experimental-extensions'
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32izbb0p92 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-ZBB %s
+// RV32-EXPERIMENTAL-ZBB: "-target-feature" "+zbb"
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32izbb0p92_zbp0p92 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-ZBB-ZBP %s
+// RV32-EXPERIMENTAL-ZBB-ZBP: "-target-feature" "+zbb"
+// RV32-EXPERIMENTAL-ZBB-ZBP: "-target-feature" "+zbp"
Index: clang/lib/Driver/ToolChains/Arch/RISCV.cpp
===
--- clang/lib/Driver/ToolChains/Arch/RISCV.cpp
+++ clang/lib/Driver/ToolChains/Arch/RISCV.cpp
@@ -22,6 +22,14 @@
 using namespace clang;
 using namespace llvm::opt;
 
+namespace {
+// Represents the major and version number components of a RISC-V extension
+struct RISCVExtensionVersion {
+  StringRef 

[PATCH] D73891: [RISCV] Support experimental/unratified extensions

[Lewis Revill via Phabricator via cfe-commits]

lewis-revill added inline comments.



Comment at: clang/lib/Driver/ToolChains/Arch/RISCV.cpp:93
+  // If experimental extension, require use of current version number number
+  if (auto ExperimentalExtension = isExperimentalExtension(Ext)) {
+if (!Args.hasArg(options::OPT_menable_experimental_extensions)) {

Hmm... Not sure it makes sense anymore for the function to be called 
`isExperimentalExtension`, because it's not just returning true or false. Just 
off the top of my head I would call it something like 
`getExperimentalExtensionVersion` or ideally something more concise.



Comment at: clang/lib/Driver/ToolChains/Arch/RISCV.cpp:100
+  return false;
+} else if (Major.empty() && Minor.empty()) {
+  std::string Error =

Is just testing `Major.empty()` not sufficient? We can't have a version with 
just a minor version number.



Comment at: clang/lib/Driver/ToolChains/Arch/RISCV.cpp:125
+  // Allow extensions to declare no version number
+  if (Major.empty() && Minor.empty())
+return true;

Ditto.



Comment at: clang/lib/Driver/ToolChains/Arch/RISCV.cpp:366
 default:
   // Currently LLVM supports only "mafdc".
   D.Diag(diag::err_drv_invalid_riscv_ext_arch_name)

Should this comment be updated?



Comment at: clang/lib/Driver/ToolChains/Arch/RISCV.cpp:102
 
-  // TODO: Handle extensions with version number.
+  // If experimental extension, require use of current version number number
+  if (auto ExperimentalExtension = isExperimentalExtension(Ext)) {

Typo 'number number' ? Also perhaps not accurate to say 'current version 
number', as opposed to something like 'a supported version number'.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D73891/new/

https://reviews.llvm.org/D73891



___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D73891: [RISCV] Support experimental/unratified extensions

[Simon Cook via Phabricator via cfe-commits]

simoncook updated this revision to Diff 243325.
simoncook added a comment.

Add support for Z extensions also under this scheme.

In order to support these I've had to tweak the multi-letter extension parsing 
a little. The net result is that error messages printed regarding version 
numbers are now consistent between single letter standard extensions and any 
multi-letter extension.

This also makes a change to the feature names used for multi-letter extensions, 
previously an architecture like `rv32isxx1_sxx2` would be accepted with the 
TargetFeatures `sxx1` and `sxx2` being added. Now an error indicating that 
`sxx` has been used multiple times in the string, with just the feature `sxx` 
being added.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D73891/new/

https://reviews.llvm.org/D73891

Files:
  clang/include/clang/Driver/Options.td
  clang/lib/Driver/ToolChains/Arch/RISCV.cpp
  clang/test/Driver/riscv-arch.c

Index: clang/test/Driver/riscv-arch.c
===
--- clang/test/Driver/riscv-arch.c
+++ clang/test/Driver/riscv-arch.c
@@ -264,20 +264,20 @@
 // RV32-IMINOR1: error: invalid arch name 'rv32i2p1', unsupported
 // RV32-IMINOR1: version number 2.1 for extension 'i'
 
