From 54e5600e4d28535d4296a6b6baeefccc9cc9d904 Mon Sep 17 00:00:00 2001 From: Alex Zinenko Date: Thu, 27 Feb 2020 14:45:54 +0100 Subject: [PATCH] [mlir] fix wrong symbol order in AffineApplyNormalizer Summary: AffineApplyNormalizer provides common logic for folding affine maps that appear in affine.apply into other affine operations that use the result of said affine.apply. In the process, affine maps of both operations are composed. During the composition `A.compose(B)` the symbols from the map A are placed before those of the map B in a single concatenated symbol list. However, AffineApplyNormalizer was ordering the operands of the operation being normalized by iteratively appending the symbols into a single list accoridng to the operand order, regardless of whether these operands are symbols of the current operation or of the map that is being folded into it. This could lead to wrong order of symbols and, when the symbols were bound to constant values, to visibly incorrect folding of constants into affine maps as reported in PR45031. Make sure symbols operands to the current operation are always placed before symbols coming from the folded maps. Update the test that was exercising the incorrect folder behavior. For some reason, the order of symbol operands was swapped in the test input compared to the previous operations, making it easy to assume the correct maps were produced whereas they were swapping the symbols back due to the problem described above. Closes https://bugs.llvm.org/show_bug.cgi?id=45031 Differential Revision: https://reviews.llvm.org/D75247 --- mlir/include/mlir/Dialect/AffineOps/AffineOps.h | 6 ++++- mlir/lib/Dialect/AffineOps/AffineOps.cpp | 8 +++++-- mlir/test/Dialect/AffineOps/canonicalize.mlir | 32 ++++++++++++++++++++++--- 3 files changed, 40 insertions(+), 6 deletions(-) diff --git a/mlir/include/mlir/Dialect/AffineOps/AffineOps.h b/mlir/include/mlir/Dialect/AffineOps/AffineOps.h index 76bb14e..6c157e2 100644 --- a/mlir/include/mlir/Dialect/AffineOps/AffineOps.h +++ b/mlir/include/mlir/Dialect/AffineOps/AffineOps.h @@ -654,6 +654,10 @@ private: SmallVector reorderedDims; SmallVector concatenatedSymbols; + /// The number of symbols in concatenated symbols that belong to the original + /// map as opposed to those concatendated during map composition. + unsigned numProperSymbols; + AffineMap affineMap; /// Used with RAII to control the depth at which AffineApply are composed @@ -667,7 +671,7 @@ private: } static constexpr unsigned kMaxAffineApplyDepth = 1; - AffineApplyNormalizer() { affineApplyDepth()++; } + AffineApplyNormalizer() : numProperSymbols(0) { affineApplyDepth()++; } public: ~AffineApplyNormalizer() { affineApplyDepth()--; } diff --git a/mlir/lib/Dialect/AffineOps/AffineOps.cpp b/mlir/lib/Dialect/AffineOps/AffineOps.cpp index 4133b66..8acc158 100644 --- a/mlir/lib/Dialect/AffineOps/AffineOps.cpp +++ b/mlir/lib/Dialect/AffineOps/AffineOps.cpp @@ -536,8 +536,12 @@ AffineApplyNormalizer::AffineApplyNormalizer(AffineMap map, auxiliaryExprs.push_back(renumberOneDim(t)); } else { // c. The mathematical composition of AffineMap concatenates symbols. - // We do the same for symbol operands. - concatenatedSymbols.push_back(t); + // Note that the map composition will put symbols already present + // in the map before any symbols coming from the auxiliary map, so + // we insert them before any symbols that are due to renumbering, + // and after the proper symbols we have seen already. + concatenatedSymbols.insert( + std::next(concatenatedSymbols.begin(), numProperSymbols++), t); } } } diff --git a/mlir/test/Dialect/AffineOps/canonicalize.mlir b/mlir/test/Dialect/AffineOps/canonicalize.mlir index be8d000..2622092 100644 --- a/mlir/test/Dialect/AffineOps/canonicalize.mlir +++ b/mlir/test/Dialect/AffineOps/canonicalize.mlir @@ -17,7 +17,7 @@ // Affine maps for test case: compose_affine_maps_dependent_loads // CHECK-DAG: [[MAP9:#map[0-9]+]] = affine_map<(d0) -> (d0 + 3)> // CHECK-DAG: [[MAP10:#map[0-9]+]] = affine_map<(d0) -> (d0 * 3)> -// CHECK-DAG: [[MAP11:#map[0-9]+]] = affine_map<(d0) -> ((d0 + 7) ceildiv 3)> +// CHECK-DAG: [[MAP11:#map[0-9]+]] = affine_map<(d0) -> ((d0 + 3) ceildiv 3)> // CHECK-DAG: [[MAP12:#map[0-9]+]] = affine_map<(d0) -> (d0 * 7 - 49)> // Affine maps for test case: compose_affine_maps_diamond_dependency @@ -187,9 +187,9 @@ func @compose_affine_maps_dependent_loads() { // Swizzle %x00, %x01 and %c3, %c7 %x10 = affine.apply affine_map<(d0, d1)[s0, s1] -> (d0 * s1)> - (%x01, %x00)[%c7, %c3] + (%x01, %x00)[%c3, %c7] %x11 = affine.apply affine_map<(d0, d1)[s0, s1] -> (d1 ceildiv s0)> - (%x01, %x00)[%c7, %c3] + (%x01, %x00)[%c3, %c7] // CHECK-NEXT: [[I2A:%[0-9]+]] = affine.apply [[MAP12]](%{{.*}}) // CHECK-NEXT: [[I2B:%[0-9]+]] = affine.apply [[MAP11]](%{{.*}}) @@ -568,3 +568,29 @@ func @affine_min(%arg0: index) { } return } + +// ----- + +// Reproducer for PR45031. This used to fold into an incorrect map because +// symbols were concatenated in the wrong order during map folding. Map +// composition places the symbols of the original map before those of the map +// it is composed with, e.g. A.compose(B) will first have all symbols of A, +// then all symbols of B. + +#map1 = affine_map<(d0)[s0, s1] -> (d0 * s0 + s1)> +#map2 = affine_map<(d0)[s0] -> (1024, -d0 + s0)> + +// CHECK: #[[MAP:.*]] = affine_map<()[s0, s1] -> (1024, s1 * -1024 + s0)> + +// CHECK: func @rep(%[[ARG0:.*]]: index, %[[ARG1:.*]]: index) +func @rep(%arg0 : index, %arg1 : index) -> index { + // CHECK-NOT: constant + %c0 = constant 0 : index + %c1024 = constant 1024 : index + // CHECK-NOT: affine.apply + %0 = affine.apply #map1(%arg0)[%c1024, %c0] + + // CHECK: affine.min #[[MAP]]()[%[[ARG1]], %[[ARG0]]] + %1 = affine.min #map2(%0)[%arg1] + return %1 : index +} -- 2.7.4