Initial support for vectorization using MASSV (IBM MASS vector library)

Part 2 (the Clang portion) of D59881.

This patch (first of two patches) enables the vectorizer to recognize the
IBM MASS vector library routines. This patch specifically adds support for
recognizing the -vector-library=MASSV option, and defines mappings from IEEE
standard scalar math functions to generic PowerPC MASS vector counterparts.
For instance, the generic PowerPC MASS vector entry for double-precision
cbrt function is __cbrtd2_massv.

The second patch will further lower the generic PowerPC vector entries to
PowerPC subtarget-specific entries.
For instance, the PowerPC generic entry cbrtd2_massv is lowered to
cbrtd2_P9 for Power9 subtarget.

The overall support for MASS vector library is presented as such in two patches
for ease of review.

Patch by Jeeva Paudel.

Differential revision: https://reviews.llvm.org/D59881


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@362571 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Basic/CodeGenOptions.h

@@ -53,6 +53,7 @@ public:
   enum VectorLibrary {
     NoLibrary,  // Don't use any vector library.
     Accelerate, // Use the Accelerate framework.
+    MASSV,      // IBM MASS vector library.
     SVML        // Intel short vector math library.
   };
 

include/clang/Driver/Options.td

@@ -1418,7 +1418,7 @@ def fno_experimental_new_pass_manager : Flag<["-"], "fno-experimental-new-pass-m
   Group<f_clang_Group>, Flags<[CC1Option]>,
   HelpText<"Disables an experimental new pass manager in LLVM.">;
 def fveclib : Joined<["-"], "fveclib=">, Group<f_Group>, Flags<[CC1Option]>,
-    HelpText<"Use the given vector functions library">, Values<"Accelerate,SVML,none">;
+    HelpText<"Use the given vector functions library">, Values<"Accelerate,MASSV,SVML,none">;
 def fno_lax_vector_conversions : Flag<["-"], "fno-lax-vector-conversions">, Group<f_Group>,
   HelpText<"Disallow implicit conversions between vectors with a different number of elements or different element types">, Flags<[CC1Option]>;
 def fno_merge_all_constants : Flag<["-"], "fno-merge-all-constants">, Group<f_Group>,

lib/CodeGen/BackendUtil.cpp

@@ -340,6 +340,9 @@ static TargetLibraryInfoImpl *createTLII(llvm::Triple &TargetTriple,
   case CodeGenOptions::Accelerate:
     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::Accelerate);
     break;
+  case CodeGenOptions::MASSV:
+    TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::MASSV);
+    break;    
   case CodeGenOptions::SVML:
     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::SVML);
     break;

lib/Frontend/CompilerInvocation.cpp

@@ -682,6 +682,8 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
     StringRef Name = A->getValue();
     if (Name == "Accelerate")
       Opts.setVecLib(CodeGenOptions::Accelerate);
+    else if (Name == "MASSV")
+      Opts.setVecLib(CodeGenOptions::MASSV);
     else if (Name == "SVML")
       Opts.setVecLib(CodeGenOptions::SVML);
     else if (Name == "none")

test/Driver/autocomplete.c

@@ -68,6 +68,7 @@
 // FLTOALL-NEXT: thin
 // RUN: %clang --autocomplete=-fveclib= | FileCheck %s -check-prefix=FVECLIBALL
 // FVECLIBALL: Accelerate
+// FVECLIBALL-NEXT: MASSV
 // FVECLIBALL-NEXT: none
 // FVECLIBALL-NEXT: SVML
 // RUN: %clang --autocomplete=-fshow-overloads= | FileCheck %s -check-prefix=FSOVERALL

test/Driver/fveclib.c

@@ -1,9 +1,11 @@
 // 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 -fveclib=MASSV %s 2>&1 | FileCheck -check-prefix CHECK-MASSV %s
 // RUN: not %clang -c -fveclib=something %s 2>&1 | FileCheck -check-prefix CHECK-INVALID %s
 
 // CHECK-NOLIB: "-fveclib=none"
 // CHECK-ACCELERATE: "-fveclib=Accelerate"
+// CHECK-MASSV: "-fveclib=MASSV"
 
 // CHECK-INVALID: error: invalid value 'something' in '-fveclib=something'