4 files changed, 53 insertions, 5 deletions
diff --git a/clang/lib/Headers/avx512fp16intrin.h b/clang/lib/Headers/avx512fp16intrin.h
index d951ba0..142cc07 100644
--- a/clang/lib/Headers/avx512fp16intrin.h
+++ b/clang/lib/Headers/avx512fp16intrin.h
@@ -112,7 +112,7 @@ static __inline__ __m512h __DEFAULT_FN_ATTRS512_CONSTEXPR _mm512_setr_ph(
                        e9, e8, e7, e6, e5, e4, e3, e2, e1, e0);
 }
 
-static __inline __m512h __DEFAULT_FN_ATTRS512
+static __inline __m512h __DEFAULT_FN_ATTRS512_CONSTEXPR
 _mm512_set1_pch(_Float16 _Complex __h) {
   return (__m512h)_mm512_set1_ps(__builtin_bit_cast(float, __h));
 }
@@ -193,17 +193,17 @@ _mm512_castsi512_ph(__m512i __a) {
   return (__m512h)__a;
 }
 
-static __inline__ __m128h __DEFAULT_FN_ATTRS256
+static __inline__ __m128h __DEFAULT_FN_ATTRS256_CONSTEXPR
 _mm256_castph256_ph128(__m256h __a) {
   return __builtin_shufflevector(__a, __a, 0, 1, 2, 3, 4, 5, 6, 7);
 }
 
-static __inline__ __m128h __DEFAULT_FN_ATTRS512
+static __inline__ __m128h __DEFAULT_FN_ATTRS512_CONSTEXPR
 _mm512_castph512_ph128(__m512h __a) {
   return __builtin_shufflevector(__a, __a, 0, 1, 2, 3, 4, 5, 6, 7);
 }
 
-static __inline__ __m256h __DEFAULT_FN_ATTRS512
+static __inline__ __m256h __DEFAULT_FN_ATTRS512_CONSTEXPR
 _mm512_castph512_ph256(__m512h __a) {
   return __builtin_shufflevector(__a, __a, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
                                  12, 13, 14, 15);
diff --git a/clang/lib/Sema/SemaConcept.cpp b/clang/lib/Sema/SemaConcept.cpp
index 999e302c..8946f1b 100644
--- a/clang/lib/Sema/SemaConcept.cpp
+++ b/clang/lib/Sema/SemaConcept.cpp
@@ -280,6 +280,11 @@ public:
     if (T->getDepth() >= TemplateArgs.getNumLevels())
       return true;
 
+    // There might not be a corresponding template argument before substituting
+    // into the parameter mapping, e.g. a sizeof... expression.
+    if (!TemplateArgs.hasTemplateArgument(T->getDepth(), T->getIndex()))
+      return true;
+
     TemplateArgument Arg = TemplateArgs(T->getDepth(), T->getIndex());
 
     if (T->isParameterPack() && SemaRef.ArgPackSubstIndex) {
diff --git a/clang/test/CodeGen/X86/avx512fp16-builtins.c b/clang/test/CodeGen/X86/avx512fp16-builtins.c
index dbf89b3..2befff0 100644
--- a/clang/test/CodeGen/X86/avx512fp16-builtins.c
+++ b/clang/test/CodeGen/X86/avx512fp16-builtins.c
@@ -117,6 +117,7 @@ __m512h test_mm512_set1_pch(_Float16 _Complex h) {
   // CHECK: bitcast <16 x float>{{.*}} to <32 x half>
   return _mm512_set1_pch(h);
 }
+TEST_CONSTEXPR(match_m512h(_mm512_set1_pch(1.0), 1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0, 0.0));
 
 __m512h test_mm512_set_ph(_Float16 __h1, _Float16 __h2, _Float16 __h3, _Float16 __h4,
                           _Float16 __h5, _Float16 __h6, _Float16 __h7, _Float16 __h8,
@@ -340,18 +341,21 @@ __m128h test_mm256_castph256_ph128(__m256h __a) {
   // CHECK: shufflevector <16 x half> %{{.*}}, <16 x half> %{{.*}}, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
   return _mm256_castph256_ph128(__a);
 }
+TEST_CONSTEXPR(match_m128h(_mm256_castph256_ph128((__m256h){-1.0, 2.0, -3.0, 4.0, -5.0, 6.0, -7.0, 8.0, -9.0, 10.0, -11.0, 12.0, -13.0, 14.0, -15.0, -16.0}), -1.0, 2.0, -3.0, 4.0, -5.0, 6.0, -7.0, 8.0));
 
