[llvm] r237990 - [Unroll] Refactor the accumulation of optimized instruction costs into
Chandler Carruth
chandlerc at gmail.com
Thu May 21 19:47:29 PDT 2015
Author: chandlerc
Date: Thu May 21 21:47:29 2015
New Revision: 237990
URL: http://llvm.org/viewvc/llvm-project?rev=237990&view=rev
Log:
[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.
Modified:
llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp
Modified: llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp?rev=237990&r1=237989&r2=237990&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp Thu May 21 21:47:29 2015
@@ -402,14 +402,10 @@ class UnrollAnalyzer : public InstVisito
else
SimpleV = SimplifyBinOp(I.getOpcode(), LHS, RHS, DL);
- if (SimpleV)
- NumberOfOptimizedInstructions += TTI.getUserCost(&I);
-
- if (Constant *C = dyn_cast_or_null<Constant>(SimpleV)) {
+ if (Constant *C = dyn_cast_or_null<Constant>(SimpleV))
SimplifiedValues[&I] = C;
- return true;
- }
- return false;
+
+ return SimpleV;
}
/// Try to fold load I.
@@ -452,7 +448,6 @@ class UnrollAnalyzer : public InstVisito
assert(CV && "Constant expected.");
SimplifiedValues[&I] = CV;
- NumberOfOptimizedInstructions += TTI.getUserCost(&I);
return true;
}
@@ -571,7 +566,13 @@ public:
// opportunities.
for (Instruction &I : *BB) {
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 (UnrolledLoopSize - NumberOfOptimizedInstructions >
MaxUnrolledLoopSize)
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