[clang] dd1ee6d - [RISCV] Support experimental/unratified extensions
Simon Cook via cfe-commits
cfe-commits at lists.llvm.org
Thu Apr 9 10:04:58 PDT 2020
Author: Simon Cook
Date: 2020-04-09T18:04:22+01:00
New Revision: dd1ee6dc076fe1da6cf6eeb9cf614d9c1796759a
URL: https://github.com/llvm/llvm-project/commit/dd1ee6dc076fe1da6cf6eeb9cf614d9c1796759a
DIFF: https://github.com/llvm/llvm-project/commit/dd1ee6dc076fe1da6cf6eeb9cf614d9c1796759a.diff
LOG: [RISCV] Support experimental/unratified extensions
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 RISC-V 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.
The bitmanip 'b' extension has been added as a first use of this support,
it should easily extend to other as yet unratified extensions (such as
the vector 'v' extension).
Differential Revision: https://reviews.llvm.org/D73891
Added:
Modified:
clang/include/clang/Driver/Options.td
clang/lib/Driver/ToolChains/Arch/RISCV.cpp
clang/test/Driver/riscv-arch.c
Removed:
################################################################################
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index a395b680eb88..5becd52dae80 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -2332,6 +2332,8 @@ def mcmodel_EQ_medlow : Flag<["-"], "mcmodel=medlow">, Group<m_riscv_Features_Gr
def mcmodel_EQ_medany : Flag<["-"], "mcmodel=medany">, Group<m_riscv_Features_Group>,
Flags<[CC1Option]>, Alias<mcmodel_EQ>, AliasArgs<["medium"]>,
HelpText<"Equivalent to -mcmodel=medium, compatible with RISC-V gcc.">;
+def menable_experimental_extensions : Flag<["-"], "menable-experimental-extensions">, Group<m_Group>,
+ HelpText<"Enable use of experimental RISC-V extensions.">;
def munaligned_access : Flag<["-"], "munaligned-access">, Group<m_arm_Features_Group>,
HelpText<"Allow memory accesses to be unaligned (AArch32/AArch64 only)">;
diff --git a/clang/lib/Driver/ToolChains/Arch/RISCV.cpp b/clang/lib/Driver/ToolChains/Arch/RISCV.cpp
index f5764ca5dc06..f16827e00f1f 100644
--- a/clang/lib/Driver/ToolChains/Arch/RISCV.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/RISCV.cpp
@@ -22,6 +22,14 @@ using namespace clang::driver::tools;
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";
@@ -29,6 +37,8 @@ static StringRef getExtensionTypeDesc(StringRef Ext) {
return "standard supervisor-level extension";
if (Ext.startswith("x"))
return "non-standard user-level extension";
+ if (Ext.startswith("z"))
+ return "standard user-level extension";
return StringRef();
}
@@ -39,10 +49,27 @@ static StringRef getExtensionType(StringRef Ext) {
return "s";
if (Ext.startswith("x"))
return "x";
+ if (Ext.startswith("z"))
+ return "z";
return StringRef();
}
+// If the extension is supported as experimental, return the version of that
+// extension that the compiler currently supports.
+static Optional<RISCVExtensionVersion>
+isExperimentalExtension(StringRef Ext) {
+ if (Ext == "b" || Ext == "zbb" || Ext == "zbc" || Ext == "zbe" ||
+ Ext == "zbf" || Ext == "zbm" || Ext == "zbp" || Ext == "zbr" ||
+ Ext == "zbs" || Ext == "zbt" || Ext == "zbproposedc")
+ return RISCVExtensionVersion{"0", "92"};
+ return None;
+}
+
static bool isSupportedExtension(StringRef Ext) {
+ // LLVM supports "z" extensions which are marked as experimental.
+ if (isExperimentalExtension(Ext))
+ return true;
+
// LLVM does not support "sx", "s" nor "x" extensions.
return false;
}
@@ -52,15 +79,13 @@ static bool isSupportedExtension(StringRef Ext) {
// 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 &D, StringRef MArch,
- StringRef Ext, StringRef In,
+static bool getExtensionVersion(const Driver &D, const ArgList &Args,
+ StringRef MArch, StringRef Ext, StringRef In,
std::string &Major, std::string &Minor) {
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 +99,43 @@ static bool getExtensionVersion(const Driver &D, StringRef MArch,
}
}
- // 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 supports "
+ + SupportedVers.Major.str() + "."
+ + SupportedVers.Minor.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 supported extensions with version number.
std::string Error = "unsupported version number " + Major;
if (!Minor.empty())
Error += "." + Minor;
@@ -89,7 +150,7 @@ static bool getExtensionVersion(const Driver &D, StringRef MArch,
// Parse the ISA string containing non-standard user-level
// extensions, standard supervisor-level extensions and
// non-standard supervisor-level extensions.
-// These extensions start with 'x', 's', 'sx' prefixes, follow a
+// These extensions start with 'z', 'x', 's', 'sx' prefixes, follow a
// canonical order, might have a version number (major, minor)
// and are separated by a single underscore '_'.
// Set the hardware features for the extensions that are supported.
@@ -105,7 +166,7 @@ static void getExtensionFeatures(const Driver &D,
SmallVector<StringRef, 8> Split;
Exts.split(Split, StringRef("_"));
- SmallVector<StringRef, 3> Prefix{"x", "s", "sx"};
+ SmallVector<StringRef, 4> Prefix{"z", "x", "s", "sx"};
auto I = Prefix.begin();
auto E = Prefix.end();
@@ -119,8 +180,10 @@ static void getExtensionFeatures(const Driver &D,
}
StringRef Type = getExtensionType(Ext);
- StringRef Name(Ext.substr(Type.size()));
StringRef Desc = getExtensionTypeDesc(Ext);
+ auto Pos = Ext.find_if(isDigit);
+ StringRef Name(Ext.substr(0, Pos));
+ StringRef Vers(Ext.substr(Pos));
if (Type.empty()) {
D.Diag(diag::err_drv_invalid_riscv_ext_arch_name)
@@ -143,35 +206,30 @@ static void getExtensionFeatures(const Driver &D,
// The order is OK, do not advance I to the next prefix
// to allow repeated extension type, e.g.: rv32ixabc_xdef.
