[llvm] [FuncAttrs] Relax norecurse attribute inference (PR #139943)

via llvm-commits llvm-commits at lists.llvm.org
Wed May 14 11:18:58 PDT 2025


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-transforms

Author: Usha Gupta (usha1830)

<details>
<summary>Changes</summary>

The current code adds `norecurse` attribute to a function only if all of its callee functions have `norecurse` attribute.

This is a little conservative check and prevents cases if there is self-recursive callee or if the callee is in a recursive chain which does not include current caller.

Example scenarios:

`main ->  callee1 -> callee2 -> callee2`

main and callee1 could have `norecurse` in this case given the other constraints are satisfied.

Similarly, main can have the `norecurse` attribute in the following case.
`main -> callee1 -> callee2 -> callee1 `


This PR relaxes the requirement that all callees must have the `norecurse` attribute. It adds a check to prevent propagating `norecurse` to functions that may indirectly call unknown external functions lacking the `NoCallback` attribute, as these may introduce callbacks.







---

Patch is 22.25 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/139943.diff


4 Files Affected:

- (modified) llvm/lib/Transforms/IPO/FunctionAttrs.cpp (+69-17) 
- (added) llvm/test/Transforms/FunctionAttrs/norecurse_multiSCC_indirect_recursion.ll (+159) 
- (added) llvm/test/Transforms/FunctionAttrs/norecurse_multiSCC_indirect_recursion1.ll (+102) 
- (added) llvm/test/Transforms/FunctionAttrs/norecurse_self_recursive_callee.ll (+173) 


``````````diff
diff --git a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
index f918d7e059b63..293699a1639c6 100644
--- a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
@@ -2059,8 +2059,49 @@ static void inferAttrsFromFunctionBodies(const SCCNodeSet &SCCNodes,
   AI.run(SCCNodes, Changed);
 }
 
+/// Returns true if N or any function it (transitively) calls makes a call
+/// to an unknown external function: either an indirect call or a declaration
+/// without the NoCallback attribute.
+static bool callsUnknownExternal(LazyCallGraph::Node *N) {
+  std::deque<LazyCallGraph::Node *> Worklist;
+  DenseSet<LazyCallGraph::Node *> Visited;
+  Worklist.push_back(N);
+  Visited.insert(N);
+
+  while (!Worklist.empty()) {
+    auto *Cur = Worklist.front();
+    Worklist.pop_front();
+
+    Function &F = Cur->getFunction();
+    for (auto &BB : F) {
+      for (auto &I : BB.instructionsWithoutDebug()) {
+        if (auto *CB = dyn_cast<CallBase>(&I)) {
+          const Function *Callee = CB->getCalledFunction();
+          // Indirect call, treat as unknown external function.
+          if (!Callee)
+            return true;
+          // Extern declaration without NoCallback attribute
+          if (Callee->isDeclaration() &&
+              !Callee->hasFnAttribute(Attribute::NoCallback))
+            return true;
+        }
+      }
+    }
+
+    // Enqueue all direct call-edge successors for further scanning
+    for (auto &Edge : Cur->populate().calls()) {
+      LazyCallGraph::Node *Succ = &Edge.getNode();
+      if (Visited.insert(Succ).second)
+        Worklist.push_back(Succ);
+    }
+  }
+
+  return false;
+}
+
 static void addNoRecurseAttrs(const SCCNodeSet &SCCNodes,
-                              SmallSet<Function *, 8> &Changed) {
+                              SmallSet<Function *, 8> &Changed,
+                              LazyCallGraph &CG) {
   // Try and identify functions that do not recurse.
 
   // If the SCC contains multiple nodes we know for sure there is recursion.
@@ -2071,24 +2112,35 @@ static void addNoRecurseAttrs(const SCCNodeSet &SCCNodes,
   if (!F || !F->hasExactDefinition() || F->doesNotRecurse())
     return;
 
-  // If all of the calls in F are identifiable and are to norecurse functions, F
-  // is norecurse. This check also detects self-recursion as F is not currently
-  // marked norecurse, so any called from F to F will not be marked norecurse.
-  for (auto &BB : *F)
-    for (auto &I : BB.instructionsWithoutDebug())
+  // If all of the calls in F are identifiable and can be proven to not
+  // callback F, F is norecurse. This check also detects self-recursion
+  // as F is not currently marked norecurse, so any call from F to F
