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| author | Andrew Trick <atrick@apple.com> | 2013-11-14 06:54:10 +0000 |
|---|---|---|
| committer | Andrew Trick <atrick@apple.com> | 2013-11-14 06:54:10 +0000 |
| commit | 72cf01cc7c8f668a17e7fdfe6aaed50e164cac1b (patch) | |
| tree | b9c818979a36538b2eb87abe8b9a543201e8cbd2 /lib | |
| parent | 27df434c5e8c78e8b3e6e9596b55a6a6bd8d5116 (diff) | |
| download | llvm-72cf01cc7c8f668a17e7fdfe6aaed50e164cac1b.tar.gz llvm-72cf01cc7c8f668a17e7fdfe6aaed50e164cac1b.tar.bz2 llvm-72cf01cc7c8f668a17e7fdfe6aaed50e164cac1b.tar.xz | |
Minor extension to llvm.experimental.patchpoint: don't require a call.
If a null call target is provided, don't emit a dummy call. This
allows the runtime to reserve as little nop space as it needs without
the requirement of emitting a call.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194676 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp | 2 | ||||
| -rw-r--r-- | lib/Target/X86/X86MCInstLower.cpp | 27 |
2 files changed, 17 insertions, 12 deletions
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp index 98e067ebd4..e80b63021f 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp @@ -6826,7 +6826,7 @@ void SelectionDAGBuilder::visitStackmap(const CallInst &CI) { /// \brief Lower llvm.experimental.patchpoint directly to its target opcode. void SelectionDAGBuilder::visitPatchpoint(const CallInst &CI) { // void|i64 @llvm.experimental.patchpoint.void|i64(i32 <id>, - // i32 <numNopBytes>, + // i32 <numBytes>, // i8* <target>, // i32 <numArgs>, // [Args...], diff --git a/lib/Target/X86/X86MCInstLower.cpp b/lib/Target/X86/X86MCInstLower.cpp index c718b1cceb..5c3f9af8bf 100644 --- a/lib/Target/X86/X86MCInstLower.cpp +++ b/lib/Target/X86/X86MCInstLower.cpp @@ -765,6 +765,8 @@ static void LowerSTACKMAP(MCStreamer &OutStreamer, OutStreamer.EmitInstruction(MCInstBuilder(X86::NOOP)); } +// Lower a patchpoint of the form: +// [<def>], <id>, <numBytes>, <target>, <numArgs> static void LowerPATCHPOINT(MCStreamer &OutStreamer, X86MCInstLower &MCInstLowering, StackMaps &SM, @@ -813,17 +815,20 @@ static void LowerPATCHPOINT(MCStreamer &OutStreamer, getStackMapEndMOP(MI.operands_begin(), MI.operands_end()), isAnyRegCC && hasDef); - // Emit MOV to materialize the target address and the CALL to target. - // This is encoded with 12-13 bytes, depending on which register is used. - // We conservatively assume that it is 12 bytes and emit in worst case one - // extra NOP byte. - unsigned EncodedBytes = 12; - OutStreamer.EmitInstruction(MCInstBuilder(X86::MOV64ri) - .addReg(MI.getOperand(ScratchIdx).getReg()) - .addImm(MI.getOperand(StartIdx + 2).getImm())); - OutStreamer.EmitInstruction(MCInstBuilder(X86::CALL64r) - .addReg(MI.getOperand(ScratchIdx).getReg())); - + unsigned EncodedBytes = 0; + int64_t CallTarget = MI.getOperand(StartIdx + 2).getImm(); + if (CallTarget) { + // Emit MOV to materialize the target address and the CALL to target. + // This is encoded with 12-13 bytes, depending on which register is used. + // We conservatively assume that it is 12 bytes and emit in worst case one + // extra NOP byte. + EncodedBytes = 12; + OutStreamer.EmitInstruction(MCInstBuilder(X86::MOV64ri) + .addReg(MI.getOperand(ScratchIdx).getReg()) + .addImm(CallTarget)); + OutStreamer.EmitInstruction(MCInstBuilder(X86::CALL64r) + .addReg(MI.getOperand(ScratchIdx).getReg())); + } // Emit padding. unsigned NumNOPBytes = MI.getOperand(StartIdx + 1).getImm(); assert(NumNOPBytes >= EncodedBytes && |