[llvm] [SPIRV] convergence anchor intrinsic does not have a parent token (PR #122230)

[Sameer Sahasrabuddhe via llvm-commits]

https://github.com/ssahasra updated https://github.com/llvm/llvm-project/pull/122230

>From f474d32bd07bc03abd2142ca022fc4d2d167671d Mon Sep 17 00:00:00 2001
From: Sameer Sahasrabuddhe <sameer.sahasrabuddhe at amd.com>
Date: Thu, 9 Jan 2025 13:26:53 +0530
Subject: [PATCH 1/2] [SPIRV] convergence anchor intrinsic does not have a
 parent token

---
 .../Analysis/SPIRVConvergenceRegionAnalysis.cpp  | 16 ++--------------
 1 file changed, 2 insertions(+), 14 deletions(-)

diff --git a/llvm/lib/Target/SPIRV/Analysis/SPIRVConvergenceRegionAnalysis.cpp b/llvm/lib/Target/SPIRV/Analysis/SPIRVConvergenceRegionAnalysis.cpp
index cc6daf7ef34426..9ac0f8700a3f66 100644
--- a/llvm/lib/Target/SPIRV/Analysis/SPIRVConvergenceRegionAnalysis.cpp
+++ b/llvm/lib/Target/SPIRV/Analysis/SPIRVConvergenceRegionAnalysis.cpp
@@ -56,20 +56,8 @@ getConvergenceTokenInternal(BasicBlockType *BB) {
       "Output type must be an intrinsic instruction.");
 
   for (auto &I : *BB) {
-    if (auto *II = dyn_cast<IntrinsicInst>(&I)) {
-      switch (II->getIntrinsicID()) {
-      case Intrinsic::experimental_convergence_entry:
-      case Intrinsic::experimental_convergence_loop:
-        return II;
-      case Intrinsic::experimental_convergence_anchor: {
-        auto Bundle = II->getOperandBundle(LLVMContext::OB_convergencectrl);
-        assert(Bundle->Inputs.size() == 1 &&
-               Bundle->Inputs[0]->getType()->isTokenTy());
-        auto TII = dyn_cast<IntrinsicInst>(Bundle->Inputs[0].get());
-        assert(TII != nullptr);
-        return TII;
-      }
-      }
+    if (auto *CI = dyn_cast<ConvergenceControlInst>(&I)) {
+      return CI;
     }
 
     if (auto *CI = dyn_cast<CallInst>(&I)) {

>From 74bd77bcf46b01d394137fc2882e09a1a1dcbd17 Mon Sep 17 00:00:00 2001
From: Sameer Sahasrabuddhe <sameer.sahasrabuddhe at amd.com>
Date: Fri, 10 Jan 2025 13:34:48 +0530
Subject: [PATCH 2/2] add asserts to catch tokens incorrectly placed on entry
 or anchor

---
 llvm/include/llvm/IR/IntrinsicInst.h                        | 6 +++---
 .../SPIRV/Analysis/SPIRVConvergenceRegionAnalysis.cpp       | 4 ++++
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/llvm/include/llvm/IR/IntrinsicInst.h b/llvm/include/llvm/IR/IntrinsicInst.h
index 3436216d478e38..6ccbb6b185c7d9 100644
--- a/llvm/include/llvm/IR/IntrinsicInst.h
+++ b/llvm/include/llvm/IR/IntrinsicInst.h
@@ -1873,13 +1873,13 @@ class ConvergenceControlInst : public IntrinsicInst {
     return isa<IntrinsicInst>(V) && classof(cast<IntrinsicInst>(V));
   }
 
-  bool isAnchor() {
+  bool isAnchor() const {
     return getIntrinsicID() == Intrinsic::experimental_convergence_anchor;
   }
-  bool isEntry() {
+  bool isEntry() const {
     return getIntrinsicID() == Intrinsic::experimental_convergence_entry;
   }
-  bool isLoop() {
+  bool isLoop() const {
     return getIntrinsicID() == Intrinsic::experimental_convergence_loop;
   }
 };
diff --git a/llvm/lib/Target/SPIRV/Analysis/SPIRVConvergenceRegionAnalysis.cpp b/llvm/lib/Target/SPIRV/Analysis/SPIRVConvergenceRegionAnalysis.cpp
index 9ac0f8700a3f66..c23a6c3e8bbe85 100644
--- a/llvm/lib/Target/SPIRV/Analysis/SPIRVConvergenceRegionAnalysis.cpp
+++ b/llvm/lib/Target/SPIRV/Analysis/SPIRVConvergenceRegionAnalysis.cpp
@@ -57,6 +57,10 @@ getConvergenceTokenInternal(BasicBlockType *BB) {
 
   for (auto &I : *BB) {
     if (auto *CI = dyn_cast<ConvergenceControlInst>(&I)) {
+      // Make sure that the anchor or entry intrinsics did not reach here with a
+      // parent token. This should have failed the verifier.
+      assert(CI->isLoop() ||
+             !CI->getOperandBundle(LLVMContext::OB_convergencectrl));
       return CI;
     }