[flang-commits] [flang] 23fbe52 - [flang] do not merge block after lowering
Jean Perier via flang-commits
flang-commits at lists.llvm.org
Tue Jun 27 23:30:27 PDT 2023
Author: Jean Perier
Date: 2023-06-28T08:28:07+02:00
New Revision: 23fbe525ce0645341610b751184882fea264c99e
URL: https://github.com/llvm/llvm-project/commit/23fbe525ce0645341610b751184882fea264c99e
DIFF: https://github.com/llvm/llvm-project/commit/23fbe525ce0645341610b751184882fea264c99e.diff
LOG: [flang] do not merge block after lowering
Lowering relies on dead code generation / unreachable block deletion
to delete some code that is potentially invalid.
However, calling mlir::simplifyRegion also merges block, which may
promote SSA values to block arguments. Not all FIR types are intended
to be block arguments.
The added test shows an example where block merging led to
fir.shape<> being block arguments (and a failure later in codegen).
Reviewed By: tblah, clementval, vdonaldson
Differential Revision: https://reviews.llvm.org/D153858
Added:
flang/test/Lower/HLFIR/no-block-merging.f90
Modified:
flang/lib/Lower/Bridge.cpp
flang/test/Lower/block.f90
flang/test/Lower/entry-statement.f90
Removed:
################################################################################
diff --git a/flang/lib/Lower/Bridge.cpp b/flang/lib/Lower/Bridge.cpp
index 23a58eb4679d6..bc0c13e44ed39 100644
--- a/flang/lib/Lower/Bridge.cpp
+++ b/flang/lib/Lower/Bridge.cpp
@@ -4156,6 +4156,12 @@ class FirConverter : public Fortran::lower::AbstractConverter {
startBlock(newBlock);
}
+ void eraseDeadCodeAndBlocks(mlir::RewriterBase &rewriter,
+ llvm::MutableArrayRef<mlir::Region> regions) {
+ (void)mlir::eraseUnreachableBlocks(rewriter, regions);
+ (void)mlir::runRegionDCE(rewriter, regions);
+ }
+
/// Finish translation of a function.
void endNewFunction(Fortran::lower::pft::FunctionLikeUnit &funit) {
setCurrentPosition(Fortran::lower::pft::stmtSourceLoc(funit.endStmt));
@@ -4174,7 +4180,7 @@ class FirConverter : public Fortran::lower::AbstractConverter {
// Eliminate dead code as a prerequisite to calling other IR passes.
// FIXME: This simplification should happen in a normal pass, not here.
mlir::IRRewriter rewriter(*builder);
- (void)mlir::simplifyRegions(rewriter, {builder->getRegion()});
+ (void)eraseDeadCodeAndBlocks(rewriter, {builder->getRegion()});
delete builder;
builder = nullptr;
hostAssocTuple = mlir::Value{};
diff --git a/flang/test/Lower/HLFIR/no-block-merging.f90 b/flang/test/Lower/HLFIR/no-block-merging.f90
new file mode 100644
index 0000000000000..7d0eb836b324d
--- /dev/null
+++ b/flang/test/Lower/HLFIR/no-block-merging.f90
@@ -0,0 +1,59 @@
+! Test that dead code elimination after lowering does not merge
+! blocks. This test was added because block merging on the
+! code below created a block with a fir.shape<> block argument
+! which FIR codegen is not intended to support.
