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.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@43447 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Sema/SemaExpr.cpp b/Sema/SemaExpr.cpp
index 36112e6..59cff7c 100644
--- a/Sema/SemaExpr.cpp
+++ b/Sema/SemaExpr.cpp
@@ -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;
}
diff --git a/test/Sema/floating-point-compare.c b/test/Sema/floating-point-compare.c
index 6adc228..6238891 100644
--- a/test/Sema/floating-point-compare.c
+++ b/test/Sema/floating-point-compare.c
@@ -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
+}