[PATCH] D73685: Fix conversion of loops to GPU with no block/thread dimensions.

[Stephan Herhut via Phabricator via llvm-commits]

herhut created this revision.
Herald added subscribers: llvm-commits, liufengdb, aartbik, lucyrfox, mgester, arpith-jacob, csigg, antiagainst, shauheen, burmako, jpienaar, rriddle, mehdi_amini.
Herald added a reviewer: nicolasvasilache.
Herald added a project: LLVM.

The current code assumes that one always maps at least one loop to block
dimensions and at least one loop to thread dimensions. If either is not
the case, a loop would get mapped twice.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D73685

Files:
  mlir/lib/Conversion/LoopsToGPU/LoopsToGPU.cpp
  mlir/test/Conversion/LoopsToGPU/no_blocks_no_threads.mlir


Index: mlir/test/Conversion/LoopsToGPU/no_blocks_no_threads.mlir
===================================================================
--- /dev/null
+++ mlir/test/Conversion/LoopsToGPU/no_blocks_no_threads.mlir
@@ -0,0 +1,34 @@
+// RUN: mlir-opt -convert-loops-to-gpu -gpu-block-dims=0 -gpu-thread-dims=1 %s | FileCheck --check-prefix=CHECK-THREADS %s --dump-input-on-failure
+// RUN: mlir-opt -convert-loops-to-gpu -gpu-block-dims=1 -gpu-thread-dims=0 %s | FileCheck --check-prefix=CHECK-BLOCKS %s --dump-input-on-failure
+
+// CHECK-THREADS-LABEL: @one_d_loop
+// CHECK-BLOCKS-LABEL: @one_d_loop
+func @one_d_loop(%A : memref<?xf32>, %B : memref<?xf32>) {
+  // Bounds of the loop, its range and step.
+  // CHECK-THREADS-NEXT: %{{.*}} = constant 0 : index
+  // CHECK-THREADS-NEXT: %{{.*}} = constant 42 : index
+  // CHECK-THREADS-NEXT: %[[BOUND:.*]] = subi %{{.*}}, %{{.*}} : index
+  // CHECK-THREADS-NEXT: %{{.*}} = constant 1 : index
+  // CHECK-THREADS-NEXT: %[[ONE:.*]] = constant 1 : index
+  //
+  // CHECK-BLOCKS-NEXT: %{{.*}} = constant 0 : index
+  // CHECK-BLOCKS-NEXT: %{{.*}} = constant 42 : index
+  // CHECK-BLOCKS-NEXT: %[[BOUND:.*]] = subi %{{.*}}, %{{.*}} : index
+  // CHECK-BLOCKS-NEXT: %{{.*}} = constant 1 : index
+  // CHECK-BLOCKS-NEXT: %[[ONE:.*]] = constant 1 : index
+
+  // CHECK-THREADS-NEXT: gpu.launch blocks(%[[B0:.*]], %[[B1:.*]], %[[B2:.*]]) in (%{{.*}} = %[[ONE]], %{{.*}} = %[[ONE]], %{{.*}}0 = %[[ONE]]) threads(%[[T0:.*]], %[[T1:.*]], %[[T2:.*]]) in (%{{.*}} = %[[BOUND]], %{{.*}} = %[[ONE]], %{{.*}} = %[[ONE]])
+  // CHECK-BLOCKS-NEXT: gpu.launch blocks(%[[B0:.*]], %[[B1:.*]], %[[B2:.*]]) in (%{{.*}} = %[[BOUND]], %{{.*}} = %[[ONE]], %{{.*}}0 = %[[ONE]]) threads(%[[T0:.*]], %[[T1:.*]], %[[T2:.*]]) in (%{{.*}} = %[[ONE]], %{{.*}} = %[[ONE]], %{{.*}} = %[[ONE]])
+  affine.for %i = 0 to 42 {
+  // CHECK-THREADS-NEXT: %[[INDEX:.*]] = addi %{{.*}}, %[[T0]]
+  // CHECK-THREADS-NEXT: load %{{.*}}[%[[INDEX]]]
+  // CHECK-BLOCKS-NEXT: %[[INDEX:.*]] = addi %{{.*}}, %[[B0]]
+  // CHECK-BLOCKS-NEXT: load %{{.*}}[%[[INDEX]]]
+    %0 = load %A[%i] : memref<?xf32>
+    store %0, %B[%i] : memref<?xf32>
+    // CHECK-THREADS: gpu.return
+    // CHECK-BLOCKS: gpu.return
+  }
+  return
+}
+
Index: mlir/lib/Conversion/LoopsToGPU/LoopsToGPU.cpp
===================================================================
--- mlir/lib/Conversion/LoopsToGPU/LoopsToGPU.cpp
+++ mlir/lib/Conversion/LoopsToGPU/LoopsToGPU.cpp
@@ -403,10 +403,10 @@
   Value constOne = (numBlockDims < 3 || numThreadDims < 3)
                        ? builder.create<ConstantIndexOp>(rootForOp.getLoc(), 1)
                        : nullptr;
-  Value gridSizeX = dims[0];
+  Value gridSizeX = numBlockDims > 0 ? dims[0] : constOne;
   Value gridSizeY = numBlockDims > 1 ? dims[1] : constOne;
   Value gridSizeZ = numBlockDims > 2 ? dims[2] : constOne;
-  Value blockSizeX = dims[numBlockDims];
+  Value blockSizeX = numThreadDims > 0 ? dims[numBlockDims] : constOne;
   Value blockSizeY = numThreadDims > 1 ? dims[numBlockDims + 1] : constOne;
   Value blockSizeZ = numThreadDims > 2 ? dims[numBlockDims + 2] : constOne;
 


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D73685.241381.patch
Type: text/x-patch
Size: 3128 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20200130/d644369f/attachment.bin>