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llvm-project/llvm/test/CodeGen/X86/switch-order-weight.ll

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SelectionDAGBuilder: When emitting small compare chains for switches order them by using edge weights. SimplifyCFG tends to form a lot of 2-3 case switches when merging branches. Move the most likely condition to the front so it is checked first and the others can be skipped. This is currently not as effective as it could be because SimplifyCFG destroys profiling metadata when merging branches and switches. Merging branch weight metadata is tricky though. This code touches at most 3 cases so I didn't use a proper sorting algorithm. llvm-svn: 157521
2012-05-27 04:01:32 +08:00
; RUN: llc -mtriple=x86_64-apple-darwin11 < %s | FileCheck %s
; Check that the cases which lead to unreachable are checked after "10"
define void @test1(i32 %x) nounwind uwtable ssp {
entry:
switch i32 %x, label %if.end7 [
i32 0, label %if.then
i32 10, label %if.then2
i32 20, label %if.then5
]
Convert CodeGen/*/*.ll tests to use the new CHECK-LABEL for easier debugging. No functionality change and all tests pass after conversion. This was done with the following sed invocation to catch label lines demarking function boundaries: sed -i '' "s/^;\( *\)\([A-Z0-9_]*\):\( *\)test\([A-Za-z0-9_-]*\):\( *\)$/;\1\2-LABEL:\3test\4:\5/g" test/CodeGen/*/*.ll which was written conservatively to avoid false positives rather than false negatives. I scanned through all the changes and everything looks correct. llvm-svn: 186258
2013-07-14 04:38:47 +08:00
; CHECK-LABEL: test1:
SelectionDAGBuilder: When emitting small compare chains for switches order them by using edge weights. SimplifyCFG tends to form a lot of 2-3 case switches when merging branches. Move the most likely condition to the front so it is checked first and the others can be skipped. This is currently not as effective as it could be because SimplifyCFG destroys profiling metadata when merging branches and switches. Merging branch weight metadata is tricky though. This code touches at most 3 cases so I didn't use a proper sorting algorithm. llvm-svn: 157521
2012-05-27 04:01:32 +08:00
; CHECK-NOT: unr
; CHECK: cmpl $10
; CHECK: bar
; CHECK: cmpl $20
if.then:
tail call void @unr(i32 23) noreturn nounwind
unreachable
if.then2:
tail call void @bar(i32 42) nounwind
br label %if.end7
if.then5:
tail call void @unr(i32 5) noreturn nounwind
unreachable
if.end7:
ret void
}
declare void @unr(i32) noreturn
declare void @bar(i32)