-// RUN: %clang -target riscv32-unknown-elf -march=rv32ix2p -### %s \
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ixt2p -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-XMINOR-MISS %s
-// RV32-XMINOR-MISS: error: invalid arch name 'rv32ix2p',
-// RV32-XMINOR-MISS: minor version number missing after 'p' for extension 'x2p'
+// RV32-XMINOR-MISS: error: invalid arch name 'rv32ixt2p',
+// RV32-XMINOR-MISS: minor version number missing after 'p' for extension 'xt'
 
-// RUN: %clang -target riscv32-unknown-elf -march=rv32is2p0 -### %s \
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ist2p0 -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-SMINOR0 %s
-// RV32-SMINOR0: error: invalid arch name 'rv32is2p0',
-// RV32-SMINOR0: unsupported version number 2.0 for extension 's2p0'
+// RV32-SMINOR0: error: invalid arch name 'rv32ist2p0',
+// RV32-SMINOR0: unsupported version number 2.0 for extension 'st'
 
-// RUN: %clang -target riscv32-unknown-elf -march=rv32isx2p1 -### %s \
+// RUN: %clang -target riscv32-unknown-elf -march=rv32isxt2p1 -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-SXMINOR1 %s
-// RV32-SXMINOR1: error: invalid arch name 'rv32isx2p1', unsupported
-// RV32-SXMINOR1: version number 2.1 for extension 'sx2p1'
+// RV32-SXMINOR1: error: invalid arch name 'rv32isxt2p1', unsupported
+// RV32-SXMINOR1: version number 2.1 for extension 'sxt'
 
 // RUN: %clang -target riscv32-unknown-elf -march=rv32ixabc_ -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-XSEP %s
@@ -327,3 +327,36 @@
 // RUN: %clang -target riscv64-unknown-elf -march=rv64i -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV64-TARGET %s
 // RV64-TARGET: "-triple" "riscv64-unknown-unknown-elf"
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-NOFLAG %s
+// RV32-EXPERIMENTAL-NOFLAG: error: invalid arch name 'rv32ib'
+// RV32-EXPERIMENTAL-NOFLAG: requires '-menable-experimental-extensions'
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-NOVERS %s
+// RV32-EXPERIMENTAL-NOVERS: error: invalid arch name 'rv32ib'
+// RV32-EXPERIMENTAL-NOVERS: experimental extension requires explicit version number
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib0p1 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-BADVERS %s
+// RV32-EXPERIMENTAL-BADVERS: error: invalid arch name 'rv32ib0p1'
+// RV32-EXPERIMENTAL-BADVERS: unsupported version number 0.1 for experimental extension
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib0p92 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-GOODVERS %s
+// RV32-EXPERIMENTAL-GOODVERS: "-target-feature" "+b"
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32izbb -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-ZBB-NOFLAG %s
+// RV32-EXPERIMENTAL-ZBB-NOFLAG: error: invalid arch name 'rv32izbb'
+// RV32-EXPERIMENTAL-ZBB-NOFLAG: requires '-menable-experimental-extensions'
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32izbb0p92 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-ZBB %s
+// RV32-EXPERIMENTAL-ZBB: "-target-feature" "+zbb"
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32izbb0p92_zbp0p92 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck 

[PATCH] D73891: [RISCV] Support experimental/unratified extensions

[Simon Cook via Phabricator via cfe-commits]

simoncook planned changes to this revision.
simoncook added a comment.

With the update to D69987  adding the `Zvqmac` 
predicate, it seems both the `b` and `v` extensions have Z extensions that also 
need supporting using this method, I'll update this to also support Z shortly, 
but don't expect the general method to change, just adding the same version 
check elsewhere.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D73891/new/

https://reviews.llvm.org/D73891



___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D73891: [RISCV] Support experimental/unratified extensions

[Simon Cook via Phabricator via cfe-commits]

simoncook updated this revision to Diff 242286.
simoncook added a comment.

