From 2a6c59ea2ad67c93cce309945a97379337dd6be0 Mon Sep 17 00:00:00 2001
From: Bill Wendling <isanbard@gmail.com>
Date: Thu, 22 Nov 2018 09:31:08 +0000
Subject: [PATCH] The result of is.constant() is unsigned.

llvm-svn: 347446
---
 clang/lib/CodeGen/CGBuiltin.cpp         |   2 +-
 clang/test/CodeGen/builtin-constant-p.c | 130 ++++++++++++++++++++++++++++++++
 2 files changed, 131 insertions(+), 1 deletion(-)
 create mode 100644 clang/test/CodeGen/builtin-constant-p.c

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 62316d5..9301bfb 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -1943,7 +1943,7 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
     Value *F = CGM.getIntrinsic(Intrinsic::is_constant, ConvertType(ArgType));
     Value *Result = Builder.CreateCall(F, ArgValue);
     if (Result->getType() != ResultType)
-      Result = Builder.CreateIntCast(Result, ResultType, /*isSigned*/true);
+      Result = Builder.CreateIntCast(Result, ResultType, /*isSigned*/false);
     return RValue::get(Result);
   }
   case Builtin::BI__builtin_object_size: {
diff --git a/clang/test/CodeGen/builtin-constant-p.c b/clang/test/CodeGen/builtin-constant-p.c
new file mode 100644
index 0000000..978ec4c
--- /dev/null
+++ b/clang/test/CodeGen/builtin-constant-p.c
@@ -0,0 +1,130 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -emit-llvm -o - %s -O2 | FileCheck %s
+
+int a = 42;
+
+inline int bcp(int x) {
+  return __builtin_constant_p(x);
+}
+
+/* --- Compound literals */
+
+struct foo { int x, y; };
+
+struct foo test0(int expr) {
+  // CHECK: define i64 @test0(i32 %expr)
+  // CHECK: call i1 @llvm.is.constant.i32(i32 %expr)
+  struct foo f = (struct foo){ __builtin_constant_p(expr), 42 };
+  return f;
+}
+
+/* --- Pointer types */
+
+inline int test1_i(int *x) {
+  return *x;
+}
+
+int test1() {
+  // CHECK: define i32 @test1
+  // CHECK: add nsw i32 %0, -13
+  // CHECK-NEXT: call i1 @llvm.is.constant.i32(i32 %sub)
+  return bcp(test1_i(&a) - 13);
+}
+
+int test2() {
+  // CHECK: define i32 @test2
+  // CHECK: ret i32 0
+  return __builtin_constant_p(&a - 13);
+}
+
+inline int test3_i(int *x) {
+  return 42;
+}
+
+int test3() {
+  // CHECK: define i32 @test3
+  // CHECK: ret i32 1
+  return bcp(test3_i(&a) - 13);
+}
+
+/* --- Aggregate types */
+
+int b[] = {1, 2, 3};
+
+int test4() {
+  // CHECK: define i32 @test4
+  // CHECK: ret i32 0
+  return __builtin_constant_p(b);
+}
+
+const char test5_c[] = {1, 2, 3, 0};
+
+int test5() {
+  // CHECK: define i32 @test5
+  // CHECK: ret i32 0
+  return __builtin_constant_p(test5_c);
+}
+
+inline char test6_i(const char *x) {
+  return x[1];
+}
+
+int test6() {
+  // CHECK: define i32 @test6
+  // CHECK: ret i32 0
+  return __builtin_constant_p(test6_i(test5_c));
+}
+
+/* --- Non-constant global variables */
+
+int test7() {
+  // CHECK: define i32 @test7
+  // CHECK: call i1 @llvm.is.constant.i32(i32 %0)
+  return bcp(a);
+}
+
+/* --- Constant global variables */
+
+const int c = 42;
+
+int test8() {
+  // CHECK: define i32 @test8
+  // CHECK: ret i32 1
+  return bcp(c);
+}
+
+/* --- Array types */
+
+int arr[] = { 1, 2, 3 };
+const int c_arr[] = { 1, 2, 3 };
+
+int test9() {
+  // CHECK: define i32 @test9
+  // CHECK: call i1 @llvm.is.constant.i32(i32 %0)
+  return __builtin_constant_p(arr[2]);
+}
+
+int test10() {
+  // CHECK: define i32 @test10
+  // CHECK: ret i32 1
+  return __builtin_constant_p(c_arr[2]);
+}
+
+int test11() {
+  // CHECK: define i32 @test11
+  // CHECK: ret i32 0
+  return __builtin_constant_p(c_arr);
+}
+
+/* --- Function pointers */
+
+int test12() {
+  // CHECK: define i32 @test12
+  // CHECK: ret i32 0
+  return __builtin_constant_p(&test10);
+}
+
+int test13() {
+  // CHECK: define i32 @test13
+  // CHECK: ret i32 1
+  return __builtin_constant_p(&test10 != 0);
+}
-- 
2.7.4