[llvm] 593cb46 - Revert "[LoopInterchange] Fix transformation bugs in loop interchange"

via llvm-commits llvm-commits at lists.llvm.org
Wed Apr 7 18:18:18 PDT 2021


Author: Congzhe Cao
Date: 2021-04-07T21:17:30-04:00
New Revision: 593cb4655097552ac6d81ce18a2851ae0feb8d3c

URL: https://github.com/llvm/llvm-project/commit/593cb4655097552ac6d81ce18a2851ae0feb8d3c
DIFF: https://github.com/llvm/llvm-project/commit/593cb4655097552ac6d81ce18a2851ae0feb8d3c.diff

LOG: Revert "[LoopInterchange] Fix transformation bugs in loop interchange"

This reverts commit 6ec68bd815d00c1eec2a6b9766452554f0e6cb61.

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/LoopInterchange.cpp
    llvm/test/Transforms/LoopInterchange/lcssa-preheader.ll

Removed: 
    llvm/test/Transforms/LoopInterchange/outer-header-jump-to-inner-latch.ll


################################################################################
diff  --git a/llvm/lib/Transforms/Scalar/LoopInterchange.cpp b/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
index 36acf4624697b..5da619fc08f26 100644
--- a/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
@@ -1551,12 +1551,9 @@ bool LoopInterchangeTransform::adjustLoopBranches() {
                   InnerLoopPreHeader, DTUpdates, /*MustUpdateOnce=*/false);
   // The outer loop header might or might not branch to the outer latch.
   // We are guaranteed to branch to the inner loop preheader.
-  if (llvm::is_contained(OuterLoopHeaderBI->successors(), OuterLoopLatch)) {
-    // In this case the outerLoopHeader should branch to the InnerLoopLatch.
-    updateSuccessor(OuterLoopHeaderBI, OuterLoopLatch, InnerLoopLatch,
-                    DTUpdates,
+  if (llvm::is_contained(OuterLoopHeaderBI->successors(), OuterLoopLatch))
+    updateSuccessor(OuterLoopHeaderBI, OuterLoopLatch, LoopExit, DTUpdates,
                     /*MustUpdateOnce=*/false);
-  }
   updateSuccessor(OuterLoopHeaderBI, InnerLoopPreHeader,
                   InnerLoopHeaderSuccessor, DTUpdates,
                   /*MustUpdateOnce=*/false);

