[Attributor] Identify and remove no-op fences
The logic and implementation follows the removal of no-op barriers. If
the fence is not making updates visible, either to the world or the
current thread, it is not needed. Said differently, the fences we remove
do not establish synchronization (happens-before) edges.
This allows us to eliminate some of the regression caused by:
https://reviews.llvm.org/D145290
GitOrigin-RevId: cb17c48fdd8c0f8ab6cd7ad3f197b052db20d1f6
diff --git a/libomptarget/test/jit/empty_kernel_lvl2.c b/libomptarget/test/jit/empty_kernel_lvl2.c
index 5818104..01270cf 100644
--- a/libomptarget/test/jit/empty_kernel_lvl2.c
+++ b/libomptarget/test/jit/empty_kernel_lvl2.c
@@ -5,8 +5,7 @@
// RUN: env LIBOMPTARGET_JIT_PRE_OPT_IR_MODULE=%t.pre.ll \
// RUN: LIBOMPTARGET_JIT_SKIP_OPT=true \
// RUN: %libomptarget-run-generic
-// TODO:
-// RUN: not %fcheck-plain-generic --input-file %t.pre.ll %S/empty_kernel.inc --check-prefix=FIRST
+// RUN: %fcheck-plain-generic --input-file %t.pre.ll %S/empty_kernel.inc --check-prefix=FIRST
// RUN: %libomptarget-compileoptxx-generic -fopenmp-target-jit \
// RUN: -DTGT1_DIRECTIVE="target" \
// RUN: -DTGT2_DIRECTIVE="target" \
@@ -14,8 +13,7 @@
// RUN: env LIBOMPTARGET_JIT_PRE_OPT_IR_MODULE=%t.pre.ll \
// RUN: LIBOMPTARGET_JIT_SKIP_OPT=true \
// RUN: %libomptarget-run-generic
-// TODO:
-// RUN: not %fcheck-plain-generic --input-file %t.pre.ll %S/empty_kernel.inc --check-prefixes=FIRST,SECOND
+// RUN: %fcheck-plain-generic --input-file %t.pre.ll %S/empty_kernel.inc --check-prefixes=FIRST,SECOND
//
// RUN: %libomptarget-compileoptxx-generic -fopenmp-target-jit \
// RUN: -DTGT1_DIRECTIVE="target" \
