From 03e84c9df91cbc1fe0219a51109e260cacdfd2b7 Mon Sep 17 00:00:00 2001 From: Owen Anderson Date: Thu, 3 Oct 2013 21:08:05 +0000 Subject: Pull fptrunc's upwards through selects when one of the select's selectands was a constant. This has a number of benefits, including producing small immediates (easier to materialize, smaller constant pools) as well as being more likely to allow the fptrunc to fuse with a preceding instruction (truncating selects are unusual). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191929 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/InstCombine/InstCombineCasts.cpp | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'lib/Transforms/InstCombine') diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp index a35631fc15..01894cbfdc 100644 --- a/lib/Transforms/InstCombine/InstCombineCasts.cpp +++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp @@ -1229,6 +1229,19 @@ Instruction *InstCombiner::visitFPTrunc(FPTruncInst &CI) { } } + // (fptrunc (select cond, R1, Cst)) --> + // (select cond, (fptrunc R1), (fptrunc Cst)) + SelectInst *SI = dyn_cast(CI.getOperand(0)); + if (SI && + (isa(SI->getOperand(1)) || + isa(SI->getOperand(2)))) { + Value *LHSTrunc = Builder->CreateFPTrunc(SI->getOperand(1), + CI.getType()); + Value *RHSTrunc = Builder->CreateFPTrunc(SI->getOperand(2), + CI.getType()); + return SelectInst::Create(SI->getOperand(0), LHSTrunc, RHSTrunc); + } + IntrinsicInst *II = dyn_cast(CI.getOperand(0)); if (II) { switch (II->getIntrinsicID()) { -- cgit v1.2.3