[PowerPC] Semachecking for XL compat builtin icbt

This patch is in a series of patches to provide builtins for compatibility with the XL compiler.
This patch adds semachecking for an already implemented builtin, `__icbt`. `__icbt` is only
valid for Power8 and up.

Reviewed By: #powerpc, nemanjai

Differential Revision: https://reviews.llvm.org/D105834

clang/lib/Sema/SemaChecking.cpp

@@ -3433,6 +3433,9 @@ bool Sema::CheckPPCBuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
     return SemaBuiltinConstantArgPower2(TheCall, 0);
   case PPC::BI__builtin_ppc_rdlam:
     return SemaValueIsRunOfOnes(TheCall, 2);
+  case PPC::BI__builtin_ppc_icbt:
+    return SemaFeatureCheck(*this, TheCall, "isa-v207-instructions",
+                            diag::err_ppc_builtin_only_on_arch, "8");
 #define CUSTOM_BUILTIN(Name, Intr, Types, Acc) \
   case PPC::BI__builtin_##Name: \
     return SemaBuiltinPPCMMACall(TheCall, Types);

clang/test/CodeGen/builtins-ppc-xlcompat-pwr8.c

@@ -0,0 +1,33 @@
+// REQUIRES: powerpc-registered-target
+// RUN: %clang_cc1 -triple powerpc64-unknown-unknown -emit-llvm %s \
+// RUN:   -target-cpu pwr8 -o - | FileCheck %s -check-prefix=CHECK-PWR8
+// RUN: %clang_cc1 -triple powerpc64le-unknown-unknown -emit-llvm %s \
+// RUN:   -target-cpu pwr8 -o - | FileCheck %s -check-prefix=CHECK-PWR8
+// RUN: %clang_cc1 -triple powerpc64-unknown-aix -emit-llvm %s \
+// RUN:   -target-cpu pwr8 -o - | FileCheck %s -check-prefix=CHECK-PWR8
+// RUN: %clang_cc1 -triple powerpc-unknown-aix %s -emit-llvm %s \
+// RUN:   -target-cpu pwr8 -o - | FileCheck %s -check-prefix=CHECK-PWR8
+// RUN: not %clang_cc1 -triple powerpc64-unknown-unknown -emit-llvm %s \
+// RUN:   -target-cpu pwr7 2>&1 | FileCheck %s -check-prefix=CHECK-NOPWR8
+// RUN: not %clang_cc1 -triple powerpc64-unknown-aix -emit-llvm %s \
+// RUN:   -target-cpu pwr7 2>&1 | FileCheck %s -check-prefix=CHECK-NOPWR8
+// RUN: not %clang_cc1 -triple powerpc-unknown-aix %s -emit-llvm %s \
+// RUN:   -target-cpu pwr7 2>&1 | FileCheck %s -check-prefix=CHECK-NOPWR8
+
+extern void *a;
+
+void test_icbt() {
+// CHECK-LABEL: @test_icbt(
+
+  __icbt(a);
+// CHECK-PWR8: call void @llvm.ppc.icbt(i8* %0)
+// CHECK-NOPWR8: error: this builtin is only valid on POWER8 or later CPUs
+}
+
+void test_builtin_ppc_icbt() {
+// CHECK-LABEL: @test_builtin_ppc_icbt(
+
+  __builtin_ppc_icbt(a);
+// CHECK-PWR8: call void @llvm.ppc.icbt(i8* %0)
+// CHECK-NOPWR8: error: this builtin is only valid on POWER8 or later CPUs
+}