[flang-commits] [flang] 11fb1aa - [flang] Upstream the lowering of the while loop
Diana Picus via flang-commits
flang-commits at lists.llvm.org
Tue May 31 00:27:48 PDT 2022
Author: Diana Picus
Date: 2022-05-31T07:27:16Z
New Revision: 11fb1aa5a40885188b014b3ccd326cc92e4a3b9e
URL: https://github.com/llvm/llvm-project/commit/11fb1aa5a40885188b014b3ccd326cc92e4a3b9e
DIFF: https://github.com/llvm/llvm-project/commit/11fb1aa5a40885188b014b3ccd326cc92e4a3b9e.diff
LOG: [flang] Upstream the lowering of the while loop
Upstream the code for handling while loops from the fir-dev branch at
https://github.com/flang-compiler/f18-llvm-project/tree/fir-dev/
Also add tests.
The while loop is lowered to a header block that checks the loop
condition and branches either to the exit block or to the body of the
loop. The body of the loop will unconditionally branch back to the
header.
Differential Revision: https://reviews.llvm.org/D126636
Co-authored-by: Eric Schweitz <eschweitz at nvidia.com>
Co-authored-by: V Donaldson <vdonaldson at nvidia.com>
Added:
flang/test/Lower/mixed_loops.f90
flang/test/Lower/while_loop.f90
Modified:
flang/lib/Lower/Bridge.cpp
Removed:
################################################################################
diff --git a/flang/lib/Lower/Bridge.cpp b/flang/lib/Lower/Bridge.cpp
index 28dbc8b8b0b4..a33ddee64e19 100644
--- a/flang/lib/Lower/Bridge.cpp
+++ b/flang/lib/Lower/Bridge.cpp
@@ -981,8 +981,16 @@ class FirConverter : public Fortran::lower::AbstractConverter {
mlir::Block *bodyBlock = doStmtEval.lexicalSuccessor->block;
mlir::Block *exitBlock = doStmtEval.parentConstruct->constructExit->block;
IncrementLoopNestInfo incrementLoopNestInfo;
- if (const auto *bounds = std::get_if<Fortran::parser::LoopControl::Bounds>(
- &loopControl->u)) {
+ const Fortran::parser::ScalarLogicalExpr *whileCondition = nullptr;
+ if ((whileCondition = std::get_if<Fortran::parser::ScalarLogicalExpr>(
+ &loopControl->u))) {
+ assert(unstructuredContext && "while loop must be unstructured");
+ maybeStartBlock(preheaderBlock); // no block or empty block
+ startBlock(headerBlock);
+ genFIRConditionalBranch(*whileCondition, bodyBlock, exitBlock);
+ } else if (const auto *bounds =
+ std::get_if<Fortran::parser::LoopControl::Bounds>(
+ &loopControl->u)) {
// Non-concurrent increment loop.
IncrementLoopInfo &info = incrementLoopNestInfo.emplace_back(
*bounds->name.thing.symbol, bounds->lower, bounds->upper,
@@ -999,15 +1007,19 @@ class FirConverter : public Fortran::lower::AbstractConverter {
// Increment loop begin code. (TODO: Infinite/while code was already
// generated.)
- genFIRIncrementLoopBegin(incrementLoopNestInfo);
+ if (!whileCondition)
+ genFIRIncrementLoopBegin(incrementLoopNestInfo);
// Loop body code - NonLabelDoStmt and EndDoStmt code is generated here.
// Their genFIR calls are nops except for block management in some cases.
for (Fortran::lower::pft::Evaluation &e : eval.getNestedEvaluations())
genFIR(e, unstructuredContext);
- // Loop end code. (TODO: infinite/while loop)
- genFIRIncrementLoopEnd(incrementLoopNestInfo);
+ // Loop end code. (TODO: infinite loop)
+ if (whileCondition)
+ genFIRBranch(headerBlock);
+ else
+ genFIRIncrementLoopEnd(incrementLoopNestInfo);
}
/// Generate FIR to begin a structured or unstructured increment loop nest.
diff --git a/flang/test/Lower/mixed_loops.f90 b/flang/test/Lower/mixed_loops.f90
new file mode 100644
index 000000000000..3135f8a86a2c
--- /dev/null
+++ b/flang/test/Lower/mixed_loops.f90
@@ -0,0 +1,118 @@
+! RUN: bbc -emit-fir -o - %s | FileCheck %s
+! RUN: %flang_fc1 -emit-fir -o - %s | FileCheck %s
+
+! Test while loop inside do loop.