Switch to using `Optional` for returning version numbers.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D73891/new/

https://reviews.llvm.org/D73891

Files:
  clang/include/clang/Driver/Options.td
  clang/lib/Driver/ToolChains/Arch/RISCV.cpp
  clang/test/Driver/riscv-arch.c

Index: clang/test/Driver/riscv-arch.c
===
--- clang/test/Driver/riscv-arch.c
+++ clang/test/Driver/riscv-arch.c
@@ -327,3 +327,22 @@
 // RUN: %clang -target riscv64-unknown-elf -march=rv64i -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV64-TARGET %s
 // RV64-TARGET: "-triple" "riscv64-unknown-unknown-elf"
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-NOFLAG %s
+// RV32-EXPERIMENTAL-NOFLAG: error: invalid arch name 'rv32ib'
+// RV32-EXPERIMENTAL-NOFLAG: requires '-menable-experimental-extensions'
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-NOVERS %s
+// RV32-EXPERIMENTAL-NOVERS: error: invalid arch name 'rv32ib'
+// RV32-EXPERIMENTAL-NOVERS: experimental extension requires explicit version number
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib0p1 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-BADVERS %s
+// RV32-EXPERIMENTAL-BADVERS: error: invalid arch name 'rv32ib0p1'
+// RV32-EXPERIMENTAL-BADVERS: unsupported version number 0.1 for experimental extension
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib0p92 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-GOODVERS %s
+// RV32-EXPERIMENTAL-GOODVERS: "-target-feature" "+b"
Index: clang/lib/Driver/ToolChains/Arch/RISCV.cpp
===
--- clang/lib/Driver/ToolChains/Arch/RISCV.cpp
+++ clang/lib/Driver/ToolChains/Arch/RISCV.cpp
@@ -22,6 +22,14 @@
 using namespace clang;
 using namespace llvm::opt;
 
+namespace {
+// Represents the major and version number components of a RISC-V extension
+struct RISCVExtensionVersion {
+  StringRef Major;
+  StringRef Minor;
+};
+} // end anonymous namespace
+
 static StringRef getExtensionTypeDesc(StringRef Ext) {
   if (Ext.startswith("sx"))
 return "non-standard supervisor-level extension";
@@ -47,20 +55,27 @@
   return false;
 }
 
+// If the extension is supported as experimental, return the version of that
+// extension that the compiler currently supports.
+static Optional
+isExperimentalExtension(StringRef Ext) {
+  if (Ext == "b")
+return RISCVExtensionVersion{"0", "92"};
+  return None;
+}
+
 // Extensions may have a version number, and may be separated by
 // an underscore '_' e.g.: rv32i2_m2.
 // Version number is divided into major and minor version numbers,
 // separated by a 'p'. If the minor version is 0 then 'p0' can be
 // omitted from the version string. E.g., rv32i2p0, rv32i2, rv32i2p1.
-static bool getExtensionVersion(const Driver , StringRef MArch,
-StringRef Ext, StringRef In,
+static bool getExtensionVersion(const Driver , const ArgList ,
+StringRef MArch, StringRef Ext, StringRef In,
 std::string , std::string ) {
   Major = std::string(In.take_while(isDigit));
   In = In.substr(Major.size());
-  if (Major.empty())
-return true;
 
-  if (In.consume_front("p")) {
+  if (Major.size() && In.consume_front("p")) {
 Minor = std::string(In.take_while(isDigit));
 In = In.substr(Major.size());
 
@@ -74,7 +89,43 @@
 }
   }
 
-  // TODO: Handle extensions with version number.
+  // If experimental extension, require use of current version number number
+  if (auto ExperimentalExtension = isExperimentalExtension(Ext)) {
+if (!Args.hasArg(options::OPT_menable_experimental_extensions)) {
+  std::string Error =
+  "requires '-menable-experimental-extensions' for experimental extension";
+  D.Diag(diag::err_drv_invalid_riscv_ext_arch_name)
+  << MArch << Error << Ext;
+  return false;
+} else if (Major.empty() && Minor.empty()) {
+  std::string Error =
+  "experimental extension requires explicit version number";
+  D.Diag(diag::err_drv_invalid_riscv_ext_arch_name)
+  << MArch << Error << Ext;
+  return false;
+}
+auto SupportedVers = *ExperimentalExtension;
+if (Major != SupportedVers.Major || Minor != SupportedVers.Minor) {
+  std::string Error =
+  "unsupported version number " + Major;
+  if (!Minor.empty())
+Error += "." + Minor;
+  Error += " for experimental extension (this compiler 

[PATCH] D73891: [RISCV] Support experimental/unratified extensions

[Simon Cook via Phabricator via cfe-commits]

simoncook marked 2 inline comments as done.
simoncook added inline comments.



