llvm/llvm/test/Transforms/LoopStrengthReduce/X86/2011-11-29-postincphi.ll

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s | FileCheck %s
;
; PR11431: handle a phi operand that is replaced by a postinc user.
; LSR first expands %t3 to %t2 in %phi
; LSR then expands %t2 in %phi into two decrements, one on each loop exit.

target datalayout = "e-p:64:64:64-S128-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-f128:128:128-n8:16:32:64"
target triple = "x86_64-unknown-linux-gnu"

declare i1 @check() nounwind

; Check that LSR did something close to the behavior at the time of the bug.
define i64 @sqlite3DropTriggerPtr() nounwind {
; CHECK-LABEL: sqlite3DropTriggerPtr:
; CHECK:       # %bb.0: # %bb
; CHECK-NEXT:    pushq %rbx
; CHECK-NEXT:    movl $1, %ebx
; CHECK-NEXT:    callq check@PLT
; CHECK-NEXT:    .p2align 4, 0x90
; CHECK-NEXT:  .LBB0_1: # %bb1
; CHECK-NEXT:    # =>This Inner Loop Header: Depth=1
; CHECK-NEXT:    testb %al, %al
; CHECK-NEXT:    je .LBB0_4
; CHECK-NEXT:  # %bb.2: # %bb4
; CHECK-NEXT:    # in Loop: Header=BB0_1 Depth=1
; CHECK-NEXT:    incq %rbx
; CHECK-NEXT:    testb %al, %al
; CHECK-NEXT:    jne .LBB0_1
; CHECK-NEXT:  # %bb.3: # %bb8split
; CHECK-NEXT:    decq %rbx
; CHECK-NEXT:  .LBB0_4: # %bb8
; CHECK-NEXT:    movq %rbx, %rax
; CHECK-NEXT:    popq %rbx
; CHECK-NEXT:    retq
bb:
  %cmp = call zeroext i1 @check()
  br label %bb1

bb1:                                              ; preds = %bb4, %bb
  %t0 = phi i64 [ 0, %bb ], [ %t3, %bb4 ]
  %t2 = phi i64 [ 1, %bb ], [ %t5, %bb4 ]
  %t3 = add nsw i64 %t0, 1
  br i1 %cmp, label %bb4, label %bb8

bb4:                                              ; preds = %bb1
  %t5 = add nsw i64 %t2, 1
  br i1 %cmp, label %bb1, label %bb8

bb8:                                              ; preds = %bb8, %bb4
  %phi = phi i64 [ %t3, %bb1 ], [ %t2, %bb4 ]
  ret i64 %phi
}