[llvm] r207569 - Reapply r207271 without the testcase
Adam Nemet
anemet at apple.com
Tue Apr 29 11:25:29 PDT 2014
Author: anemet
Date: Tue Apr 29 13:25:28 2014
New Revision: 207569
URL: http://llvm.org/viewvc/llvm-project?rev=207569&view=rev
Log:
Reapply r207271 without the testcase
PR19608 was filed to find a suitable testcase.
Modified:
llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp
Modified: llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp?rev=207569&r1=207568&r2=207569&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp Tue Apr 29 13:25:28 2014
@@ -256,7 +256,7 @@ struct Formula {
void InitialMatch(const SCEV *S, Loop *L, ScalarEvolution &SE);
- unsigned getNumRegs() const;
+ size_t getNumRegs() const;
Type *getType() const;
void DeleteBaseReg(const SCEV *&S);
@@ -351,7 +351,7 @@ void Formula::InitialMatch(const SCEV *S
/// getNumRegs - Return the total number of register operands used by this
/// formula. This does not include register uses implied by non-constant
/// addrec strides.
-unsigned Formula::getNumRegs() const {
+size_t Formula::getNumRegs() const {
return !!ScaledReg + BaseRegs.size();
}
@@ -4132,19 +4132,22 @@ void LSRInstance::SolveRecurse(SmallVect
E = LU.Formulae.end(); I != E; ++I) {
const Formula &F = *I;
- // Ignore formulae which do not use any of the required registers.
- bool SatisfiedReqReg = true;
+ // Ignore formulae which may not be ideal in terms of register reuse of
+ // ReqRegs. The formula should use all required registers before
+ // introducing new ones.
+ int NumReqRegsToFind = std::min(F.getNumRegs(), ReqRegs.size());
for (SmallSetVector<const SCEV *, 4>::const_iterator J = ReqRegs.begin(),
JE = ReqRegs.end(); J != JE; ++J) {
const SCEV *Reg = *J;
- if ((!F.ScaledReg || F.ScaledReg != Reg) &&
- std::find(F.BaseRegs.begin(), F.BaseRegs.end(), Reg) ==
+ if ((F.ScaledReg && F.ScaledReg == Reg) ||
+ std::find(F.BaseRegs.begin(), F.BaseRegs.end(), Reg) !=
F.BaseRegs.end()) {
- SatisfiedReqReg = false;
- break;
+ --NumReqRegsToFind;
+ if (NumReqRegsToFind == 0)
+ break;
}
}
- if (!SatisfiedReqReg) {
+ if (NumReqRegsToFind != 0) {
// If none of the formulae satisfied the required registers, then we could
// clear ReqRegs and try again. Currently, we simply give up in this case.
continue;
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