+! CHECK-LABEL: while_inside_do_loop
+subroutine while_inside_do_loop
+ ! CHECK-DAG: %[[T_REF:.*]] = fir.alloca i32
+ ! CHECK-DAG: %[[I_REF:.*]] = fir.alloca i32 {bindc_name = "i", uniq_name = "_QFwhile_inside_do_loopEi"}
+ ! CHECK-DAG: %[[J_REF:.*]] = fir.alloca i32 {bindc_name = "j", uniq_name = "_QFwhile_inside_do_loopEj"}
+ integer :: i, j
+
+ ! CHECK-DAG: %[[C1:.*]] = arith.constant 1 : i32
+ ! CHECK-DAG: %[[C8:.*]] = arith.constant 8 : i32
+ ! CHECK-DAG: %[[C13:.*]] = arith.constant 13 : i32
+ ! CHECK: %[[DIFF:.*]] = arith.subi %[[C13]], %[[C8]] : i32
+ ! CHECK: %[[RANGE:.*]] = arith.addi %[[DIFF]], %[[C1]] : i32
+ ! CHECK: %[[HIGH:.*]] = arith.divsi %[[RANGE]], %[[C1]] : i32
+ ! CHECK: fir.store %[[HIGH]] to %[[T_REF]] : !fir.ref<i32>
+ ! CHECK: fir.store %[[C8]] to %[[I_REF]] : !fir.ref<i32>
+
+ ! CHECK: br ^[[HDR1:.*]]
+ ! CHECK: ^[[HDR1]]: // 2 preds: ^{{.*}}, ^[[EXIT2:.*]]
+ ! CHECK-DAG: %[[T:.*]] = fir.load %[[T_REF]] : !fir.ref<i32>
+ ! CHECK-DAG: %[[C0:.*]] = arith.constant 0 : i32
+ ! CHECK: %[[COND:.*]] = arith.cmpi sgt, %[[T]], %[[C0]] : i32
+ ! CHECK: cond_br %[[COND]], ^[[BODY1:.*]], ^[[EXIT1:.*]]
+ do i=8,13
+ ! CHECK: ^[[BODY1]]: // pred: ^[[HDR1]]
+ ! CHECK: %[[C3:.*]] = arith.constant 3 : i32
+ ! CHECK: fir.store %[[C3]] to %[[J_REF]] : !fir.ref<i32>
+ j=3
+
+ ! CHECK: br ^[[HDR2:.*]]
+ ! CHECK: ^[[HDR2]]: // 2 preds: ^[[BODY1]], ^[[BODY2:.*]]
+ ! CHECK-DAG: %[[J:.*]] = fir.load %[[J_REF]] : !fir.ref<i32>
+ ! CHECK-DAG: %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
+ ! CHECK: %[[COND2:.*]] = arith.cmpi slt, %[[J]], %[[I]] : i32
+ ! CHECK: cond_br %[[COND2]], ^[[BODY2]], ^[[EXIT2]]
+ do while (j .lt. i)
+ ! CHECK: ^[[BODY2]]: // pred: ^[[HDR2]]
+ ! CHECK-DAG: %[[J2:.*]] = fir.load %[[J_REF]] : !fir.ref<i32>
+ ! CHECK-DAG: %[[C2:.*]] = arith.constant 2 : i32
+ ! CHECK: %[[INC2:.*]] = arith.muli %[[C2]], %[[J2]] : i32
+ ! CHECK: fir.store %[[INC2]] to %[[J_REF]] : !fir.ref<i32>
+ j=j*2
+ ! CHECK: br ^[[HDR2]]
+ end do
+
+ ! CHECK: ^[[EXIT2]]: // pred: ^[[HDR2]]
+ ! CHECK-DAG: %[[T2:.*]] = fir.load %[[T_REF]] : !fir.ref<i32>
+ ! CHECK-DAG: %[[C1_AGAIN:.*]] = arith.constant 1 : i32
+ ! CHECK: %[[TDEC:.*]] = arith.subi %[[T2]], %[[C1_AGAIN]] : i32
+ ! CHECK: fir.store %[[TDEC]] to %[[T_REF]]
