From b6b5b7b69113c5c3e49caf78adb1c2c4cf216db3 Mon Sep 17 00:00:00 2001 From: Andrew Trick Date: Fri, 15 Jun 2012 20:07:29 +0000 Subject: [PATCH] LSR: fix expansion of scaled reg in non-address type formulae. For non-address users, Base and Scaled registers are not specially associated to fit an address mode, so SCEVExpander should apply normal expansion rules. Otherwise we may sink computation into inner loops that have already been optimized. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158537 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/LoopStrengthReduce.cpp | 30 +++++++++++--------- 1 file changed, 17 insertions(+), 13 deletions(-) diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp index 963811ee279..4ba969e6750 100644 --- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp +++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp @@ -4268,13 +4268,6 @@ Value *LSRInstance::Expand(const LSRFixup &LF, Ops.push_back(SE.getUnknown(Rewriter.expandCodeFor(Reg, 0, IP))); } - // Flush the operand list to suppress SCEVExpander hoisting. - if (!Ops.empty()) { - Value *FullV = Rewriter.expandCodeFor(SE.getAddExpr(Ops), Ty, IP); - Ops.clear(); - Ops.push_back(SE.getUnknown(FullV)); - } - // Expand the ScaledReg portion. Value *ICmpScaledV = 0; if (F.AM.Scale != 0) { @@ -4296,23 +4289,34 @@ Value *LSRInstance::Expand(const LSRFixup &LF, } else { // Otherwise just expand the scaled register and an explicit scale, // which is expected to be matched as part of the address. + + // Flush the operand list to suppress SCEVExpander hoisting address modes. + if (!Ops.empty() && LU.Kind == LSRUse::Address) { + Value *FullV = Rewriter.expandCodeFor(SE.getAddExpr(Ops), Ty, IP); + Ops.clear(); + Ops.push_back(SE.getUnknown(FullV)); + } ScaledS = SE.getUnknown(Rewriter.expandCodeFor(ScaledS, 0, IP)); ScaledS = SE.getMulExpr(ScaledS, SE.getConstant(ScaledS->getType(), F.AM.Scale)); Ops.push_back(ScaledS); - - // Flush the operand list to suppress SCEVExpander hoisting. - Value *FullV = Rewriter.expandCodeFor(SE.getAddExpr(Ops), Ty, IP); - Ops.clear(); - Ops.push_back(SE.getUnknown(FullV)); } } // Expand the GV portion. if (F.AM.BaseGV) { + // Flush the operand list to suppress SCEVExpander hoisting. + if (!Ops.empty()) { + Value *FullV = Rewriter.expandCodeFor(SE.getAddExpr(Ops), Ty, IP); + Ops.clear(); + Ops.push_back(SE.getUnknown(FullV)); + } Ops.push_back(SE.getUnknown(F.AM.BaseGV)); + } - // Flush the operand list to suppress SCEVExpander hoisting. + // Flush the operand list to suppress SCEVExpander hoisting of both folded and + // unfolded offsets. LSR assumes they both live next to their uses. + if (!Ops.empty()) { Value *FullV = Rewriter.expandCodeFor(SE.getAddExpr(Ops), Ty, IP); Ops.clear(); Ops.push_back(SE.getUnknown(FullV)); -- 2.34.1