Comment at: clang/lib/Driver/ToolChains/Arch/RISCV.cpp:50
 
+static bool isExperimentalExtension(StringRef Ext) {
+  // Currently 'b' is the only supported experimental extension

rogfer01 wrote:
> Suggestion: I think we can avoid these two functions 
> (`isExperimentalExtension` and `getExperimentalExtensionVersion`) going out 
> of sync if we have only one of them and make it return an `llvm::Optional` of 
> the pair of versions.
> 
> Thent it can be used like this
> 
> ```lang=cpp
> if (auto ExperimentalExtension = isExperimentalExtension(Ext)) {
>std::pair SupportedVers = *ExperimentalVersion;
>...
> }
> ```
> 
> I'd also add a comment that the pair's `first` is the major version and 
> `second` is the minor version (or alternative use a struct with two public 
> fields `Major` and `Minor`)
That's a good idea, I'll update this to use this pattern.



Comment at: clang/lib/Driver/ToolChains/Arch/RISCV.cpp:396
+  I += Minor.size() + 1 /*'p'*/;
+if (*I == '_')
+  ++I;

rogfer01 wrote:
> There is no test for that case but I'm afraid we can't test it yet, can we?
We can test for e.g. `rv32i_m` which is now accepted (GCC also accepts this 
option we didn't before), but the version number code I don't think there is 
until we support versions on more than one extension.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D73891/new/

https://reviews.llvm.org/D73891



___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D73891: [RISCV] Support experimental/unratified extensions

[Roger Ferrer Ibanez via Phabricator via cfe-commits]

rogfer01 added inline comments.



Comment at: clang/lib/Driver/ToolChains/Arch/RISCV.cpp:50
 
+static bool isExperimentalExtension(StringRef Ext) {
+  // Currently 'b' is the only supported experimental extension

Suggestion: I think we can avoid these two functions (`isExperimentalExtension` 
and `getExperimentalExtensionVersion`) going out of sync if we have only one of 
them and make it return an `llvm::Optional` of the pair of versions.

Thent it can be used like this

```lang=cpp
if (auto ExperimentalExtension = isExperimentalExtension(Ext)) {
   std::pair SupportedVers = *ExperimentalVersion;
   ...
}
```

I'd also add a comment that the pair's `first` is the major version and 
`second` is the minor version (or alternative use a struct with two public 
fields `Major` and `Minor`)



Comment at: clang/lib/Driver/ToolChains/Arch/RISCV.cpp:396
+  I += Minor.size() + 1 /*'p'*/;
+if (*I == '_')
+  ++I;

There is no test for that case but I'm afraid we can't test it yet, can we?


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D73891/new/

https://reviews.llvm.org/D73891



___
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

[PATCH] D73891: [RISCV] Support experimental/unratified extensions

[Simon Cook via Phabricator via cfe-commits]

simoncook updated this revision to Diff 242080.
simoncook added a comment.

Don't put option in m_riscv_Features_Group, we don't want it being handled like 
a feature.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D73891/new/

https://reviews.llvm.org/D73891

Files:
  clang/include/clang/Driver/Options.td
  clang/lib/Driver/ToolChains/Arch/RISCV.cpp
  clang/test/Driver/riscv-arch.c

