[Clang][Driver][fveclib] Fix target parsing for -fveclib=AMDLIBM option (#140544)

The behavior of -fveclib=AMDLIBM should be similar to -fveclib=libmvec. 
Example - Error message for unsupported target usage should be same.

We are handling the missed cases for -fveclib=AMDLIBM and aligning it to
-fveclib=libmvec usage.

---------

Co-authored-by: Rohit Aggarwal <[email protected]>

Author: rohitaggarwal007

clang/include/clang/Basic/CodeGenOptions.def

@@ -389,7 +389,7 @@ ENUM_CODEGENOPT(Inlining, InliningMethod, 2, NormalInlining)
 VALUE_CODEGENOPT(InlineMaxStackSize, 32, UINT_MAX)
 
 // Vector functions library to use.
-ENUM_CODEGENOPT(VecLib, llvm::driver::VectorLibrary, 3, llvm::driver::VectorLibrary::NoLibrary)
+ENUM_CODEGENOPT(VecLib, llvm::driver::VectorLibrary, 4, llvm::driver::VectorLibrary::NoLibrary)
 
 /// The default TLS model to use.
 ENUM_CODEGENOPT(DefaultTLSModel, TLSModel, 2, GeneralDynamicTLSModel)

clang/lib/Driver/ToolChains/Clang.cpp

@@ -5851,7 +5851,7 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
           Triple.getArch() != llvm::Triple::x86_64)
         D.Diag(diag::err_drv_unsupported_opt_for_target)
             << Name << Triple.getArchName();
-    } else if (Name == "libmvec") {
+    } else if (Name == "libmvec" || Name == "AMDLIBM") {
       if (Triple.getArch() != llvm::Triple::x86 &&
           Triple.getArch() != llvm::Triple::x86_64)
         D.Diag(diag::err_drv_unsupported_opt_for_target)

clang/lib/Driver/ToolChains/CommonArgs.cpp

@@ -935,6 +935,7 @@ void tools::addLTOOptions(const ToolChain &ToolChain, const ArgList &Args,
         llvm::StringSwitch<std::optional<StringRef>>(ArgVecLib->getValue())
             .Case("Accelerate", "Accelerate")
             .Case("libmvec", "LIBMVEC")
+            .Case("AMDLIBM", "AMDLIBM")
             .Case("MASSV", "MASSV")
             .Case("SVML", "SVML")
             .Case("SLEEF", "sleefgnuabi")

clang/test/Driver/fveclib.c

@@ -1,6 +1,7 @@
 // RUN: %clang -### -c -fveclib=none %s 2>&1 | FileCheck --check-prefix=CHECK-NOLIB %s
 // RUN: %clang -### -c -fveclib=Accelerate %s 2>&1 | FileCheck --check-prefix=CHECK-ACCELERATE %s
 // RUN: %clang -### -c --target=x86_64-unknown-linux-gnu -fveclib=libmvec %s 2>&1 | FileCheck --check-prefix=CHECK-libmvec %s
+// RUN: %clang -### -c --target=x86_64-unknown-linux-gnu -fveclib=AMDLIBM %s 2>&1 | FileCheck --check-prefix=CHECK-AMDLIBM %s
 // RUN: %clang -### -c -fveclib=MASSV %s 2>&1 | FileCheck --check-prefix=CHECK-MASSV %s
 // RUN: %clang -### -c -fveclib=Darwin_libsystem_m %s 2>&1 | FileCheck --check-prefix=CHECK-DARWIN_LIBSYSTEM_M %s
 // RUN: %clang -### -c --target=aarch64 -fveclib=SLEEF %s 2>&1 | FileCheck --check-prefix=CHECK-SLEEF %s
@@ -11,6 +12,7 @@
 // CHECK-NOLIB: "-fveclib=none"
 // CHECK-ACCELERATE: "-fveclib=Accelerate"
 // CHECK-libmvec: "-fveclib=libmvec"
+// CHECK-AMDLIBM: "-fveclib=AMDLIBM"
 // CHECK-MASSV: "-fveclib=MASSV"
 // CHECK-DARWIN_LIBSYSTEM_M: "-fveclib=Darwin_libsystem_m"
 // CHECK-SLEEF: "-fveclib=SLEEF"
@@ -23,6 +25,7 @@
 // RUN: not %clang --target=x86 -c -fveclib=ArmPL %s 2>&1 | FileCheck --check-prefix=CHECK-ERROR %s
 // RUN: not %clang --target=aarch64 -c -fveclib=libmvec %s 2>&1 | FileCheck --check-prefix=CHECK-ERROR %s
 // RUN: not %clang --target=aarch64 -c -fveclib=SVML %s 2>&1 | FileCheck --check-prefix=CHECK-ERROR %s
+// RUN: not %clang --target=aarch64 -c -fveclib=AMDLIBM %s 2>&1 | FileCheck --check-prefix=CHECK-ERROR %s
 // CHECK-ERROR: unsupported option {{.*}} for target
 
