[flang-commits] [flang] [flang][cuda] Make sure global device descriptor is allocated in managed memory (PR #160596)

[via flang-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-flang-codegen

Author: Valentin Clement (バレンタイン クレメン) (clementval)

<details>
<summary>Changes</summary>

When the descriptor of a global device variable is re-materialized to be passed to a kernel, make sure it is allocated in managed memory otherwise the kernel launch will fail. 

---
Full diff: https://github.com/llvm/llvm-project/pull/160596.diff


2 Files Affected:

- (modified) flang/lib/Optimizer/CodeGen/CodeGen.cpp (+10) 
- (modified) flang/test/Fir/CUDA/cuda-code-gen.mlir (+35) 


``````````diff
diff --git a/flang/lib/Optimizer/CodeGen/CodeGen.cpp b/flang/lib/Optimizer/CodeGen/CodeGen.cpp
index 9d707250d11d9..a746beae8d9c2 100644
--- a/flang/lib/Optimizer/CodeGen/CodeGen.cpp
+++ b/flang/lib/Optimizer/CodeGen/CodeGen.cpp
@@ -12,6 +12,7 @@
 
 #include "flang/Optimizer/CodeGen/CodeGen.h"
 
+#include "flang/Optimizer/Builder/CUFCommon.h"
 #include "flang/Optimizer/CodeGen/CodeGenOpenMP.h"
 #include "flang/Optimizer/CodeGen/FIROpPatterns.h"
 #include "flang/Optimizer/CodeGen/LLVMInsertChainFolder.h"
@@ -1846,6 +1847,15 @@ struct EmboxOpConversion : public EmboxCommonConversion<fir::EmboxOp> {
 };
 
 static bool isDeviceAllocation(mlir::Value val, mlir::Value adaptorVal) {
+  // Check if the global symbol is in the device module.
+  if (auto addr = mlir::dyn_cast_or_null<fir::AddrOfOp>(val.getDefiningOp()))
+    if (auto gpuMod =
+            addr->getParentOfType<mlir::ModuleOp>()
+                .lookupSymbol<mlir::gpu::GPUModuleOp>(cudaDeviceModuleName))
+      if (gpuMod.lookupSymbol<mlir::LLVM::GlobalOp>(addr.getSymbol()) ||
+          gpuMod.lookupSymbol<fir::GlobalOp>(addr.getSymbol()))
+        return true;
+
   if (auto loadOp = mlir::dyn_cast_or_null<fir::LoadOp>(val.getDefiningOp()))
     return isDeviceAllocation(loadOp.getMemref(), {});
   if (auto boxAddrOp =
diff --git a/flang/test/Fir/CUDA/cuda-code-gen.mlir b/flang/test/Fir/CUDA/cuda-code-gen.mlir
index 672be13beae24..632f8afebbb92 100644
--- a/flang/test/Fir/CUDA/cuda-code-gen.mlir
+++ b/flang/test/Fir/CUDA/cuda-code-gen.mlir
@@ -221,3 +221,38 @@ module attributes {dlti.dl_spec = #dlti.dl_spec<#dlti.dl_entry<f80, dense<128> :
 
   func.func private @__tgt_acc_get_deviceptr() -> !fir.ref<!fir.box<none>>
 }
+
+// -----
+
+module attributes {gpu.container_module, dlti.dl_spec = #dlti.dl_spec<#dlti.dl_entry<f80, dense<128> : vector<2xi64>>, #dlti.dl_entry<i128, dense<128> : vector<2xi64>>, #dlti.dl_entry<i64, dense<64> : vector<2xi64>>, #dlti.dl_entry<!llvm.ptr<272>, dense<64> : vector<4xi64>>, #dlti.dl_entry<!llvm.ptr<271>, dense<32> : vector<4xi64>>, #dlti.dl_entry<!llvm.ptr<270>, dense<32> : vector<4xi64>>, #dlti.dl_entry<f128, dense<128> : vector<2xi64>>, #dlti.dl_entry<f64, dense<64> : vector<2xi64>>, #dlti.dl_entry<f16, dense<16> : vector<2xi64>>, #dlti.dl_entry<i32, dense<32> : vector<2xi64>>, #dlti.dl_entry<i16, dense<16> : vector<2xi64>>, #dlti.dl_entry<i8, dense<8> : vector<2xi64>>, #dlti.dl_entry<i1, dense<8> : vector<2xi64>>, #dlti.dl_entry<!llvm.ptr, dense<64> : vector<4xi64>>, #dlti.dl_entry<"dlti.endianness", "little">, #dlti.dl_entry<"dlti.stack_alignment", 128 : i64>>} {
