Summary: We need `__stosb` to be an intrinsic, because SecureZeroMemory function uses it without including intrin.h. Implementing it as a volatile memset is not consistent with MSDN specification, but it gives us target-independent IR while keeping the most important properties of `__stosb`.
Reviewers: rnk, hans, thakis, majnemer
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D25334
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@284253
91177308-0d34-0410-b5e6-
96231b3b80d8
TARGET_HEADER_BUILTIN(_AddressOfReturnAddress, "v*", "nh", "intrin.h", ALL_MS_LANGUAGES, "")
+TARGET_HEADER_BUILTIN(__stosb, "vUc*Ucz", "nh", "intrin.h", ALL_MS_LANGUAGES, "")
+
#undef BUILTIN
#undef TARGET_BUILTIN
#undef TARGET_HEADER_BUILTIN
Value *F = CGM.getIntrinsic(Intrinsic::addressofreturnaddress);
return Builder.CreateCall(F);
}
+ case X86::BI__stosb: {
+ // We treat __stosb as a volatile memset - it may not generate "rep stosb"
+ // instruction, but it will create a memset that won't be optimized away.
+ return Builder.CreateMemSet(Ops[0], Ops[1], Ops[2], 1, true);
+ }
}
}
: "%edi", "%esi", "%ecx");
}
static __inline__ void __DEFAULT_FN_ATTRS
-__stosb(unsigned char *__dst, unsigned char __x, size_t __n) {
- __asm__("rep stosb" : : "D"(__dst), "a"(__x), "c"(__n)
- : "%edi", "%ecx");
-}
-static __inline__ void __DEFAULT_FN_ATTRS
__stosd(unsigned long *__dst, unsigned long __x, size_t __n) {
__asm__("rep stosl" : : "D"(__dst), "a"(__x), "c"(__n)
: "%edi", "%ecx");
#include <intrin.h>
+#if defined(__i386__) || defined(__x86_64__)
+void test__stosb(unsigned char *Dest, unsigned char Data, size_t Count) {
+ return __stosb(Dest, Data, Count);
+}
+
+// CHECK-I386: define{{.*}}void @test__stosb
+// CHECK-I386: tail call void @llvm.memset.p0i8.i32(i8* %Dest, i8 %Data, i32 %Count, i32 1, i1 true)
+// CHECK-I386: ret void
+// CHECK-I386: }
+
+// CHECK-X64: define{{.*}}void @test__stosb
+// CHECK-X64: tail call void @llvm.memset.p0i8.i64(i8* %Dest, i8 %Data, i64 %Count, i32 1, i1 true)
+// CHECK-X64: ret void
+// CHECK-X64: }
+#endif
+
void *test_ReturnAddress() {
return _ReturnAddress();
}
__movsd(0, 0, 0);
__movsw(0, 0, 0);
- __stosb(0, 0, 0);
__stosd(0, 0, 0);
__stosw(0, 0, 0);