From bf5d4fb7d8ee4537955610ef9c48f7009418efc3 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Thu, 21 Apr 2005 05:31:13 +0000 Subject: [PATCH] Teach simplifycfg that setcc is cheap and non-trapping, so that it can convert this: %tmp.1 = seteq int %i, 0 ; [#uses=1] br bool %tmp.1, label %shortcirc_done, label %shortcirc_next shortcirc_next: ; preds = %entry %tmp.4 = seteq int %j, 0 ; [#uses=1] br label %shortcirc_done shortcirc_done: ; preds = %shortcirc_next, %entry %shortcirc_val = phi bool [ %tmp.4, %shortcirc_next ], [ true, %entry ] ; [#uses=1] to this: %tmp.1 = seteq int %i, 0 ; [#uses=1] %tmp.4 = seteq int %j, 0 ; [#uses=1] %shortcirc_val = select bool %tmp.1, bool true, bool %tmp.4 ; [#uses=1] ... which is later simplified by instcombine into an or. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21388 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Utils/SimplifyCFG.cpp | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp index 12af5b04d59..986a53f11ff 100644 --- a/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/lib/Transforms/Utils/SimplifyCFG.cpp @@ -232,6 +232,12 @@ static bool DominatesMergePoint(Value *V, BasicBlock *BB, case Instruction::Xor: case Instruction::Shl: case Instruction::Shr: + case Instruction::SetEQ: + case Instruction::SetNE: + case Instruction::SetLT: + case Instruction::SetGT: + case Instruction::SetLE: + case Instruction::SetGE: break; // These are all cheap and non-trapping instructions. }