mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-21 16:31:16 +00:00
d0dbe02fd2
The C and C++ semantics for compare_exchange require it to return a bool
indicating success. This gets mapped to LLVM IR which follows each cmpxchg with
an icmp of the value loaded against the desired value.
When lowered to ldxr/stxr loops, this extra comparison is redundant: its
results are implicit in the control-flow of the function.
This commit makes two changes: it replaces that icmp with appropriate PHI
nodes, and then makes sure earlyCSE is called after expansion to actually make
use of the opportunities revealed.
I've also added -{arm,aarch64}-enable-atomic-tidy options, so that
existing fragile tests aren't perturbed too much by the change. Many
of them either rely on undef/unreachable too pervasively to be
restored to something well-defined (particularly while making sure
they test the same obscure assert from many years ago), or depend on a
particular CFG shape, which is disrupted by SimplifyCFG.
rdar://problem/16227836
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209883 91177308-0d34-0410-b5e6-96231b3b80d8
49 lines
1.2 KiB
LLVM
49 lines
1.2 KiB
LLVM
; RUN: llc -verify-machineinstrs -o - %s -mtriple=arm64-apple-ios7.0 -aarch64-atomic-cfg-tidy=0 | FileCheck %s
|
|
|
|
; We've got the usual issues with LLVM reordering blocks here. The
|
|
; tests are correct for the current order, but who knows when that
|
|
; will change. Beware!
|
|
@var32 = global i32 0
|
|
@var64 = global i64 0
|
|
|
|
define i32 @test_tbz() {
|
|
; CHECK-LABEL: test_tbz:
|
|
|
|
%val = load i32* @var32
|
|
%val64 = load i64* @var64
|
|
|
|
%tbit0 = and i32 %val, 32768
|
|
%tst0 = icmp ne i32 %tbit0, 0
|
|
br i1 %tst0, label %test1, label %end1
|
|
; CHECK: tbz {{w[0-9]+}}, #15, [[LBL_end1:.?LBB0_[0-9]+]]
|
|
|
|
test1:
|
|
%tbit1 = and i32 %val, 4096
|
|
%tst1 = icmp ne i32 %tbit1, 0
|
|
br i1 %tst1, label %test2, label %end1
|
|
; CHECK: tbz {{w[0-9]+}}, #12, [[LBL_end1]]
|
|
|
|
test2:
|
|
%tbit2 = and i64 %val64, 32768
|
|
%tst2 = icmp ne i64 %tbit2, 0
|
|
br i1 %tst2, label %test3, label %end1
|
|
; CHECK: tbz {{[wx][0-9]+}}, #15, [[LBL_end1]]
|
|
|
|
test3:
|
|
%tbit3 = and i64 %val64, 4096
|
|
%tst3 = icmp ne i64 %tbit3, 0
|
|
br i1 %tst3, label %end2, label %end1
|
|
; CHECK: tbz {{[wx][0-9]+}}, #12, [[LBL_end1]]
|
|
|
|
end2:
|
|
; CHECK: {{movz x0, #1|orr w0, wzr, #0x1}}
|
|
; CHECK-NEXT: ret
|
|
ret i32 1
|
|
|
|
end1:
|
|
; CHECK: [[LBL_end1]]:
|
|
; CHECK-NEXT: {{mov x0, xzr|mov w0, wzr}}
|
|
; CHECK-NEXT: ret
|
|
ret i32 0
|
|
}
|