[Clang,Driver] Add -fveclib=Darwin_libsystem_m support.

[fhahn]

Summary

Support for Darwin's libsystem_m's vector functions has been added to
LLVM in 93a9a8a8d90f.

This patch adds support for -fveclib=Darwin_libsystem_m to Clang.

[arphaman]

clang/lib/CodeGen/BackendUtil.cpp

405

Can you add an IRGen testcase that verifies that TLII is setting the vecLib correctly here?

[fhahn]

clang/lib/CodeGen/BackendUtil.cpp

405

Like a test that generates IR using a vector function from Darwin's libsystem m?

[arphaman]

clang/lib/CodeGen/BackendUtil.cpp

405

Sure, I think that should cover this switch case.

[fhahn]

Add end-to-end test, as suggested. Thanks!

[fhahn]

clang/lib/CodeGen/BackendUtil.cpp

405

I added clang/test/CodeGen/veclib-darwin-libsystem-m.c which should contain an end-to-end test.

[dyung]

The test added in this commit was failing on the PS4 bot (https://lab.llvm.org/buildbot/#/builders/139/builds/4059). I've reverted the change in 59b419adc6e608db8d7c31efcc37f34c0b57b7d0 to get the bot green again.

[thakis]

(Failed on our bots too -- the new test probably just needs a REQUIRES: aarch64-registered-target)

[fhahn]

In D102489#2761195, @dyung wrote:

The test added in this commit was failing on the PS4 bot (https://lab.llvm.org/buildbot/#/builders/139/builds/4059). I've reverted the change in 59b419adc6e608db8d7c31efcc37f34c0b57b7d0 to get the bot green again.

In D102489#2761313, @thakis wrote:

(Failed on our bots too -- the new test probably just needs a REQUIRES: aarch64-registered-target)

Thanks! I re-landed the change in 803c52d0dba9 with REQUIRES: aarch64-registered-target

clang/include/clang/Basic/CodeGenOptions.h

 public:
   enum InliningMethod {
     NormalInlining,     // Use the standard function inlining pass.
     OnlyHintInlining,   // Inline only (implicitly) hinted functions.
     OnlyAlwaysInlining  // Only run the always inlining pass.
   };
 
   enum VectorLibrary {
-    NoLibrary,  // Don't use any vector library.
-    Accelerate, // Use the Accelerate framework.
-    LIBMVEC,    // GLIBC vector math library.
-    MASSV,      // IBM MASS vector library.
-    SVML        // Intel short vector math library.
+    NoLibrary,         // Don't use any vector library.
+    Accelerate,        // Use the Accelerate framework.
+    LIBMVEC,           // GLIBC vector math library.
+    MASSV,             // IBM MASS vector library.
+    SVML,              // Intel short vector math library.
+    Darwin_libsystem_m // Use Darwin's libsytem_m vector functions.
   };
 
   enum ObjCDispatchMethodKind {
     Legacy = 0,
     NonLegacy = 1,
     Mixed = 2
   };
 

clang/include/clang/Driver/Options.td

 def fno_inline_functions : Flag<["-"], "fno-inline-functions">, Group<f_clang_Group>, Flags<[CC1Option]>;
 def fno_inline : Flag<["-"], "fno-inline">, Group<f_clang_Group>, Flags<[CC1Option]>;
 def fno_global_isel : Flag<["-"], "fno-global-isel">, Group<f_clang_Group>,
   HelpText<"Disables the global instruction selector">;
 def fno_experimental_isel : Flag<["-"], "fno-experimental-isel">, Group<f_clang_Group>,
   Alias<fno_global_isel>;
 def fveclib : Joined<["-"], "fveclib=">, Group<f_Group>, Flags<[CC1Option]>,
     HelpText<"Use the given vector functions library">,
-    Values<"Accelerate,libmvec,MASSV,SVML,none">,
+    Values<"Accelerate,libmvec,MASSV,SVML,Darwin_libsystem_m,none">,
     NormalizedValuesScope<"CodeGenOptions">,
-    NormalizedValues<["Accelerate", "LIBMVEC", "MASSV", "SVML", "NoLibrary"]>,
+    NormalizedValues<["Accelerate", "LIBMVEC", "MASSV", "SVML",
+                      "Darwin_libsystem_m", "NoLibrary"]>,
     MarshallingInfoEnum<CodeGenOpts<"VecLib">, "NoLibrary">;
 def fno_lax_vector_conversions : Flag<["-"], "fno-lax-vector-conversions">, Group<f_Group>,
   Alias<flax_vector_conversions_EQ>, AliasArgs<["none"]>;
 def fno_implicit_module_maps : Flag <["-"], "fno-implicit-module-maps">, Group<f_Group>,
   Flags<[NoXarchOption]>;
 def fno_module_maps : Flag <["-"], "fno-module-maps">, Alias<fno_implicit_module_maps>;
 def fno_modules_strict_decluse : Flag <["-"], "fno-strict-modules-decluse">, Group<f_Group>,
   Flags<[NoXarchOption]>;

