Much improved pic jumptable codegen:
Then:
call "L1$pb"
"L1$pb":
popl %eax
...
LBB1_1: # entry
imull $4, %ecx, %ecx
leal LJTI1_0-"L1$pb"(%eax), %edx
addl LJTI1_0-"L1$pb"(%ecx,%eax), %edx
jmpl *%edx
.align 2
.set L1_0_set_3,LBB1_3-LJTI1_0
.set L1_0_set_2,LBB1_2-LJTI1_0
.set L1_0_set_5,LBB1_5-LJTI1_0
.set L1_0_set_4,LBB1_4-LJTI1_0
LJTI1_0:
.long L1_0_set_3
.long L1_0_set_2
Now:
call "L1$pb"
"L1$pb":
popl %eax
...
LBB1_1: # entry
addl LJTI1_0-"L1$pb"(%eax,%ecx,4), %eax
jmpl *%eax
.align 2
.set L1_0_set_3,LBB1_3-"L1$pb"
.set L1_0_set_2,LBB1_2-"L1$pb"
.set L1_0_set_5,LBB1_5-"L1$pb"
.set L1_0_set_4,LBB1_4-"L1$pb"
LJTI1_0:
.long L1_0_set_3
.long L1_0_set_2
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43924 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 6e58631..0731299 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -1599,21 +1599,17 @@
case 8: LD = DAG.getLoad(MVT::i64, Chain, Addr, NULL, 0); break;
}
+ Addr = LD;
if (TLI.getTargetMachine().getRelocationModel() == Reloc::PIC_) {
// For PIC, the sequence is:
// BRIND(load(Jumptable + index) + RelocBase)
- // RelocBase is the JumpTable on PPC and X86, GOT on Alpha
- SDOperand Reloc;
- if (TLI.usesGlobalOffsetTable())
- Reloc = DAG.getNode(ISD::GLOBAL_OFFSET_TABLE, PTy);
- else
- Reloc = Table;
- Addr = (PTy != MVT::i32) ? DAG.getNode(ISD::SIGN_EXTEND, PTy, LD) : LD;
- Addr = DAG.getNode(ISD::ADD, PTy, Addr, Reloc);
- Result = DAG.getNode(ISD::BRIND, MVT::Other, LD.getValue(1), Addr);
- } else {
- Result = DAG.getNode(ISD::BRIND, MVT::Other, LD.getValue(1), LD);
+ // RelocBase can be JumpTable, GOT or some sort of global base.
+ if (PTy != MVT::i32)
+ Addr = DAG.getNode(ISD::SIGN_EXTEND, PTy, Addr);
+ Addr = DAG.getNode(ISD::ADD, PTy, Addr,
+ TLI.getPICJumpTableRelocBase(Table, DAG));
}
+ Result = DAG.getNode(ISD::BRIND, MVT::Other, LD.getValue(1), Addr);
}
}
break;
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 3708b1c..eadfa1f 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -393,6 +393,13 @@
return 1;
}
+SDOperand TargetLowering::getPICJumpTableRelocBase(SDOperand Table,
+ SelectionDAG &DAG) const {
+ if (usesGlobalOffsetTable())
+ return DAG.getNode(ISD::GLOBAL_OFFSET_TABLE, getPointerTy());
+ return Table;
+}
+
//===----------------------------------------------------------------------===//
// Optimization Methods
//===----------------------------------------------------------------------===//