[llvm] d3f89d4 - Revert "[LoopInterchange] Fix legality for triangular loops"
via llvm-commits
llvm-commits at lists.llvm.org
Tue May 11 15:13:44 PDT 2021
Author: Congzhe Cao
Date: 2021-05-11T18:10:58-04:00
New Revision: d3f89d4d16883b2bcf5f032152f10e384b53d92a
URL: https://github.com/llvm/llvm-project/commit/d3f89d4d16883b2bcf5f032152f10e384b53d92a
DIFF: https://github.com/llvm/llvm-project/commit/d3f89d4d16883b2bcf5f032152f10e384b53d92a.diff
LOG: Revert "[LoopInterchange] Fix legality for triangular loops"
This reverts commit 29342291d25b83da97e74d75004b177ba41114fc.
The test case requires an assert build. Will add REQUIRES and re-commit.
Added:
Modified:
llvm/lib/Transforms/Scalar/LoopInterchange.cpp
Removed:
llvm/test/Transforms/LoopInterchange/inner-indvar-depend-on-outer-indvar.ll
################################################################################
diff --git a/llvm/lib/Transforms/Scalar/LoopInterchange.cpp b/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
index 58b456d5615fd..5aed49dccf820 100644
--- a/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopInterchange.cpp
@@ -656,65 +656,6 @@ bool LoopInterchangeLegality::isLoopStructureUnderstood(
return false;
}
}
-
- // TODO: Handle triangular loops of another form.
- // e.g. for(int i=0;i<N;i++)
- // for(int j=0;j<i;j++)
- // or,
- // for(int i=0;i<N;i++)
- // for(int j=0;j*i<N;j++)
- BasicBlock *InnerLoopLatch = InnerLoop->getLoopLatch();
- BranchInst *InnerLoopLatchBI =
- dyn_cast<BranchInst>(InnerLoopLatch->getTerminator());
- if (!InnerLoopLatchBI->isConditional())
- return false;
- if (CmpInst *InnerLoopCmp =
- dyn_cast<CmpInst>(InnerLoopLatchBI->getCondition())) {
- Value *Op0 = InnerLoopCmp->getOperand(0);
- Value *Op1 = InnerLoopCmp->getOperand(1);
-
- // LHS and RHS of the inner loop exit condition, e.g.,
- // in "for(int j=0;j<i;j++)", LHS is j and RHS is i.
- Value *Left = nullptr;
- Value *Right = nullptr;
-
- // Check if V only involves inner loop induction variable.
- // Return true if V is InnerInduction, or a cast from
- // InnerInduction, or a binary operator that involves
- // InnerInduction and a constant.
- std::function<bool(Value *)> IsPathToIndVar;
- IsPathToIndVar = [&InnerInduction, &IsPathToIndVar](Value *V) -> bool {
- if (V == InnerInduction)
- return true;
- if (isa<Constant>(V))
- return true;
- Instruction *I = dyn_cast<Instruction>(V);
- if (!I)
- return false;
- if (isa<CastInst>(I))
- return IsPathToIndVar(I->getOperand(0));
- if (isa<BinaryOperator>(I))
- return IsPathToIndVar(I->getOperand(0)) &&
- IsPathToIndVar(I->getOperand(1));
- return false;
- };
-
- if (IsPathToIndVar(Op0) && !isa<Constant>(Op0)) {
- Left = Op0;
- Right = Op1;
- } else if (IsPathToIndVar(Op1) && !isa<Constant>(Op1)) {
- Left = Op1;
- Right = Op0;
- }
-
- if (Left == nullptr)
- return false;
-
- const SCEV *S = SE->getSCEV(Right);
- if (!SE->isLoopInvariant(S, OuterLoop))
- return false;
- }
-
return true;
}
diff --git a/llvm/test/Transforms/LoopInterchange/inner-indvar-depend-on-outer-indvar.ll b/llvm/test/Transforms/LoopInterchange/inner-indvar-depend-on-outer-indvar.ll
deleted file mode 100644
index 9a571acc47ec9..0000000000000
--- a/llvm/test/Transforms/LoopInterchange/inner-indvar-depend-on-outer-indvar.ll
+++ /dev/null
@@ -1,152 +0,0 @@
-; RUN: opt < %s -basic-aa -loop-interchange -verify-dom-info -verify-loop-info \
-; RUN: -S -debug 2>&1 | FileCheck %s
-
- at A = common global [100 x [100 x i64]] zeroinitializer
- at N = dso_local local_unnamed_addr global i64 100, align 8
-
-
-;; for(int i=0;i<100;i++)
-;; for(int j=0;j<i;j++)
-;; A[j][i] = A[j][i]+k;
-
-;; Inner loop induction variable exit condition depends on the
-;; outer loop induction variable, i.e., triangular loops.
-; CHECK: Loop structure not understood by pass
-; CHECK: Not interchanging loops. Cannot prove legality.
