[llvm] r330582 - [LoopRotate] Fix incorrect SCEV invalidation in loop rotation
Max Kazantsev via llvm-commits
llvm-commits at lists.llvm.org
Mon Apr 23 05:33:31 PDT 2018
Author: mkazantsev
Date: Mon Apr 23 05:33:31 2018
New Revision: 330582
URL: http://llvm.org/viewvc/llvm-project?rev=330582&view=rev
Log:
[LoopRotate] Fix incorrect SCEV invalidation in loop rotation
LoopRotate only invalidates innermost loops while the changes that it makes may
also affert any of this parents. With patch rL329047, SCEV becomes much smarter
about calculation of exit counts for outer loops, so we cannot assume that they are
not affected.
Differential Revision: https://reviews.llvm.org/D45945
Added:
llvm/trunk/test/Transforms/LoopRotate/pr37205.ll
Modified:
llvm/trunk/lib/Transforms/Utils/LoopRotationUtils.cpp
Modified: llvm/trunk/lib/Transforms/Utils/LoopRotationUtils.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/LoopRotationUtils.cpp?rev=330582&r1=330581&r2=330582&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/LoopRotationUtils.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/LoopRotationUtils.cpp Mon Apr 23 05:33:31 2018
@@ -259,9 +259,10 @@ bool LoopRotate::rotateLoop(Loop *L, boo
return false;
// Anything ScalarEvolution may know about this loop or the PHI nodes
- // in its header will soon be invalidated.
+ // in its header will soon be invalidated, and it can also affect its parent
+ // loops as well.
if (SE)
- SE->forgetLoop(L);
+ SE->forgetTopmostLoop(L);
DEBUG(dbgs() << "LoopRotation: rotating "; L->dump());
@@ -476,6 +477,12 @@ bool LoopRotate::rotateLoop(Loop *L, boo
DEBUG(dbgs() << "LoopRotation: into "; L->dump());
+#ifndef NDEBUG
+ // Make sure that after all our transforms SE is correct.
+ if (SE)
+ SE->verify();
+#endif
+
++NumRotated;
return true;
}
Added: llvm/trunk/test/Transforms/LoopRotate/pr37205.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopRotate/pr37205.ll?rev=330582&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LoopRotate/pr37205.ll (added)
+++ llvm/trunk/test/Transforms/LoopRotate/pr37205.ll Mon Apr 23 05:33:31 2018
@@ -0,0 +1,116 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -indvars -verify -loop-rotate -loop-idiom < %s | FileCheck %s
+target triple = "x86_64-unknown-linux-gnu"
+
+; Verify that we invalidate SCEV properly.
+
+define void @test_01() {
+; CHECK-LABEL: @test_01(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br label [[LBL1:%.*]]
+; CHECK: lbl1:
+; CHECK-NEXT: br label [[FOR_COND:%.*]]
+; CHECK: for.cond:
+; CHECK-NEXT: br i1 false, label [[FOR_BODY3_LR_PH:%.*]], label [[FOR_COND_FOR_END5_CRIT_EDGE:%.*]]
+; CHECK: for.body3.lr.ph:
+; CHECK-NEXT: br label [[FOR_BODY3:%.*]]
+; CHECK: for.cond1:
+; CHECK-NEXT: br i1 false, label [[FOR_BODY3]], label [[FOR_COND1_FOR_END5_CRIT_EDGE:%.*]]
+; CHECK: for.body3:
+; CHECK-NEXT: br i1 false, label [[IF_THEN:%.*]], label [[FOR_COND1:%.*]]
+; CHECK: if.then:
+; CHECK-NEXT: br label [[LBL1]]
+; CHECK: for.cond.for.end5_crit_edge:
+; CHECK-NEXT: br label [[FOR_END5:%.*]]
+; CHECK: for.cond1.for.end5_crit_edge:
+; CHECK-NEXT: br label [[FOR_END5]]
+; CHECK: for.end5:
+; CHECK-NEXT: ret void
+;
+entry:
+ br label %lbl1
+
+lbl1: ; preds = %if.then, %entry
+ br label %for.cond
+
+for.cond: ; preds = %lbl1
+ br label %for.cond1
+
+for.cond1: ; preds = %if.end, %for.cond
+ br i1 false, label %for.body3, label %for.end5
+
+for.body3: ; preds = %for.cond1
+ br i1 false, label %if.then, label %if.end
+
+if.then: ; preds = %for.body3
+ br label %lbl1
+
+if.end: ; preds = %for.body3
+ br label %for.cond1
+
+for.end5: ; preds = %for.cond1
+ ret void
+}
+
+define void @test_02() {
+; CHECK-LABEL: @test_02(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br label [[LBL1:%.*]]
+; CHECK: lbl1:
+; CHECK-NEXT: br label [[FOR_COND:%.*]]
+; CHECK: for.cond:
+; CHECK-NEXT: br i1 false, label [[IF_THEN:%.*]], label [[IF_END7:%.*]]
+; CHECK: if.then:
+; CHECK-NEXT: br i1 false, label [[FOR_BODY_LR_PH:%.*]], label [[IF_THEN_FOR_END6_CRIT_EDGE:%.*]]
+; CHECK: for.body.lr.ph:
+; CHECK-NEXT: br label [[FOR_BODY:%.*]]
+; CHECK: for.body:
+; CHECK-NEXT: br i1 false, label [[IF_THEN3:%.*]], label [[IF_END:%.*]]
+; CHECK: if.then3:
+; CHECK-NEXT: br label [[LBL1]]
+; CHECK: if.end:
+; CHECK-NEXT: br label [[FOR_COND4:%.*]]
+; CHECK: for.cond4:
+; CHECK-NEXT: br i1 false, label [[FOR_BODY]], label [[FOR_COND1_FOR_END6_CRIT_EDGE:%.*]]
+; CHECK: if.then.for.end6_crit_edge:
+; CHECK-NEXT: br label [[FOR_END6:%.*]]
+; CHECK: for.cond1.for.end6_crit_edge:
+; CHECK-NEXT: br label [[FOR_END6]]
+; CHECK: for.end6:
+; CHECK-NEXT: ret void
+; CHECK: if.end7:
+; CHECK-NEXT: unreachable
+;
+entry:
+ br label %lbl1
+
+lbl1: ; preds = %if.then3, %entry
+ br label %for.cond
+
+for.cond: ; preds = %lbl1
+ br i1 false, label %if.then, label %if.end7
+
+if.then: ; preds = %for.cond
+ br label %for.cond1
+
+for.cond1: ; preds = %for.cond4, %if.then
+ br i1 undef, label %for.body, label %for.end6
+
+for.body: ; preds = %for.cond1
+ br i1 false, label %if.then3, label %if.end
+
+if.then3: ; preds = %for.body
+ br label %lbl1
+
+if.end: ; preds = %for.body
+ br label %for.cond4
+
+for.cond4: ; preds = %if.end
+ br label %for.cond1
+
+for.end6: ; preds = %for.cond1
+ ret void
+
+if.end7: ; preds = %for.cond
+ unreachable
+}
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