clang/lib/CodeGen/BackendUtil.cpp

case CodeGenOptions::LIBMVEC:
     }
     break;
   case CodeGenOptions::MASSV:
     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::MASSV);
     break;
   case CodeGenOptions::SVML:
     TLII->addVectorizableFunctionsFromVecLib(TargetLibraryInfoImpl::SVML);
     break;
+  case CodeGenOptions::Darwin_libsystem_m:
+    TLII->addVectorizableFunctionsFromVecLib(
+        TargetLibraryInfoImpl::DarwinLibSystemM);
+    break;
   default:
     break;
   }
   return TLII;
 }
 
 static void addSymbolRewriterPass(const CodeGenOptions &Opts,
                                   legacy::PassManager *MPM) {

clang/test/CodeGen/veclib-darwin-libsystem-m.c

+// RUN: %clang_cc1 -fveclib=Darwin_libsystem_m -triple arm64-apple-darwin %s -target-cpu apple-a7 -vectorize-loops -emit-llvm -O3 -o - | FileCheck %s
+
+// Make sure -fveclib=Darwin_libsystem_m gets passed through to LLVM as
+// expected: a call to _simd_sin_f4 should be generated.
+
+extern float sinf(float);
+
+// CHECK-LABEL: define{{.*}}@apply_sin
+// CHECK: call <4 x float> @_simd_sin_f4(
+//
+void apply_sin(float *A, float *B, float *C, unsigned N) {
+  for (unsigned i = 0; i < N; i++)
+    C[i] = sinf(A[i]) + sinf(B[i]);
+}

clang/test/Driver/autocomplete.c

 // FFPALL-NEXT: fast-honor-pragmas 
 // FFPALL-NEXT: off
 // FFPALL-NEXT: on
 // RUN: %clang --autocomplete=-flto= | FileCheck %s -check-prefix=FLTOALL
 // FLTOALL: full
 // FLTOALL-NEXT: thin
 // RUN: %clang --autocomplete=-fveclib= | FileCheck %s -check-prefix=FVECLIBALL
 // FVECLIBALL: Accelerate
+// FVECLIBALL-NEXT: Darwin_libsystem_m
 // FVECLIBALL-NEXT: libmvec
 // FVECLIBALL-NEXT: MASSV
 // FVECLIBALL-NEXT: none
 // FVECLIBALL-NEXT: SVML
 // RUN: %clang --autocomplete=-fshow-overloads= | FileCheck %s -check-prefix=FSOVERALL
 // FSOVERALL: all
 // FSOVERALL-NEXT: best
 // RUN: %clang --autocomplete=-fvisibility= | FileCheck %s -check-prefix=FVISIBILITYALL

clang/test/Driver/fveclib.c

 // 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=libmvec %s 2>&1 | FileCheck -check-prefix CHECK-libmvec %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: not %clang -c -fveclib=something %s 2>&1 | FileCheck -check-prefix CHECK-INVALID %s
 
 // CHECK-NOLIB: "-fveclib=none"
 // CHECK-ACCELERATE: "-fveclib=Accelerate"
 // CHECK-libmvec: "-fveclib=libmvec"
 // CHECK-MASSV: "-fveclib=MASSV"
+// CHECK-DARWIN_LIBSYSTEM_M: "-fveclib=Darwin_libsystem_m"
 
 // CHECK-INVALID: error: invalid value 'something' in '-fveclib=something'
 
 // RUN: %clang -fveclib=Accelerate %s -target arm64-apple-ios8.0.0 -### 2>&1 | FileCheck --check-prefix=CHECK-LINK %s
 // CHECK-LINK: "-framework" "Accelerate"
 
 // RUN: %clang -fveclib=Accelerate %s -nostdlib -target arm64-apple-ios8.0.0 -### 2>&1 | FileCheck --check-prefix=CHECK-LINK-NOSTDLIB %s
 // CHECK-LINK-NOSTDLIB-NOT: "-framework" "Accelerate"
 
 // RUN: %clang -fveclib=Accelerate %s -nodefaultlibs -target arm64-apple-ios8.0.0 -### 2>&1 | FileCheck --check-prefix=CHECK-LINK-NODEFAULTLIBS %s
 // CHECK-LINK-NODEFAULTLIBS-NOT: "-framework" "Accelerate"