test/CodeGen/SystemZ/cmpxchg-01.ll

; Test 8-bit compare and swap.
;
; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s -check-prefix=CHECK-MAIN
; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s -check-prefix=CHECK-SHIFT

; Check compare and swap with a variable.
; - CHECK is for the main loop.
; - CHECK-SHIFT makes sure that the negated shift count used by the second
;   RLL is set up correctly.  The negation is independent of the NILL and L
;   tested in CHECK.  CHECK-SHIFT also checks that %r3 is not modified before
;   being used in the RISBG (in contrast to things like atomic addition,
;   which shift %r3 left so that %b is at the high end of the word).
define i8 @f1(i8 %dummy, i8 *%src, i8 %cmp, i8 %swap) {
; CHECK-MAIN: f1:
; CHECK-MAIN: sllg [[SHIFT:%r[1-9]+]], %r3, 3
; CHECK-MAIN: nill %r3, 65532
; CHECK-MAIN: l [[OLD:%r[0-9]+]], 0(%r3)
; CHECK-MAIN: [[LOOP:\.[^ ]*]]:
; CHECK-MAIN: rll %r2, [[OLD]], 8([[SHIFT]])
; CHECK-MAIN: risbg %r4, %r2, 32, 55, 0
; CHECK-MAIN: cr %r2, %r4
; CHECK-MAIN: j{{g?}}lh [[EXIT:\.[^ ]*]]
; CHECK-MAIN: risbg %r5, %r2, 32, 55, 0
; CHECK-MAIN: rll [[NEW:%r[0-9]+]], %r5, -8({{%r[1-9]+}})
; CHECK-MAIN: cs [[OLD]], [[NEW]], 0(%r3)
; CHECK-MAIN: j{{g?}}lh [[LOOP]]
; CHECK-MAIN: [[EXIT]]:
; CHECK-MAIN-NOT: %r2
; CHECK-MAIN: br %r14
;
; CHECK-SHIFT: f1:
; CHECK-SHIFT: sllg [[SHIFT:%r[1-9]+]], %r3, 3
; CHECK-SHIFT: lcr [[NEGSHIFT:%r[1-9]+]], [[SHIFT]]
; CHECK-SHIFT: rll
; CHECK-SHIFT: rll {{%r[0-9]+}}, %r5, -8([[NEGSHIFT]])
  %res = cmpxchg i8 *%src, i8 %cmp, i8 %swap seq_cst
  ret i8 %res
}

; Check compare and swap with constants.  We should force the constants into
; registers and use the sequence above.
define i8 @f2(i8 *%src) {
; CHECK: f2:
; CHECK: lhi [[CMP:%r[0-9]+]], 42
; CHECK: risbg [[CMP]], {{%r[0-9]+}}, 32, 55, 0
; CHECK: risbg
; CHECK: br %r14
;
; CHECK-SHIFT: f2:
; CHECK-SHIFT: lhi [[SWAP:%r[0-9]+]], 88
; CHECK-SHIFT: risbg
; CHECK-SHIFT: risbg [[SWAP]], {{%r[0-9]+}}, 32, 55, 0
; CHECK-SHIFT: br %r14
  %res = cmpxchg i8 *%src, i8 42, i8 88 seq_cst
  ret i8 %res
}