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llvm-project/llvm/test/CodeGen/AArch64/tailcall_misched_graph.ll

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ScheduleDAGInstrs: In functions with tail calls PseudoSourceValues are not non-aliasing distinct objects The code that builds the dependence graph assumes that two PseudoSourceValues don't alias. In a tail calling function two FixedStackObjects might refer to the same location. Worse 'immutable' fixed stack objects like function arguments are not immutable and will be clobbered. Change this so that a load from a FixedStackObject is not invariant in a tail calling function and don't return a PseudoSourceValue for an instruction in tail calling functions when building the dependence graph so that we handle function arguments conservatively. Fix for PR23459. rdar://20740035 llvm-svn: 236916
2015-05-09 07:52:00 +08:00
; RUN: llc -mcpu=cyclone -debug-only=misched < %s 2>&1 | FileCheck %s
llvm/test/CodeGen/AArch64/tailcall_misched_graph.ll: s/REQUIRE/REQUIRES/ llvm-svn: 236928
2015-05-09 13:59:00 +08:00
; REQUIRES: asserts
ScheduleDAGInstrs: In functions with tail calls PseudoSourceValues are not non-aliasing distinct objects The code that builds the dependence graph assumes that two PseudoSourceValues don't alias. In a tail calling function two FixedStackObjects might refer to the same location. Worse 'immutable' fixed stack objects like function arguments are not immutable and will be clobbered. Change this so that a load from a FixedStackObject is not invariant in a tail calling function and don't return a PseudoSourceValue for an instruction in tail calling functions when building the dependence graph so that we handle function arguments conservatively. Fix for PR23459. rdar://20740035 llvm-svn: 236916
2015-05-09 07:52:00 +08:00
target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
target triple = "arm64-apple-ios7.0.0"
define void @caller2(i8* %a0, i8* %a1, i8* %a2, i8* %a3, i8* %a4, i8* %a5, i8* %a6, i8* %a7, i8* %a8, i8* %a9) {
entry:
tail call void @callee2(i8* %a1, i8* %a2, i8* %a3, i8* %a4, i8* %a5, i8* %a6, i8* %a7, i8* %a8, i8* %a9, i8* %a0)
ret void
}
declare void @callee2(i8*, i8*, i8*, i8*, i8*,
i8*, i8*, i8*, i8*, i8*)
; Make sure there is a dependence between the load and store to the same stack
; location during a tail call. Tail calls clobber the incoming argument area and
; therefore it is not safe to assume argument locations are invariant.
; PR23459 has a test case that we where miscompiling because of this at the
; time.
; CHECK: Frame Objects
; CHECK: fi#-4: {{.*}} fixed, at location [SP+8]
; CHECK: fi#-3: {{.*}} fixed, at location [SP]
; CHECK: fi#-2: {{.*}} fixed, at location [SP+8]
; CHECK: fi#-1: {{.*}} fixed, at location [SP]
; CHECK: [[VRA:%vreg.*]]<def> = LDRXui <fi#-1>
; CHECK: [[VRB:%vreg.*]]<def> = LDRXui <fi#-2>
; CHECK: STRXui %vreg{{.*}}, <fi#-4>
; CHECK: STRXui [[VRB]], <fi#-3>
; Make sure that there is an dependence edge between fi#-2 and fi#-4.
; Without this edge the scheduler would be free to move the store accross the load.
; CHECK: SU({{.*}}): [[VRB]]<def> = LDRXui <fi#-2>
; CHECK-NOT: SU
; CHECK: Successors:
; CHECK: ch SU([[DEPSTORE:.*]]): Latency=0
; CHECK: SU([[DEPSTORE]]): STRXui %vreg0, <fi#-4>