[llvm] [SelectionDAG][X86] Handle `llvm.type.test` in DAGBuilder (PR #142939)

[Abhishek Kaushik via llvm-commits]

https://github.com/abhishek-kaushik22 created https://github.com/llvm/llvm-project/pull/142939

Closes #142937

>From 736bd91c9c82219514c72ba2772948b99ac33330 Mon Sep 17 00:00:00 2001
From: Abhishek Kaushik <abhishek.kaushik at intel.com>
Date: Thu, 5 Jun 2025 15:35:55 +0530
Subject: [PATCH] [SelectionDAG][X86] Handle `llvm.type.test` in DAGBuilder

Closes #142937
---
 .../SelectionDAG/SelectionDAGBuilder.cpp      | 16 +++++
 llvm/test/CodeGen/X86/pr142937.ll             | 62 +++++++++++++++++++
 2 files changed, 78 insertions(+)
 create mode 100644 llvm/test/CodeGen/X86/pr142937.ll

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 2460c864b0815..6bb8368252537 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -7384,6 +7384,22 @@ void SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I,
     setValue(&I, getValue(I.getOperand(0)));
     return;
 
+  case Intrinsic::type_test:
+  case Intrinsic::public_type_test: {
+    bool AllUsersAreAssume = llvm::all_of(I.users(), [](const User *U) {
+      if (const auto *call = dyn_cast<CallInst>(U)) {
+        return call->getIntrinsicID() == Intrinsic::assume;
+      }
+      return false;
+    });
+
+    if (AllUsersAreAssume)
+      setValue(&I, DAG.getUNDEF(MVT::i1));
+    else
+      setValue(&I, DAG.getConstant(1, sdl, MVT::i1));
+    return;
+  }
+
   case Intrinsic::assume:
   case Intrinsic::experimental_noalias_scope_decl:
   case Intrinsic::var_annotation:
diff --git a/llvm/test/CodeGen/X86/pr142937.ll b/llvm/test/CodeGen/X86/pr142937.ll
new file mode 100644
index 0000000000000..269433d86ba7d
--- /dev/null
+++ b/llvm/test/CodeGen/X86/pr142937.ll
@@ -0,0 +1,62 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc < %s -mtriple=i686-- -opt-bisect-limit=0   | FileCheck %s --check-prefix=X86
+; RUN: llc < %s -mtriple=x86_64-- -opt-bisect-limit=0 | FileCheck %s --check-prefix=X64
+
+define void @public_type_test() {
+; X86-LABEL: public_type_test:
+; X86:       # %bb.0: # %bb
+; X86-NEXT:  # %bb.1: # %bb1
+; X86-NEXT:    retl
+;
+; X64-LABEL: public_type_test:
+; X64:       # %bb.0: # %bb
+; X64-NEXT:  # %bb.1: # %bb1
+; X64-NEXT:    retq
+bb:
+  %call = call i1 @llvm.public.type.test(ptr null, metadata !"typeinfo")
+  br label %bb1
+
+bb1:
+  call void @llvm.assume(i1 %call)
+  ret void
+}
+
+define void @type_test() {
+; X86-LABEL: type_test:
+; X86:       # %bb.0: # %bb
+; X86-NEXT:    movb $1, %al
+; X86-NEXT:    testb $1, %al
+; X86-NEXT:    jne .LBB1_2
+; X86-NEXT:  # %bb.1: # %bb1
+; X86-NEXT:    ud1l 2(%eax), %eax
+; X86-NEXT:  .LBB1_2: # %bb2
+; X86-NEXT:    retl
+;
+; X64-LABEL: type_test:
+; X64:       # %bb.0: # %bb
+; X64-NEXT:    movb $1, %al
+; X64-NEXT:    testb $1, %al
+; X64-NEXT:    jne .LBB1_2
+; X64-NEXT:  # %bb.1: # %bb1
+; X64-NEXT:    ud1l 2(%eax), %eax
+; X64-NEXT:  .LBB1_2: # %bb2
+; X64-NEXT:    retq
+bb:
+  %call = tail call i1 @llvm.type.test(ptr null, metadata !"typeinfo")
+  br i1 %call, label %bb2, label %bb1
+
+bb1:
+  tail call void @llvm.ubsantrap(i8 2)
+  unreachable
+
+bb2:
+  ret void
+}
+
+declare i1 @llvm.public.type.test(ptr, metadata)
+
+declare void @llvm.assume(i1 noundef)
+
+declare i1 @llvm.type.test(ptr, metadata)
+
+declare void @llvm.ubsantrap(i8 immarg)