Fix for Issue #1413 (cherry-pick #179 to release_18x) (#185)

PGMATH has AVX512 runtime functions and can be executed only when the application is compiled
in avx512 mode. The VecFuncs.def has no information about the TargetOptions and avx512 functions
are selected even in avx2 mode. This issue is fixed by creating separate table for AVX512 functions
and using them only when avx512 mode is specified.

Author: shivaramaarao

clang/lib/CodeGen/BackendUtil.cpp

@@ -557,8 +557,11 @@ bool EmitAssemblyHelper::AddEmitPasses(legacy::PassManager &CodeGenPasses,
                                        raw_pwrite_stream &OS,
                                        raw_pwrite_stream *DwoOS) {
   // Add LibraryInfo.
-  std::unique_ptr<TargetLibraryInfoImpl> TLII(
-      llvm::driver::createTLII(TargetTriple, CodeGenOpts.getVecLib()));
+  bool TargetHasAVX512 =
+      std::find(TargetOpts.Features.begin(), TargetOpts.Features.end(),
+                "+avx512f") != TargetOpts.Features.end();
+  std::unique_ptr<TargetLibraryInfoImpl> TLII(llvm::driver::createTLII(
+      TargetTriple, CodeGenOpts.getVecLib(), TargetHasAVX512));
   CodeGenPasses.add(new TargetLibraryInfoWrapperPass(*TLII));
 
   // Normal mode, emit a .s or .o file by running the code generator. Note,
@@ -890,8 +893,11 @@ void EmitAssemblyHelper::RunOptimizationPipeline(
 
   // Register the target library analysis directly and give it a customized
   // preset TLI.
-  std::unique_ptr<TargetLibraryInfoImpl> TLII(
-      llvm::driver::createTLII(TargetTriple, CodeGenOpts.getVecLib()));
+  bool TargetHasAVX512 =
+      std::find(TargetOpts.Features.begin(), TargetOpts.Features.end(),
+                "+avx512f") != TargetOpts.Features.end();
+  std::unique_ptr<TargetLibraryInfoImpl> TLII(llvm::driver::createTLII(
+      TargetTriple, CodeGenOpts.getVecLib(), TargetHasAVX512));
   FAM.registerPass([&] { return TargetLibraryAnalysis(*TLII); });
 
   // Register all the basic analyses with the managers.

llvm/include/llvm/Analysis/TargetLibraryInfo.h

@@ -130,6 +130,7 @@ class TargetLibraryInfoImpl {
     MASSV,            // IBM MASS vector library.
 #ifdef ENABLE_CLASSIC_FLANG
     PGMATH,           // PGI math library.
+    PGMATH_AVX512,    // PGI math library (AVX512 subset).
 #endif
     SVML,             // Intel short vector math library.
     SLEEFGNUABI, // SLEEF - SIMD Library for Evaluating Elementary Functions.