+! RUN: bbc -emit-hlfir -o - %s | FileCheck %s
+
+subroutine test(res, selector, x1, x2, x3, x4, x5, x6, x7, x8)
+ integer :: res
+ character(*) :: selector
+ real(8), dimension(7) :: x1, x2, x3, x4, x5, x6, x7, x8
+ interface
+ integer function foo(x)
+ real(8) :: x(:)
+ end function
+ end interface
+ select case (selector)
+ case ("01")
+ res = foo(x1)
+ res = foo(x1)
+ case ("02")
+ res = foo(x2)
+ res = foo(x2)
+ case ("03")
+ res = foo(x3)
+ res = foo(x3)
+ case ("04")
+ res = foo(x4)
+ res = foo(x4)
+ case ("05")
+ res = foo(x5)
+ res = foo(x5)
+ case ("06")
+ res = foo(x6)
+ res = foo(x6)
+ case ("07")
+ res = foo(x7)
+ res = foo(x7)
+ case ("08")
+ res = foo(x8)
+ res = foo(x8)
+ case default
+ end select
+end subroutine
+! CHECK: fir.call @_QPfoo
+! CHECK: fir.call @_QPfoo
+! CHECK: fir.call @_QPfoo
+! CHECK: fir.call @_QPfoo
+! CHECK: fir.call @_QPfoo
+! CHECK: fir.call @_QPfoo
+! CHECK: fir.call @_QPfoo
+! CHECK: fir.call @_QPfoo
+! CHECK: fir.call @_QPfoo
+! CHECK: fir.call @_QPfoo
+! CHECK: fir.call @_QPfoo
+! CHECK: fir.call @_QPfoo
+! CHECK: fir.call @_QPfoo
+! CHECK: fir.call @_QPfoo
+! CHECK: fir.call @_QPfoo
+! CHECK: fir.call @_QPfoo
diff --git a/flang/test/Lower/block.f90 b/flang/test/Lower/block.f90
index 520af068c5b74..5a73a43eb50fb 100644
--- a/flang/test/Lower/block.f90
+++ b/flang/test/Lower/block.f90
@@ -9,8 +9,8 @@ program bb ! block stack management and exits
! CHECK: %[[V_3:[0-9]+]] = fir.call @llvm.stacksave()
! CHECK: fir.store %{{.*}} to %[[V_1]] : !fir.ref<i32>
! CHECK: br ^bb1
- ! CHECK: ^bb1: // 2 preds: ^bb0, ^bb15
- ! CHECK: cond_br %{{.*}}, ^bb2, ^bb16
+ ! CHECK: ^bb1: // 2 preds: ^bb0, ^bb16
+ ! CHECK: cond_br %{{.*}}, ^bb2, ^bb17
! CHECK: ^bb2: // pred: ^bb1
! CHECK: %[[V_11:[0-9]+]] = fir.call @llvm.stacksave()
! CHECK: fir.store %{{.*}} to %[[V_1]] : !fir.ref<i32>
@@ -21,44 +21,46 @@ program bb ! block stack management and exits
! CHECK: fir.store %{{.*}} to %[[V_1]] : !fir.ref<i32>
! CHECK: cond_br %{{.*}}, ^bb5, ^bb6
! CHECK: ^bb5: // pred: ^bb4
- ! CHECK: br ^bb7
+ ! CHECK: br ^bb14
! CHECK: ^bb6: // pred: ^bb4
! CHECK: fir.store %{{.*}} to %[[V_1]] : !fir.ref<i32>
! CHECK: cond_br %{{.*}}, ^bb7, ^bb8
- ! CHECK: ^bb7: // 3 preds: ^bb5, ^bb6, ^bb12
+ ! CHECK: ^bb7: // pred: ^bb6
! CHECK: fir.call @llvm.stackrestore(%[[V_11]])
- ! CHECK: br ^bb14
+ ! CHECK: br ^bb15
! CHECK: ^bb8: // pred: ^bb6
! CHECK: fir.store %{{.*}} to %[[V_1]] : !fir.ref<i32>
! CHECK: cond_br %{{.*}}, ^bb9, ^bb10
! CHECK: ^bb9: // pred: ^bb8
! CHECK: fir.call @llvm.stackrestore(%[[V_11]])
- ! CHECK: br ^bb15
+ ! CHECK: br ^bb16
! CHECK: ^bb10: // 2 preds: ^bb3, ^bb8
! CHECK: fir.store %{{.*}} to %[[V_1]] : !fir.ref<i32>
! CHECK: cond_br %{{.*}}, ^bb11, ^bb12
! CHECK: ^bb11: // pred: ^bb10
! CHECK: fir.call @llvm.stackrestore(%[[V_11]])
- ! CHECK: br ^bb17
+ ! CHECK: br ^bb18
! CHECK: ^bb12: // pred: ^bb10
! CHECK: fir.store %{{.*}} to %[[V_1]] : !fir.ref<i32>
