Skip negative length while inferring initializes attr

[haopliu]

Bail out negative length while inferring initializes attr. Otherwise it causes an assertion error:
Attribute 'initializes' does not support unordered ranges

[llvmbot]

@llvm/pr-subscribers-llvm-transforms

Author: Haopeng Liu (haopliu)

Changes

Bail out negative length while inferring initializes attr. Otherwise it causes an assertion error:
Attribute 'initializes' does not support unordered ranges

---

Full diff: https://github.com/llvm/llvm-project/pull/120874.diff

2 Files Affected:

• (modified) llvm/lib/Transforms/IPO/FunctionAttrs.cpp (+4-1)
• (modified) llvm/test/Transforms/FunctionAttrs/initializes.ll (+11)

diff --git a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
index afb0ea72b269c8..0a83bb1cd60535 100644
--- a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
@@ -633,10 +633,13 @@ ArgumentAccessInfo getArgmentAccessInfo(const Instruction *I,
       [](Value *Length,
          std::optional<int64_t> Offset) -> std::optional<ConstantRange> {
     auto *ConstantLength = dyn_cast<ConstantInt>(Length);
-    if (ConstantLength && Offset)
+    if (ConstantLength && Offset) {
+      if (ConstantLength->getSExtValue() < 0)
+        return std::nullopt;
       return ConstantRange(
           APInt(64, *Offset, true),
           APInt(64, *Offset + ConstantLength->getSExtValue(), true));
+    }
     return std::nullopt;
   };
   if (auto *SI = dyn_cast<StoreInst>(I)) {
diff --git a/llvm/test/Transforms/FunctionAttrs/initializes.ll b/llvm/test/Transforms/FunctionAttrs/initializes.ll
index 2aa8385fe4ca7b..c607fbeabb5087 100644
--- a/llvm/test/Transforms/FunctionAttrs/initializes.ll
+++ b/llvm/test/Transforms/FunctionAttrs/initializes.ll
@@ -423,6 +423,17 @@ define void @memset_offset(ptr %p) {
   ret void
 }
 
+define void @memset_neg(ptr %p) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(argmem: write)
+; CHECK-LABEL: define void @memset_neg(
+; CHECK-SAME: ptr nocapture writeonly [[P:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:    call void @llvm.memset.p0.i64(ptr [[P]], i8 2, i64 -1, i1 false)
+; CHECK-NEXT:    ret void
+;
+  call void @llvm.memset(ptr %p, i8 2, i64 -1, i1 false)
+  ret void
+}
+
 define void @memset_volatile(ptr %p) {
 ; CHECK: Function Attrs: mustprogress nofree norecurse nounwind willreturn memory(argmem: write)
 ; CHECK-LABEL: define void @memset_volatile(

[nikic]

Include in the if condition?

Suggested change

	if (ConstantLength && Offset) {
	if (ConstantLength && Offset && ConstantLength->isNonNegative()) {

[haopliu]

Done, thanks!

[nikic]

LGTM

[llvm-ci]

LLVM Buildbot has detected a new failure on builder llvm-clang-aarch64-darwin running on doug-worker-5 while building llvm at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/190/builds/11874

Here is the relevant piece of the build log for the reference

Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'Clang-Unit :: DirectoryWatcher/./DirectoryWatcherTests/5/8' FAILED ********************
Script(shard):
--
GTEST_OUTPUT=json:/Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/unittests/DirectoryWatcher/./DirectoryWatcherTests-Clang-Unit-73509-5-8.json GTEST_SHUFFLE=0 GTEST_TOTAL_SHARDS=8 GTEST_SHARD_INDEX=5 /Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/unittests/DirectoryWatcher/./DirectoryWatcherTests
--

Script:
--
/Users/buildbot/buildbot-root/aarch64-darwin/build/tools/clang/unittests/DirectoryWatcher/./DirectoryWatcherTests --gtest_filter=DirectoryWatcherTest.DeleteWatchedDir
--
/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/unittests/DirectoryWatcher/DirectoryWatcherTest.cpp:259: Failure
Value of: WaitForExpectedStateResult.wait_for(EventualResultTimeout) == std::future_status::ready
  Actual: false
Expected: true
The expected result state wasn't reached before the time-out.

/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/unittests/DirectoryWatcher/DirectoryWatcherTest.cpp:262: Failure
Value of: TestConsumer.result().has_value()
  Actual: false
Expected: true


/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/unittests/DirectoryWatcher/DirectoryWatcherTest.cpp:259
Value of: WaitForExpectedStateResult.wait_for(EventualResultTimeout) == std::future_status::ready
  Actual: false
Expected: true
The expected result state wasn't reached before the time-out.

/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/clang/unittests/DirectoryWatcher/DirectoryWatcherTest.cpp:262
Value of: TestConsumer.result().has_value()
  Actual: false
Expected: true



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