[clang] d3aed4f - MachO use generic code to detect atomic support.

[Tim Northover via cfe-commits]

Author: Tim Northover
Date: 2023-04-04T13:44:45+01:00
New Revision: d3aed4f401fa35ea986d3967c529f4d2b24e2bb6

URL: https://github.com/llvm/llvm-project/commit/d3aed4f401fa35ea986d3967c529f4d2b24e2bb6
DIFF: https://github.com/llvm/llvm-project/commit/d3aed4f401fa35ea986d3967c529f4d2b24e2bb6.diff

LOG: MachO use generic code to detect atomic support.

The default code can detect what width of atomic instructions are supported
based on the targeted architecture profile, version etc so there's no need to
hard-code 64 on Darwin targets (especially as it's wrong in most M-class
cases).

Added: 
    clang/test/CodeGen/atomic-arm.c

Modified: 
    clang/lib/Basic/Targets/ARM.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Basic/Targets/ARM.cpp b/clang/lib/Basic/Targets/ARM.cpp
index 5e0e8f5c476af..a0ffbcf78001e 100644
--- a/clang/lib/Basic/Targets/ARM.cpp
+++ b/clang/lib/Basic/Targets/ARM.cpp
@@ -1406,11 +1406,6 @@ DarwinARMTargetInfo::DarwinARMTargetInfo(const llvm::Triple &Triple,
                                          const TargetOptions &Opts)
     : DarwinTargetInfo<ARMleTargetInfo>(Triple, Opts) {
   HasAlignMac68kSupport = true;
-  // iOS always has 64-bit atomic instructions.
-  // FIXME: This should be based off of the target features in
-  // ARMleTargetInfo.
-  MaxAtomicInlineWidth = 64;
-
   if (Triple.isWatchABI()) {
     // Darwin on iOS uses a variant of the ARM C++ ABI.
     TheCXXABI.set(TargetCXXABI::WatchOS);

diff  --git a/clang/test/CodeGen/atomic-arm.c b/clang/test/CodeGen/atomic-arm.c
new file mode 100644
index 0000000000000..6952b4d0099b5
--- /dev/null
+++ b/clang/test/CodeGen/atomic-arm.c
@@ -0,0 +1,57 @@
+// RUN: %clang_cc1 -triple thumbv6m-apple-unknown-macho %s -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,CHECK-V6M
+// RUN: %clang_cc1 -triple thumbv7m-apple-unknown-macho %s -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,CHECK-V7M
+// RUN: %clang_cc1 -triple thumbv7-apple-ios13.0 %s -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,CHECK-HOSTED
+// RUN: %clang_cc1 -triple thumbv7k-apple-watchos5.0 %s -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,CHECK-HOSTED
+
+
+// CHECK-V6M: @always1 = global i32 0
+// CHECK-V6M: @always4 = global i32 0
+// CHECK-V6M: @always8 = global i32 0
+
+// CHECK-V7M: @always1 = global i32 1
+// CHECK-V7M: @always4 = global i32 1
+// CHECK-V7M: @always8 = global i32 0
+
+// CHECK-HOSTED: @always1 = global i32 1
+// CHECK-HOSTED: @always4 = global i32 1
+// CHECK-HOSTED: @always8 = global i32 1
+
+int always1 = __atomic_always_lock_free(1, 0);
+int always4 = __atomic_always_lock_free(4, 0);
+int always8 = __atomic_always_lock_free(8, 0);
+
+int lock_free_1() {
+  // CHECK-LABEL: @lock_free_1
+  // CHECK-V6M:   [[RES:%.*]] = call arm_aapcscc zeroext i1 @__atomic_is_lock_free(i32 noundef 1, ptr noundef null)
+  // CHECK-V6M:   [[RES32:%.*]] = zext i1 [[RES]] to i32
+  // CHECK-V6M:   ret i32 [[RES32]]
+
+  // CHECK-V7M: ret i32 1
+  // CHECK-HOSTED: ret i32 1
+  return __c11_atomic_is_lock_free(1);
+}
+
+int lock_free_4() {
+  // CHECK-LABEL: @lock_free_4
+  // CHECK-V6M:   [[RES:%.*]] = call arm_aapcscc zeroext i1 @__atomic_is_lock_free(i32 noundef 4, ptr noundef null)
+  // CHECK-V6M:   [[RES32:%.*]] = zext i1 [[RES]] to i32
+  // CHECK-V6M:   ret i32 [[RES32]]
+
+  // CHECK-V7M: ret i32 1
+  // CHECK-HOSTED: ret i32 1
+  return __c11_atomic_is_lock_free(4);
+}
+
+int lock_free_8() {
+  // CHECK-LABEL: @lock_free_8
+  // CHECK-V6M:   [[RES:%.*]] = call arm_aapcscc zeroext i1 @__atomic_is_lock_free(i32 noundef 8, ptr noundef null)
+  // CHECK-V6M:   [[RES32:%.*]] = zext i1 [[RES]] to i32
+  // CHECK-V6M:   ret i32 [[RES32]]
+
+  // CHECK-V7M:   [[RES:%.*]] = call arm_aapcscc zeroext i1 @__atomic_is_lock_free(i32 noundef 8, ptr noundef null)
+  // CHECK-V7M:   [[RES32:%.*]] = zext i1 [[RES]] to i32
+  // CHECK-V7M:   ret i32 [[RES32]]
+
+  // CHECK-HOSTED: ret i32 1
+  return __c11_atomic_is_lock_free(8);
+}