[cfe-commits] r43447 - in /cfe/trunk: Sema/SemaExpr.cpp test/Sema/floating-point-compare.c

[Ted Kremenek]

Author: kremenek
Date: Mon Oct 29 11:40:01 2007
New Revision: 43447

URL: http://llvm.org/viewvc/llvm-project?rev=43447&view=rev
Log:
For checking for floating point comparison using == or !=, we now suppress
errors for cases such as "x == x".

Added test case to test this feature.

Modified:
    cfe/trunk/Sema/SemaExpr.cpp
    cfe/trunk/test/Sema/floating-point-compare.c

Modified: cfe/trunk/Sema/SemaExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/Sema/SemaExpr.cpp?rev=43447&r1=43446&r2=43447&view=diff

==============================================================================
--- cfe/trunk/Sema/SemaExpr.cpp (original)
+++ cfe/trunk/Sema/SemaExpr.cpp Mon Oct 29 11:40:01 2007
@@ -1208,9 +1208,19 @@
     if (lType->isRealType() && rType->isRealType())
       return Context.IntTy;
   } else {
-    if (lType->isFloatingType() && rType->isFloatingType()) 
-      Diag(loc, diag::warn_floatingpoint_eq);
-
+    if (lType->isFloatingType() && rType->isFloatingType()) {
+      // Special case: check for x == x (which is OK).
+      bool EmitWarning = true;
+      
+      if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(lex))
+        if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(rex))
+          if (DRL->getDecl() == DRR->getDecl())
+            EmitWarning = false;
+      
+      if (EmitWarning)
+        Diag(loc, diag::warn_floatingpoint_eq);
+    }
+    
     if (lType->isArithmeticType() && rType->isArithmeticType())
       return Context.IntTy;
   }

Modified: cfe/trunk/test/Sema/floating-point-compare.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/floating-point-compare.c?rev=43447&r1=43446&r2=43447&view=diff

==============================================================================
--- cfe/trunk/test/Sema/floating-point-compare.c (original)
+++ cfe/trunk/test/Sema/floating-point-compare.c Mon Oct 29 11:40:01 2007
@@ -7,3 +7,7 @@
 int bar(float x, float y) {
   return x != y; // expected-warning {{comparing floating point with ==}}
 }
+
+int qux(float x) {
+  return x == x; // no-warning
+}