[Xtensa 1/10] Recognize Xtensa in triple parsing code

I'm sharing initial set of patches that adds LLVM backend for Xtensa architecture.
It is based on this LLVM fork https://github.com/espressif/llvm-xtensa.
I prepared patches by similar way like it was already successfully done for RISCV, i.e. incrementally add an initial MC layer for Xtensa by small chunks which could be reviewable.

Differential Revision: https://reviews.llvm.org/D64826

4 files changed, 37 insertions, 0 deletions

diff --git a/llvm/CODE_OWNERS.TXT b/llvm/CODE_OWNERS.TXT
index c6ac488..64e646d 100644
--- a/llvm/CODE_OWNERS.TXT
+++ b/llvm/CODE_OWNERS.TXT
@@ -201,6 +201,10 @@ N: Chad Rosier
 E: mcrosier@codeaurora.org
 D: Fast-Isel
 
+N: Andrei Safronov
+E: andrei.safronov@espressif.com
+D: Xtensa backend (lib/Target/Xtensa/*)
+
 N: Duncan Sands
 E: baldrick@free.fr
 D: DragonEgg
diff --git a/llvm/include/llvm/TargetParser/Triple.h b/llvm/include/llvm/TargetParser/Triple.h
index c8046ab..3db4194 100644
--- a/llvm/include/llvm/TargetParser/Triple.h
+++ b/llvm/include/llvm/TargetParser/Triple.h
@@ -85,6 +85,7 @@ public:
     x86,            // X86: i[3-9]86
     x86_64,         // X86-64: amd64, x86_64
     xcore,          // XCore: xcore
+    xtensa,         // Tensilica: Xtensa
     nvptx,          // NVPTX: 32-bit
     nvptx64,        // NVPTX: 64-bit
     le32,           // le32: generic little-endian 32-bit CPU (PNaCl)
diff --git a/llvm/lib/TargetParser/Triple.cpp b/llvm/lib/TargetParser/Triple.cpp
index b3fddc14..a680359 100644
--- a/llvm/lib/TargetParser/Triple.cpp
+++ b/llvm/lib/TargetParser/Triple.cpp
@@ -83,6 +83,7 @@ StringRef Triple::getArchTypeName(ArchType Kind) {
   case x86:            return "i386";
   case x86_64:         return "x86_64";
   case xcore:          return "xcore";
+  case xtensa:         return "xtensa";
   }
 
   llvm_unreachable("Invalid ArchType!");
@@ -172,6 +173,8 @@ StringRef Triple::getArchTypePrefix(ArchType Kind) {
   case loongarch64: return "loongarch";
 
   case dxil:        return "dx";
+
+  case xtensa:      return "xtensa";
   }
 }
 
@@ -374,6 +377,7 @@ Triple::ArchType Triple::getArchTypeForLLVMName(StringRef Name) {
     .Case("loongarch32", loongarch32)
     .Case("loongarch64", loongarch64)
     .Case("dxil", dxil)
+    .Case("xtensa", xtensa)
     .Default(UnknownArch);
 }
 
@@ -515,6 +519,7 @@ static Triple::ArchType parseArch(StringRef ArchName) {
     .Case("loongarch32", Triple::loongarch32)
     .Case("loongarch64", Triple::loongarch64)
     .Case("dxil", Triple::dxil)
+    .Case("xtensa", Triple::xtensa)
     .Default(Triple::UnknownArch);
 
   // Some architectures require special parsing logic just to compute the
@@ -849,6 +854,7 @@ static Triple::ObjectFormatType getDefaultFormat(const Triple &T) {
   case Triple::thumbeb:
   case Triple::ve:
   case Triple::xcore:
+  case Triple::xtensa:
     return Triple::ELF;
 
   case Triple::ppc64:
@@ -1429,6 +1435,7 @@ static unsigned getArchPointerBitWidth(llvm::Triple::ArchType Arch) {
   case llvm::Triple::wasm32:
   case llvm::Triple::x86:
   case llvm::Triple::xcore:
+  case llvm::Triple::xtensa:
     return 32;
 
   case llvm::Triple::aarch64:
@@ -1519,6 +1526,7 @@ Triple Triple::get32BitArchVariant() const {
   case Triple::wasm32:
   case Triple::x86:
   case Triple::xcore:
+  case Triple::xtensa:
     // Already 32-bit.
     break;
 
