[RISCV] Support experimental 'P' extension 0.9

[Jim]

Summary

Support arch feature for experimental 'P' extension with version 0.9.

[Jim]

Merge this patch into https://reviews.llvm.org/D95588

[Jim]

Recover it. Split arch version for P extension of D95588 to this.

[Jim]

Rebase

[Jim]

Rebase

[zixuan-wu]

Could abandon it due to D108189?

clang/lib/Driver/ToolChains/Arch/RISCV.cpp

 // 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 == "zba" || Ext == "zbb" || Ext == "zbc" ||
       Ext == "zbe" || Ext == "zbf" || Ext == "zbm" || Ext == "zbp" ||
       Ext == "zbr" || Ext == "zbs" || Ext == "zbt" || Ext == "zbproposedc")
     return RISCVExtensionVersion{"0", "93"};
+  if (Ext == "p")
+    return RISCVExtensionVersion{"0", "9"};
   if (Ext == "v" || Ext == "zvamo" || Ext == "zvlsseg")
     return RISCVExtensionVersion{"1", "0"};
   if (Ext == "zfh")
     return RISCVExtensionVersion{"0", "1"};
   return None;
 }
 
 static bool isSupportedExtension(StringRef Ext) {
case 'b':
       Features.push_back("+experimental-zbe");
       Features.push_back("+experimental-zbf");
       Features.push_back("+experimental-zbm");
       Features.push_back("+experimental-zbp");
       Features.push_back("+experimental-zbr");
       Features.push_back("+experimental-zbs");
       Features.push_back("+experimental-zbt");
       break;
+    case 'p':
+      Features.push_back("+experimental-p");
+      break;
     case 'v':
       Features.push_back("+experimental-v");
       Features.push_back("+experimental-zvamo");
       Features.push_back("+experimental-zvlsseg");
       break;
     }
 
     // Consume full extension name and version, including any optional '_'

clang/test/Driver/riscv-arch.c

 // RUN: %clang -target riscv32-unknown-elf -march=rv32izbb0p93zbp0p93 -menable-experimental-extensions -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-ZBB-ZBP-UNDERSCORE %s
 // RV32-EXPERIMENTAL-ZBB-ZBP-UNDERSCORE: error: invalid arch name 'rv32izbb0p93zbp0p93', multi-character extensions must be separated by underscores
 
 // RUN: %clang -target riscv32-unknown-elf -march=rv32izba0p93 -menable-experimental-extensions -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-EXPERIMENTAL-ZBA %s
 // RV32-EXPERIMENTAL-ZBA: "-target-feature" "+experimental-zba"
 
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ip -### %s -c 2>&1 | \
+// RUN:   FileCheck -check-prefix=RV32-EXPERIMENTAL-P-NOFLAG %s
+// RV32-EXPERIMENTAL-P-NOFLAG: error: invalid arch name 'rv32ip'
+// RV32-EXPERIMENTAL-P-NOFLAG: requires '-menable-experimental-extensions'
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ip -menable-experimental-extensions -### %s -c 2>&1 | \
+// RUN:   FileCheck -check-prefix=RV32-EXPERIMENTAL-P-NOVERS %s
+// RV32-EXPERIMENTAL-P-NOVERS: error: invalid arch name 'rv32ip'
+// RV32-EXPERIMENTAL-P-NOVERS: experimental extension requires explicit version number
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ip0p1 -menable-experimental-extensions -### %s -c 2>&1 | \
+// RUN:   FileCheck -check-prefix=RV32-EXPERIMENTAL-P-BADVERS %s
+// RV32-EXPERIMENTAL-P-BADVERS: error: invalid arch name 'rv32ip0p1'
+// RV32-EXPERIMENTAL-P-BADVERS: unsupported version number 0.1 for experimental extension
+
+// RUN: %clang -target riscv32-unknown-elf -march=rv32ip0p9 -menable-experimental-extensions -### %s -c 2>&1 | \
+// RUN:   FileCheck -check-prefix=RV32-EXPERIMENTAL-P-GOODVERS %s
+// RV32-EXPERIMENTAL-P-GOODVERS: "-target-feature" "+experimental-p"
+
 // RUN: %clang -target riscv32-unknown-elf -march=rv32iv -### %s -c 2>&1 | \
 // RUN:   FileCheck -check-prefix=RV32-EXPERIMENTAL-V-NOFLAG %s
 // RV32-EXPERIMENTAL-V-NOFLAG: error: invalid arch name 'rv32iv'
 // RV32-EXPERIMENTAL-V-NOFLAG: requires '-menable-experimental-extensions'
 
 // RUN: %clang -target riscv32-unknown-elf -march=rv32iv -menable-experimental-extensions -### %s -c 2>&1 | \
 // RUN:   FileCheck -check-prefix=RV32-EXPERIMENTAL-V-NOVERS %s
 // RV32-EXPERIMENTAL-V-NOVERS: error: invalid arch name 'rv32iv'