[DropUnnecessaryAssumes] Don't drop public_type_test intrinsic

[hassnaaHamdi]

Don't drop assume intrinsic when it's using public_type_test intrinsic,
as it could be used by devirtualization.

[llvmbot]

@llvm/pr-subscribers-llvm-transforms

Author: Hassnaa Hamdi (hassnaaHamdi)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/166034.diff

2 Files Affected:

• (modified) llvm/lib/Transforms/Scalar/DropUnnecessaryAssumes.cpp (+2-1)
• (modified) llvm/test/Transforms/DropUnnecessaryAssumes/basic.ll (+12)

diff --git a/llvm/lib/Transforms/Scalar/DropUnnecessaryAssumes.cpp b/llvm/lib/Transforms/Scalar/DropUnnecessaryAssumes.cpp
index 89980d54ee897..a577f517d1e89 100644
--- a/llvm/lib/Transforms/Scalar/DropUnnecessaryAssumes.cpp
+++ b/llvm/lib/Transforms/Scalar/DropUnnecessaryAssumes.cpp
@@ -122,7 +122,8 @@ DropUnnecessaryAssumesPass::run(Function &F, FunctionAnalysisManager &FAM) {
 
     Value *Cond = Assume->getArgOperand(0);
     // Don't drop type tests, which have special semantics.
-    if (match(Cond, m_Intrinsic<Intrinsic::type_test>()))
+    if (match(Cond, m_Intrinsic<Intrinsic::type_test>()) ||
+        match(Cond, m_Intrinsic<Intrinsic::public_type_test>()))
       continue;
 
     SmallVector<Value *> Affected;
diff --git a/llvm/test/Transforms/DropUnnecessaryAssumes/basic.ll b/llvm/test/Transforms/DropUnnecessaryAssumes/basic.ll
index 8a6f60ba7a204..87aed77d06ef8 100644
--- a/llvm/test/Transforms/DropUnnecessaryAssumes/basic.ll
+++ b/llvm/test/Transforms/DropUnnecessaryAssumes/basic.ll
@@ -184,6 +184,18 @@ define void @type_test(ptr %x) {
   ret void
 }
 
+define void @public_type_test(ptr %x) {
+; CHECK-LABEL: define void @public_type_test(
+; CHECK-SAME: ptr [[X:%.*]]) {
+; CHECK-NEXT:    [[TEST:%.*]] = call i1 @llvm.public.type.test(ptr [[X]], metadata !"typeid")
+; CHECK-NEXT:    call void @llvm.assume(i1 [[TEST]])
+; CHECK-NEXT:    ret void
+;
+  %test = call i1 @llvm.public.type.test(ptr %x, metadata !"typeid")
+  call void @llvm.assume(i1 %test)
+  ret void
+}
+
 define void @multiple_dead_conds(i32 %x) {
 ; CHECK-LABEL: define void @multiple_dead_conds(
 ; CHECK-SAME: i32 [[X:%.*]]) {

[hassnaaHamdi]

@nikic Doesn't the name of 'basic.ll' file seem a bit weird? :'D

[dtcxzyw]

LGTM

[dtcxzyw]

Doesn't the name of 'basic.ll' file seem a bit weird? :'D

It is fine for a newly added pass :)

./llvm-project/llvm/test/Transforms/LowerGuardIntrinsic/basic.ll
./llvm-project/llvm/test/Transforms/LoopInstSimplify/basic.ll
./llvm-project/llvm/test/Transforms/UnifyLoopExits/basic.ll
./llvm-project/llvm/test/Transforms/JumpThreading/basic.ll
./llvm-project/llvm/test/Transforms/Util/DeclareRuntimeLibcalls/basic.ll
./llvm-project/llvm/test/Transforms/StripDeadPrototypes/basic.ll
./llvm-project/llvm/test/Transforms/SimplifyTypeTests/basic.ll
./llvm-project/llvm/test/Transforms/RewriteStatepointsForGC/basic.ll
./llvm-project/llvm/test/Transforms/GuardWidening/basic.ll
./llvm-project/llvm/test/Transforms/PhaseOrdering/basic.ll
./llvm-project/llvm/test/Transforms/DropUnnecessaryAssumes/basic.ll
./llvm-project/llvm/test/Transforms/CrossDSOCFI/basic.ll
./llvm-project/llvm/test/Transforms/LowerWidenableCondition/basic.ll
./llvm-project/llvm/test/Transforms/GVN/basic.ll
./llvm-project/llvm/test/Transforms/BDCE/basic.ll
./llvm-project/llvm/test/Transforms/AddDiscriminators/basic.ll
./llvm-project/llvm/test/Transforms/FixIrreducible/basic.ll
./llvm-project/llvm/test/Transforms/LoopRotate/basic.ll
./llvm-project/llvm/test/Transforms/LoopIdiom/basic.ll
./llvm-project/llvm/test/Transforms/PlaceSafepoints/basic.ll
./llvm-project/llvm/test/Transforms/EarlyCSE/basic.ll
./llvm-project/llvm/test/Transforms/TailCallElim/basic.ll
./llvm-project/llvm/test/Transforms/InferAddressSpaces/AMDGPU/basic.ll
./llvm-project/llvm/test/Transforms/GlobalSplit/basic.ll
./llvm-project/llvm/test/Transforms/Sink/basic.ll
./llvm-project/llvm/test/Transforms/LoopVersioning/basic.ll
./llvm-project/llvm/test/Transforms/GlobalMerge/basic.ll
./llvm-project/llvm/test/Transforms/InstNamer/basic.ll
./llvm-project/llvm/test/Transforms/LoopDataPrefetch/LoongArch/basic.ll
./llvm-project/llvm/test/Transforms/LoopDataPrefetch/RISCV/basic.ll
./llvm-project/llvm/test/Transforms/LoopDataPrefetch/PowerPC/basic.ll
./llvm-project/llvm/test/Transforms/Scalarizer/basic.ll
./llvm-project/llvm/test/Transforms/DCE/basic.ll
./llvm-project/llvm/test/Transforms/LowerExpectIntrinsic/basic.ll
./llvm-project/llvm/test/Transforms/MemProfContextDisambiguation/basic.ll
./llvm-project/llvm/test/Transforms/LoopPredication/basic.ll
./llvm-project/llvm/test/Transforms/LoopUnroll/basic.ll
./llvm-project/llvm/test/Transforms/IndirectBrExpand/basic.ll
./llvm-project/llvm/test/Transforms/LoopDistribute/basic.ll
./llvm-project/llvm/test/Transforms/CorrelatedValuePropagation/basic.ll
./llvm-project/llvm/test/Transforms/NewGVN/basic.ll
./llvm-project/llvm/test/Transforms/JumpTableToSwitch/basic.ll
./llvm-project/llvm/test/Transforms/Float2Int/basic.ll
./llvm-project/llvm/test/Transforms/ObjCARC/basic.ll
./llvm-project/llvm/test/Transforms/MakeGuardsExplicit/basic.ll

[hassnaaHamdi]

@dtcxzyw Thanks for the clarification and the review :))