@@ -1569,6 +1577,7 @@ Triple Triple::get64BitArchVariant() const {
   case Triple::tce:
   case Triple::tcele:
   case Triple::xcore:
+  case Triple::xtensa:
     T.setArch(UnknownArch);
     break;
 
@@ -1669,6 +1678,7 @@ Triple Triple::getBigEndianArchVariant() const {
   case Triple::xcore:
   case Triple::ve:
   case Triple::csky:
+  case Triple::xtensa:
 
   // ARM is intentionally unsupported here, changing the architecture would
   // drop any arch suffixes.
@@ -1778,6 +1788,7 @@ bool Triple::isLittleEndian() const {
   case Triple::x86:
   case Triple::x86_64:
   case Triple::xcore:
+  case Triple::xtensa:
     return true;
   default:
     return false;
diff --git a/llvm/unittests/TargetParser/TripleTest.cpp b/llvm/unittests/TargetParser/TripleTest.cpp
index 5039758..77de43a 100644
--- a/llvm/unittests/TargetParser/TripleTest.cpp
+++ b/llvm/unittests/TargetParser/TripleTest.cpp
@@ -864,6 +864,18 @@ TEST(TripleTest, ParsedIDs) {
   EXPECT_EQ(Triple::Amplification, T.getEnvironment());
   EXPECT_FALSE(T.supportsCOMDAT());
 
+  T = Triple("xtensa");
+  EXPECT_EQ(Triple::xtensa, T.getArch());
+  EXPECT_EQ(Triple::UnknownVendor, T.getVendor());
+  EXPECT_EQ(Triple::UnknownOS, T.getOS());
+  EXPECT_EQ(Triple::UnknownEnvironment, T.getEnvironment());
+
+  T = Triple("xtensa-unknown-unknown");
+  EXPECT_EQ(Triple::xtensa, T.getArch());
+  EXPECT_EQ(Triple::UnknownVendor, T.getVendor());
+  EXPECT_EQ(Triple::UnknownOS, T.getOS());
+  EXPECT_EQ(Triple::UnknownEnvironment, T.getEnvironment());
+
   T = Triple("huh");
   EXPECT_EQ(Triple::UnknownArch, T.getArch());
 }
@@ -1225,6 +1237,11 @@ TEST(TripleTest, BitWidthPredicates) {
   EXPECT_TRUE(T.isArch32Bit());
   EXPECT_FALSE(T.isArch64Bit());
   EXPECT_TRUE(T.isDXIL());
+
+  T.setArch(Triple::xtensa);
+  EXPECT_FALSE(T.isArch16Bit());
+  EXPECT_TRUE(T.isArch32Bit());
+  EXPECT_FALSE(T.isArch64Bit());
 }
 
 TEST(TripleTest, BitWidthArchVariants) {
@@ -1419,6 +1436,10 @@ TEST(TripleTest, BitWidthArchVariants) {
   T.setArch(Triple::dxil);
   EXPECT_EQ(Triple::dxil, T.get32BitArchVariant().getArch());
   EXPECT_EQ(Triple::UnknownArch, T.get64BitArchVariant().getArch());
+
+  T.setArch(Triple::xtensa);
+  EXPECT_EQ(Triple::xtensa, T.get32BitArchVariant().getArch());
+  EXPECT_EQ(Triple::UnknownArch, T.get64BitArchVariant().getArch());
 }
 
 TEST(TripleTest, EndianArchVariants) {