Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -4390,11 +4390,16 @@
   if (ReciprocalMath)
     CmdArgs.push_back("-freciprocal-math");
 
-  if (!TrappingMath) 
+  if (!TrappingMath)
     CmdArgs.push_back("-fno-trapping-math");
 
-  if (Args.hasArg(options::OPT_fdenormal_fp_math_EQ))
-    Args.AddLastArg(CmdArgs, options::OPT_fdenormal_fp_math_EQ);
+
+  if (Arg *A = Args.getLastArg(options::OPT_ffast_math, FastMathAliasOption,
+                               options::OPT_fno_fast_math,
+                               options::OPT_fdenormal_fp_math_EQ))
+    if (A->getOption().getID() != options::OPT_fno_fast_math &&
+        A->getOption().getID() != options::OPT_fno_unsafe_math_optimizations)
+      Args.AddLastArg(CmdArgs, options::OPT_fdenormal_fp_math_EQ);
 
   // Validate and pass through -fp-contract option.
   if (Arg *A = Args.getLastArg(options::OPT_ffast_math, FastMathAliasOption,
Index: test/Driver/denormal-fp-math.c
===================================================================
--- test/Driver/denormal-fp-math.c
+++ test/Driver/denormal-fp-math.c
@@ -1,9 +1,11 @@
 // RUN: %clang -### -target arm-unknown-linux-gnu -c %s -fdenormal-fp-math=ieee -v 2>&1 | FileCheck -check-prefix=CHECK-IEEE %s
 // RUN: %clang -### -target arm-unknown-linux-gnu -c %s -fdenormal-fp-math=preserve-sign -v 2>&1 | FileCheck -check-prefix=CHECK-PS %s
 // RUN: %clang -### -target arm-unknown-linux-gnu -c %s -fdenormal-fp-math=positive-zero -v 2>&1 | FileCheck -check-prefix=CHECK-PZ %s
+// RUN: %clang -### -target arm-unknown-linux-gnu -c %s -fdenormal-fp-math=ieee -fno-fast-math -v 2>&1 | FileCheck -check-prefix=CHECK-NO-UNSAFE %s
 // RUN: not %clang -target arm-unknown-linux-gnu -c %s -fdenormal-fp-math=foo -v 2>&1 | FileCheck -check-prefix=CHECK-INVALID %s
 
 // CHECK-IEEE: "-fdenormal-fp-math=ieee"
 // CHECK-PS: "-fdenormal-fp-math=preserve-sign"
 // CHECK-PZ: "-fdenormal-fp-math=positive-zero"
+// CHECK-NO-UNSAFE-NOT: "-fdenormal-fp-math=ieee"
 // CHECK-INVALID: error: invalid value 'foo' in '-fdenormal-fp-math=foo'