Correct atomic libcall support for __atomic_*_fetch builtins.

In r244063, I had caused these builtins to call the same-named library
functions, __atomic_*_fetch_SIZE. However, this was incorrect: while
those functions are in fact supported by GCC's libatomic, they're not
documented by the spec (and gcc doesn't ever call them).

Instead, you're /supposed/ to call the __atomic_fetch_* builtins and
then redo the operation inline to return the final value.

Differential Revision: http://reviews.llvm.org/D14385

llvm-svn: 252920

1 files changed, 13 insertions, 6 deletions

diff --git a/clang/test/CodeGen/atomic-ops-libcall.c b/clang/test/CodeGen/atomic-ops-libcall.c
index 5b9ba467d81..0093a8cbbbb 100644
--- a/clang/test/CodeGen/atomic-ops-libcall.c
+++ b/clang/test/CodeGen/atomic-ops-libcall.c
@@ -74,36 +74,43 @@ int test_atomic_fetch_nand(int *p) {
 
 int test_atomic_add_fetch(int *p) {
   // CHECK: test_atomic_add_fetch
-  // CHECK: {{%[^ ]*}} = tail call i32 @__atomic_add_fetch_4(i8* {{%[0-9]+}}, i32 55, i32 5)
+  // CHECK: [[CALL:%[^ ]*]] = tail call i32 @__atomic_fetch_add_4(i8* {{%[0-9]+}}, i32 55, i32 5)
+  // CHECK: {{%[^ ]*}} = add i32 [[CALL]], 55
   return __atomic_add_fetch(p, 55, memory_order_seq_cst);
 }
 
 int test_atomic_sub_fetch(int *p) {
   // CHECK: test_atomic_sub_fetch
-  // CHECK: {{%[^ ]*}} = tail call i32 @__atomic_sub_fetch_4(i8* {{%[0-9]+}}, i32 55, i32 5)
+  // CHECK: [[CALL:%[^ ]*]] = tail call i32 @__atomic_fetch_sub_4(i8* {{%[0-9]+}}, i32 55, i32 5)
+  // CHECK: {{%[^ ]*}} = add i32 [[CALL]], -55
   return __atomic_sub_fetch(p, 55, memory_order_seq_cst);
 }
 
 int test_atomic_and_fetch(int *p) {
   // CHECK: test_atomic_and_fetch
-  // CHECK: {{%[^ ]*}} = tail call i32 @__atomic_and_fetch_4(i8* {{%[0-9]+}}, i32 55, i32 5)
+  // CHECK: [[CALL:%[^ ]*]] = tail call i32 @__atomic_fetch_and_4(i8* {{%[0-9]+}}, i32 55, i32 5)
+  // CHECK: {{%[^ ]*}} = and i32 [[CALL]], 55
   return __atomic_and_fetch(p, 55, memory_order_seq_cst);
 }
 
 int test_atomic_or_fetch(int *p) {
   // CHECK: test_atomic_or_fetch
-  // CHECK: {{%[^ ]*}} = tail call i32 @__atomic_or_fetch_4(i8* {{%[0-9]+}}, i32 55, i32 5)
+  // CHECK: [[CALL:%[^ ]*]] = tail call i32 @__atomic_fetch_or_4(i8* {{%[0-9]+}}, i32 55, i32 5)
+  // CHECK: {{%[^ ]*}} = or i32 [[CALL]], 55
   return __atomic_or_fetch(p, 55, memory_order_seq_cst);
 }
 
 int test_atomic_xor_fetch(int *p) {
   // CHECK: test_atomic_xor_fetch
-  // CHECK: {{%[^ ]*}} = tail call i32 @__atomic_xor_fetch_4(i8* {{%[0-9]+}}, i32 55, i32 5)
+  // CHECK: [[CALL:%[^ ]*]] = tail call i32 @__atomic_fetch_xor_4(i8* {{%[0-9]+}}, i32 55, i32 5)
+  // CHECK: {{%[^ ]*}} = xor i32 [[CALL]], 55
   return __atomic_xor_fetch(p, 55, memory_order_seq_cst);
 }
 
 int test_atomic_nand_fetch(int *p) {
   // CHECK: test_atomic_nand_fetch
-  // CHECK: {{%[^ ]*}} = tail call i32 @__atomic_nand_fetch_4(i8* {{%[0-9]+}}, i32 55, i32 5)
+  // CHECK: [[CALL:%[^ ]*]] = tail call i32 @__atomic_fetch_nand_4(i8* {{%[0-9]+}}, i32 55, i32 5)
+  // CHECK: [[OR:%[^ ]*]] = or i32 [[CALL]], -56
+  // CHECK: {{%[^ ]*}} = xor i32 [[OR]], 55
   return __atomic_nand_fetch(p, 55, memory_order_seq_cst);
 }