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[PowerPC] Use the ABI indirect-call protocol for patchpoints

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We used to take the address specified as the direct target of the patchpoint
and did no TOC-pointer handling.  This, however, as not all that useful,
because MCJIT tends to create a lot of modules, and they have their own TOC
sections. Thus, to call from the generated code to other generated code, you
really need to switch TOC pointers. Make this work as expected, and under
ELFv1, tread the address as the function descriptor address so that the correct
TOC pointer can be loaded.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242217 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Hal Finkel
2015-07-14 22:26:06 +00:00
parent 7a6e3434ba
commit a8eaf29f90
5 changed files with 78 additions and 26 deletions
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44
lib/Target/PowerPC/PPCAsmPrinter.cpp
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@@ -369,28 +369,70 @@ void PPCAsmPrinter::LowerPATCHPOINT(MCStreamer &OutStreamer, StackMaps &SM,
assert((CallTarget & 0xFFFFFFFFFFFF) == CallTarget &&
"High 16 bits of call target should be zero.");
unsigned ScratchReg = MI.getOperand(Opers.getNextScratchIdx()).getReg();
EncodedBytes = 6*4;
EncodedBytes = 0;
// Materialize the jump address:
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::LI8)
.addReg(ScratchReg)
.addImm((CallTarget >> 32) & 0xFFFF));
++EncodedBytes;
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::RLDIC)
.addReg(ScratchReg)
.addReg(ScratchReg)
.addImm(32).addImm(16));
++EncodedBytes;
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ORIS8)
.addReg(ScratchReg)
.addReg(ScratchReg)
.addImm((CallTarget >> 16) & 0xFFFF));
++EncodedBytes;
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ORI8)
.addReg(ScratchReg)
.addReg(ScratchReg)
.addImm(CallTarget & 0xFFFF));
// Save the current TOC pointer before the remote call.
int TOCSaveOffset = Subtarget->isELFv2ABI() ? 24 : 40;
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::STD)
.addReg(PPC::X2)
.addImm(TOCSaveOffset)
.addReg(PPC::X1));
++EncodedBytes;
// If we're on ELFv1, then we need to load the actual function pointer from
// the function descriptor.
if (!Subtarget->isELFv2ABI()) {
// Load the new TOC pointer and the function address, but not r11
// (needing this is rare, and loading it here would prevent passing it
// via a 'nest' parameter.
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::LD)
.addReg(PPC::X2)
.addImm(8)
.addReg(ScratchReg));
++EncodedBytes;
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::LD)
.addReg(ScratchReg)
.addImm(0)
.addReg(ScratchReg));
++EncodedBytes;
}
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::MTCTR8).addReg(ScratchReg));
++EncodedBytes;
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BCTRL8));
++EncodedBytes;
// Restore the TOC pointer after the call.
EmitToStreamer(OutStreamer, MCInstBuilder(PPC::LD)
.addReg(PPC::X2)
.addImm(TOCSaveOffset)
.addReg(PPC::X1));
++EncodedBytes;
}
// Each instruction is 4 bytes.
EncodedBytes *= 4;
// Emit padding.
unsigned NumBytes = Opers.getMetaOper(PatchPointOpers::NBytesPos).getImm();
assert(NumBytes >= EncodedBytes &&