+  // will not be marked norecurse.
+  for (auto &BB : *F) {
+    for (auto &I : BB.instructionsWithoutDebug()) {
       if (auto *CB = dyn_cast<CallBase>(&I)) {
         Function *Callee = CB->getCalledFunction();
-        if (!Callee || Callee == F ||
-            (!Callee->doesNotRecurse() &&
-             !(Callee->isDeclaration() &&
-               Callee->hasFnAttribute(Attribute::NoCallback))))
-          // Function calls a potentially recursive function.
+
+        if (!Callee || Callee == F)
+          return;
+
+        // External call with NoCallback attribute.
+        if (Callee->isDeclaration()) {
+          if (Callee->hasFnAttribute(Attribute::NoCallback))
+            continue;
           return;
+        }
+
+        if (auto *CNode = CG.lookup(*Callee))
+          if (callsUnknownExternal(CNode))
+            return;
       }
+    }
+  }
 
-  // Every call was to a non-recursive function other than this function, and
-  // we have no indirect recursion as the SCC size is one. This function cannot
-  // recurse.
+  // Every call was either to an external function guaranteed to not make a
+  // call to this function or a direct call to internal function and we have no
+  // indirect recursion as the SCC size is one. This function cannot recurse.
   F->setDoesNotRecurse();
   ++NumNoRecurse;
   Changed.insert(F);
@@ -2248,7 +2300,7 @@ static SCCNodesResult createSCCNodeSet(ArrayRef<Function *> Functions) {
 template <typename AARGetterT>
 static SmallSet<Function *, 8>
 deriveAttrsInPostOrder(ArrayRef<Function *> Functions, AARGetterT &&AARGetter,
-                       bool ArgAttrsOnly) {
+                       bool ArgAttrsOnly, LazyCallGraph &CG) {
   SCCNodesResult Nodes = createSCCNodeSet(Functions);
 
   // Bail if the SCC only contains optnone functions.
@@ -2279,7 +2331,7 @@ deriveAttrsInPostOrder(ArrayRef<Function *> Functions, AARGetterT &&AARGetter,
     addNoAliasAttrs(Nodes.SCCNodes, Changed);
     addNonNullAttrs(Nodes.SCCNodes, Changed);
     inferAttrsFromFunctionBodies(Nodes.SCCNodes, Changed);
-    addNoRecurseAttrs(Nodes.SCCNodes, Changed);
+    addNoRecurseAttrs(Nodes.SCCNodes, Changed, CG);
   }
 
   // Finally, infer the maximal set of attributes from the ones we've inferred
@@ -2323,7 +2375,7 @@ PreservedAnalyses PostOrderFunctionAttrsPass::run(LazyCallGraph::SCC &C,
   }
 
   auto ChangedFunctions =
-      deriveAttrsInPostOrder(Functions, AARGetter, ArgAttrsOnly);
+      deriveAttrsInPostOrder(Functions, AARGetter, ArgAttrsOnly, CG);
   if (ChangedFunctions.empty())
     return PreservedAnalyses::all();
 
diff --git a/llvm/test/Transforms/FunctionAttrs/norecurse_multiSCC_indirect_recursion.ll b/llvm/test/Transforms/FunctionAttrs/norecurse_multiSCC_indirect_recursion.ll
new file mode 100644
index 0000000000000..c0af16b069bde
--- /dev/null
+++ b/llvm/test/Transforms/FunctionAttrs/norecurse_multiSCC_indirect_recursion.ll
@@ -0,0 +1,159 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-attributes --version 5
+; RUN: opt < %s -passes=function-attrs -S | FileCheck %s
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128-Fn32"
+target triple = "aarch64-unknown-linux-gnu"
+
+; This test includes a call graph with multiple SCCs. The purpose of this is 
+; to check that norecurse is not added when a function is part of non-singular 
+; SCC.
+; There are three different SCCs in this test:
+;  SCC#1:  main, foo, bar, foo1, bar1
+;  SCC#2:  bar2, bar3, bar4
+;  SCC#3:  baz, fun
+; None of these functions should be marked as norecurse
+
+; Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+define dso_local void @bar1() local_unnamed_addr #0 {
+; CHECK: Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+; CHECK-LABEL: define dso_local void @bar1(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR0:[0-9]+]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[CALL:%.*]] = tail call i32 @main()
+; CHECK-NEXT:    ret void
+;
+entry:
+  %call = tail call i32 @main()
+  ret void
+}
+
+; Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+define dso_local noundef i32 @main() local_unnamed_addr #0 {
+; CHECK: Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+; CHECK-LABEL: define dso_local noundef i32 @main(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR0]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    tail call void @foo()
