mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-21 00:32:23 +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
75 lines
1.8 KiB
LLVM
75 lines
1.8 KiB
LLVM
; RUN: llc < %s -mtriple=thumbv7-apple-darwin -mattr=+thumb2 -arm-atomic-cfg-tidy=0 | FileCheck %s
|
|
; If-conversion defeats the purpose of this test, which is to check
|
|
; conditional branch generation, so a call to make sure it doesn't
|
|
; happen and we get actual branches.
|
|
|
|
declare void @foo()
|
|
|
|
define i32 @f1(i32 %a, i32 %b, i32* %v) {
|
|
entry:
|
|
; CHECK-LABEL: f1:
|
|
; CHECK: bne LBB
|
|
%tmp = icmp eq i32 %a, %b ; <i1> [#uses=1]
|
|
br i1 %tmp, label %cond_true, label %return
|
|
|
|
cond_true: ; preds = %entry
|
|
call void @foo()
|
|
store i32 0, i32* %v
|
|
ret i32 0
|
|
|
|
return: ; preds = %entry
|
|
call void @foo()
|
|
ret i32 1
|
|
}
|
|
|
|
define i32 @f2(i32 %a, i32 %b, i32* %v) {
|
|
entry:
|
|
; CHECK-LABEL: f2:
|
|
; CHECK: bge LBB
|
|
%tmp = icmp slt i32 %a, %b ; <i1> [#uses=1]
|
|
br i1 %tmp, label %cond_true, label %return
|
|
|
|
cond_true: ; preds = %entry
|
|
call void @foo()
|
|
store i32 0, i32* %v
|
|
ret i32 0
|
|
|
|
return: ; preds = %entry
|
|
call void @foo()
|
|
ret i32 1
|
|
}
|
|
|
|
define i32 @f3(i32 %a, i32 %b, i32* %v) {
|
|
entry:
|
|
; CHECK-LABEL: f3:
|
|
; CHECK: bhs LBB
|
|
%tmp = icmp ult i32 %a, %b ; <i1> [#uses=1]
|
|
br i1 %tmp, label %cond_true, label %return
|
|
|
|
cond_true: ; preds = %entry
|
|
call void @foo()
|
|
store i32 0, i32* %v
|
|
ret i32 0
|
|
|
|
return: ; preds = %entry
|
|
call void @foo()
|
|
ret i32 1
|
|
}
|
|
|
|
define i32 @f4(i32 %a, i32 %b, i32* %v) {
|
|
entry:
|
|
; CHECK-LABEL: f4:
|
|
; CHECK: blo LBB
|
|
%tmp = icmp uge i32 %a, %b ; <i1> [#uses=1]
|
|
br i1 %tmp, label %cond_true, label %return
|
|
|
|
cond_true: ; preds = %entry
|
|
call void @foo()
|
|
store i32 0, i32* %v
|
|
ret i32 0
|
|
|
|
return: ; preds = %entry
|
|
call void @foo()
|
|
ret i32 1
|
|
}
|