From 3769d6fffbfaef97d8de87849e6bde6a46434a4a Mon Sep 17 00:00:00 2001
From: Romaric Jodin <89833130+rjodinchr@users.noreply.github.com>
Date: Wed, 30 Aug 2023 16:54:08 +0200
Subject: [PATCH] add support for ptrtoint in LowerPrivatePointerPHI (#1210)

also avoid accessing nullptr in BitcastUtils::IsImplicitCast

Ref #1209
---
 lib/BitcastUtils.cpp               | 10 ++++++----
 lib/LowerPrivatePointerPHIPass.cpp |  8 ++++++++
 test/PrivatePointerPHI/ptrtoint.ll | 32 ++++++++++++++++++++++++++++++
 3 files changed, 46 insertions(+), 4 deletions(-)
 create mode 100644 test/PrivatePointerPHI/ptrtoint.ll

diff --git a/lib/BitcastUtils.cpp b/lib/BitcastUtils.cpp
index fee7ce512..a2761e1cf 100644
--- a/lib/BitcastUtils.cpp
+++ b/lib/BitcastUtils.cpp
@@ -882,13 +882,15 @@ bool IsImplicitCasts(Module &M, DenseMap<Value *, Type *> &type_cache,
       for (unsigned i = 1; i < phi->getNumIncomingValues(); i++) {
         auto Op = phi->getIncomingValue(i);
         auto OpTy = clspv::InferType(Op, M.getContext(), &type_cache);
-        if (SizeInBits(M.getDataLayout(), OpTy) >
-            SizeInBits(M.getDataLayout(), RefOpTy)) {
+        if (OpTy && RefOpTy &&
+            SizeInBits(M.getDataLayout(), OpTy) >
+                SizeInBits(M.getDataLayout(), RefOpTy)) {
           source = Op;
           source_ty = OpTy;
           dest_ty = RefOpTy;
-        } else if (SizeInBits(M.getDataLayout(), OpTy) <
-                   SizeInBits(M.getDataLayout(), RefOpTy)) {
+        } else if (OpTy && RefOpTy &&
+                   SizeInBits(M.getDataLayout(), OpTy) <
+                       SizeInBits(M.getDataLayout(), RefOpTy)) {
           source = RefOp;
           source_ty = RefOpTy;
           dest_ty = OpTy;
diff --git a/lib/LowerPrivatePointerPHIPass.cpp b/lib/LowerPrivatePointerPHIPass.cpp
index 3d652b93c..821eaf774 100644
--- a/lib/LowerPrivatePointerPHIPass.cpp
+++ b/lib/LowerPrivatePointerPHIPass.cpp
@@ -191,6 +191,14 @@ void clspv::LowerPrivatePointerPHIPass::runOnFunction(Function &F) {
                        store->getType(), CstVal, DynVal, SmallerBitWidths);
         B.CreateStore(store->getValueOperand(), gep);
         ToBeErased.push_back(store);
+      } else if (auto ptrtoint = dyn_cast<PtrToIntInst>(node)) {
+        IRBuilder<> B(ptrtoint);
+        auto gep = makeNewGEP(DL, B, alloca, alloca->getAllocatedType(),
+                              B.getIntNTy(SmallerBitWidths), CstVal, DynVal,
+                              SmallerBitWidths);
+        auto newPtrToInt = B.CreatePtrToInt(gep, ptrtoint->getDestTy());
+        ptrtoint->replaceAllUsesWith(newPtrToInt);
+        ToBeErased.push_back(ptrtoint);
       } else {
         llvm_unreachable("Unexpected node when traversing alloca users");
       }
diff --git a/test/PrivatePointerPHI/ptrtoint.ll b/test/PrivatePointerPHI/ptrtoint.ll
new file mode 100644
index 000000000..93b52af89
--- /dev/null
+++ b/test/PrivatePointerPHI/ptrtoint.ll
@@ -0,0 +1,32 @@
+; RUN: clspv-opt %s -o %t.ll --passes=lower-private-pointer-phi
+; RUN: FileCheck %s < %t.ll
+
+; CHECK: loop:
+; CHECK-NEXT: [[phi:%[^ ]+]] = phi i32 [ 0, %entry ], [ [[add:%[^ ]+]], %loop ]
+; CHECK: [[gep:%[^ ]+]] = getelementptr inbounds [64 x i32], ptr %alloca, i32 0, i32 [[phi]]
+; CHECK: load i32, ptr [[gep]], align 4
+; CHECK: [[add]] = add i32 1, [[phi]]
+; CHECK: [[gep:%[^ ]+]] = getelementptr inbounds [64 x i32], ptr %alloca, i32 0, i32 [[phi]]
+; CHECK: ptrtoint ptr [[gep]] to i32
+
+target datalayout = "e-p:32:32-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024"
+target triple = "spir-unknown-unknown"
+
+define void @test() {
+entry:
+  %alloca = alloca [64 x i32]
+  br label %loop
+
+loop:
+  %phi = phi ptr [ %alloca, %entry ], [ %gep, %loop ]
+  %count = phi i32 [ 0, %entry ], [ %next, %loop ]
+  %load = load i32, ptr %phi
+  %gep = getelementptr i32, ptr %phi, i32 1
+  %next = add i32 %count, 1
+  %cmp = icmp eq i32 %next, 64
+  %ptrtoint = ptrtoint ptr %phi to i32
+  br i1 %cmp, label %exit, label %loop
+
+exit:
+  ret void
+}