-
-define void @interchange_01(i64 %k) {
-entry:
- br label %for1.header
-
-for1.header:
- %i = phi i64 [ 0, %entry ], [ %i.next, %for1.inc10 ]
- br label %for2
-
-for2:
- %j = phi i64 [ %j.next, %for2 ], [ 0, %for1.header ]
- %arrayidx5 = getelementptr inbounds [100 x [100 x i64]], [100 x [100 x i64]]* @A, i64 0, i64 %j, i64 %i
- %lv = load i64, i64* %arrayidx5
- %add = add nsw i64 %lv, %k
- store i64 %add, i64* %arrayidx5
- %j.next = add nuw nsw i64 %j, 1
- %exitcond = icmp eq i64 %j, %i
- br i1 %exitcond, label %for1.inc10, label %for2
-
-for1.inc10:
- %i.next = add nuw nsw i64 %i, 1
- %exitcond26 = icmp eq i64 %i, 99
- br i1 %exitcond26, label %for.end12, label %for1.header
-
-for.end12:
- ret void
-}
-
-
-;; for(int i=0;i<100;i++)
-;; for(int j=0;j+i<100;j++)
-;; A[j][i] = A[j][i]+k;
-
-;; Inner loop induction variable exit condition depends on the
-;; outer loop induction variable, i.e., triangular loops.
-; CHECK: Loop structure not understood by pass
-; CHECK: Not interchanging loops. Cannot prove legality.
-
-define void @interchange_02(i64 %k) {
-entry:
- br label %for1.header
-
-for1.header:
- %i = phi i64 [ 0, %entry ], [ %i.next, %for1.inc10 ]
- br label %for2
-
-for2:
- %j = phi i64 [ %j.next, %for2 ], [ 0, %for1.header ]
- %arrayidx5 = getelementptr inbounds [100 x [100 x i64]], [100 x [100 x i64]]* @A, i64 0, i64 %j, i64 %i
- %lv = load i64, i64* %arrayidx5
- %add = add nsw i64 %lv, %k
- store i64 %add, i64* %arrayidx5
- %0 = add nuw nsw i64 %j, %i
- %j.next = add nuw nsw i64 %j, 1
- %exitcond = icmp eq i64 %0, 100
- br i1 %exitcond, label %for1.inc10, label %for2
-
-for1.inc10:
- %i.next = add nuw nsw i64 %i, 1
- %exitcond26 = icmp eq i64 %i, 99
- br i1 %exitcond26, label %for.end12, label %for1.header
-
-for.end12:
- ret void
-}
-
-;; for(int i=0;i<100;i++)
-;; for(int j=0;i>j;j++)
-;; A[j][i] = A[j][i]+k;
-
-;; Inner loop induction variable exit condition depends on the
-;; outer loop induction variable, i.e., triangular loops.
-; CHECK: Loop structure not understood by pass
-; CHECK: Not interchanging loops. Cannot prove legality.
-
-define void @interchange_03(i64 %k) {
-entry:
- br label %for1.header
-
-for1.header:
- %i = phi i64 [ 0, %entry ], [ %i.next, %for1.inc10 ]
- br label %for2
-
-for2:
- %j = phi i64 [ %j.next, %for2 ], [ 0, %for1.header ]
- %arrayidx5 = getelementptr inbounds [100 x [100 x i64]], [100 x [100 x i64]]* @A, i64 0, i64 %j, i64 %i
- %lv = load i64, i64* %arrayidx5
- %add = add nsw i64 %lv, %k
- store i64 %add, i64* %arrayidx5
- %j.next = add nuw nsw i64 %j, 1
- %exitcond = icmp ne i64 %i, %j
- br i1 %exitcond, label %for2, label %for1.inc10
-
-for1.inc10:
- %i.next = add nuw nsw i64 %i, 1
- %exitcond26 = icmp eq i64 %i, 99
- br i1 %exitcond26, label %for.end12, label %for1.header
-
-for.end12:
- ret void
-}
-
-;; for(int i=0;i<100;i++)
-;; for(int j=0;N>j;j++)
-;; A[j][i] = A[j][i]+k;
-
-;; Inner loop induction variable exit condition depends on
-;; an outer loop invariant, can do interchange.
-; CHECK: Loops interchanged
-
-define void @interchange_04(i64 %k) {
-entry:
- %0 = load i64, i64* @N, align 4
- br label %for1.header
-
-for1.header:
- %i = phi i64 [ 0, %entry ], [ %i.next, %for1.inc10 ]
- br label %for2
-
-for2:
- %j = phi i64 [ %j.next, %for2 ], [ 0, %for1.header ]
- %arrayidx5 = getelementptr inbounds [100 x [100 x i64]], [100 x [100 x i64]]* @A, i64 0, i64 %j, i64 %i
- %lv = load i64, i64* %arrayidx5
- %add = add nsw i64 %lv, %k
- store i64 %add, i64* %arrayidx5
- %j.next = add nuw nsw i64 %j, 1
- %exitcond = icmp ne i64 %0, %j
- br i1 %exitcond, label %for2, label %for1.inc10
-
-for1.inc10:
- %i.next = add nuw nsw i64 %i, 1
- %exitcond26 = icmp eq i64 %i, 99
- br i1 %exitcond26, label %for.end12, label %for1.header
-
-for.end12:
- ret void
-}
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