diff --git a/llvm/include/llvm/IR/Assumptions.h b/llvm/include/llvm/IR/Assumptions.h
--- a/llvm/include/llvm/IR/Assumptions.h
+++ b/llvm/include/llvm/IR/Assumptions.h
@@ -34,6 +34,10 @@
 /// Helper that allows to insert a new assumption string in the known assumption
 /// set by creating a (static) object.
 struct KnownAssumptionString {
+  KnownAssumptionString(const char *AssumptionStr)
+      : AssumptionStr(AssumptionStr) {
+    KnownAssumptionStrings.insert(AssumptionStr);
+  }
   KnownAssumptionString(StringRef AssumptionStr)
       : AssumptionStr(AssumptionStr) {
     KnownAssumptionStrings.insert(AssumptionStr);
diff --git a/llvm/lib/IR/Assumptions.cpp b/llvm/lib/IR/Assumptions.cpp
--- a/llvm/lib/IR/Assumptions.cpp
+++ b/llvm/lib/IR/Assumptions.cpp
@@ -107,4 +107,5 @@
     "omp_no_openmp_routines", // OpenMP 5.1
     "omp_no_parallelism",     // OpenMP 5.1
     "ompx_spmd_amenable",     // OpenMPOpt extension
+    "ompx_no_call_asm",       // OpenMPOpt extension
 });
diff --git a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
--- a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
+++ b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
@@ -32,6 +32,7 @@
 #include "llvm/Analysis/ScalarEvolution.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/Analysis/ValueTracking.h"
+#include "llvm/IR/Argument.h"
 #include "llvm/IR/Assumptions.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DataLayout.h"
@@ -9540,7 +9541,9 @@
     CallBase *CB = cast<CallBase>(getCtxI());
 
     if (CB->isInlineAsm()) {
-      setHasUnknownCallee(false, Change);
+      if (!hasAssumption(*CB->getCaller(), "ompx_no_call_asm") &&
+          !hasAssumption(*CB, "ompx_no_call_asm"))
+        setHasUnknownCallee(false, Change);
       return Change;
     }
 
diff --git a/llvm/test/Transforms/Attributor/reachability.ll b/llvm/test/Transforms/Attributor/reachability.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Transforms/Attributor/reachability.ll
@@ -0,0 +1,49 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --function-signature --check-attributes --check-globals
+; RUN: opt -attributor -enable-new-pm=0 -attributor-manifest-internal  -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=2 -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_CGSCC_NPM,NOT_CGSCC_OPM,NOT_TUNIT_NPM,IS__TUNIT____,IS________OPM,IS__TUNIT_OPM
+; RUN: opt -aa-pipeline=basic-aa -passes=attributor -attributor-manifest-internal  -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=2 -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_CGSCC_OPM,NOT_CGSCC_NPM,NOT_TUNIT_OPM,IS__TUNIT____,IS________NPM,IS__TUNIT_NPM
+; RUN: opt -attributor-cgscc -enable-new-pm=0 -attributor-manifest-internal  -attributor-annotate-decl-cs -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_TUNIT_NPM,NOT_TUNIT_OPM,NOT_CGSCC_NPM,IS__CGSCC____,IS________OPM,IS__CGSCC_OPM
+; RUN: opt -aa-pipeline=basic-aa -passes=attributor-cgscc -attributor-manifest-internal  -attributor-annotate-decl-cs -S < %s | FileCheck %s --check-prefixes=CHECK,NOT_TUNIT_NPM,NOT_TUNIT_OPM,NOT_CGSCC_OPM,IS__CGSCC____,IS________NPM,IS__CGSCC_NPM
+
+define void @non_recursive_asm_fn() #0 {
+; CHECK: Function Attrs: norecurse
+; CHECK-LABEL: define {{[^@]+}}@non_recursive_asm_fn
+; CHECK-SAME: () #[[ATTR0:[0-9]+]] {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    call void asm sideeffect "barrier.sync $0
+; CHECK-NEXT:    ret void
+;
+entry:
+  call void asm sideeffect "barrier.sync $0;", "r,~{memory},~{dirflag},~{fpsr},~{flags}"(i32 1)
+  ret void
+}
+
+define void @non_recursive_asm_cs() {
+; CHECK: Function Attrs: norecurse
+; CHECK-LABEL: define {{[^@]+}}@non_recursive_asm_cs
+; CHECK-SAME: () #[[ATTR1:[0-9]+]] {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    call void asm sideeffect "barrier.sync $0
+; CHECK-NEXT:    ret void
+;
+entry:
+  call void asm sideeffect "barrier.sync $0;", "r,~{memory},~{dirflag},~{fpsr},~{flags}"(i32 1) #0
+  ret void
+}
+
+define void @recursive_asm() {
+; CHECK-LABEL: define {{[^@]+}}@recursive_asm() {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    call void asm sideeffect "barrier.sync $0
+; CHECK-NEXT:    ret void
+;
+entry:
+  call void asm sideeffect "barrier.sync $0;", "r,~{memory},~{dirflag},~{fpsr},~{flags}"(i32 1)
+  ret void
+}
+
+attributes #0 = { "llvm.assume"="ompx_no_call_asm" }
+;.
+; CHECK: attributes #[[ATTR0]] = { norecurse "llvm.assume"="ompx_no_call_asm" }
+; CHECK: attributes #[[ATTR1]] = { norecurse }
+; CHECK: attributes #[[ATTR2:[0-9]+]] = { "llvm.assume"="ompx_no_call_asm" }
+;.
diff --git a/openmp/libomptarget/DeviceRTL/include/Types.h b/openmp/libomptarget/DeviceRTL/include/Types.h
--- a/openmp/libomptarget/DeviceRTL/include/Types.h
+++ b/openmp/libomptarget/DeviceRTL/include/Types.h
@@ -12,6 +12,15 @@
 #ifndef OMPTARGET_TYPES_H
 #define OMPTARGET_TYPES_H
 
+// Tell the compiler that we do not have any "call-like" inline assembly in the
+// device rutime. That means we cannot have inline assembly which will call
+// another function but only inline assembly that performs some operation or
+// side-effect and then continues execution with something on the existing call
+// stack.
+//
+// TODO: Find a good place for this
+#pragma omp assumes ext_no_call_asm
+
 /// Base type declarations for freestanding mode
 ///
 ///{