mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-20 09:30:43 +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
32 lines
611 B
LLVM
32 lines
611 B
LLVM
; RUN: llc < %s -mtriple=armv6-apple-darwin -mcpu=arm1136jf-s -arm-atomic-cfg-tidy=0 | FileCheck %s
|
|
; Radar 8589805: Counting the number of microcoded operations, such as for an
|
|
; LDM instruction, was causing an assertion failure because the microop count
|
|
; was being treated as an instruction count.
|
|
|
|
; CHECK: push
|
|
; CHECK: pop
|
|
; CHECK: pop
|
|
; CHECK: pop
|
|
|
|
define i32 @test(i32 %x) {
|
|
entry:
|
|
%0 = tail call signext i16 undef(i32* undef)
|
|
switch i32 %x, label %bb3 [
|
|
i32 0, label %bb4
|
|
i32 1, label %bb1
|
|
i32 2, label %bb2
|
|
]
|
|
|
|
bb1:
|
|
ret i32 1
|
|
|
|
bb2:
|
|
ret i32 2
|
|
|
|
bb3:
|
|
ret i32 1
|
|
|
|
bb4:
|
|
ret i32 3
|
|
}
|