57c33acac8
Do not consider profile data when choosing a successor block to sink
into for optsize functions. This should result in more consistent
instruction sequences which will improve outlining and ICF. We've
observed a slight codesize improvement in a large binary. This is
similar reasoning to https://github.com/llvm/llvm-project/pull/114607.
Using profile data to select a block to sink into was original added in
d04f7596e7.
63 lines
2.2 KiB
LLVM
63 lines
2.2 KiB
LLVM
; RUN: llc -disable-preheader-prot=true -disable-machine-licm -machine-sink-bfi=true -mtriple=x86_64-apple-darwin < %s | FileCheck %s -check-prefix=MSINK_BFI
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; RUN: llc -disable-preheader-prot=true -disable-machine-licm -machine-sink-bfi=false -mtriple=x86_64-apple-darwin < %s | FileCheck %s -check-prefix=MSINK_NOBFI
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; RUN: llc -disable-preheader-prot=true -disable-machine-licm -machine-sink-bfi=true -force-pgso -mtriple=x86_64-apple-darwin < %s | FileCheck %s -check-prefix=MSINK_NOBFI
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; Test that by changing BlockFrequencyInfo we change the order in which
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; machine-sink looks for successor blocks. By not using BFI, both G and B
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; have the same loop depth and no instructions is sinked - B is selected but
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; can't be used as to avoid breaking a non profitable critical edge. By using
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; BFI, "mul" is sinked into the less frequent block G.
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define i32 @sink_freqinfo(i32 %a, i32 %b) nounwind uwtable ssp !prof !14 {
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; MSINK_BFI-LABEL: sink_freqinfo
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; MSINK_BFI: jl
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; MSINK_BFI-NEXT: ## %bb.
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; MSINK_BFI-NEXT: imull
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; MSINK_NOBFI-LABEL: sink_freqinfo
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; MSINK_NOBFI: imull
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; MSINK_NOBFI: jl
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entry:
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br label %B
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B:
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%ee = phi i32 [ 0, %entry ], [ %inc, %F ]
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%xx = sub i32 %a, %ee
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%cond0 = icmp slt i32 %xx, 0
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br i1 %cond0, label %F, label %exit, !prof !15
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F:
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%inc = add nsw i32 %xx, 2
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%aa = mul nsw i32 %b, %inc
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%exitcond = icmp slt i32 %inc, %a
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br i1 %exitcond, label %B, label %G, !prof !16
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G:
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%ii = add nsw i32 %aa, %a
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%ll = add i32 %b, 45
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%exitcond2 = icmp sge i32 %ii, %b
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br i1 %exitcond2, label %G, label %exit, !prof !17
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exit:
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ret i32 0
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}
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!llvm.module.flags = !{!0}
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!0 = !{i32 1, !"ProfileSummary", !1}
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!1 = !{!2, !3, !4, !5, !6, !7, !8, !9}
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!2 = !{!"ProfileFormat", !"InstrProf"}
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!3 = !{!"TotalCount", i64 10000}
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!4 = !{!"MaxCount", i64 10}
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!5 = !{!"MaxInternalCount", i64 1}
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!6 = !{!"MaxFunctionCount", i64 1000}
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!7 = !{!"NumCounts", i64 3}
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!8 = !{!"NumFunctions", i64 3}
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!9 = !{!"DetailedSummary", !10}
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!10 = !{!11, !12, !13}
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!11 = !{i32 10000, i64 100, i32 1}
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!12 = !{i32 999000, i64 100, i32 1}
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!13 = !{i32 999999, i64 1, i32 2}
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!14 = !{!"function_entry_count", i64 1000}
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!15 = !{!"branch_weights", i32 4, i32 1}
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!16 = !{!"branch_weights", i32 128, i32 1}
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!17 = !{!"branch_weights", i32 1, i32 1}
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