Index: clang/test/Driver/riscv-arch.c
===
--- clang/test/Driver/riscv-arch.c
+++ clang/test/Driver/riscv-arch.c
@@ -327,3 +327,22 @@
 // RUN: %clang -target riscv64-unknown-elf -march=rv64i -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV64-TARGET %s
 // RV64-TARGET: "-triple" "riscv64-unknown-unknown-elf"
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-NOFLAG %s
+// RV32-EXPERIMENTAL-NOFLAG: error: invalid arch name 'rv32ib'
+// RV32-EXPERIMENTAL-NOFLAG: requires '-menable-experimental-extensions'
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-NOVERS %s
+// RV32-EXPERIMENTAL-NOVERS: error: invalid arch name 'rv32ib'
+// RV32-EXPERIMENTAL-NOVERS: experimental extension requires explicit version number
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib0p1 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-BADVERS %s
+// RV32-EXPERIMENTAL-BADVERS: error: invalid arch name 'rv32ib0p1'
+// RV32-EXPERIMENTAL-BADVERS: unsupported version number 0.1 for experimental extension
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib0p92 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-GOODVERS %s
+// RV32-EXPERIMENTAL-GOODVERS: "-target-feature" "+b"
Index: clang/lib/Driver/ToolChains/Arch/RISCV.cpp
===
--- clang/lib/Driver/ToolChains/Arch/RISCV.cpp
+++ clang/lib/Driver/ToolChains/Arch/RISCV.cpp
@@ -47,20 +47,32 @@
   return false;
 }
 
+static bool isExperimentalExtension(StringRef Ext) {
+  // Currently 'b' is the only supported experimental extension
+  if (Ext == "b")
+return true;
+  return false;
+}
+
+static std::pair
+getExperimentalExtensionVersion(StringRef Ext) {
+  if (Ext == "b")
+return {"0", "92"};
+  return {"", ""};
+}
+
 // Extensions may have a version number, and may be separated by
 // an underscore '_' e.g.: rv32i2_m2.
 // Version number is divided into major and minor version numbers,
 // separated by a 'p'. If the minor version is 0 then 'p0' can be
 // omitted from the version string. E.g., rv32i2p0, rv32i2, rv32i2p1.
-static bool getExtensionVersion(const Driver , StringRef MArch,
-StringRef Ext, StringRef In,
+static bool getExtensionVersion(const Driver , const ArgList ,
+StringRef MArch, StringRef Ext, StringRef In,
 std::string , std::string ) {
   Major = std::string(In.take_while(isDigit));
   In = In.substr(Major.size());
-  if (Major.empty())
-return true;
 
-  if (In.consume_front("p")) {
+  if (Major.size() && In.consume_front("p")) {
 Minor = std::string(In.take_while(isDigit));
 In = In.substr(Major.size());
 
@@ -74,7 +86,43 @@
 }
   }
 
-  // TODO: Handle extensions with version number.
+  // If experimental extension, require use of current version number number
+  if (isExperimentalExtension(Ext)) {
+if (!Args.hasArg(options::OPT_menable_experimental_extensions)) {
+  std::string Error =
+  "requires '-menable-experimental-extensions' for experimental extension";
+  D.Diag(diag::err_drv_invalid_riscv_ext_arch_name)
+  << MArch << Error << Ext;
+  return false;
+} else if (Major.empty() && Minor.empty()) {
+  std::string Error =
+  "experimental extension requires explicit version number";
+  D.Diag(diag::err_drv_invalid_riscv_ext_arch_name)
+  << MArch << Error << Ext;
+  return false;
+}
+auto SupportedVers = getExperimentalExtensionVersion(Ext);
+if (Major != SupportedVers.first || Minor != SupportedVers.second) {
+  std::string Error =
+  "unsupported version number " + Major;
+  if (!Minor.empty())
+Error += "." + Minor;
+  Error += " for experimental extension (this compiler supports "
++ SupportedVers.first.str() + "."
++ SupportedVers.second.str() + ")";
+
+  D.Diag(diag::err_drv_invalid_riscv_ext_arch_name)
+  << MArch << Error << Ext;
+  return false;
+}
+return true;
+  }
+
+  // Allow extensions to declare no version number
+  if (Major.empty() && Minor.empty())
+return true;
+
+  // TODO: Handle 

[PATCH] D73891: [RISCV] Support experimental/unratified extensions

[Simon Cook via Phabricator via cfe-commits]

simoncook created this revision.
simoncook added reviewers: asb, lenary, PaoloS, s.egerton.
Herald added subscribers: cfe-commits, luismarques, apazos, sameer.abuasal, 
pzheng, Jim, benna, psnobl, jocewei, PkmX, rkruppe, the_o, brucehoult, 
MartinMosbeck, rogfer01, edward-jones, zzheng, MaskRay, jrtc27, shiva0217, 
kito-cheng, niosHD, sabuasal, johnrusso, rbar.
Herald added a project: clang.
simoncook added a parent revision: D65649: [RISCV] Add MC encodings and tests 
of the Bit Manipulation extension.