diff  --git a/llvm/test/Transforms/LoopInterchange/lcssa-preheader.ll b/llvm/test/Transforms/LoopInterchange/lcssa-preheader.ll
index 73fa3c36790b0..3205a5465817a 100644
--- a/llvm/test/Transforms/LoopInterchange/lcssa-preheader.ll
+++ b/llvm/test/Transforms/LoopInterchange/lcssa-preheader.ll
@@ -25,12 +25,12 @@ define void @lcssa_08(i32 %n, i32 %m) {
 ; CHECK-NEXT:    [[INDVARS_IV27:%.*]] = phi i64 [ 0, [[OUTER_PREHEADER:%.*]] ], [ [[INDVARS_IV_NEXT28:%.*]], [[OUTER_LATCH:%.*]] ]
 ; CHECK-NEXT:    [[CMP222:%.*]] = icmp sgt i32 [[M:%.*]], 0
 ; CHECK-NEXT:    [[WIDE_TRIP_COUNT:%.*]] = zext i32 [[M]] to i64
-; CHECK-NEXT:    br i1 [[CMP222]], label [[INNER_FOR_BODY_SPLIT1:%.*]], label [[INNER_FOR_BODY_SPLIT:%.*]]
+; CHECK-NEXT:    br i1 [[CMP222]], label [[INNER_FOR_BODY_SPLIT1:%.*]], label [[OUTER_CRIT_EDGE:%.*]]
 ; CHECK:       inner.preheader:
 ; CHECK-NEXT:    [[WIDE_TRIP_COUNT29:%.*]] = zext i32 [[N]] to i64
 ; CHECK-NEXT:    br label [[INNER_FOR_BODY:%.*]]
 ; CHECK:       inner.for.body:
-; CHECK-NEXT:    [[INDVARS_IV:%.*]] = phi i64 [ 0, [[INNER_PREHEADER]] ], [ [[TMP1:%.*]], [[INNER_FOR_BODY_SPLIT]] ]
+; CHECK-NEXT:    [[INDVARS_IV:%.*]] = phi i64 [ 0, [[INNER_PREHEADER]] ], [ [[TMP1:%.*]], [[INNER_FOR_BODY_SPLIT:%.*]] ]
 ; CHECK-NEXT:    br label [[OUTER_PREHEADER]]
 ; CHECK:       inner.for.body.split1:
 ; CHECK-NEXT:    [[ARRAYIDX6:%.*]] = getelementptr inbounds [16 x [16 x i32]], [16 x [16 x i32]]* [[TEMP]], i64 0, i64 [[INDVARS_IV]], i64 [[INDVARS_IV27]]
@@ -41,10 +41,10 @@ define void @lcssa_08(i32 %n, i32 %m) {
 ; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i64 [[INDVARS_IV_NEXT]], [[WIDE_TRIP_COUNT]]
 ; CHECK-NEXT:    br label [[INNER_CRIT_EDGE:%.*]]
 ; CHECK:       inner.for.body.split:
-; CHECK-NEXT:    [[WIDE_TRIP_COUNT_LCSSA:%.*]] = phi i64 [ [[WIDE_TRIP_COUNT]], [[OUTER_LATCH]] ], [ [[WIDE_TRIP_COUNT]], [[OUTER_HEADER]] ]
+; CHECK-NEXT:    [[WIDE_TRIP_COUNT_LCSSA2:%.*]] = phi i64 [ [[WIDE_TRIP_COUNT]], [[OUTER_LATCH]] ]
 ; CHECK-NEXT:    [[TMP1]] = add nuw nsw i64 [[INDVARS_IV]], 1
-; CHECK-NEXT:    [[TMP2:%.*]] = icmp ne i64 [[TMP1]], [[WIDE_TRIP_COUNT_LCSSA]]
-; CHECK-NEXT:    br i1 [[TMP2]], label [[INNER_FOR_BODY]], label [[OUTER_CRIT_EDGE:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp ne i64 [[TMP1]], [[WIDE_TRIP_COUNT_LCSSA2]]
+; CHECK-NEXT:    br i1 [[TMP2]], label [[INNER_FOR_BODY]], label [[OUTER_CRIT_EDGE]]
 ; CHECK:       inner.crit_edge:
 ; CHECK-NEXT:    br label [[OUTER_LATCH]]
 ; CHECK:       outer.latch:

diff  --git a/llvm/test/Transforms/LoopInterchange/outer-header-jump-to-inner-latch.ll b/llvm/test/Transforms/LoopInterchange/outer-header-jump-to-inner-latch.ll
deleted file mode 100644
index 3a7c82b83bfc6..0000000000000
--- a/llvm/test/Transforms/LoopInterchange/outer-header-jump-to-inner-latch.ll
+++ /dev/null
@@ -1,202 +0,0 @@
-; RUN: opt -basic-aa -loop-interchange -verify-dom-info -verify-loop-info -verify-loop-lcssa -S %s | FileCheck %s
-
- at b = global [3 x [5 x [8 x i16]]] [[5 x [8 x i16]] zeroinitializer, [5 x [8 x i16]] [[8 x i16] zeroinitializer, [8 x i16] [i16 0, i16 0, i16 0, i16 6, i16 1, i16 6, i16 0, i16 0], [8 x i16] zeroinitializer, [8 x i16] zeroinitializer, [8 x i16] zeroinitializer], [5 x [8 x i16]] zeroinitializer], align 2
- at a = common global i32 0, align 4
- at d = common dso_local local_unnamed_addr global [1 x [6 x i32]] zeroinitializer, align 4
-
-
-;  Doubly nested loop
-;; C test case:
-;; int a;
-;; short b[3][5][8] = {{}, {{}, 0, 0, 0, 6, 1, 6}};
-;; void test1() {
-;;   int c = 0, d;
-;;   for (; c <= 2; c++) {
-;;     if (c)
-;;       continue;
-;;     d = 0;
-;;     for (; d <= 2; d++)
-;;       a |= b[d][d][c + 5];
-;;   }
-;; }
-
-define void @test1() {
-;CHECK-LABEL: @test1(
-;CHECK:          entry:
-;CHECK-NEXT:       br label [[FOR_COND1_PREHEADER:%.*]]
-;CHECK:          for.body.preheader:
-;CHECK-NEXT:       br label  [[FOR_BODY:%.*]]
-;CHECK:          for.body:
-;CHECK-NEXT:       [[INDVARS_IV22:%.*]] = phi i64 [ [[INDVARS_IV_NEXT23:%.*]], [[FOR_INC8:%.*]] ], [ 0, [[FOR_BODY_PREHEADER:%.*]] ]
-;CHECK-NEXT:       [[TOBOOL:%.*]] = icmp eq i64 [[INDVARS_IV22:%.*]], 0
-;CHECK-NEXT:       br i1 [[TOBOOL]], label [[FOR_BODY3_SPLIT1:%.*]], label [[FOR_BODY3_SPLIT:%.*]]
-;CHECK:          for.cond1.preheader:
-;CHECK-NEXT:       br label [[FOR_BODY3:%.*]]
-;CHECK:          for.body3:
-;CHECK-NEXT:       [[INDVARS_IV:%.*]] = phi i64 [ 0, [[FOR_COND1_PREHEADER]] ], [ %3, [[FOR_BODY3_SPLIT]] ]
-;CHECK-NEXT:        br label [[FOR_BODY_PREHEADER]]
-;CHECK:          for.body3.split1:
-;CHECK-NEXT:       [[TMP0:%.*]] = add nuw nsw i64 [[INDVARS_IV22]], 5
-;CHECK-NEXT:       [[ARRAYIDX7:%.*]] = getelementptr inbounds [3 x [5 x [8 x i16]]], [3 x [5 x [8 x i16]]]* @b, i64 0, i64 [[INDVARS_IV]], i64 [[INDVARS_IV]], i64 [[TMP0]]
-;CHECK-NEXT:       [[TMP1:%.*]] = load i16, i16* [[ARRAYIDX7]]
-;CHECK-NEXT:       [[CONV:%.*]] = sext i16 [[TMP1]] to i32
-;CHECK-NEXT:       [[TMP2:%.*]] = load i32, i32* @a
-;CHECK-NEXT:       [[TMP_OR:%.*]] = or i32 [[TMP2]], [[CONV]]
-;CHECK-NEXT:       store i32 [[TMP_OR]], i32* @a
-;CHECK-NEXT:       [[INDVARS_IV_NEXT:%.*]] = add nuw nsw i64 [[INDVARS_IV]], 1
-;CHECK-NEXT:       [[EXITCOND:%.*]] = icmp ne i64 [[INDVARS_IV_NEXT]], 3
-;CHECK-NEXT:       br label [[FOR_INC8_LOOPEXIT:%.*]]
-;CHECK:          for.body3.split:
-;CHECK-NEXT:       [[TMP3:%.*]] = add nuw nsw i64 [[INDVARS_IV]], 1
-;CHECK-NEXT:       [[TMP4:%.*]] = icmp ne i64 [[TMP3]], 3
-;CHECK-NEXT:       br i1 %4, label [[FOR_BODY3]], label [[FOR_END10:%.*]]
-;CHECK:          for.inc8.loopexit:
-;CHECK-NEXT:       br label [[FOR_INC8]]
-;CHECK:          for.inc8:
-;CHECK-NEXT:       [[INDVARS_IV_NEXT23]] = add nuw nsw i64 [[INDVARS_IV22]], 1
-;CHECK-NEXT:       [[EXITCOND25:%.*]] = icmp ne i64 [[INDVARS_IV_NEXT23]], 3
-;CHECK-NEXT:       br i1 [[EXITCOND25]], label [[FOR_BODY]], label [[FOR_BODY3_SPLIT]]
