[VFABI] Read/Write functions for the VFABI attribute.

The attribute is stored at the `FunctionIndex` attribute set, with the
name "vector-function-abi-variant".

The get/set methods of the attribute have assertion to verify that:

1. Each name in the attribute is a valid VFABI mangled name.

2. Each name in the attribute correspond to a function declared in the
   module.

Differential Revision: https://reviews.llvm.org/D69976

1 files changed, 55 insertions, 0 deletions

diff --git a/llvm/unittests/Transforms/Utils/VFABIUtils.cpp b/llvm/unittests/Transforms/Utils/VFABIUtils.cpp
new file mode 100644
index 00000000000..f69e31cd610
--- /dev/null
+++ b/llvm/unittests/Transforms/Utils/VFABIUtils.cpp
@@ -0,0 +1,55 @@
+//===------- VFABIUtils.cpp - VFABI Unittests  ----------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/AsmParser/Parser.h"
+#include "llvm/IR/InstIterator.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/SourceMgr.h"
+#include "llvm/Transforms/Utils/ModuleUtils.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+
+class VFABIAttrTest : public testing::Test {
+protected:
+  void SetUp() override {
+    M = parseAssemblyString(IR, Err, Ctx);
+    // Get the only call instruction in the block, which is the first
+    // instruction.
+    CI = dyn_cast<CallInst>(&*(instructions(M->getFunction("f")).begin()));
+  }
+  const char *IR = "define i32 @f(i32 %a) {\n"
+                   " %1 = call i32 @g(i32 %a) #0\n"
+                   "  ret i32 %1\n"
+                   "}\n"
+                   "declare i32 @g(i32)\n"
+                   "declare <2 x i32> @custom_vg(<2 x i32>)"
+                   "declare <4 x i32> @_ZGVnN4v_g(<4 x i32>)"
+                   "declare <8 x i32> @_ZGVnN8v_g(<8 x i32>)"
+                   "attributes #0 = { "
+                   "\"vector-function-abi-variant\"=\""
+                   "_ZGVnN2v_g(custom_vg),_ZGVnN4v_g\" }";
+  LLVMContext Ctx;
+  SMDiagnostic Err;
+  std::unique_ptr<Module> M;
+  CallInst *CI;
+  SmallVector<std::string, 8> Mappings;
+};
+
+TEST_F(VFABIAttrTest, Write) {
+  Mappings.push_back("_ZGVnN8v_g");
+  Mappings.push_back("_ZGVnN2v_g(custom_vg)");
+  VFABI::setVectorVariantNames(CI, Mappings);
+  const AttributeList Attrs = CI->getAttributes();
+  const AttributeSet FnAttrs = Attrs.getFnAttributes();
+  const StringRef S = CI->getAttribute(AttributeList::FunctionIndex,
+                                       "vector-function-abi-variant")
+                          .getValueAsString();
+  EXPECT_EQ(S, "_ZGVnN8v_g,_ZGVnN2v_g(custom_vg)");
+}