path: root/test/CodeGen/X86/block-placement.ll

; RUN: llc -mtriple=i686-linux -enable-block-placement < %s | FileCheck %s

declare void @error(i32 %i, i32 %a, i32 %b)

define i32 @test_ifchains(i32 %i, i32* %a, i32 %b) {
; Test a chain of ifs, where the block guarded by the if is error handling code
; that is not expected to run.
; CHECK: test_ifchains:
; CHECK: %entry
; CHECK: %else1
; CHECK: %else2
; CHECK: %else3
; CHECK: %else4
; CHECK: %exit
; CHECK: %then1
; CHECK: %then2
; CHECK: %then3
; CHECK: %then4
; CHECK: %then5

entry:
  %gep1 = getelementptr i32* %a, i32 1
  %val1 = load i32* %gep1
  %cond1 = icmp ugt i32 %val1, 1
  br i1 %cond1, label %then1, label %else1, !prof !0

then1:
  call void @error(i32 %i, i32 1, i32 %b)
  br label %else1

else1:
  %gep2 = getelementptr i32* %a, i32 2
  %val2 = load i32* %gep2
  %cond2 = icmp ugt i32 %val2, 2
  br i1 %cond2, label %then2, label %else2, !prof !0

then2:
  call void @error(i32 %i, i32 1, i32 %b)
  br label %else2

else2:
  %gep3 = getelementptr i32* %a, i32 3
  %val3 = load i32* %gep3
  %cond3 = icmp ugt i32 %val3, 3
  br i1 %cond3, label %then3, label %else3, !prof !0

then3:
  call void @error(i32 %i, i32 1, i32 %b)
  br label %else3

else3:
  %gep4 = getelementptr i32* %a, i32 4
  %val4 = load i32* %gep4
  %cond4 = icmp ugt i32 %val4, 4
  br i1 %cond4, label %then4, label %else4, !prof !0

then4:
  call void @error(i32 %i, i32 1, i32 %b)
  br label %else4

else4:
  %gep5 = getelementptr i32* %a, i32 3
  %val5 = load i32* %gep5
  %cond5 = icmp ugt i32 %val5, 3
  br i1 %cond5, label %then5, label %exit, !prof !0

then5:
  call void @error(i32 %i, i32 1, i32 %b)
  br label %exit

exit:
  ret i32 %b
}

define i32 @test_loop_cold_blocks(i32 %i, i32* %a) {
; Check that we sink cold loop blocks after the hot loop body.
; CHECK: test_loop_cold_blocks:
; CHECK: %entry
; CHECK: %body1
; CHECK: %body2
; CHECK: %body3
; CHECK: %unlikely1
; CHECK: %unlikely2
; CHECK: %exit

entry:
  br label %body1

body1:
  %iv = phi i32 [ 0, %entry ], [ %next, %body3 ]
  %base = phi i32 [ 0, %entry ], [ %sum, %body3 ]
  %unlikelycond1 = icmp slt i32 %base, 42
  br i1 %unlikelycond1, label %unlikely1, label %body2, !prof !0

unlikely1:
  call void @error(i32 %i, i32 1, i32 %base)
  br label %body2

body2:
  %unlikelycond2 = icmp sgt i32 %base, 21
  br i1 %unlikelycond2, label %unlikely2, label %body3, !prof !0

unlikely2:
  call void @error(i32 %i, i32 2, i32 %base)
  br label %body3

body3:
  %arrayidx = getelementptr inbounds i32* %a, i32 %iv
  %0 = load i32* %arrayidx
  %sum = add nsw i32 %0, %base
  %next = add i32 %iv, 1
  %exitcond = icmp eq i32 %next, %i
  br i1 %exitcond, label %exit, label %body1

exit:
  ret i32 %sum
}

!0 = metadata !{metadata !"branch_weights", i32 4, i32 64}

define i32 @test_loop_early_exits(i32 %i, i32* %a) {
; Check that we sink early exit blocks out of loop bodies.
; CHECK: test_loop_early_exits:
; CHECK: %entry
; CHECK: %body1
; CHECK: %body2
; CHECK: %body3
; CHECK: %body4
; CHECK: %exit
; CHECK: %bail1
; CHECK: %bail2
; CHECK: %bail3

entry:
  br label %body1

body1:
  %iv = phi i32 [ 0, %entry ], [ %next, %body4 ]
  %base = phi i32 [ 0, %entry ], [ %sum,