From 54ed08e250a76b570c2162d49633e11b8ebb2d98 Mon Sep 17 00:00:00 2001 From: Tim Northover Date: Mon, 9 Dec 2013 09:05:30 +0000 Subject: Merge r196725 (conflicts on same API as before): ------------------------------------------------------------------------ r196725 | tnorthover | 2013-12-08 15:56:50 +0000 (Sun, 08 Dec 2013) | 19 lines ARM: fix folding of stack-adjustment (yet again). When trying to eliminate an "sub sp, sp, #N" instruction by folding it into an existing push/pop using dummy registers, we need to account for the fact that this might affect precisely how "fp" gets set in the prologue. We were attempting this, but assuming that *whenever* we performed a fold it would make a difference. This is false, for example, in: push {r4, r7, lr} add fp, sp, #4 vpush {d8} sub sp, sp, #8 we can fold the "sub" into the "vpush", forming "vpush {d7, d8}". However, in that case the "add fp" instruction mustn't change, which we were getting wrong before. Should fix PR18160. ------------------------------------------------------------------------ git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_34@196769 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/ARM/ARMFrameLowering.cpp | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'lib') diff --git a/lib/Target/ARM/ARMFrameLowering.cpp b/lib/Target/ARM/ARMFrameLowering.cpp index 1457ace..d32bdbc 100644 --- a/lib/Target/ARM/ARMFrameLowering.cpp +++ b/lib/Target/ARM/ARMFrameLowering.cpp @@ -256,9 +256,10 @@ void ARMFrameLowering::emitPrologue(MachineFunction &MF) const { if (NumBytes) { // Adjust SP after all the callee-save spills. - if (tryFoldSPUpdateIntoPushPop(MF, LastPush, NumBytes)) - FramePtrOffsetInPush += NumBytes; - else + if (tryFoldSPUpdateIntoPushPop(MF, LastPush, NumBytes)) { + if (LastPush == FramePtrPush) + FramePtrOffsetInPush += NumBytes; + } else emitSPUpdate(isARM, MBB, MBBI, dl, TII, -NumBytes, MachineInstr::FrameSetup); -- cgit v1.1