From 081ffcd00bc00fbbf6fbbf22df5e21634b44c48c Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Fri, 13 Aug 2010 21:17:19 +0000 Subject: Fix LSR's ExtractImmediate and ExtractSymbol to avoid calling ScalarEvolution::getAddExpr, which can be pretty expensive, when nothing has changed, which is pretty common. llvm-svn: 111042 --- llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'llvm/lib/Transforms') diff --git a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp index f7b22a0966b..a040e8acc7d 100644 --- a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp +++ b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp @@ -505,12 +505,14 @@ static int64_t ExtractImmediate(const SCEV *&S, ScalarEvolution &SE) { } else if (const SCEVAddExpr *Add = dyn_cast(S)) { SmallVector NewOps(Add->op_begin(), Add->op_end()); int64_t Result = ExtractImmediate(NewOps.front(), SE); - S = SE.getAddExpr(NewOps); + if (Result != 0) + S = SE.getAddExpr(NewOps); return Result; } else if (const SCEVAddRecExpr *AR = dyn_cast(S)) { SmallVector NewOps(AR->op_begin(), AR->op_end()); int64_t Result = ExtractImmediate(NewOps.front(), SE); - S = SE.getAddRecExpr(NewOps, AR->getLoop()); + if (Result != 0) + S = SE.getAddRecExpr(NewOps, AR->getLoop()); return Result; } return 0; @@ -528,12 +530,14 @@ static GlobalValue *ExtractSymbol(const SCEV *&S, ScalarEvolution &SE) { } else if (const SCEVAddExpr *Add = dyn_cast(S)) { SmallVector NewOps(Add->op_begin(), Add->op_end()); GlobalValue *Result = ExtractSymbol(NewOps.back(), SE); - S = SE.getAddExpr(NewOps); + if (Result) + S = SE.getAddExpr(NewOps); return Result; } else if (const SCEVAddRecExpr *AR = dyn_cast(S)) { SmallVector NewOps(AR->op_begin(), AR->op_end()); GlobalValue *Result = ExtractSymbol(NewOps.front(), SE); - S = SE.getAddRecExpr(NewOps, AR->getLoop()); + if (Result) + S = SE.getAddRecExpr(NewOps, AR->getLoop()); return Result; } return 0; -- cgit v1.2.3