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[Unroll] Refactor the accumulation of optimized instruction costs into 

a single location.

This reduces code duplication a bit and will also pave the way for
a better separation between the visitation algorithm and the unroll
analysis.

No functionality changed.

llvm-svn: 237990
This commit is contained in:
Chandler Carruth 2015-05-22 02:47:29 +00:00
parent 1fca2edc48
commit f174a156c3
1 changed files with 10 additions and 9 deletions
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19
llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
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@ -402,14 +402,10 @@ class UnrollAnalyzer : public InstVisitor<UnrollAnalyzer, bool> {
else else
SimpleV = SimplifyBinOp(I.getOpcode(), LHS, RHS, DL); SimpleV = SimplifyBinOp(I.getOpcode(), LHS, RHS, DL);
if (SimpleV) if (Constant *C = dyn_cast_or_null<Constant>(SimpleV))
NumberOfOptimizedInstructions += TTI.getUserCost(&I);
if (Constant *C = dyn_cast_or_null<Constant>(SimpleV)) {
SimplifiedValues[&I] = C; SimplifiedValues[&I] = C;
return true;
} return SimpleV;
return false;
} }
/// Try to fold load I. /// Try to fold load I.
@ -452,7 +448,6 @@ class UnrollAnalyzer : public InstVisitor<UnrollAnalyzer, bool> {
assert(CV && "Constant expected."); assert(CV && "Constant expected.");
SimplifiedValues[&I] = CV; SimplifiedValues[&I] = CV;
NumberOfOptimizedInstructions += TTI.getUserCost(&I);
return true; return true;
} }
@ -571,7 +566,13 @@ public:
// opportunities. // opportunities.
for (Instruction &I : *BB) { for (Instruction &I : *BB) {
UnrolledLoopSize += TTI.getUserCost(&I); UnrolledLoopSize += TTI.getUserCost(&I);
Base::visit(I);
// Visit the instruction to analyze its loop cost after unrolling,
// and if the visitor returns true, then we can optimize this
// instruction away.
if (Base::visit(I))
NumberOfOptimizedInstructions += TTI.getUserCost(&I);
// If unrolled body turns out to be too big, bail out. // If unrolled body turns out to be too big, bail out.
if (UnrolledLoopSize - NumberOfOptimizedInstructions > if (UnrolledLoopSize - NumberOfOptimizedInstructions >
MaxUnrolledLoopSize) MaxUnrolledLoopSize)