[llvm] r327369 - bpf: Don't expand BSWAP on i32, promote it
Yonghong Song via llvm-commits
llvm-commits at lists.llvm.org
Mon Mar 12 23:47:05 PDT 2018
Author: yhs
Date: Mon Mar 12 23:47:05 2018
New Revision: 327369
URL: http://llvm.org/viewvc/llvm-project?rev=327369&view=rev
Log:
bpf: Don't expand BSWAP on i32, promote it
Currently, there is no ALU32 bswap support in eBPF ISA.
BSWAP on i32 was set to EXPAND which would need about eight instructions
for single BSWAP.
It would be more efficient to promote it to i64, then doing BSWAP on i64.
For eBPF programs, most of the promotion are zero extensions which are
likely be elimiated later by peephole optimizations.
Signed-off-by: Jiong Wang <jiong.wang at netronome.com>
Signed-off-by: Yonghong Song <yhs at fb.com>
Modified:
llvm/trunk/lib/Target/BPF/BPFISelLowering.cpp
Modified: llvm/trunk/lib/Target/BPF/BPFISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/BPF/BPFISelLowering.cpp?rev=327369&r1=327368&r2=327369&view=diff
==============================================================================
--- llvm/trunk/lib/Target/BPF/BPFISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/BPF/BPFISelLowering.cpp Mon Mar 12 23:47:05 2018
@@ -105,7 +105,7 @@ BPFTargetLowering::BPFTargetLowering(con
}
if (STI.getHasAlu32()) {
- setOperationAction(ISD::BSWAP, MVT::i32, Expand);
+ setOperationAction(ISD::BSWAP, MVT::i32, Promote);
setOperationAction(ISD::BR_CC, MVT::i32, Promote);
}
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