The frexp, modf, and remquo builtins are not 'const'.

These functions return a second value by writing to a pointer argument,
so they cannot be marked 'readnone' which implies that they don't access
memory.

<rdar://problem/10070234>

llvm-svn: 139319

2 files changed, 50 insertions, 9 deletions

diff --git a/clang/include/clang/Basic/Builtins.def b/clang/include/clang/Basic/Builtins.def
index 50cf872668b..b8916d23e0e 100644
--- a/clang/include/clang/Basic/Builtins.def
+++ b/clang/include/clang/Basic/Builtins.def
@@ -97,9 +97,9 @@ BUILTIN(__builtin_fabsl, "LdLd", "ncF")
 BUILTIN(__builtin_fmod , "ddd"  , "Fnc")
 BUILTIN(__builtin_fmodf, "fff"  , "Fnc")
 BUILTIN(__builtin_fmodl, "LdLdLd", "Fnc")
-BUILTIN(__builtin_frexp , "ddi*"  , "Fnc")
-BUILTIN(__builtin_frexpf, "ffi*"  , "Fnc")
-BUILTIN(__builtin_frexpl, "LdLdi*", "Fnc")
+BUILTIN(__builtin_frexp , "ddi*"  , "Fn")
+BUILTIN(__builtin_frexpf, "ffi*"  , "Fn")
+BUILTIN(__builtin_frexpl, "LdLdi*", "Fn")
 BUILTIN(__builtin_huge_val, "d", "nc")
 BUILTIN(__builtin_huge_valf, "f", "nc")
 BUILTIN(__builtin_huge_vall, "Ld", "nc")
@@ -109,9 +109,9 @@ BUILTIN(__builtin_infl , "Ld"  , "nc")
 BUILTIN(__builtin_ldexp , "ddi"  , "Fnc")
 BUILTIN(__builtin_ldexpf, "ffi"  , "Fnc")
 BUILTIN(__builtin_ldexpl, "LdLdi", "Fnc")
-BUILTIN(__builtin_modf , "ddd*"  , "Fnc")
-BUILTIN(__builtin_modff, "fff*"  , "Fnc")
-BUILTIN(__builtin_modfl, "LdLdLd*", "Fnc")
+BUILTIN(__builtin_modf , "ddd*"  , "Fn")
+BUILTIN(__builtin_modff, "fff*"  , "Fn")
+BUILTIN(__builtin_modfl, "LdLdLd*", "Fn")
 BUILTIN(__builtin_nan,  "dcC*" , "ncF")
 BUILTIN(__builtin_nanf, "fcC*" , "ncF")
 BUILTIN(__builtin_nanl, "LdcC*", "ncF")
@@ -234,9 +234,9 @@ BUILTIN(__builtin_nexttowardl, "LdLdLd", "Fnc")
 BUILTIN(__builtin_remainder , "ddd", "Fnc")
 BUILTIN(__builtin_remainderf, "fff", "Fnc")
 BUILTIN(__builtin_remainderl, "LdLdLd", "Fnc")
-BUILTIN(__builtin_remquo , "dddi*", "Fnc")
-BUILTIN(__builtin_remquof, "fffi*", "Fnc")
-BUILTIN(__builtin_remquol, "LdLdLdi*", "Fnc")
+BUILTIN(__builtin_remquo , "dddi*", "Fn")
+BUILTIN(__builtin_remquof, "fffi*", "Fn")
+BUILTIN(__builtin_remquol, "LdLdLdi*", "Fn")
 BUILTIN(__builtin_rint , "dd", "Fnc")
 BUILTIN(__builtin_rintf, "ff", "Fnc")
 BUILTIN(__builtin_rintl, "LdLd", "Fnc")
diff --git a/clang/test/CodeGen/builtin-attributes.c b/clang/test/CodeGen/builtin-attributes.c
index 822b8eecf7d..3781eba2669 100644
--- a/clang/test/CodeGen/builtin-attributes.c
+++ b/clang/test/CodeGen/builtin-attributes.c
@@ -15,3 +15,44 @@ void f1() {
 char* f2(char* a, char* b) {
   return __builtin_strstr(a, b);
 }
+
+// frexp is NOT readnone. It writes to its pointer argument.
+// <rdar://problem/10070234>
+//
+// CHECK: f3
+// CHECK: call double @frexp(double %
+// CHECK-NOT: readnone
+// CHECK: call float @frexpf(float %
+// CHECK-NOT: readnone
+// CHECK: call double @frexpl(double %
+// CHECK-NOT: readnone
+//
+// Same thing for modf and friends.
+//
+// CHECK: call double @modf(double %
+// CHECK-NOT: readnone
+// CHECK: call float @modff(float %
+// CHECK-NOT: readnone
+// CHECK: call double @modfl(double %
+// CHECK-NOT: readnone
+//
+// CHECK: call double @remquo(double %
+// CHECK-NOT: readnone
+// CHECK: call float @remquof(float %
+// CHECK-NOT: readnone
+// CHECK: call double @remquol(double %
+// CHECK-NOT: readnone
+// CHECK: ret
+int f3(double x) {
+  int e;
+  __builtin_frexp(x, &e);
+  __builtin_frexpf(x, &e);
+  __builtin_frexpl(x, &e);
+  __builtin_modf(x, &e);
+  __builtin_modff(x, &e);
+  __builtin_modfl(x, &e);
+  __builtin_remquo(x, x, &e);
+  __builtin_remquof(x, x, &e);
+  __builtin_remquol(x, x, &e);
+  return e;
+}