[PATCH] D131289: [ADT] Add is_splat overload accepting initializer_list

[Jakub Kuderski via Phabricator via llvm-commits]

kuhar created this revision.
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Allow for `is_splat` to be used inline, similar to `is_contained`, e.g.,

  if (is_splat({type1, type2, type3, type4}))
    ...

which is much more concise and less typo-prone than an equivalent chain of equality comparisons.

My immediate motivation is to clean up some code in the SPIR-V dialect that currently needs to either construct a temporary container or use `makeArrayRef` before calling `is_splat`.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D131289

Files:
  llvm/include/llvm/ADT/STLExtras.h
  llvm/unittests/ADT/STLExtrasTest.cpp


Index: llvm/unittests/ADT/STLExtrasTest.cpp
===================================================================
--- llvm/unittests/ADT/STLExtrasTest.cpp
+++ llvm/unittests/ADT/STLExtrasTest.cpp
@@ -606,7 +606,7 @@
   EXPECT_EQ(EIR.end(), I);
 }
 
-TEST(STLExtrasTest, splat) {
+TEST(STLExtrasTest, IsSplat) {
   std::vector<int> V;
   EXPECT_FALSE(is_splat(V));
 
@@ -621,6 +621,13 @@
   EXPECT_FALSE(is_splat(V));
 }
 
+TEST(STLExtrasTest, IsSplatInitializerList) {
+  EXPECT_TRUE(is_splat({1}));
+  EXPECT_TRUE(is_splat({1, 1}));
+  EXPECT_FALSE(is_splat({1, 2}));
+  EXPECT_TRUE(is_splat({1, 1, 1}));
+}
+
 TEST(STLExtrasTest, to_address) {
   int *V1 = new int;
   EXPECT_EQ(V1, to_address(V1));
Index: llvm/include/llvm/ADT/STLExtras.h
===================================================================
--- llvm/include/llvm/ADT/STLExtras.h
+++ llvm/include/llvm/ADT/STLExtras.h
@@ -1796,6 +1796,11 @@
          std::equal(adl_begin(Range) + 1, adl_end(Range), adl_begin(Range)));
 }
 
+/// Returns true iff all Values in the initializer lists are same.
+template <typename T> bool is_splat(std::initializer_list<T> Values) {
+  return is_splat(make_range(Values.begin(), Values.end()));
+}
+
 /// Provide a container algorithm similar to C++ Library Fundamentals v2's
 /// `erase_if` which is equivalent to:
 ///


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