-;CHECK:         for.end10:
-;CHECK-NEXT:       [[TMP5:%.*]] = load i32, i32* @a
-;CHECK-NEXT:       ret void
-
-entry:
-  br label %for.body
-
-for.body:                                         ; preds = %entry, %for.inc8
-  %indvars.iv22 = phi i64 [ 0, %entry ], [ %indvars.iv.next23, %for.inc8 ]
-  %tobool = icmp eq i64 %indvars.iv22, 0
-  br i1 %tobool, label %for.cond1.preheader, label %for.inc8
-
-for.cond1.preheader:                              ; preds = %for.body
-  br label %for.body3
-
-for.body3:                                        ; preds = %for.cond1.preheader, %for.body3
-  %indvars.iv = phi i64 [ 0, %for.cond1.preheader ], [ %indvars.iv.next, %for.body3 ]
-  %0 = add nuw nsw i64 %indvars.iv22, 5
-  %arrayidx7 = getelementptr inbounds [3 x [5 x [8 x i16]]], [3 x [5 x [8 x i16]]]* @b, i64 0, i64 %indvars.iv, i64 %indvars.iv, i64 %0
-  %1 = load i16, i16* %arrayidx7
-  %conv = sext i16 %1 to i32
-  %2 = load i32, i32* @a
-  %or = or i32 %2, %conv
-  store i32 %or, i32* @a
-  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
-  %exitcond = icmp ne i64 %indvars.iv.next, 3
-  br i1 %exitcond, label %for.body3, label %for.inc8.loopexit
-
-for.inc8.loopexit:                                ; preds = %for.body3
-  br label %for.inc8
-
-for.inc8:                                         ; preds = %for.inc8.loopexit, %for.body
-  %indvars.iv.next23 = add nuw nsw i64 %indvars.iv22, 1
-  %exitcond25 = icmp ne i64 %indvars.iv.next23, 3
-  br i1 %exitcond25, label %for.body, label %for.end10
-
-for.end10:                                        ; preds = %for.inc8
-  %3 = load i32, i32* @a
-  ret void
-}
-
-; Triply nested loop
-; The innermost and the middle loop are interchanged.
-; C test case:
-;; a;
-;; d[][6];
-;; void test2() {
-;;   int g = 10;
-;;   for (; g; g = g - 5) {
-;;     short c = 4;
-;;     for (; c; c--) {
-;;       int i = 4;
-;;       for (; i; i--) {
-;;         if (a)
-;;           break;
-;;         d[i][c] = 0;
-;;       }
-;;     }
-;;   }
-;; }
-
-define void @test2() {
-; CHECK-LABEL: @test2(
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    br label [[OUTERMOST_HEADER:%.*]]
-; CHECK:       outermost.header:
-; CHECK-NEXT:    [[INDVAR_OUTERMOST:%.*]] = phi i32 [ 10, [[ENTRY:%.*]] ], [ [[INDVAR_OUTERMOST_NEXT:%.*]], [[OUTERMOST_LATCH:%.*]] ]
-; CHECK-NEXT:    [[TMP0:%.*]] = load i32, i32* @a, align 4
-; CHECK-NEXT:    [[TOBOOL71_I:%.*]] = icmp eq i32 [[TMP0]], 0
-; CHECK-NEXT:    br label [[INNERMOST_PREHEADER:%.*]]
-; CHECK:       middle.header.preheader:
-; CHECK-NEXT:    br label [[MIDDLE_HEADER:%.*]]
-; CHECK:       middle.header:
-; CHECK-NEXT:    [[INDVAR_MIDDLE:%.*]] = phi i64 [ [[INDVAR_MIDDLE_NEXT:%.*]], [[MIDDLE_LATCH:%.*]] ], [ 4, [[MIDDLE_HEADER_PREHEADER:%.*]] ]
-; CHECK-NEXT:    br i1 [[TOBOOL71_I]], label [[INNERMOST_BODY_SPLIT1:%.*]], label [[INNERMOST_BODY_SPLIT:%.*]]
-; CHECK:       innermost.preheader:
-; CHECK-NEXT:    br label [[INNERMOST_BODY:%.*]]
-; CHECK:       innermost.body:
-; CHECK-NEXT:    [[INDVAR_INNERMOST:%.*]] = phi i64 [ [[TMP1:%.*]], [[INNERMOST_BODY_SPLIT]] ], [ 4, [[INNERMOST_PREHEADER]] ]
-; CHECK-NEXT:    br label [[MIDDLE_HEADER_PREHEADER]]
-; CHECK:       innermost.body.split1:
-; CHECK-NEXT:    [[ARRAYIDX9_I:%.*]] = getelementptr inbounds [1 x [6 x i32]], [1 x [6 x i32]]* @d, i64 0, i64 [[INDVAR_INNERMOST]], i64 [[INDVAR_MIDDLE]]