+ ! CHECK: %[[I3:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
+ ! CHECK: %[[IINC:.*]] = arith.addi %[[I3]], %[[C1]] : i32
+ ! CHECK: fir.store %[[IINC]] to %[[I_REF]] : !fir.ref<i32>
+ ! CHECK: br ^[[HDR1]]
+ end do
+
+ ! CHECK: ^[[EXIT1]]: // pred: ^[[HDR1]]
+ ! CHECK: %[[IPRINT:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
+ ! CHECK: fir.call @_FortranAioOutputInteger32(%{{.*}}, %[[IPRINT]]) : (!fir.ref<i8>, i32) -> i1
+ ! CHECK: %[[JPRINT:.*]] = fir.load %[[J_REF]] : !fir.ref<i32>
+ ! CHECK: fir.call @_FortranAioOutputInteger32(%{{.*}}, %[[JPRINT]]) : (!fir.ref<i8>, i32) -> i1
+ print *, i, j
+end subroutine
+
+! Test do loop inside while loop.
+! CHECK-LABEL: do_inside_while_loop
+subroutine do_inside_while_loop
+ ! CHECK-DAG: %[[I_REF:.*]] = fir.alloca i32 {bindc_name = "i", uniq_name = "_QFdo_inside_while_loopEi"}
+ ! CHECK-DAG: %[[J_REF:.*]] = fir.alloca i32 {bindc_name = "j", uniq_name = "_QFdo_inside_while_loopEj"}
+ integer :: i, j
+
+ ! CHECK: %[[C3:.*]] = arith.constant 3 : i32
+ ! CHECK: fir.store %[[C3]] to %[[J_REF]] : !fir.ref<i32>
+ j=3
+
+ ! CHECK: br ^[[HDR1:.*]]
+ ! CHECK: ^[[HDR1]]: // 2 preds: ^{{.*}}, ^[[BODY1:.*]]
+ ! CHECK-DAG: %[[J:.*]] = fir.load %[[J_REF]] : !fir.ref<i32>
+ ! CHECK-DAG: %[[UL:.*]] = arith.constant 21 : i32
+ ! CHECK: %[[COND:.*]] = arith.cmpi slt, %[[J]], %[[UL]] : i32
+ ! CHECK: cond_br %[[COND]], ^[[BODY1]], ^[[EXIT1:.*]]
+ do while (j .lt. 21)
+ ! CHECK: ^[[BODY1]]: // pred: ^[[HDR1]]
+
+ ! CHECK-DAG: %[[C8_I32:.*]] = arith.constant 8 : i32
+ ! CHECK-DAG: %[[C8:.*]] = fir.convert %[[C8_I32]] : (i32) -> index
+ ! CHECK-DAG: %[[C13_I32:.*]] = arith.constant 13 : i32
+ ! CHECK-DAG: %[[C13:.*]] = fir.convert %[[C13_I32]] : (i32) -> index
+ ! CHECK-DAG: %[[C1:.*]] = arith.constant 1 : index
+ ! CHECK: %[[RESULT:.*]] = fir.do_loop %[[IDX:.*]] = %[[C8]] to %[[C13]] step %[[C1]] -> index {
+ ! CHECK: %[[I32:.*]] = fir.convert %[[IDX]] : (index) -> i32
+ ! CHECK: fir.store %[[I32]] to %[[I_REF]] : !fir.ref<i32>
+ ! CHECK-DAG: %[[J2:.*]] = fir.load %[[J_REF]] : !fir.ref<i32>
+ ! CHECK-DAG: %[[C2:.*]] = arith.constant 2 : i32
+ ! CHECK: %[[JINC:.*]] = arith.muli %[[C2]], %[[J2]] : i32
+ ! CHECK: fir.store %[[JINC]] to %[[J_REF]] : !fir.ref<i32>
