[llvm] r269969 - When looking for a spill slot in reg scavenger, find one that matches RC

[Krzysztof Parzyszek via llvm-commits]

Committed in r270219.

-Krzysztof

On 5/20/2016 9:05 AM, Jordy Potman wrote:
> Yes, this fix works for me.
>
> Jordy
>
> On Fri, May 20, 2016 at 3:12 PM, Krzysztof Parzyszek
> <kparzysz at codeaurora.org <mailto:kparzysz at codeaurora.org>> wrote:
>
>     Hi Jordy,
>
>     Does this fix work for you?
>
>       unsigned SI = Scavenged.size(), Diff = UINT_MAX;
>     + int FIB = MFI.getObjectIndexBegin(), FIE = MFI.getObjectIndexEnd();
>       for (unsigned I = 0; I < Scavenged.size(); ++I) {
>         if (Scavenged[I].Reg != 0)
>           continue;
>         // Verify that this slot is valid for this register.
>         int FI = Scavenged[I].FrameIndex;
>     +   if (FI < FIB || FI >= FIE)
>     +     continue;
>         unsigned S = MFI.getObjectSize(FI);
>         unsigned A = MFI.getObjectAlignment(FI);
>
>     -Krzysztof
>
>
>
>     On 5/20/2016 7:04 AM, Jordy Potman wrote:
>
>         Hi Krzysztof,
>
>         I'm seeing an "Invalid Object Idx" assert in the call to
>         MFI.getObjectSize(FI) in the code below on my out of tree target
>         after
>         this commit.
>
>             +    // Verify that this slot is valid for this register.
>             +    int FI = Scavenged[I].FrameIndex;
>             +    unsigned S = MFI.getObjectSize(FI);
>             +    unsigned A = MFI.getObjectAlignment(FI);
>             +    if (NeedSize > S || NeedAlign > A)
>             +      continue;
>
>
>         The reason for this is that the Scavenged vector may contain a
>         ScavengedInfo structure with a FrameIndex of -1 after the first
>         call of
>         scavengeRegister on targets where there is no spill slot but the
>         target
>         knows how to save/restore the register (using
>         TRI->saveScavengerRegister). This ScavengedInfo structure with a
>         FrameIndex of -1 is added to the Scavenged vector by the code on
>         lines
>         425-429 in the first call of scavengeRegister.
>
>         I have fixed this in my tree by adding
>
>         if (FI < 0)
>           continue;
>
>         before the the call to MFI.getObjectSize(FI) in the code above,
>         see the
>         attached patch, but there may be a cleaner/better solution.
>
>         Jordy
>
>
>
>     --
>     Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
>     hosted by The Linux Foundation
>
>


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