 __m128h test_mm512_castph512_ph128(__m512h __a) {
   // CHECK-LABEL: test_mm512_castph512_ph128
   // CHECK: shufflevector <32 x half> %{{.*}}, <32 x half> %{{.*}}, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
   return _mm512_castph512_ph128(__a);
 }
+TEST_CONSTEXPR(match_m128h(_mm512_castph512_ph128((__m512h){0.0, -1.0, 2.0, -3.0, 4.0, -5.0, 6.0, -7.0, 8.0, -9.0, 10.0, -11.0, 12.0, -13.0, 14.0, -15.0, -16.0, -17.0, 18.0, -19.0, 20.0, -21.0, 22.0, -23.0, 24.0, -25.0, 26.0, -27.0, 28.0, -29.0, 30.0, -31.0}), 0.0, -1.0, 2.0, -3.0, 4.0, -5.0, 6.0, -7.0));
 
 __m256h test_mm512_castph512_ph256(__m512h __a) {
   // CHECK-LABEL: test_mm512_castph512_ph256
   // CHECK: shufflevector <32 x half> %{{.*}}, <32 x half> %{{.*}}, <16 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>
   return _mm512_castph512_ph256(__a);
 }
+TEST_CONSTEXPR(match_m256h(_mm512_castph512_ph256((__m512h){-1.0, 2.0, -3.0, 4.0, -5.0, 6.0, -7.0, 8.0, -9.0, 10.0, -11.0, 12.0, -13.0, 14.0, -15.0, -16.0, -17.0, 18.0, -19.0, 20.0, -21.0, 22.0, -23.0, 24.0, -25.0, 26.0, -27.0, 28.0, -29.0, 30.0, -31.0, 32.0}), -1.0, 2.0, -3.0, 4.0, -5.0, 6.0, -7.0, 8.0, -9.0, 10.0, -11.0, 12.0, -13.0, 14.0, -15.0, -16.0));
 
 __m256h test_mm256_castph128_ph256(__m128h __a) {
   // CHECK-LABEL: test_mm256_castph128_ph256
diff --git a/clang/test/SemaTemplate/concepts.cpp b/clang/test/SemaTemplate/concepts.cpp
index e5e081f..3b7c138 100644
--- a/clang/test/SemaTemplate/concepts.cpp
+++ b/clang/test/SemaTemplate/concepts.cpp
@@ -1,4 +1,5 @@
-// RUN: %clang_cc1 -std=c++20 -ferror-limit 0 -verify %s
+// RUN: %clang_cc1 -std=c++20 -ferror-limit 0 -verify=expected,cxx20 %s
+// RUN: %clang_cc1 -std=c++2c -ferror-limit 0 -verify=expected %s
 
 namespace PR47043 {
   template<typename T> concept True = true;
@@ -1405,3 +1406,41 @@ static_assert(!std::is_constructible_v<span<4>, array<int, 3>>);
 }
 
 }
+
+
+namespace GH162125 {
+template<typename, int size>
+concept true_int = (size, true);
+
+template<typename, typename... Ts>
+concept true_types = true_int<void, sizeof...(Ts)>;
+
+template<typename, typename... Ts>
+concept true_types2 = true_int<void, Ts...[0]{1}>; // cxx20-warning {{pack indexing is a C++2c extension}}
+
+template<typename... Ts>
+struct s {
+  template<typename T> requires true_types<T, Ts...> && true_types2<T, Ts...>
+  static void f(T);
+};
+void(*test)(int) = &s<bool>::f<int>;
+}
+
+namespace GH162125_reversed {
+template<int size, typename>
+concept true_int = (size, true);
+
+template<typename, typename... Ts>
+concept true_types = true_int<sizeof...(Ts), void>;
+
+template<typename, typename... Ts>
+concept true_types2 = true_int<Ts...[0]{1}, void>; // cxx20-warning {{pack indexing is a C++2c extension}}
+
+template<typename... Ts>
+struct s {
+  template<typename T> requires true_types<T, Ts...> && true_types2<T, Ts...>
+  static void f(T);
+};
+
+void(*test)(int) = &s<bool>::f<int>;
+}