+; CHECK-NEXT:    tail call void @bar2()
+; CHECK-NEXT:    tail call void @baz()
+; CHECK-NEXT:    ret i32 0
+;
+entry:
+  tail call void @foo()
+  tail call void @bar2()
+  tail call void @baz()
+  ret i32 0
+}
+
+; Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+define dso_local void @foo1() local_unnamed_addr #0 {
+; CHECK: Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+; CHECK-LABEL: define dso_local void @foo1(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR0]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    tail call void @bar1()
+; CHECK-NEXT:    ret void
+;
+entry:
+  tail call void @bar1()
+  ret void
+}
+
+; Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+define dso_local void @bar() local_unnamed_addr #0 {
+; CHECK: Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+; CHECK-LABEL: define dso_local void @bar(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR0]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    tail call void @foo1()
+; CHECK-NEXT:    ret void
+;
+entry:
+  tail call void @foo1()
+  ret void
+}
+
+; Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+define dso_local void @foo() local_unnamed_addr #0 {
+; CHECK: Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+; CHECK-LABEL: define dso_local void @foo(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR0]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    tail call void @bar()
+; CHECK-NEXT:    ret void
+;
+entry:
+  tail call void @bar()
+  ret void
+}
+
+; Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+define dso_local void @bar4() local_unnamed_addr #0 {
+; CHECK: Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+; CHECK-LABEL: define dso_local void @bar4(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR0]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    tail call void @bar2()
+; CHECK-NEXT:    ret void
+;
+entry:
+  tail call void @bar2()
+  ret void
+}
+
+; Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+define dso_local void @bar2() local_unnamed_addr #0 {
+; CHECK: Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+; CHECK-LABEL: define dso_local void @bar2(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR0]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    tail call void @bar3()
+; CHECK-NEXT:    ret void
+;
+entry:
+  tail call void @bar3()
+  ret void
+}
+
+; Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+define dso_local void @bar3() local_unnamed_addr #0 {
+; CHECK: Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+; CHECK-LABEL: define dso_local void @bar3(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR0]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    tail call void @bar4()
+; CHECK-NEXT:    ret void
+;
+entry:
+  tail call void @bar4()
+  ret void
+}
+
+; Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+define dso_local void @fun() local_unnamed_addr #0 {
+; CHECK: Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+; CHECK-LABEL: define dso_local void @fun(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR0]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    tail call void @baz()
+; CHECK-NEXT:    ret void
+;
+entry:
+  tail call void @baz()
+  ret void
+}
+
+; Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+define dso_local void @baz() local_unnamed_addr #0 {
+; CHECK: Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+; CHECK-LABEL: define dso_local void @baz(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR0]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    tail call void @fun()
+; CHECK-NEXT:    ret void
+;
+entry:
+  tail call void @fun()
+  ret void
+}
+
+attributes #0 = { nofree noinline nosync nounwind memory(none) uwtable "frame-pointer"="non-leaf" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="generic" "target-features"="+fp-armv8,+neon,+outline-atomics,+v8a,-fmv" }
diff --git a/llvm/test/Transforms/FunctionAttrs/norecurse_multiSCC_indirect_recursion1.ll b/llvm/test/Transforms/FunctionAttrs/norecurse_multiSCC_indirect_recursion1.ll
new file mode 100644
index 0000000000000..60bbaab2a7d66
--- /dev/null
+++ b/llvm/test/Transforms/FunctionAttrs/norecurse_multiSCC_indirect_recursion1.ll
@@ -0,0 +1,102 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-attributes --version 5
