[flang-commits] [flang] cccf4d6 - [flang] Skip OPTIONAL arguments in LoopVersioning.

[Slava Zakharin via flang-commits]

Author: Slava Zakharin
Date: 2023-08-25T08:33:49-07:00
New Revision: cccf4d6e4a331487590f1d2c1cd3b8ef3b66fbd9

URL: https://github.com/llvm/llvm-project/commit/cccf4d6e4a331487590f1d2c1cd3b8ef3b66fbd9
DIFF: https://github.com/llvm/llvm-project/commit/cccf4d6e4a331487590f1d2c1cd3b8ef3b66fbd9.diff

LOG: [flang] Skip OPTIONAL arguments in LoopVersioning.

This patch fixes multiple tests failing with segfault due to accessing
absent argument box before the loop versioning check.
The absent arguments might be treated as contiguous for the purpose
of loop versioning, but this is not done in this patch.

Reviewed By: PeteSteinfeld

Differential Revision: https://reviews.llvm.org/D158800

Added: 
    

Modified: 
    flang/lib/Optimizer/Transforms/LoopVersioning.cpp
    flang/test/Transforms/loop-versioning.fir

Removed: 
    


################################################################################
diff  --git a/flang/lib/Optimizer/Transforms/LoopVersioning.cpp b/flang/lib/Optimizer/Transforms/LoopVersioning.cpp
index 56dcadf6cbab39..56a6e71f8677c4 100644
--- a/flang/lib/Optimizer/Transforms/LoopVersioning.cpp
+++ b/flang/lib/Optimizer/Transforms/LoopVersioning.cpp
@@ -141,6 +141,14 @@ void LoopVersioningPass::runOnOperation() {
   fir::KindMapping kindMap = fir::getKindMapping(module);
   mlir::SmallVector<ArgInfo, 4> argsOfInterest;
   for (auto &arg : args) {
+    // Optional arguments must be checked for IsPresent before
+    // looking for the bounds. They are unsupported for the time being.
+    if (func.getArgAttrOfType<mlir::UnitAttr>(arg.getArgNumber(),
+                                              fir::getOptionalAttrName())) {
+      LLVM_DEBUG(llvm::dbgs() << "OPTIONAL is not supported\n");
+      continue;
+    }
+
     if (auto seqTy = getAsSequenceType(&arg)) {
       unsigned rank = seqTy.getDimension();
       if (rank > 0 &&

diff  --git a/flang/test/Transforms/loop-versioning.fir b/flang/test/Transforms/loop-versioning.fir
index 8e2fde0711f2cb..5a33f386f9119d 100644
--- a/flang/test/Transforms/loop-versioning.fir
+++ b/flang/test/Transforms/loop-versioning.fir
@@ -522,4 +522,52 @@ func.func @sum1dfixed(%arg0: !fir.ref<!fir.array<?xf64>> {fir.bindc_name = "a"},
 // CHECK: fir.store %[[IF_RES]]#1 to %{{.*}}
 // CHECK: return
 
+// Check that OPTIONAL argument's box is not accessed illegally
+// before the loop.
+func.func @test_optional_arg(%arg0: !fir.box<!fir.array<?xf32>> {fir.bindc_name = "x", fir.optional}) {
+  %c1 = arith.constant 1 : index
+  %c20 = arith.constant 20 : index
+  %c0_i64 = arith.constant 0 : i64
+  %0 = fir.alloca i32 {bindc_name = "i", uniq_name = "_QMcheck_modFtestEi"}
+  %1 = fir.convert %c1 : (index) -> i32
+  %2:2 = fir.do_loop %arg1 = %c1 to %c20 step %c1 iter_args(%arg2 = %1) -> (index, i32) {
+    fir.store %arg2 to %0 : !fir.ref<i32>
+    %3 = fir.is_present %arg0 : (!fir.box<!fir.array<?xf32>>) -> i1
+    fir.if %3 {
+      %8 = fir.coordinate_of %arg0, %c0_i64 : (!fir.box<!fir.array<?xf32>>, i64) -> !fir.ref<f32>
+    } else {
+    }
+    %4 = arith.addi %arg1, %c1 : index
+    %5 = fir.convert %c1 : (index) -> i32
+    %6 = fir.load %0 : !fir.ref<i32>
+    %7 = arith.addi %6, %5 : i32
+    fir.result %4, %7 : index, i32
+  }
+  fir.store %2#1 to %0 : !fir.ref<i32>
+  return
+}
+// CHECK-LABEL:   func.func @test_optional_arg(
+// CHECK-SAME:                                 %[[VAL_0:.*]]: !fir.box<!fir.array<?xf32>> {fir.bindc_name = "x", fir.optional}) {
+// CHECK-NEXT:           %[[VAL_1:.*]] = arith.constant 1 : index
+// CHECK-NEXT:           %[[VAL_2:.*]] = arith.constant 20 : index
+// CHECK-NEXT:           %[[VAL_3:.*]] = arith.constant 0 : i64
+// CHECK-NEXT:           %[[VAL_4:.*]] = fir.alloca i32 {bindc_name = "i", uniq_name = "_QMcheck_modFtestEi"}
+// CHECK-NEXT:           %[[VAL_5:.*]] = fir.convert %[[VAL_1]] : (index) -> i32
+// CHECK-NEXT:           %[[VAL_6:.*]]:2 = fir.do_loop %[[VAL_7:.*]] = %[[VAL_1]] to %[[VAL_2]] step %[[VAL_1]] iter_args(%[[VAL_8:.*]] = %[[VAL_5]]) -> (index, i32) {
+// CHECK-NEXT:             fir.store %[[VAL_8]] to %[[VAL_4]] : !fir.ref<i32>
+// CHECK-NEXT:             %[[VAL_9:.*]] = fir.is_present %[[VAL_0]] : (!fir.box<!fir.array<?xf32>>) -> i1
+// CHECK-NEXT:             fir.if %[[VAL_9]] {
+// CHECK-NEXT:               %[[VAL_10:.*]] = fir.coordinate_of %[[VAL_0]], %[[VAL_3]] : (!fir.box<!fir.array<?xf32>>, i64) -> !fir.ref<f32>
+// CHECK-NEXT:             } else {
+// CHECK-NEXT:             }
+// CHECK-NEXT:             %[[VAL_11:.*]] = arith.addi %[[VAL_7]], %[[VAL_1]] : index
+// CHECK-NEXT:             %[[VAL_12:.*]] = fir.convert %[[VAL_1]] : (index) -> i32
+// CHECK-NEXT:             %[[VAL_13:.*]] = fir.load %[[VAL_4]] : !fir.ref<i32>
+// CHECK-NEXT:             %[[VAL_14:.*]] = arith.addi %[[VAL_13]], %[[VAL_12]] : i32
+// CHECK-NEXT:             fir.result %[[VAL_11]], %[[VAL_14]] : index, i32
+// CHECK-NEXT:           }
+// CHECK-NEXT:           fir.store %[[VAL_15:.*]]#1 to %[[VAL_4]] : !fir.ref<i32>
+// CHECK-NEXT:           return
+// CHECK-NEXT:         }
+
 } // End module