[cfe-commits] r57624 - in /cfe/trunk: lib/AST/ExprConstant.cpp test/Sema/constant-builtins-2.c

[Daniel Dunbar]

Author: ddunbar
Date: Wed Oct 15 22:51:50 2008
New Revision: 57624

URL: http://llvm.org/viewvc/llvm-project?rev=57624&view=rev
Log:
Teach tryEvaluate that fabs, copysign, and unary +/- are constants for
floats.
 - With testcase, which also has some other things GCC folds but we
   don't commented out in it.

Added:
    cfe/trunk/test/Sema/constant-builtins-2.c
Modified:
    cfe/trunk/lib/AST/ExprConstant.cpp

Modified: cfe/trunk/lib/AST/ExprConstant.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=57624&r1=57623&r2=57624&view=diff

==============================================================================
--- cfe/trunk/lib/AST/ExprConstant.cpp (original)
+++ cfe/trunk/lib/AST/ExprConstant.cpp Wed Oct 15 22:51:50 2008
@@ -586,6 +586,7 @@
   bool VisitParenExpr(ParenExpr *E) { return Visit(E->getSubExpr()); }
   bool VisitCallExpr(const CallExpr *E);
 
+  bool VisitUnaryOperator(const UnaryOperator *E);
   bool VisitBinaryOperator(const BinaryOperator *E);
   bool VisitFloatingLiteral(const FloatingLiteral *E);
 };
@@ -625,14 +626,48 @@
       }
     }
     return false;
+
+  case Builtin::BI__builtin_fabs:
+  case Builtin::BI__builtin_fabsf:
+  case Builtin::BI__builtin_fabsl:
+    if (!EvaluateFloat(E->getArg(0), Result, Info))
+      return false;
+    
+    if (Result.isNegative())
+      Result.changeSign();
+    return true;
+
+  case Builtin::BI__builtin_copysign: 
+  case Builtin::BI__builtin_copysignf: 
+  case Builtin::BI__builtin_copysignl: {
+    APFloat RHS(0.);
+    if (!EvaluateFloat(E->getArg(0), Result, Info) ||
+        !EvaluateFloat(E->getArg(1), RHS, Info))
+      return false;
+    Result.copySign(RHS);
+    return true;
+  }
   }
 }
 
+bool FloatExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
+  if (!EvaluateFloat(E->getSubExpr(), Result, Info))
+    return false;
+
+  switch (E->getOpcode()) {
+  default: return false;
+  case UnaryOperator::Plus: 
+    return true;
+  case UnaryOperator::Minus:
+    Result.changeSign();
+    return true;
+  }
+}
 
 bool FloatExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
   // FIXME: Diagnostics?  I really don't understand how the warnings
   // and errors are supposed to work.
-  APFloat LHS(0.0), RHS(0.0);
+  APFloat RHS(0.0);
   if (!EvaluateFloat(E->getLHS(), Result, Info))
     return false;
   if (!EvaluateFloat(E->getRHS(), RHS, Info))

Added: cfe/trunk/test/Sema/constant-builtins-2.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/constant-builtins-2.c?rev=57624&view=auto

==============================================================================
--- cfe/trunk/test/Sema/constant-builtins-2.c (added)
+++ cfe/trunk/test/Sema/constant-builtins-2.c Wed Oct 15 22:51:50 2008
@@ -0,0 +1,50 @@
+// RUN: clang -fsyntax-only %s
+
+// Math stuff
+
+double       g0  = __builtin_huge_val();
+float        g1  = __builtin_huge_valf();
+long double  g2  = __builtin_huge_vall();
+
+double       g3  = __builtin_inf();
+float        g4  = __builtin_inff();
+long double  g5  = __builtin_infl();
+
+double       g6  = __builtin_nan("");
+float        g7  = __builtin_nanf("");
+long double  g8  = __builtin_nanl("");
+
+// GCC constant folds these too (via native strtol):
+//double       g6_1  = __builtin_nan("1");
+//float        g7_1  = __builtin_nanf("1");
+//long double  g8_1  = __builtin_nanl("1");
+
+// APFloat doesn't have signalling NaN functions.
+//double       g9  = __builtin_nans("");
+//float        g10 = __builtin_nansf("");
+//long double  g11 = __builtin_nansl("");
+
+//int          g12 = __builtin_abs(-12);
+
+double       g13 = __builtin_fabs(-12.);
+double       g13_0 = __builtin_fabs(-0.);
+double       g13_1 = __builtin_fabs(-__builtin_inf());
+float        g14 = __builtin_fabsf(-12.f);
+// GCC doesn't eat this one.
+//long double  g15 = __builtin_fabsfl(-12.0L);
+
+float        g16 = __builtin_copysign(1.0, -1.0);
+double       g17 = __builtin_copysignf(1.0f, -1.0f);
+long double  g18 = __builtin_copysignl(1.0L, -1.0L);
+
+//double       g19 = __builtin_powi(2.0, 4);
+//float        g20 = __builtin_powif(2.0f, 4);
+//long double  g21 = __builtin_powil(2.0L, 4);
+
+// GCC misc stuff
+
+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);