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; RUN: llc -march=bpfel -mcpu=v4 -gotol-abs-low-bound 0 -verify-machineinstrs -show-mc-encoding < %s | FileCheck %s
; Source:
; // This test covers all three cases:
; // (1). jmp to another basic block (not the follow-through one)
; // (2). conditional jmp (follow-through and non-follow-through)
; // (3). conditional jmp followed by an unconditional jmp
; // To trigger case (3) the following code is developed which
; // covers case (1) and (2) as well.
; unsigned foo(unsigned a, unsigned b) {
; unsigned s = b;
; if (a < b)
; goto next;
; else
; goto next2;
; begin:
; s /= b;
; if (s > a)
; return s * s;
; next:
; s *= a;
; if (s > b)
; goto begin;
; next2:
; s *= b;
; if (s > a)
; goto begin;
; return s;
; }
; Compilation flags:
; clang -target bpf -O2 -mcpu=v4 -S -emit-llvm t.c
; Function Attrs: nofree norecurse nosync nounwind memory(none)
define dso_local i32 @foo(i32 noundef %a, i32 noundef %b) local_unnamed_addr #0 {
entry:
%cmp = icmp ult i32 %a, %b
br i1 %cmp, label %next, label %next2
; case (3): conditional jmp followed by an unconditional jmp
; CHECK: w0 = w2
; CHECK-NEXT: if w1 < w2 goto
; CHECK: gotol LBB0_4 # encoding: [0x06'A',A,A,A,0x00,0x00,0x00,0x00]
; CHECK-NEXT: # fixup A - offset: 0, value: LBB0_4, kind: FK_BPF_PCRel_4
begin: ; preds = %next2, %next
%s.0 = phi i32 [ %mul3, %next ], [ %mul7, %next2 ]
%div = udiv i32 %s.0, %b
%cmp1 = icmp ugt i32 %div, %a
br i1 %cmp1, label %if.then2, label %next
; case (2): conditional jmp
; CHECK: w0 *= w1
; CHECK-NEXT: if w0 > w2 goto LBB0_7
; CHECK: goto LBB0_4
; CHECK-LABEL: LBB0_7:
; CHECK: gotol
; CHECK-LABEL: LBB0_4:
if.then2: ; preds = %begin
%mul = mul i32 %div, %div
br label %cleanup
; case (1): unconditional jmp
; CHECK: w0 *= w0
; CHECK-NEXT: gotol
next: ; preds = %begin, %entry
%s.1 = phi i32 [ %b, %entry ], [ %div, %begin ]
%mul3 = mul i32 %s.1, %a
%cmp4 = icmp ugt i32 %mul3, %b
br i1 %cmp4, label %begin, label %next2
next2: ; preds = %next, %entry
%s.2 = phi i32 [ %mul3, %next ], [ %b, %entry ]
%mul7 = mul i32 %s.2, %b
%cmp8 = icmp ugt i32 %mul7, %a
br i1 %cmp8, label %begin, label %cleanup
cleanup: ; preds = %next2, %if.then2
%retval.0 = phi i32 [ %mul, %if.then2 ], [ %mul7, %next2 ]
ret i32 %retval.0
}
attributes #0 = { nofree norecurse nosync nounwind memory(none) "frame-pointer"="all" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="v4" }
!llvm.module.flags = !{!0, !1}
!llvm.ident = !{!2}
!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 7, !"frame-pointer", i32 2}
!2 = !{!"clang version 18.0.0 (https://github.com/llvm/llvm-project.git dccf0f74657ce8c50eb1e997bae356c32d7b1ffe)"}
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