[SPIRV_LLVM_Backend] ship patch for alloca issue

fixes JuliaGPU/OpenCL.jl#384

upstream PR is llvm/llvm-project#164175

Author: simeonschaub

S/SPIRV_LLVM_Backend/build_tarballs.jl

@@ -28,6 +28,7 @@ LLVM_SRCDIR=$(pwd)
 atomic_patch -p1 $WORKSPACE/srcdir/patches/avoid_builtin_available.patch
 atomic_patch -p1 $WORKSPACE/srcdir/patches/fix_insertvalue.patch
 atomic_patch -p1 $WORKSPACE/srcdir/patches/atomic_cmpxchg_64bit.patch
+atomic_patch -p1 $WORKSPACE/srcdir/patches/alloca_aggregate_type.patch
 
 install_license LICENSE.TXT
 

S/SPIRV_LLVM_Backend/bundled/patches/alloca_aggregate_type.patch

@@ -0,0 +1,73 @@
+From 4fdb0945f3a3eeb2602dc5460563922b2e50e027 Mon Sep 17 00:00:00 2001
+From: Simeon David Schaub <[email protected]>
+Date: Sun, 19 Oct 2025 19:49:09 +0200
+Subject: [PATCH] [SPIRV] fix `alloca` -> `OpVariable` lowering
+
+fixes #163777
+
+Test was written with help from Copilot
+---
+ lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp    |  3 +-
+ test/CodeGen/SPIRV/alloca-aggregate-type.ll | 36 +++++++++++++++++++++
+ 2 files changed, 38 insertions(+), 1 deletion(-)
+ create mode 100644 llvm/test/CodeGen/SPIRV/alloca-aggregate-type.ll
+
+diff --git a/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp b/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
+index 702206b8e0dc..52357f53df19 100644
+--- a/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
++++ b/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
+@@ -1553,7 +1553,8 @@ void SPIRVEmitIntrinsics::replacePointerOperandWithPtrCast(
+       return;
+     } else if (isTodoType(Pointer)) {
+       eraseTodoType(Pointer);
+-      if (!isa<CallInst>(Pointer) && !isa<GetElementPtrInst>(Pointer)) {
++      if (!isa<CallInst>(Pointer) && !isa<GetElementPtrInst>(Pointer) &&
++          !isa<AllocaInst>(Pointer)) {
+         //  If this wouldn't be the first spv_ptrcast but existing type info is
+         //  uncomplete, update spv_assign_ptr_type arguments.
+         if (CallInst *AssignCI = GR->findAssignPtrTypeInstr(Pointer)) {
+diff --git a/test/CodeGen/SPIRV/alloca-aggregate-type.ll b/test/CodeGen/SPIRV/alloca-aggregate-type.ll
+new file mode 100644
+index 000000000000..82cbae2d8d90
+--- /dev/null
++++ b/test/CodeGen/SPIRV/alloca-aggregate-type.ll
+@@ -0,0 +1,36 @@
++; Test that alloca with aggregate type generates correct OpVariable
++; with the array type as the pointee, not a pointer-to-pointer type
++;
++; This test verifies that when we have an alloca of an array containing
++; structs with pointers, the OpVariable uses the correct array type
++; instead of incorrectly using a pointer-to-pointer type.
++
++; RUN: llc -O0 -mtriple=spirv64-unknown-unknown %s -o - | FileCheck %s
++; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv64-unknown-unknown %s -o - -filetype=obj | spirv-val %}
++
++; CHECK-DAG: %[[#Int8:]] = OpTypeInt 8 0
++; CHECK-DAG: %[[#Int64:]] = OpTypeInt 64 0
++; CHECK-DAG: %[[#Int32:]] = OpTypeInt 32 0
++; CHECK-DAG: %[[#One:]] = OpConstant %[[#Int32]] 1
++; CHECK-DAG: %[[#Two:]] = OpConstant %[[#Int32]] 2
++; CHECK-DAG: %[[#PtrCross:]] = OpTypePointer CrossWorkgroup %[[#Int8]]
++; CHECK-DAG: %[[#Array1:]] = OpTypeArray %[[#Int64]] %[[#One]]
++; CHECK-DAG: %[[#Struct1:]] = OpTypeStruct %[[#PtrCross]] %[[#Int64]] %[[#Array1]] %[[#Int64]]
++; CHECK-DAG: %[[#Array2:]] = OpTypeArray %[[#Array1]] %[[#Two]]
++; CHECK-DAG: %[[#Struct2:]] = OpTypeStruct %[[#Struct1]] %[[#Array2]]
++; CHECK-DAG: %[[#Struct3:]] = OpTypeStruct %[[#Struct2]]
++; CHECK-DAG: %[[#ArrayStruct:]] = OpTypeArray %[[#Struct3]] %[[#One]]
++; CHECK-DAG: %[[#PtrFunc:]] = OpTypePointer Function %[[#ArrayStruct]]
++
++; Verify OpVariable uses the array type, not pointer-to-pointer
++; CHECK: %[[#Var:]] = OpVariable %[[#PtrFunc]] Function
++
++target datalayout = "e-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024-G1"
++target triple = "spirv64-unknown-unknown"
++
++define spir_kernel void @test_alloca_aggregate() local_unnamed_addr {
++entry:
++  %y = alloca [1 x { { { ptr addrspace(1), i64, [1 x i64], i64 }, [2 x [1 x i64]] } }], align 8
++  %ptr = load ptr addrspace(1), ptr %y, align 8
++  ret void
++}
+-- 
+2.51.0
+