llvm-project/llvm/test/CodeGen/X86/sink-blockfreq.ll

46 lines
1.4 KiB
LLVM

; RUN: llc -disable-machine-licm -machine-sink-bfi=true -mtriple=x86_64-apple-darwin < %s | FileCheck %s -check-prefix=MSINK_BFI
; RUN: llc -disable-machine-licm -machine-sink-bfi=false -mtriple=x86_64-apple-darwin < %s | FileCheck %s -check-prefix=MSINK_NOBFI
; Test that by changing BlockFrequencyInfo we change the order in which
; machine-sink looks for sucessor blocks. By not using BFI, both G and B
; have the same loop depth and no instructions is sinked - B is selected but
; can't be used as to avoid breaking a non profitable critical edge. By using
; BFI, "mul" is sinked into the less frequent block G.
define i32 @sink_freqinfo(i32 %a, i32 %b) nounwind uwtable ssp {
; MSINK_BFI-LABEL: sink_freqinfo
; MSINK_BFI: jl
; MSINK_BFI-NEXT: ## BB#
; MSINK_BFI-NEXT: imull
; MSINK_NOBFI-LABEL: sink_freqinfo
; MSINK_NOBFI: imull
; MSINK_NOBFI: jl
entry:
br label %B
B:
%ee = phi i32 [ 0, %entry ], [ %inc, %F ]
%xx = sub i32 %a, %ee
%cond0 = icmp slt i32 %xx, 0
br i1 %cond0, label %F, label %exit, !prof !0
F:
%inc = add nsw i32 %xx, 2
%aa = mul nsw i32 %b, %inc
%exitcond = icmp slt i32 %inc, %a
br i1 %exitcond, label %B, label %G, !prof !1
G:
%ii = add nsw i32 %aa, %a
%ll = add i32 %b, 45
%exitcond2 = icmp sge i32 %ii, %b
br i1 %exitcond2, label %G, label %exit, !prof !2
exit:
ret i32 0
}
!0 = !{!"branch_weights", i32 4, i32 1}
!1 = !{!"branch_weights", i32 128, i32 1}
!2 = !{!"branch_weights", i32 1, i32 1}