[llvm] f285be6 - [SCEV][NFC] Introduce API for getting basic block's symbolic max exit count
Max Kazantsev via llvm-commits
llvm-commits at lists.llvm.org
Tue Nov 22 01:09:17 PST 2022
Author: Max Kazantsev
Date: 2022-11-22T16:02:58+07:00
New Revision: f285be6214fdd5dc650438baea563e11ade4d5cd
URL: https://github.com/llvm/llvm-project/commit/f285be6214fdd5dc650438baea563e11ade4d5cd
DIFF: https://github.com/llvm/llvm-project/commit/f285be6214fdd5dc650438baea563e11ade4d5cd.diff
LOG: [SCEV][NFC] Introduce API for getting basic block's symbolic max exit count
Currently, it just returns exact exit count. This is a refectoring step
before it is actually implemented.
Added:
Modified:
llvm/include/llvm/Analysis/ScalarEvolution.h
llvm/lib/Analysis/ScalarEvolution.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/Analysis/ScalarEvolution.h b/llvm/include/llvm/Analysis/ScalarEvolution.h
index 49f8ae84f46f5..47fddb389e01f 100644
--- a/llvm/include/llvm/Analysis/ScalarEvolution.h
+++ b/llvm/include/llvm/Analysis/ScalarEvolution.h
@@ -1462,6 +1462,10 @@ class ScalarEvolution {
/// Get the symbolic max backedge taken count for the loop.
const SCEV *getSymbolicMax(const Loop *L, ScalarEvolution *SE);
+ /// Get the symbolic max backedge taken count for the particular loop exit.
+ const SCEV *getSymbolicMax(const BasicBlock *ExitingBlock,
+ ScalarEvolution *SE) const;
+
/// Return true if the number of times this backedge is taken is either the
/// value returned by getConstantMax or zero.
bool isConstantMaxOrZero(ScalarEvolution *SE) const;
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index dd4fd89319451..6bd4aa32cd8e9 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -8223,8 +8223,9 @@ const SCEV *ScalarEvolution::getExitCount(const Loop *L,
ExitCountKind Kind) {
switch (Kind) {
case Exact:
- case SymbolicMaximum:
return getBackedgeTakenInfo(L).getExact(ExitingBlock, this);
+ case SymbolicMaximum:
+ return getBackedgeTakenInfo(L).getSymbolicMax(ExitingBlock, this);
case ConstantMaximum:
return getBackedgeTakenInfo(L).getConstantMax(ExitingBlock, this);
};
@@ -8556,6 +8557,12 @@ const SCEV *ScalarEvolution::BackedgeTakenInfo::getConstantMax(
return SE->getCouldNotCompute();
}
+const SCEV *ScalarEvolution::BackedgeTakenInfo::getSymbolicMax(
+ const BasicBlock *ExitingBlock, ScalarEvolution *SE) const {
+ // FIXME: Need to implement this. Return exact for now.
+ return getExact(ExitingBlock, SE);
+}
+
/// getConstantMax - Get the constant max backedge taken count for the loop.
const SCEV *
ScalarEvolution::BackedgeTakenInfo::getConstantMax(ScalarEvolution *SE) const {
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