[X86InstPrinter] Change printPCRelImm to print the target address in hexadecimal form

```
// llvm-objdump -d output (before)
400000: e8 0b 00 00 00   callq 11
400005: e8 0b 00 00 00   callq 11

// llvm-objdump -d output (after)
400000: e8 0b 00 00 00  callq 0x400010
400005: e8 0b 00 00 00  callq 0x400015

// GNU objdump -d. The lack of 0x is not ideal because the result cannot be re-assembled
400000: e8 0b 00 00 00  callq 400010
400005: e8 0b 00 00 00  callq 400015
```

In llvm-objdump, we pass the address of the next MCInst. Ideally we
should just thread the address of the current address, unfortunately we
cannot call X86MCCodeEmitter::encodeInstruction (X86MCCodeEmitter
requires MCInstrInfo and MCContext) to get the length of the MCInst.

MCInstPrinter::printInst has other callers (e.g llvm-mc -filetype=asm, llvm-mca) which set Address to 0.
They leave MCInstPrinter::PrintBranchImmAsAddress as false and this change is a no-op for them.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D76580

1 files changed, 9 insertions, 3 deletions

diff --git a/llvm/tools/llvm-objdump/llvm-objdump.cpp b/llvm/tools/llvm-objdump/llvm-objdump.cpp
index e9cd34e..4514f3c 100644
--- a/llvm/tools/llvm-objdump/llvm-objdump.cpp
+++ b/llvm/tools/llvm-objdump/llvm-objdump.cpp
@@ -735,9 +735,15 @@ public:
     unsigned Column = OS.tell() - Start;
     OS.indent(Column < TabStop - 1 ? TabStop - 1 - Column : 7 - Column % 8);
 
-    if (MI)
-      IP.printInst(MI, Address.Address, "", STI, OS);
-    else
+    if (MI) {
+      // See MCInstPrinter::printInst. On targets where a PC relative immediate
+      // is relative to the next instruction and the length of a MCInst is
+      // difficult to measure (x86), this is the address of the next
+      // instruction.
+      uint64_t Addr =
+          Address.Address + (STI.getTargetTriple().isX86() ? Bytes.size() : 0);
+      IP.printInst(MI, Addr, "", STI, OS);
+    } else
       OS << "\t<unknown>";
   }
 };