[Mlir-commits] [mlir] 984d1bf - Remove empty AffineExpr stride canonicalization in makeCanonicalStridedLayoutExpr

[Tres Popp]

Author: Tres Popp
Date: 2022-08-01T11:15:32+02:00
New Revision: 984d1bf8c0b9aec2ab7e2ddd1917641ed10f5428

URL: https://github.com/llvm/llvm-project/commit/984d1bf8c0b9aec2ab7e2ddd1917641ed10f5428
DIFF: https://github.com/llvm/llvm-project/commit/984d1bf8c0b9aec2ab7e2ddd1917641ed10f5428.diff

LOG: Remove empty AffineExpr stride canonicalization in makeCanonicalStridedLayoutExpr

The "optimization" would replace the AffineMap for an empty shape with a 0 to represent its indexing (stride * dimension) logic. Meanwhile other pieces of core logic (such as getStridesAndOffset and makeStridedLinearLayoutMap) require strides for all dimensions to ensure no aliasing can occur which would occur if the shape was not empty. For now, this optimization is removed as different pieces of core types disagree on this, so the optimization should be caller supplied or should be consistent throughout the infrastructure.

Differential Revision: https://reviews.llvm.org/D130772

Added: 
    

Modified: 
    mlir/lib/IR/BuiltinTypes.cpp
    mlir/test/Conversion/MemRefToLLVM/memref-to-llvm.mlir

Removed: 
    


################################################################################
diff  --git a/mlir/lib/IR/BuiltinTypes.cpp b/mlir/lib/IR/BuiltinTypes.cpp
index 5459841c8391a..bffd4188929cf 100644
--- a/mlir/lib/IR/BuiltinTypes.cpp
+++ b/mlir/lib/IR/BuiltinTypes.cpp
@@ -988,7 +988,7 @@ AffineExpr mlir::makeCanonicalStridedLayoutExpr(ArrayRef<int64_t> sizes,
                                                 ArrayRef<AffineExpr> exprs,
                                                 MLIRContext *context) {
   // Size 0 corner case is useful for canonicalizations.
-  if (sizes.empty() || llvm::is_contained(sizes, 0))
+  if (sizes.empty())
     return getAffineConstantExpr(0, context);
 
   assert(!exprs.empty() && "expected exprs");
@@ -1001,9 +1001,6 @@ AffineExpr mlir::makeCanonicalStridedLayoutExpr(ArrayRef<int64_t> sizes,
   int64_t runningSize = 1;
   for (auto en : llvm::zip(llvm::reverse(exprs), llvm::reverse(sizes))) {
     int64_t size = std::get<1>(en);
-    // Degenerate case, no size =-> no stride
-    if (size == 0)
-      continue;
     AffineExpr dimExpr = std::get<0>(en);
     AffineExpr stride = dynamicPoisonBit
                             ? getAffineSymbolExpr(nSymbols++, context)

diff  --git a/mlir/test/Conversion/MemRefToLLVM/memref-to-llvm.mlir b/mlir/test/Conversion/MemRefToLLVM/memref-to-llvm.mlir
index 4b0dc3b756839..0822852d5c99e 100644
--- a/mlir/test/Conversion/MemRefToLLVM/memref-to-llvm.mlir
+++ b/mlir/test/Conversion/MemRefToLLVM/memref-to-llvm.mlir
@@ -99,11 +99,11 @@ func.func @view_empty_memref(%offset: index, %mem: memref<0xi8>) {
   // CHECK: llvm.insertvalue %{{.*}}, %{{.*}}[2] : !llvm.struct<(ptr<f32>, ptr<f32>, i64, array<2 x i64>, array<2 x i64>)>
   // CHECK: llvm.mlir.constant(4 : index) : i64
   // CHECK: llvm.insertvalue %{{.*}}, %{{.*}}[3, 1] : !llvm.struct<(ptr<f32>, ptr<f32>, i64, array<2 x i64>, array<2 x i64>)>
-  // CHECK: llvm.mlir.constant(0 : index) : i64
+  // CHECK: llvm.mlir.constant(1 : index) : i64
   // CHECK: llvm.insertvalue %{{.*}}, %{{.*}}[4, 1] : !llvm.struct<(ptr<f32>, ptr<f32>, i64, array<2 x i64>, array<2 x i64>)>
   // CHECK: llvm.mlir.constant(0 : index) : i64
   // CHECK: llvm.insertvalue %{{.*}}, %{{.*}}[3, 0] : !llvm.struct<(ptr<f32>, ptr<f32>, i64, array<2 x i64>, array<2 x i64>)>
-  // CHECK: llvm.mlir.constant(0 : index) : i64
+  // CHECK: llvm.mlir.constant(4 : index) : i64
   // CHECK: = llvm.insertvalue %{{.*}}, %{{.*}}[4, 0] : !llvm.struct<(ptr<f32>, ptr<f32>, i64, array<2 x i64>, array<2 x i64>)>
   %0 = memref.view %mem[%offset][] : memref<0xi8> to memref<0x4xf32>