Pass an ArrayRef to MCDisassembler::getInstruction.
With this patch MCDisassembler::getInstruction takes an ArrayRef<uint8_t>
instead of a MemoryObject.
Even on X86 there is a maximum size an instruction can have. Given
that, it seems way simpler and more efficient to just pass an ArrayRef
to the disassembler instead of a MemoryObject and have it do a virtual
call every time it wants some extra bytes.
llvm-svn: 221751
diff --git a/llvm/lib/Target/SystemZ/Disassembler/SystemZDisassembler.cpp b/llvm/lib/Target/SystemZ/Disassembler/SystemZDisassembler.cpp
index 2b0ae3c..23173bf 100644
--- a/llvm/lib/Target/SystemZ/Disassembler/SystemZDisassembler.cpp
+++ b/llvm/lib/Target/SystemZ/Disassembler/SystemZDisassembler.cpp
@@ -12,7 +12,6 @@
#include "llvm/MC/MCFixedLenDisassembler.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCSubtargetInfo.h"
-#include "llvm/Support/MemoryObject.h"
#include "llvm/Support/TargetRegistry.h"
using namespace llvm;
@@ -28,8 +27,8 @@
: MCDisassembler(STI, Ctx) {}
virtual ~SystemZDisassembler() {}
- DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
- const MemoryObject &Region, uint64_t Address,
+ DecodeStatus getInstruction(MCInst &instr, uint64_t &Size,
+ ArrayRef<uint8_t> Bytes, uint64_t Address,
raw_ostream &VStream,
raw_ostream &CStream) const override;
};
@@ -287,14 +286,13 @@
#include "SystemZGenDisassemblerTables.inc"
DecodeStatus SystemZDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
- const MemoryObject &Region,
+ ArrayRef<uint8_t> Bytes,
uint64_t Address,
raw_ostream &OS,
raw_ostream &CS) const {
// Get the first two bytes of the instruction.
- uint8_t Bytes[6];
Size = 0;
- if (Region.readBytes(Address, 2, Bytes) == -1)
+ if (Bytes.size() < 2)
return MCDisassembler::Fail;
// The top 2 bits of the first byte specify the size.
@@ -311,7 +309,7 @@
}
// Read any remaining bytes.
- if (Size > 2 && Region.readBytes(Address + 2, Size - 2, Bytes + 2) == -1)
+ if (Bytes.size() < Size)
return MCDisassembler::Fail;
// Construct the instruction.