[clang] [Clang][CodeGen] Optimised LLVM IR for atomic increments/decrements on floats (PR #89362)

[Simon Pilgrim via cfe-commits]

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@@ -0,0 +1,69 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --version 4
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -target-cpu core2 %s -S -emit-llvm -o - | FileCheck -check-prefixes=CHECK,CHECK64 %s
+// RUN: %clang_cc1 -triple i686-linux-gnu -target-cpu core2 %s -S -emit-llvm -o - | FileCheck -check-prefixes=CHECK,CHECK32 %s
+
+
+// CHECK-LABEL: define dso_local i32 @test_int_inc(
+// CHECK-SAME: ) #[[ATTR0:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[TMP0:%.*]] = atomicrmw add ptr @test_int_inc.n, i32 1 seq_cst, align 4
+// CHECK-NEXT:    ret i32 [[TMP0]]
+//
+int test_int_inc()
+{
+    static _Atomic int n;
+    return n++;
+}
+
+// CHECK-LABEL: define dso_local float @test_float_post_inc(
+// CHECK-SAME: ) #[[ATTR0]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[TMP0:%.*]] = atomicrmw fadd ptr @test_float_post_inc.n, float 1.000000e+00 seq_cst, align 4
+// CHECK-NEXT:    ret float [[TMP0]]
+//
+float test_float_post_inc()
+{
+    static _Atomic float n;
+    return n++;
+}
+
+// CHECK-LABEL: define dso_local float @test_float_post_dc(
+// CHECK-SAME: ) #[[ATTR0]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[TMP0:%.*]] = atomicrmw fsub ptr @test_float_post_dc.n, float -1.000000e+00 seq_cst, align 4
----------------
RKSimon wrote:

`fsub x, -1.0`? Should it be `fsub x, 1.0`?

https://github.com/llvm/llvm-project/pull/89362