- if (Name.empty()) {
+ if (Name.size() == Type.size()) {
std::string Error = std::string(Desc);
Error += " name missing after";
D.Diag(diag::err_drv_invalid_riscv_ext_arch_name)
- << MArch << Error << Ext;
+ << MArch << Error << Type;
return;
}
std::string Major, Minor;
- auto Pos = Name.find_if(isDigit);
- if (Pos != StringRef::npos) {
- auto Next = Name.substr(Pos);
- Name = Name.substr(0, Pos);
- if (!getExtensionVersion(D, MArch, Ext, Next, Major, Minor))
- return;
- }
+ if (!getExtensionVersion(D, Args, MArch, Name, Vers, Major, Minor))
+ return;
// Check if duplicated extension.
- if (llvm::is_contained(AllExts, Ext)) {
+ if (llvm::is_contained(AllExts, Name)) {
std::string Error = "duplicated ";
Error += Desc;
D.Diag(diag::err_drv_invalid_riscv_ext_arch_name)
- << MArch << Error << Ext;
+ << MArch << Error << Name;
return;
}
// Extension format is correct, keep parsing the extensions.
// TODO: Save Type, Name, Major, Minor to avoid parsing them later.
- AllExts.push_back(Ext);
+ AllExts.push_back(Name);
}
// Set target features.
@@ -186,7 +244,10 @@ static void getExtensionFeatures(const Driver &D,
<< MArch << Error << Ext;
return;
}
- Features.push_back(Args.MakeArgString("+" + Ext));
+ if (isExperimentalExtension(Ext))
+ Features.push_back(Args.MakeArgString("+experimental-" + Ext));
+ else
+ Features.push_back(Args.MakeArgString("+" + Ext));
}
}
@@ -251,28 +312,35 @@ static bool getArchFeatures(const Driver &D, StringRef MArch,
// Skip rvxxx
StringRef Exts = MArch.substr(5);
- // Remove non-standard extensions and supervisor-level extensions.
- // They have 'x', 's', 'sx' prefixes. Parse them at the end.
- // Find the very first occurrence of 's' or 'x'.
+ // Remove multi-letter standard extensions, non-standard extensions and
+ // supervisor-level extensions. They have 'z', 'x', 's', 'sx' prefixes.
+ // Parse them at the end.
+ // Find the very first occurrence of 's', 'x' or 'z'.
StringRef OtherExts;
- size_t Pos = Exts.find_first_of("sx");
+ size_t Pos = Exts.find_first_of("zsx");
if (Pos != StringRef::npos) {
OtherExts = Exts.substr(Pos);
Exts = Exts.substr(0, Pos);
}
std::string Major, Minor;
- if (!getExtensionVersion(D, MArch, std::string(1, Baseline), Exts, Major,
- Minor))
+ if (!getExtensionVersion(D, Args, MArch, std::string(1, Baseline), Exts,
+ Major, Minor))
return false;
+ // Consume the base ISA version number and any '_' between rvxxx and the
+ // first extension
+ Exts = Exts.drop_front(Major.size());
+ if (!Minor.empty())
+ Exts = Exts.drop_front(Minor.size() + 1 /*'p'*/);
+ Exts.consume_front("_");
+
// TODO: Use version number when setting target features
- // and consume the underscore '_' that might follow.
auto StdExtsItr = StdExts.begin();
auto StdExtsEnd = StdExts.end();
- for (auto I = Exts.begin(), E = Exts.end(); I != E; ++I) {
+ for (auto I = Exts.begin(), E = Exts.end(); I != E; ) {
char c = *I;
// Check ISA extensions are specified in the canonical order.
@@ -295,18 +363,15 @@ static bool getArchFeatures(const Driver &D, StringRef MArch,
// Move to next char to prevent repeated letter.
++StdExtsItr;
- if (std::next(I) != E) {
- // Skip c.
- std::string Next = std::string(std::next(I), E);
- std::string Major, Minor;
- if (!getExtensionVersion(D, MArch, std::string(1, c), Next, Major, Minor))
- return false;
-
- // TODO: Use version number when setting target features
- // and consume the underscore '_' that might follow.
- }
+ std::string Next, Major, Minor;
+ if (std::next(I) != E)
+ Next = std::string(std::next(I), E);
+ if (!getExtensionVersion(D, Args, MArch, std::string(1, c), Next, Major,
+ Minor))
+ return false;
// The order is OK, then push it into features.
+ // TODO: Use version number when setting target features
switch (c) {
default:
// Currently LLVM supports only "mafdc".
@@ -331,7 +396,19 @@ static bool getArchFeatures(const Driver &D, StringRef MArch,
case 'c':
Features.push_back("+c");
break;
+ case 'b':
+ Features.push_back("+experimental-b");
+ break;
}
+
+ // Consume full extension name and version, including any optional '_'
+ // between this extension and the next
+ ++I;
+ I += Major.size();
+ if (Minor.size())
+ I += Minor.size() + 1 /*'p'*/;
+ if (*I == '_')
+ ++I;
}
// Dependency check.
diff --git a/clang/test/Driver/riscv-arch.c b/clang/test/Driver/riscv-arch.c
index 3e1be9a011bf..ba93be9caa36 100644
--- a/clang/test/Driver/riscv-arch.c
+++ b/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"
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