Allow __builtin_bswap32/64 in constant expressions, like gcc does. Patch by Tijl...

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@164841 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index 8f3f84d07d7a5dca3a2e2d355b755510e2bbbe8d..c4fd70a8c8bdb76a303c685da573f6a26e8e64af 100644 (file)
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -4296,6 +4296,15 @@ bool IntExprEvaluator::VisitCallExpr(const CallExpr *E) {
     return Error(E);
   }
 
+  case Builtin::BI__builtin_bswap32:
+  case Builtin::BI__builtin_bswap64: {
+    APSInt Val;
+    if (!EvaluateInteger(E->getArg(0), Val, Info))
+      return false;
+
+    return Success(Val.byteSwap(), E);
+  }
+
   case Builtin::BI__builtin_classify_type:
     return Success(EvaluateBuiltinClassifyType(E), E);
 

diff --git a/test/Sema/constant-builtins-2.c b/test/Sema/constant-builtins-2.c
index 68b46bf19ad90ea3cfa2ccd556004a3d45d6c931..d78a176ef4964df702b4f879bc8773b0d079202d 100644 (file)
--- a/test/Sema/constant-builtins-2.c
+++ b/test/Sema/constant-builtins-2.c
@@ -48,6 +48,8 @@ extern int f();
 int h0 = __builtin_types_compatible_p(int, float);
 //int h1 = __builtin_choose_expr(1, 10, f());
 //int h2 = __builtin_expect(0, 0);
+int h3 = __builtin_bswap32(0x1234) == 0x34120000 ? 1 : f();
+int h4 = __builtin_bswap64(0x1234) == 0x3412000000000000 ? 1 : f();
 extern long int bi0;
 extern __typeof__(__builtin_expect(0, 0)) bi0;
 

diff --git a/test/Sema/constant-builtins.c b/test/Sema/constant-builtins.c
index 5d67fc7cb7177ecc73dd510c54c576e62b3bb420..1562623c0affcba67d5086f5e11cdfd1f9019124 100644 (file)
--- a/test/Sema/constant-builtins.c
+++ b/test/Sema/constant-builtins.c
@@ -16,6 +16,8 @@ extern int f();
 int h0 = __builtin_types_compatible_p(int,float);
 //int h1 = __builtin_choose_expr(1, 10, f());
 //int h2 = __builtin_expect(0, 0);
+int h3 = __builtin_bswap32(0x1234) == 0x34120000 ? 1 : f();
+int h4 = __builtin_bswap64(0x1234) == 0x3412000000000000 ? 1 : f();
 
 short somefunc();