+ ! CHECK: %[[IINC:.*]] = arith.addi %[[IDX]], %[[C1]] : index
+ ! CHECK: fir.result %[[IINC]] : index
+ do i=8,13
+ j=j*2
+
+ ! CHECK: %[[IFINAL:.*]] = fir.convert %[[RESULT]] : (index) -> i32
+ ! CHECK: fir.store %[[IFINAL]] to %[[I_REF]] : !fir.ref<i32>
+ end do
+
+ ! CHECK: br ^[[HDR1]]
+ end do
+
+ ! CHECK: ^[[EXIT1]]: // pred: ^[[HDR1]]
+ ! CHECK: %[[IPRINT:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
+ ! CHECK: fir.call @_FortranAioOutputInteger32(%{{.*}}, %[[IPRINT]]) : (!fir.ref<i8>, i32) -> i1
+ ! CHECK: %[[JPRINT:.*]] = fir.load %[[J_REF]] : !fir.ref<i32>
+ ! CHECK: fir.call @_FortranAioOutputInteger32(%{{.*}}, %[[JPRINT]]) : (!fir.ref<i8>, i32) -> i1
+ print *, i, j
+end subroutine
diff --git a/flang/test/Lower/while_loop.f90 b/flang/test/Lower/while_loop.f90
new file mode 100644
index 000000000000..8320b366ff00
--- /dev/null
+++ b/flang/test/Lower/while_loop.f90
@@ -0,0 +1,91 @@
+! RUN: bbc -emit-fir -o - %s | FileCheck %s
+! RUN: %flang_fc1 -emit-fir -o - %s | FileCheck %s
+
+! Test a simple while loop.
+! CHECK-LABEL: simple_loop
+subroutine simple_loop
+ ! CHECK: %[[I_REF:.*]] = fir.alloca i32 {bindc_name = "i", uniq_name = "_QFsimple_loopEi"}
+ integer :: i
+
+ ! CHECK: %[[C5:.*]] = arith.constant 5 : i32
+ ! CHECK: fir.store %[[C5]] to %[[I_REF]]
+ i = 5
+
+ ! CHECK: br ^[[BB1:.*]]
+ ! CHECK: ^[[BB1]]: // 2 preds: ^{{.*}}, ^[[BB2:.*]]
+ ! CHECK-DAG: %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
+ ! CHECK-DAG: %[[C1:.*]] = arith.constant 1 : i32
+ ! CHECK: %[[COND:.*]] = arith.cmpi sgt, %[[I]], %[[C1]] : i32
+ ! CHECK: cond_br %[[COND]], ^[[BB2]], ^[[BB3:.*]]
+ ! CHECK: ^[[BB2]]: // pred: ^[[BB1]]
+ ! CHECK-DAG: %[[I2:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
+ ! CHECK-DAG: %[[C2:.*]] = arith.constant 2 : i32
+ ! CHECK: %[[INC:.*]] = arith.subi %[[I2]], %[[C2]] : i32
+ ! CHECK: fir.store %[[INC]] to %[[I_REF]] : !fir.ref<i32>
+ ! CHECK: br ^[[BB1]]
+ do while (i .gt. 1)
+ i = i - 2
+ end do
+
+ ! CHECK: ^[[BB3]]: // pred: ^[[BB1]]
+ ! CHECK: %[[I3:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
+ ! CHECK: fir.call @_FortranAioOutputInteger32(%{{.*}}, %[[I3]]) : (!fir.ref<i8>, i32) -> i1
+ print *, i
+end subroutine
+
+! Test 2 nested while loops.