This adds support for enabling experimental/unratified RISC-V ISA
extensions in the -march string in the case where an explicit version
number has been declared, and the -menable-experimental-extensions flag
has been provided.

This follows the design as discussed on the mailing lists in the
following RFC: http://lists.llvm.org/pipermail/llvm-dev/2020-January/138364.html

Since the RISCV ToolChain definition currently rejects any extension
with an explicit version number, the parsing logic has been tweaked to
support this, and to allow standard extensions to have their versions
checked in future patches.

Support for the bitmanip 'b' extension has been added as a first example,
it should be clear how to extend this should vector 'v' land first.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D73891

Files:
  clang/include/clang/Driver/Options.td
  clang/lib/Driver/ToolChains/Arch/RISCV.cpp
  clang/test/Driver/riscv-arch.c

Index: clang/test/Driver/riscv-arch.c
===
--- clang/test/Driver/riscv-arch.c
+++ clang/test/Driver/riscv-arch.c
@@ -327,3 +327,22 @@
 // RUN: %clang -target riscv64-unknown-elf -march=rv64i -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV64-TARGET %s
 // RV64-TARGET: "-triple" "riscv64-unknown-unknown-elf"
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-NOFLAG %s
+// RV32-EXPERIMENTAL-NOFLAG: error: invalid arch name 'rv32ib'
+// RV32-EXPERIMENTAL-NOFLAG: requires '-menable-experimental-extensions'
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-NOVERS %s
+// RV32-EXPERIMENTAL-NOVERS: error: invalid arch name 'rv32ib'
+// RV32-EXPERIMENTAL-NOVERS: experimental extension requires explicit version number
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib0p1 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-BADVERS %s
+// RV32-EXPERIMENTAL-BADVERS: error: invalid arch name 'rv32ib0p1'
+// RV32-EXPERIMENTAL-BADVERS: unsupported version number 0.1 for experimental extension
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ib0p92 -menable-experimental-extensions -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-GOODVERS %s
+// RV32-EXPERIMENTAL-GOODVERS: "-target-feature" "+b"
Index: clang/lib/Driver/ToolChains/Arch/RISCV.cpp
===
--- clang/lib/Driver/ToolChains/Arch/RISCV.cpp
+++ clang/lib/Driver/ToolChains/Arch/RISCV.cpp
@@ -47,20 +47,32 @@
   return false;
 }
 
+static bool isExperimentalExtension(StringRef Ext) {
+  // Currently 'b' is the only supported experimental extension
+  if (Ext == "b")
+return true;
+  return false;
+}
+
+static std::pair
+getExperimentalExtensionVersion(StringRef Ext) {
+  if (Ext == "b")
+return {"0", "92"};
+  return {"", ""};
+}
+
 // Extensions may have a version number, and may be separated by
 // an underscore '_' e.g.: rv32i2_m2.
 // Version number is divided into major and minor version numbers,
 // separated by a 'p'. If the minor version is 0 then 'p0' can be
 // omitted from the version string. E.g., rv32i2p0, rv32i2, rv32i2p1.
-static bool getExtensionVersion(const Driver , StringRef MArch,
-StringRef Ext, StringRef In,
+static bool getExtensionVersion(const Driver , const ArgList ,
+StringRef MArch, StringRef Ext, StringRef In,
 std::string , std::string ) {
   Major = std::string(In.take_while(isDigit));
   In = In.substr(Major.size());
-  if (Major.empty())
-return true;
 
-  if (In.consume_front("p")) {
+  if (Major.size() && In.consume_front("p")) {
 Minor = std::string(In.take_while(isDigit));
 In = In.substr(Major.size());
 
@@ -74,7 +86,43 @@
 }
   }
 
-  // TODO: Handle extensions with version number.
+  // If experimental extension, require use of current version number number
+  if (isExperimentalExtension(Ext)) {
+if (!Args.hasArg(options::OPT_menable_experimental_extensions)) {
+  std::string Error =
+  "requires '-menable-experimental-extensions' for experimental extension";
+