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https://github.com/c64scene-ar/llvm-6502.git
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f4230250a1
Machine Sink uses loop depth information to select between successors BBs to sink machine instructions into, where BBs within smaller loop depths are preferable. This patch adds support for choosing between successors by using profile information from BlockFrequencyInfo instead, whenever the information is available. Tested it under SPEC2006 train (average of 30 runs for each program); ~1.5% execution speedup in average on x86-64 darwin. <rdar://problem/18021659> git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218472 91177308-0d34-0410-b5e6-96231b3b80d8
46 lines
1.5 KiB
LLVM
46 lines
1.5 KiB
LLVM
; RUN: llc -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-machine-licm -machine-sink-bfi=false -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 sucessor 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 {
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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 !0
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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 !1
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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 !2
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exit:
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ret i32 0
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}
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!0 = metadata !{metadata !"branch_weights", i32 4, i32 1}
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!1 = metadata !{metadata !"branch_weights", i32 128, i32 1}
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!2 = metadata !{metadata !"branch_weights", i32 1, i32 1}
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