+; RUN: opt < %s -passes=function-attrs -S | FileCheck %s
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128-Fn32"
+target triple = "aarch64-unknown-linux-gnu"
+
+; This test includes a call graph with multiple SCCs. The purpose of this is 
+; to check that norecurse is added to a function which calls a function which 
+; is indirectly recursive but is not part of the recursive chain. 
+; There are two SCCs in this test:
+;  SCC#1:  bar2, bar3, bar4
+;  SCC#2:  baz, fun
+; main() calls bar2 and baz, both of which are part of some indirect recursive
+; chain. but does not call back main() and hence main() can be marked as 
+; norecurse.
+
+; Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+define dso_local noundef i32 @main() local_unnamed_addr #0 {
+; CHECK: Function Attrs: nofree noinline norecurse nosync nounwind memory(none) uwtable
+; CHECK-LABEL: define dso_local noundef i32 @main(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR0:[0-9]+]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    tail call void @bar2()
+; CHECK-NEXT:    tail call void @baz()
+; CHECK-NEXT:    ret i32 0
+;
+entry:
+  tail call void @bar2()
+  tail call void @baz()
+  ret i32 0
+}
+
+; Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+define dso_local void @bar4() local_unnamed_addr #0 {
+; CHECK: Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+; CHECK-LABEL: define dso_local void @bar4(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR1:[0-9]+]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    tail call void @bar2()
+; CHECK-NEXT:    ret void
+;
+entry:
+  tail call void @bar2()
+  ret void
+}
+
+; Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+define dso_local void @bar2() local_unnamed_addr #0 {
+; CHECK: Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+; CHECK-LABEL: define dso_local void @bar2(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR1]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    tail call void @bar3()
+; CHECK-NEXT:    ret void
+;
+entry:
+  tail call void @bar3()
+  ret void
+}
+
+; Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+define dso_local void @bar3() local_unnamed_addr #0 {
+; CHECK: Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+; CHECK-LABEL: define dso_local void @bar3(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR1]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    tail call void @bar4()
+; CHECK-NEXT:    ret void
+;
+entry:
+  tail call void @bar4()
+  ret void
+}
+
+; Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+define dso_local void @fun() local_unnamed_addr #0 {
+; CHECK: Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+; CHECK-LABEL: define dso_local void @fun(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR1]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    tail call void @baz()
+; CHECK-NEXT:    ret void
+;
+entry:
+  tail call void @baz()
+  ret void
+}
+
+; Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+define dso_local void @baz() local_unnamed_addr #0 {
+; CHECK: Function Attrs: nofree noinline nosync nounwind memory(none) uwtable
+; CHECK-LABEL: define dso_local void @baz(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR1]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    tail call void @fun()
+; CHECK-NEXT:    ret void
+;
+entry:
+  tail call void @fun()
+  ret void
+}
+
+attributes #0 = { nofree noinline nosync nounwind memory(none) uwtable "frame-pointer"="non-leaf" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="generic" "target-features"="+fp-armv8,+neon,+outline-atomics,+v8a,-fmv" }
diff --git a/llvm/test/Transforms/FunctionAttrs/norecurse_self_recursive_callee.ll b/llvm/test/Transforms/FunctionAttrs/norecurse_self_recursive_callee.ll
new file mode 100644
index 0000000000000..9b87c4e4ad76c
--- /dev/null
+++ b/llvm/test/Transforms/FunctionAttrs/norecurse_self_recursive_callee.ll
@@ -0,0 +1,173 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-attributes --version 5
+; RUN: opt < %s -passes=function-attrs -S | FileCheck %s
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128-Fn32"
+target triple = "aarch64-unknown-linux-gnu"
+
+; This test includes a call graph with a self recursive function. 
+; The purpose of this is to check that norecurse is added to functions 
