llvm-6502/test/Transforms/SimplifyCFG/trapping-load-unreachable.ll
Tim Northover ca396e391e IR: add a second ordering operand to cmpxhg for failure
The syntax for "cmpxchg" should now look something like:

	cmpxchg i32* %addr, i32 42, i32 3 acquire monotonic

where the second ordering argument gives the required semantics in the case
that no exchange takes place. It should be no stronger than the first ordering
constraint and cannot be either "release" or "acq_rel" (since no store will
have taken place).

rdar://problem/15996804

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203559 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-11 10:48:52 +00:00

88 lines
1.6 KiB
LLVM

; RUN: opt < %s -simplifycfg -S | FileCheck %s
; PR2967
target datalayout =
"e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32"
target triple = "i386-pc-linux-gnu"
define void @test1(i32 %x) nounwind {
entry:
%0 = icmp eq i32 %x, 0 ; <i1> [#uses=1]
br i1 %0, label %bb, label %return
bb: ; preds = %entry
%1 = load volatile i32* null
unreachable
br label %return
return: ; preds = %entry
ret void
; CHECK-LABEL: @test1(
; CHECK: load volatile
}
; rdar://7958343
define void @test2() nounwind {
entry:
store i32 4,i32* null
ret void
; CHECK-LABEL: @test2(
; CHECK: call void @llvm.trap
; CHECK: unreachable
}
; PR7369
define void @test3() nounwind {
entry:
store volatile i32 4, i32* null
ret void
; CHECK-LABEL: @test3(
; CHECK: store volatile i32 4, i32* null
; CHECK: ret
}
; Check store before unreachable.
define void @test4(i1 %C, i32* %P) {
; CHECK-LABEL: @test4(
; CHECK: entry:
; CHECK-NEXT: br i1 %C
entry:
br i1 %C, label %T, label %F
T:
store volatile i32 0, i32* %P
unreachable
F:
ret void
}
; Check cmpxchg before unreachable.
define void @test5(i1 %C, i32* %P) {
; CHECK-LABEL: @test5(
; CHECK: entry:
; CHECK-NEXT: br i1 %C
entry:
br i1 %C, label %T, label %F
T:
cmpxchg volatile i32* %P, i32 0, i32 1 seq_cst seq_cst
unreachable
F:
ret void
}
; Check atomicrmw before unreachable.
define void @test6(i1 %C, i32* %P) {
; CHECK-LABEL: @test6(
; CHECK: entry:
; CHECK-NEXT: br i1 %C
entry:
br i1 %C, label %T, label %F
T:
atomicrmw volatile xchg i32* %P, i32 0 seq_cst
unreachable
F:
ret void
}