- ! CHECK: cond_br %{{.*}}, ^bb13, ^bb7
+ ! CHECK: cond_br %{{.*}}, ^bb13, ^bb14
! CHECK: ^bb13: // pred: ^bb12
! CHECK: fir.call @llvm.stackrestore(%[[V_11]])
! CHECK: fir.call @llvm.stackrestore(%[[V_3]])
- ! CHECK: br ^bb18
- ! CHECK: ^bb14: // pred: ^bb7
- ! CHECK: fir.store %{{.*}} to %[[V_1]] : !fir.ref<i32>
+ ! CHECK: br ^bb19
+ ! CHECK: ^bb14: // 2 preds: ^bb5, ^bb12
+ ! CHECK: fir.call @llvm.stackrestore(%[[V_11]])
! CHECK: br ^bb15
- ! CHECK: ^bb15: // 2 preds: ^bb9, ^bb14
+ ! CHECK: ^bb15: // 2 preds: ^bb7, ^bb14
+ ! CHECK: br ^bb16
+ ! CHECK: ^bb16: // 2 preds: ^bb9, ^bb15
! CHECK: br ^bb1
- ! CHECK: ^bb16: // pred: ^bb1
+ ! CHECK: ^bb17: // pred: ^bb1
! CHECK: fir.store %{{.*}} to %[[V_1]] : !fir.ref<i32>
- ! CHECK: br ^bb17
- ! CHECK: ^bb17: // 2 preds: ^bb11, ^bb16
+ ! CHECK: cf.br ^bb18
+ ! CHECK: ^bb18: // 2 preds: ^bb11, ^bb17
! CHECK: fir.call @llvm.stackrestore(%[[V_3]])
- ! CHECK: br ^bb18
- ! CHECK: ^bb18: // 2 preds: ^bb13, ^bb17
+ ! CHECK: br ^bb19
+ ! CHECK: ^bb19: // 2 preds: ^bb13, ^bb18
! CHECK: return
block
i = i + 1 ! 1 increment
diff --git a/flang/test/Lower/entry-statement.f90 b/flang/test/Lower/entry-statement.f90
index 83491bd18a156..6a857c854ff19 100644
--- a/flang/test/Lower/entry-statement.f90
+++ b/flang/test/Lower/entry-statement.f90
@@ -280,14 +280,16 @@ function f1(n1) result(res1)
! CHECK: %[[V_17:[0-9]+]] = fir.load %arg2 : !fir.ref<i32>
! CHECK: %[[V_18:[0-9]+]] = arith.cmpi eq, %[[V_17]], %c1{{.*}}_i32_4 : i32
! CHECK: cond_br %[[V_18]], ^bb2, ^bb3
- ! CHECK: ^bb2: // 2 preds: ^bb1, ^bb3
- ! CHECK: br ^bb5
+ ! CHECK: ^bb2: // pred: ^bb1
+ ! CHECK: br ^bb6
! CHECK: ^bb3: // pred: ^bb1
! CHECK: fir.call @_QFf1Ps2(%[[V_2]]) {{.*}}: (!fir.ref<tuple<!fir.boxchar<1>, !fir.boxchar<1>>>) -> ()
! CHECK: %[[V_19:[0-9]+]] = fir.load %[[V_1]] : !fir.ref<i32>
! CHECK: %[[V_20:[0-9]+]] = arith.cmpi eq, %[[V_19]], %c2{{.*}}_i32 : i32
- ! CHECK: cond_br %[[V_20]], ^bb2, ^bb4
+ ! CHECK: cond_br %[[V_20]], ^bb4, ^bb5
! CHECK: ^bb4: // pred: ^bb3
+ ! CHECK: cf.br ^bb6
+ ! CHECK: ^bb5: // pred: ^bb3
! CHECK: %[[V_21:[0-9]+]] = fir.address_of(@_QQcl.4320432043) : !fir.ref<!fir.char<1,5>>
! CHECK: %[[V_22:[0-9]+]] = arith.cmpi slt, %c5{{.*}}, %c5{{.*}} : index
! CHECK: %[[V_23:[0-9]+]] = arith.select %[[V_22]], %c5{{.*}}, %c5{{.*}} : index
@@ -305,8 +307,8 @@ function f1(n1) result(res1)
! CHECK: fir.store %[[V_30]] to %[[V_33]] : !fir.ref<!fir.char<1>>
! CHECK: }
! CHECK: fir.call @_QFf1Ps3(%[[V_2]]) {{.*}}: (!fir.ref<tuple<!fir.boxchar<1>, !fir.boxchar<1>>>) -> ()
- ! CHECK: br ^bb5
- ! CHECK: ^bb5: // 2 preds: ^bb2, ^bb4
+ ! CHECK: br ^bb6
+ ! CHECK: ^bb6: // 3 preds: ^bb2, ^bb4, ^bb5
! CHECK: %[[V_31:[0-9]+]] = fir.emboxchar %[[V_0]], %c5{{.*}} : (!fir.ref<!fir.char<1,?>>, index) -> !fir.boxchar<1>
! CHECK: return %[[V_31]] : !fir.boxchar<1>
! CHECK: }
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