+; which have a self-recursive function in the call-chain. 
+; The call-chain in this test is as follows 
+; main -> bob -> callee1 -> callee2 -> callee3 -> callee4 -> callee5
+; where callee5 is self recursive.
+
+ at x = dso_local global i32 4, align 4
+ at y = dso_local global i32 2, align 4
+
+; Function Attrs: nofree noinline norecurse nounwind memory(readwrite, argmem: none) uwtable
+define dso_local void @callee6() local_unnamed_addr #0 {
+; CHECK: Function Attrs: nofree noinline norecurse nounwind memory(readwrite, argmem: none) uwtable
+; CHECK-LABEL: define dso_local void @callee6(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR0:[0-9]+]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = load volatile i32, ptr @y, align 4, !tbaa [[TBAA8:![0-9]+]]
+; CHECK-NEXT:    [[INC:%.*]] = add nsw i32 [[TMP0]], 1
+; CHECK-NEXT:    store volatile i32 [[INC]], ptr @y, align 4, !tbaa [[TBAA8]]
+; CHECK-NEXT:    ret void
+;
+entry:
+  %0 = load volatile i32, ptr @y, align 4, !tbaa !8
+  %inc = add nsw i32 %0, 1
+  store volatile i32 %inc, ptr @y, align 4, !tbaa !8
+  ret void
+}
+
+; Function Attrs: nofree noinline nounwind uwtable
+define dso_local void @callee5(i32 noundef %x) local_unnamed_addr #1 {
+; CHECK: Function Attrs: nofree noinline nounwind uwtable
+; CHECK-LABEL: define dso_local void @callee5(
+; CHECK-SAME: i32 noundef [[X:%.*]]) local_unnamed_addr #[[ATTR1:[0-9]+]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 [[X]], 0
+; CHECK-NEXT:    br i1 [[CMP]], label %[[IF_THEN:.*]], label %[[IF_END:.*]]
+; CHECK:       [[IF_THEN]]:
+; CHECK-NEXT:    tail call void @callee5(i32 noundef [[X]])
+; CHECK-NEXT:    br label %[[IF_END]]
+; CHECK:       [[IF_END]]:
+; CHECK-NEXT:    tail call void @callee6()
+; CHECK-NEXT:    ret void
+;
+entry:
+  %cmp = icmp sgt i32 %x, 0
+  br i1 %cmp, label %if.then, label %if.end
+
+if.then:                                          ; preds = %entry
+  tail call void @callee5(i32 noundef %x)
+  br label %if.end
+
+if.end:                                           ; preds = %if.then, %entry
+  tail call void @callee6()
+  ret void
+}
+
+; Function Attrs: nofree noinline nounwind uwtable
+define dso_local void @callee4() local_unnamed_addr #1 {
+; CHECK: Function Attrs: nofree noinline norecurse nounwind uwtable
+; CHECK-LABEL: define dso_local void @callee4(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR2:[0-9]+]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[TMP0:%.*]] = load volatile i32, ptr @x, align 4, !tbaa [[TBAA8]]
+; CHECK-NEXT:    tail call void @callee5(i32 noundef [[TMP0]])
+; CHECK-NEXT:    ret void
+;
+entry:
+  %0 = load volatile i32, ptr @x, align 4, !tbaa !8
+  tail call void @callee5(i32 noundef %0)
+  ret void
+}
+
+; Function Attrs: nofree noinline nounwind uwtable
+define dso_local void @callee3() local_unnamed_addr #1 {
+; CHECK: Function Attrs: nofree noinline norecurse nounwind uwtable
+; CHECK-LABEL: define dso_local void @callee3(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR2]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    tail call void @callee4()
+; CHECK-NEXT:    ret void
+;
+entry:
+  tail call void @callee4()
+  ret void
+}
+
+; Function Attrs: nofree noinline nounwind uwtable
+define dso_local void @callee2() local_unnamed_addr #1 {
+; CHECK: Function Attrs: nofree noinline norecurse nounwind uwtable
+; CHECK-LABEL: define dso_local void @callee2(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR2]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    tail call void @callee3()
+; CHECK-NEXT:    ret void
+;
+entry:
+  tail call void @callee3()
+  ret void
+}
+
+; Function Attrs: nofree noinline nounwind uwtable
+define dso_local void @callee1() local_unnamed_addr #1 {
+; CHECK: Function Attrs: nofree noinline norecurse nounwind uwtable
+; CHECK-LABEL: define dso_local void @callee1(
+; CHECK-SAME: ) local_unnamed_addr #[[ATTR2]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    tail call void @callee2()
+; CHECK-NEXT:    ret void
+;
+entry:
+  tail call void @callee2()
+  ret void
+}
+
+; Function Attrs: nofree noinline nounwind uwtable
+define dso_local void @bob() local...
[truncated]

``````````

</details>


https://github.com/llvm/llvm-project/pull/139943


More information about the llvm-commits mailing list