-; CHECK-NEXT:    store i32 0, i32* [[ARRAYIDX9_I]], align 4
-; CHECK-NEXT:    [[INDVAR_INNERMOST_NEXT:%.*]] = add nsw i64 [[INDVAR_INNERMOST]], -1
-; CHECK-NEXT:    [[TOBOOL5_I:%.*]] = icmp eq i64 [[INDVAR_INNERMOST_NEXT]], 0
-; CHECK-NEXT:    br label [[MIDDLE_LATCH_LOOPEXIT:%.*]]
-; CHECK:       innermost.body.split:
-; CHECK-NEXT:    [[TMP1]] = add nsw i64 [[INDVAR_INNERMOST]], -1
-; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i64 [[TMP1]], 0
-; CHECK-NEXT:    br i1 [[TMP2]], label [[OUTERMOST_LATCH]], label [[INNERMOST_BODY]]
-; CHECK:       innermost.loopexit:
-; CHECK-NEXT:    br label [[MIDDLE_LATCH]]
-; CHECK:       middle.latch:
-; CHECK-NEXT:    [[INDVAR_MIDDLE_NEXT]] = add nsw i64 [[INDVAR_MIDDLE]], -1
-; CHECK-NEXT:    [[TOBOOL2_I:%.*]] = icmp eq i64 [[INDVAR_MIDDLE_NEXT]], 0
-; CHECK-NEXT:    br i1 [[TOBOOL2_I]], label [[INNERMOST_BODY_SPLIT]], label [[MIDDLE_HEADER]]
-; CHECK:       outermost.latch:
-; CHECK-NEXT:    [[INDVAR_OUTERMOST_NEXT]] = add nsw i32 [[INDVAR_OUTERMOST]], -5
-; CHECK-NEXT:    [[TOBOOL_I:%.*]] = icmp eq i32 [[INDVAR_OUTERMOST_NEXT]], 0
-; CHECK-NEXT:    br i1 [[TOBOOL_I]], label [[OUTERMOST_EXIT:%.*]], label [[OUTERMOST_HEADER]]
-; CHECK:       outermost.exit:
-; CHECK-NEXT:    ret void
-;
-
-entry:
-  br label %outermost.header
-
-outermost.header:                      ; preds = %outermost.latch, %entry
-  %indvar.outermost = phi i32 [ 10, %entry ], [ %indvar.outermost.next, %outermost.latch ]
-  %0 = load i32, i32* @a, align 4
-  %tobool71.i = icmp eq i32 %0, 0
-  br label %middle.header
-
-middle.header:                            ; preds = %middle.latch, %outermost.header
-  %indvar.middle = phi i64 [ 4, %outermost.header ], [ %indvar.middle.next, %middle.latch ]
-  br i1 %tobool71.i, label %innermost.preheader, label %middle.latch
-
-innermost.preheader:                               ; preds = %middle.header
-  br label %innermost.body
-
-innermost.body:                                         ; preds = %innermost.preheader, %innermost.body
-  %indvar.innermost = phi i64 [ %indvar.innermost.next, %innermost.body ], [ 4, %innermost.preheader ]
-  %arrayidx9.i = getelementptr inbounds [1 x [6 x i32]], [1 x [6 x i32]]* @d, i64 0, i64 %indvar.innermost, i64 %indvar.middle
-  store i32 0, i32* %arrayidx9.i, align 4
-  %indvar.innermost.next = add nsw i64 %indvar.innermost, -1
-  %tobool5.i = icmp eq i64 %indvar.innermost.next, 0
-  br i1 %tobool5.i, label %innermost.loopexit, label %innermost.body
-
-innermost.loopexit:                             ; preds = %innermost.body
-  br label %middle.latch
-
-middle.latch:                                      ; preds = %middle.latch.loopexit, %middle.header
-  %indvar.middle.next = add nsw i64 %indvar.middle, -1
-  %tobool2.i = icmp eq i64 %indvar.middle.next, 0
-  br i1 %tobool2.i, label %outermost.latch, label %middle.header
-
-outermost.latch:                                      ; preds = %middle.latch
-  %indvar.outermost.next = add nsw i32 %indvar.outermost, -5
-  %tobool.i = icmp eq i32 %indvar.outermost.next, 0
-  br i1 %tobool.i, label %outermost.exit, label %outermost.header
-
-outermost.exit:                                           ; preds = %outermost.latch
-  ret void
-}


        


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