 // RUN: %clang -fveclib=Accelerate %s -target arm64-apple-ios8.0.0 -### 2>&1 | FileCheck --check-prefix=CHECK-LINK %s
@@ -40,6 +43,9 @@
 // RUN: %clang -### --target=x86_64-unknown-linux-gnu -fveclib=libmvec -flto %s 2>&1 | FileCheck --check-prefix=CHECK-LTO-LIBMVEC %s
 // CHECK-LTO-LIBMVEC: "-plugin-opt=-vector-library=LIBMVEC"
 
+// RUN: %clang -### --target=x86_64-unknown-linux-gnu -fveclib=AMDLIBM -flto %s 2>&1 | FileCheck --check-prefix=CHECK-LTO-AMDLIBM %s
+// CHECK-LTO-AMDLIBM: "-plugin-opt=-vector-library=AMDLIBM"
+
 // RUN: %clang -### --target=powerpc64-unknown-linux-gnu -fveclib=MASSV -flto %s 2>&1 | FileCheck --check-prefix=CHECK-LTO-MASSV %s
 // CHECK-LTO-MASSV: "-plugin-opt=-vector-library=MASSV"
 
@@ -62,6 +68,10 @@
 // CHECK-ERRNO-LIBMVEC: "-fveclib=libmvec"
 // CHECK-ERRNO-LIBMVEC-SAME: "-fmath-errno"
 
+// RUN: %clang -### --target=x86_64-unknown-linux-gnu -fveclib=AMDLIBM %s 2>&1 | FileCheck --check-prefix=CHECK-ERRNO-AMDLIBM %s
+// CHECK-ERRNO-AMDLIBM: "-fveclib=AMDLIBM"
+// CHECK-ERRNO-AMDLIBM-SAME: "-fmath-errno"
+
 // RUN: %clang -### --target=powerpc64-unknown-linux-gnu -fveclib=MASSV %s 2>&1 | FileCheck --check-prefix=CHECK-ERRNO-MASSV %s
 // CHECK-ERRNO-MASSV: "-fveclib=MASSV"
 // CHECK-ERRNO-MASSV-SAME: "-fmath-errno"

llvm/include/llvm/Frontend/Driver/CodeGenOptions.h

@@ -19,6 +19,19 @@ class TargetLibraryInfoImpl;
 } // namespace llvm
 
 namespace llvm::driver {
+// The current supported vector libraries in enum \VectorLibrary are 9(including
+// the NoLibrary). Changing the bitcount from 3 to 4 so that more than 8 values
+// can be supported. Now the maximum number of vector libraries supported
+// increase from 8(2^3) to 16(2^4).
+//
+// ENUM_CODEGENOPT(VecLib, llvm::driver::VectorLibrary,
+// <bitcount>4</bitcount>, llvm::driver::VectorLibrary::NoLibrary) is the
+// currently defined in clang/include/clang/Basic/CodeGenOptions.def
+// bitcount is the number of bits used to represent the enum value.
+//
+// IMPORTANT NOTE: When adding a new vector library support, and if count of
+// supported vector libraries crosses the current max limit. Please increment
+// the bitcount value.
 
 /// Vector library option used with -fveclib=
 enum class VectorLibrary {