llvm-6502/test/CodeGen/X86/2010-01-08-Atomic64Bug.ll
Tim Northover 5c8b83eb7a X86: expand atomics in IR instead of as MachineInstrs.
The logic for expanding atomics that aren't natively supported in
terms of cmpxchg loops is much simpler to express at the IR level. It
also allows the normal optimisations and CodeGen improvements to help
out with atomics, instead of using a limited set of possible
instructions..

rdar://problem/13496295

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212119 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-01 18:53:31 +00:00

23 lines
573 B
LLVM

; RUN: llc < %s -mtriple=i386-apple-darwin -mcpu=corei7 | FileCheck %s
; rdar://r7512579
; PHI defs in the atomic loop should be used by the add / adc
; instructions. They should not be dead.
define void @t(i64* nocapture %p) nounwind ssp {
entry:
; CHECK-LABEL: t:
; CHECK: movl ([[REG:%[a-z]+]]), %eax
; CHECK: movl 4([[REG]]), %edx
; CHECK: LBB0_1:
; CHECK: movl %eax, %ebx
; CHECK: addl $1, %ebx
; CHECK: movl %edx, %ecx
; CHECK: adcl $0, %ecx
; CHECK: lock
; CHECK-NEXT: cmpxchg8b ([[REG]])
; CHECK-NEXT: jne
%0 = atomicrmw add i64* %p, i64 1 seq_cst
ret void
}