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| author | Reid Kleckner <rnk@google.com> | 2019-05-24 01:27:20 +0000 |
|---|---|---|
| committer | Reid Kleckner <rnk@google.com> | 2019-05-24 01:27:20 +0000 |
| commit | b7a78c7dff18485e5ac85aa8c902571da4b06a33 (patch) | |
| tree | 3ac414250e2a3bbd2cb3913f45198b3030d1868a /llvm | |
| parent | ed595e8627b37131d1f0146c24655a1825c5cf13 (diff) | |
| download | bcm5719-llvm-b7a78c7dff18485e5ac85aa8c902571da4b06a33.tar.gz bcm5719-llvm-b7a78c7dff18485e5ac85aa8c902571da4b06a33.zip | |
[AArch64] Preserve X8 for thunks ending in variadic musttail calls
Summary:
On Windows, X8 may be used to pass in the address of an aggregate that
is returned indirectly. Therefore, it should be forwarded to variadic
musttail calls and preserved in thunks.
Fixes PR41997
Reviewers: mgrang, efriedma
Subscribers: javed.absar, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62344
llvm-svn: 361585
Diffstat (limited to 'llvm')
| -rw-r--r-- | llvm/lib/Target/AArch64/AArch64ISelLowering.cpp | 6 | ||||
| -rw-r--r-- | llvm/test/CodeGen/AArch64/vararg-tallcall.ll | 6 |
2 files changed, 9 insertions, 3 deletions
diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp index 4b027e93633..ac656959bcb 100644 --- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp +++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp @@ -3207,6 +3207,12 @@ SDValue AArch64TargetLowering::LowerFormalArguments( FuncInfo->getForwardedMustTailRegParms(); CCInfo.analyzeMustTailForwardedRegisters(Forwards, RegParmTypes, CC_AArch64_AAPCS); + + // Conservatively forward X8, since it might be used for aggregate return. + if (!CCInfo.isAllocated(AArch64::X8)) { + unsigned X8VReg = MF.addLiveIn(AArch64::X8, &AArch64::GPR64RegClass); + Forwards.push_back(ForwardedRegister(X8VReg, AArch64::X8, MVT::i64)); + } } } diff --git a/llvm/test/CodeGen/AArch64/vararg-tallcall.ll b/llvm/test/CodeGen/AArch64/vararg-tallcall.ll index 28182226803..56c56213af3 100644 --- a/llvm/test/CodeGen/AArch64/vararg-tallcall.ll +++ b/llvm/test/CodeGen/AArch64/vararg-tallcall.ll @@ -28,7 +28,7 @@ entry: attributes #1 = { noinline optnone "thunk" } ; CHECK: mov v16.16b, v0.16b -; CHECK: ldr x8, [x0] -; CHECK: ldr x8, [x8] +; CHECK: ldr x9, [x0] +; CHECK: ldr x9, [x9] ; CHECK: mov v0.16b, v16.16b -; CHECK: br x8 +; CHECK: br x9 |
