Fix PR15630: Replace faulty stdcx. with stwcx.

When doing a partword atomic operation, a lwarx was being paired with
a stdcx. instead of a stwcx. when compiling for a 64-bit target.  The
target has nothing to do with it in this case; we always need a stwcx.

Thanks to Kai Nacke for reporting the problem.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178559 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bill Schmidt 2013-04-02 18:37:08 +00:00
parent 423d674412
commit debf7d345a
2 changed files with 17 additions and 1 deletions

View File

@ -5960,7 +5960,7 @@ PPCTargetLowering::EmitPartwordAtomicBinary(MachineInstr *MI,
.addReg(TmpReg).addReg(MaskReg);
BuildMI(BB, dl, TII->get(is64bit ? PPC::OR8 : PPC::OR), Tmp4Reg)
.addReg(Tmp3Reg).addReg(Tmp2Reg);
BuildMI(BB, dl, TII->get(is64bit ? PPC::STDCX : PPC::STWCX))
BuildMI(BB, dl, TII->get(PPC::STWCX))
.addReg(Tmp4Reg).addReg(ZeroReg).addReg(PtrReg);
BuildMI(BB, dl, TII->get(PPC::BCC))
.addImm(PPC::PRED_NE).addReg(PPC::CR0).addMBB(loopMBB);

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@ -0,0 +1,16 @@
; RUN: llc -mcpu=pwr7 -O0 < %s | FileCheck %s
target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v128:128:128-n32:64"
target triple = "powerpc64-unknown-linux-gnu"
define weak_odr void @_D4core6atomic49__T11atomicStoreVE4core6atomic11MemoryOrder3ThThZ11atomicStoreFNaNbKOhhZv(i8* %val_arg, i8 zeroext %newval_arg) {
entry:
%newval = alloca i8
%ordering = alloca i32, align 4
store i8 %newval_arg, i8* %newval
%tmp = load i8* %newval
store atomic volatile i8 %tmp, i8* %val_arg seq_cst, align 1
ret void
}
; CHECK: stwcx.