+! CHECK-LABEL: while_inside_while_loop
+subroutine while_inside_while_loop
+ ! CHECK-DAG: %[[I_REF:.*]] = fir.alloca i32 {bindc_name = "i", uniq_name = "_QFwhile_inside_while_loopEi"}
+ ! CHECK-DAG: %[[J_REF:.*]] = fir.alloca i32 {bindc_name = "j", uniq_name = "_QFwhile_inside_while_loopEj"}
+ integer :: i, j
+
+ ! CHECK: %[[C13:.*]] = arith.constant 13 : i32
+ ! CHECK: fir.store %[[C13]] to %[[I_REF]]
+ i = 13
+
+ ! CHECK: br ^[[HDR1:.*]]
+ ! CHECK: ^[[HDR1]]: // 2 preds: ^{{.*}}, ^[[EXIT2:.*]]
+ ! CHECK-DAG: %[[I:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
+ ! CHECK-DAG: %[[C8:.*]] = arith.constant 8 : i32
+ ! CHECK: %[[COND:.*]] = arith.cmpi sgt, %[[I]], %[[C8]] : i32
+ ! CHECK: cond_br %[[COND]], ^[[BODY1:.*]], ^[[EXIT1:.*]]
+ do while (i .gt. 8)
+ ! CHECK: ^[[BODY1]]: // pred: ^[[HDR1]]
+ ! CHECK-DAG: %[[I2:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
+ ! CHECK-DAG: %[[C5:.*]] = arith.constant 5 : i32
+ ! CHECK: %[[INC:.*]] = arith.subi %[[I2]], %[[C5]] : i32
+ ! CHECK: fir.store %[[INC]] to %[[I_REF]] : !fir.ref<i32>
+ i = i - 5
+
+ ! CHECK: %[[C3:.*]] = arith.constant 3 : i32
+ ! CHECK: fir.store %[[C3]] to %[[J_REF]]
+ j = 3
+
+ ! CHECK: br ^[[HDR2:.*]]
+ ! CHECK: ^[[HDR2]]: // 2 preds: ^[[BODY1]], ^[[BODY2:.*]]
+ ! CHECK-DAG: %[[J:.*]] = fir.load %[[J_REF]] : !fir.ref<i32>
+ ! CHECK-DAG: %[[I3:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
+ ! CHECK: %[[COND2:.*]] = arith.cmpi slt, %[[J]], %[[I3]] : i32
+ ! CHECK: cond_br %[[COND2]], ^[[BODY2]], ^[[EXIT2]]
+ do while (j .lt. i)
+ ! CHECK: ^[[BODY2]]: // pred: ^[[HDR2]]
+ ! CHECK-DAG: %[[J2:.*]] = fir.load %[[J_REF]] : !fir.ref<i32>
+ ! CHECK-DAG: %[[C2:.*]] = arith.constant 2 : i32
+ ! CHECK: %[[INC2:.*]] = arith.muli %[[C2]], %[[J2]] : i32
+ ! CHECK: fir.store %[[INC2]] to %[[J_REF]] : !fir.ref<i32>
+ j = j * 2
+ ! CHECK: br ^[[HDR2]]
+ end do
+
+ ! CHECK: ^[[EXIT2]]: // pred: ^[[HDR2]]
+ ! CHECK: br ^[[HDR1]]
+ end do
+
+ ! CHECK: ^[[EXIT1]]: // pred: ^[[HDR1]]
+ ! CHECK: %[[IPRINT:.*]] = fir.load %[[I_REF]] : !fir.ref<i32>
+ ! CHECK: fir.call @_FortranAioOutputInteger32(%{{.*}}, %[[IPRINT]]) : (!fir.ref<i8>, i32) -> i1
+ ! CHECK: %[[JPRINT:.*]] = fir.load %[[J_REF]] : !fir.ref<i32>
+ ! CHECK: fir.call @_FortranAioOutputInteger32(%{{.*}}, %[[JPRINT]]) : (!fir.ref<i8>, i32) -> i1
+ print *, i, j
+end subroutine
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