third_party/subzero/tests_lit/llvm2ice_tests/simple-loop.ll

; This tests a simple loop that sums the elements of an input array.
; The O2 check patterns represent the best code currently achieved.

; RUN: %p2i -i %s --filetype=obj --disassemble --args -O2 \
; RUN:   | FileCheck %s
; RUN: %p2i -i %s --filetype=obj --disassemble --args -Om1 \
; RUN:   | FileCheck --check-prefix=OPTM1 %s

define internal i32 @simple_loop(i32 %a, i32 %n) {
entry:
  %cmp4 = icmp sgt i32 %n, 0
  br i1 %cmp4, label %for.body, label %for.end

for.body:
  %i.06 = phi i32 [ %inc, %for.body ], [ 0, %entry ]
  %sum.05 = phi i32 [ %add, %for.body ], [ 0, %entry ]
  %gep_array = mul i32 %i.06, 4
  %gep = add i32 %a, %gep_array
  %__9 = inttoptr i32 %gep to i32*
  %v0 = load i32, i32* %__9, align 1
  %add = add i32 %v0, %sum.05
  %inc = add i32 %i.06, 1
  %cmp = icmp slt i32 %inc, %n
  br i1 %cmp, label %for.body, label %for.end

for.end:
  %sum.0.lcssa = phi i32 [ 0, %entry ], [ %add, %for.body ]
  ret i32 %sum.0.lcssa
}

; CHECK-LABEL: simple_loop
; CHECK:      mov ecx,DWORD PTR [esp{{.*}}+0x{{[0-9a-f]+}}]
; CHECK:      cmp ecx,0x0
; CHECK-NEXT: j{{le|g}} {{[0-9]}}

; Check for the combination of address mode inference, register
; allocation, and load/arithmetic fusing.
; CHECK: [[L:[0-9a-f]+]]{{.*}} add e{{..}},DWORD PTR [e{{..}}+[[IREG:e..]]*4]
; Check for incrementing of the register-allocated induction variable.
; CHECK-NEXT: add [[IREG]],0x1
; Check for comparing the induction variable against the loop size.
; CHECK-NEXT: cmp [[IREG]],
; CHECK-NEXT: jl [[L]]
;
; There's nothing remarkable under Om1 to test for, since Om1 generates
; such atrocious code (by design).
; OPTM1-LABEL: simple_loop
; OPTM1:      cmp {{.*}},0x0
; OPTM1:      setl
; OPTM1:      ret