JumpTable support! What this represents is working asm and jit support for
x86 and ppc for 100% dense switch statements when relocations are non-PIC.
This support will be extended and enhanced in the coming days to support
PIC, and less dense forms of jump tables.
llvm-svn: 27947
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index db2b5dd..3861fc3 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -169,6 +169,7 @@
setOperationAction(ISD::RET , MVT::Other, Custom);
// Darwin ABI issue.
setOperationAction(ISD::ConstantPool , MVT::i32 , Custom);
+ setOperationAction(ISD::JumpTable , MVT::i32 , Custom);
setOperationAction(ISD::GlobalAddress , MVT::i32 , Custom);
setOperationAction(ISD::ExternalSymbol , MVT::i32 , Custom);
// 64-bit addm sub, shl, sra, srl (iff 32-bit x86)
@@ -2792,8 +2793,8 @@
return Chain;
}
- // ConstantPool, GlobalAddress, and ExternalSymbol are lowered as their
- // target countpart wrapped in the X86ISD::Wrapper node. Suppose N is
+ // ConstantPool, JumpTable, GlobalAddress, and ExternalSymbol are lowered as
+ // their target countpart wrapped in the X86ISD::Wrapper node. Suppose N is
// one of the above mentioned nodes. It has to be wrapped because otherwise
// Select(N) returns N. So the raw TargetGlobalAddress nodes, etc. can only
// be used to form addressing mode. These wrapped nodes will be selected
@@ -2812,6 +2813,20 @@
return Result;
}
+ case ISD::JumpTable: {
+ JumpTableSDNode *JT = cast<JumpTableSDNode>(Op);
+ SDOperand Result = DAG.getNode(X86ISD::Wrapper, getPointerTy(),
+ DAG.getTargetJumpTable(JT->getIndex(),
+ getPointerTy()));
+ if (Subtarget->isTargetDarwin()) {
+ // With PIC, the address is actually $g + Offset.
+ if (getTargetMachine().getRelocationModel() == Reloc::PIC)
+ Result = DAG.getNode(ISD::ADD, getPointerTy(),
+ DAG.getNode(X86ISD::GlobalBaseReg, getPointerTy()), Result);
+ }
+
+ return Result;
+ }
case ISD::GlobalAddress: {
GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
SDOperand Result = DAG.getNode(X86ISD::Wrapper, getPointerTy(),