From 4612e597790cfed94e967860dd9bc09bd1e338aa Mon Sep 17 00:00:00 2001 From: Eli Friedman Date: Sat, 18 Jul 2009 05:26:06 +0000 Subject: [PATCH] Fix the inline cost calculation to take into account instructions which cannot be folded even if they have constant operands. Significantly helps if_spppsubr.c attached to PR4573. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76285 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Utils/InlineCost.cpp | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/lib/Transforms/Utils/InlineCost.cpp b/lib/Transforms/Utils/InlineCost.cpp index 87aff01a585..5fe85e6ef29 100644 --- a/lib/Transforms/Utils/InlineCost.cpp +++ b/lib/Transforms/Utils/InlineCost.cpp @@ -42,6 +42,13 @@ unsigned InlineCostAnalyzer::FunctionInfo:: // Figure out if this instruction will be removed due to simple constant // propagation. Instruction &Inst = cast(**UI); + + // We can't constant propagate instructions which have effects or + // read memory. + if (Inst.mayReadFromMemory() || Inst.mayHaveSideEffects() || + isa(Inst)) + continue; + bool AllOperandsConstant = true; for (unsigned i = 0, e = Inst.getNumOperands(); i != e; ++i) if (!isa(Inst.getOperand(i)) && Inst.getOperand(i) != V) { -- 2.11.0