+  fir.global @_QMm1Eda {data_attr = #cuf.cuda<device>} : !fir.box<!fir.heap<!fir.array<?x?xf32>>> {
+    %c0 = arith.constant 0 : index
+    %0 = fir.zero_bits !fir.heap<!fir.array<?x?xf32>>
+    %1 = fircg.ext_embox %0(%c0, %c0) {allocator_idx = 2 : i32} : (!fir.heap<!fir.array<?x?xf32>>, index, index) -> !fir.box<!fir.heap<!fir.array<?x?xf32>>>
+    fir.has_value %1 : !fir.box<!fir.heap<!fir.array<?x?xf32>>>
+  }
+  func.func @_QQmain() attributes {fir.bindc_name = "P", target_cpu = "x86-64", target_features = #llvm.target_features<["+cmov", "+mmx", "+sse", "+sse2", "+cx8", "+x87", "+fxsr"]>} {
+    %c64 = arith.constant 64 : index
+    %c1 = arith.constant 1 : index
+    %c0_i32 = arith.constant 0 : i32
+    %0 = fir.address_of(@_QMm1Eda) : !fir.ref<!fir.box<!fir.heap<!fir.array<?x?xf32>>>>
+    %8 = fir.load %0 : !fir.ref<!fir.box<!fir.heap<!fir.array<?x?xf32>>>>
+    %9 = fircg.ext_rebox %8 : (!fir.box<!fir.heap<!fir.array<?x?xf32>>>) -> !fir.box<!fir.array<?x?xf32>>
+    gpu.launch_func  @cuda_device_mod::@_QMm1Psub2 blocks in (%c1, %c1, %c1) threads in (%c64, %c1, %c1)  dynamic_shared_memory_size %c0_i32 args(%9 : !fir.box<!fir.array<?x?xf32>>) {cuf.proc_attr = #cuf.cuda_proc<global>}
+    return
+  }
+  gpu.module @cuda_device_mod [#nvvm.target<chip = "sm_90", features = "+ptx75", link = ["/proj/ng/Linux_x86_64/dev/compilers/lib/nvvm-next/12/libdevice_nvhpc_cuda_builtin_intrinsics_runtime.10.bc", "/proj/ng/Linux_x86_64/dev/compilers/lib/nvvm-next/12/libdevice_nvhpc_utils_runtime.10.bc", "/proj/ng/Linux_x86_64/dev/compilers/lib/nvvm-next/12/libdevice_nvhpc_cuda_cpp_builtins.10.bc", "/proj/ng/Linux_x86_64/dev/compilers/lib/nvvm-next/12/libdevice_nvhpc_cuda_runtime.10.bc", "/proj/ng/Linux_x86_64/dev/compilers/lib/nvvm-next/12//libdevice_nvhpc_cuda_runtime_builtins_cc90.10.bc", "/proj/ng/Linux_x86_64/dev/cuda/12.9/nvvm/libdevice/libdevice.10.bc"]>] attributes {llvm.data_layout = "e-p:64:64:64-p3:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-i128:128:128-f32:32:32-f64:64:64-v16:16:16-v32:32:32-v64:64:64-v128:128:128-n16:32:64"} {
+    fir.global @_QMm1Eda {data_attr = #cuf.cuda<device>} : !fir.box<!fir.heap<!fir.array<?x?xf32>>> {
+      %c0 = arith.constant 0 : index
+      %0 = fir.zero_bits !fir.heap<!fir.array<?x?xf32>>
+      %1 = fircg.ext_embox %0(%c0, %c0) {allocator_idx = 2 : i32} : (!fir.heap<!fir.array<?x?xf32>>, index, index) -> !fir.box<!fir.heap<!fir.array<?x?xf32>>>
+      fir.has_value %1 : !fir.box<!fir.heap<!fir.array<?x?xf32>>>
+    }
+    gpu.func @_QMm1Psub2(%arg0: !fir.box<!fir.array<?x?xf32>>) kernel {
+      gpu.return
+    }
+  }
+}
+
+// CHECK-LABEL: llvm.func @_QQmain()
+// CHECK: llvm.call @_FortranACUFAllocDescriptor

``````````

</details>


https://github.com/llvm/llvm-project/pull/160596