[BOLT] Correctly print preferred disassembly for annotated instructio…

…ns (llvm#120564)

This patch makes sure that `BinaryContext::printInstruction` prints the
preferred disassembly. Preferred disassembly only gets printed when
there are no annotations on the MCInst. Therefore, this patch
temporarily removes the annotations before printing it.

A few examples of before and after on AArch64 instructions are as
follows:

```
  BEFORE                     AFTER
                             (preferred disassembly)

  ret   x30                  ret
  orr   x30, xzr, x0         mov   x30, x0
  hint  llvm#29                  autiasp
  hint  #12                  autia1716
```

Clearly, the preferred disassembly is easier for developers to read, and
is the disassembly that tools should be printing.

This patch is motivated as part of future work on the
llvm-bolt-binary-analysis tool, making sure that the reports it prints
do use preferred disassembly.

This patch was cherry-picked from
https://github.com/kbeyls/llvm-project/tree/bolt-gadget-scanner-prototype.

In this current patch, this only affects existing RISCV test cases.

This patch also does improve test cases in future patches that will
introduce a binary analysis for llvm-bolt-binary-analysis that checks
for correct application of pac-ret (pointer authentication on return
addresses).

bolt/lib/Core/BinaryContext.cpp

@@ -1961,7 +1961,15 @@ void BinaryContext::printInstruction(raw_ostream &OS, const MCInst &Instruction,
     OS << "\tjit\t" << MIB->getTargetSymbol(Instruction)->getName()
        << " # ID: " << DynamicID;
   } else {
-    InstPrinter->printInst(&Instruction, 0, "", *STI, OS);
+    // If there are annotations on the instruction, the MCInstPrinter will fail
+    // to print the preferred alias as it only does so when the number of
+    // operands is as expected. See
+    // https://github.com/llvm/llvm-project/blob/782f1a0d895646c364a53f9dcdd6d4ec1f3e5ea0/llvm/lib/MC/MCInstPrinter.cpp#L142
+    // Therefore, create a temporary copy of the Inst from which the annotations
+    // are removed, and print that Inst.
+    MCInst InstNoAnnot = Instruction;
+    MIB->stripAnnotations(InstNoAnnot);
+    InstPrinter->printInst(&InstNoAnnot, 0, "", *STI, OS);
   }
   if (MIB->isCall(Instruction)) {
     if (MIB->isTailCall(Instruction))

bolt/test/RISCV/call-annotations.s

@@ -16,13 +16,13 @@ f:
 
 // CHECK-LABEL: Binary Function "_start" after building cfg {
 // CHECK:      auipc ra, f
-// CHECK-NEXT: jalr ra, -0x4(ra) # Offset: 4
-// CHECK-NEXT: jal ra, f # Offset: 8
-// CHECK-NEXT: jal zero, f # TAILCALL  # Offset: 12
+// CHECK-NEXT: jalr -0x4(ra) # Offset: 4
+// CHECK-NEXT: jal f # Offset: 8
+// CHECK-NEXT: j f # TAILCALL  # Offset: 12
 
 // CHECK-LABEL: Binary Function "long_tail" after building cfg {
 // CHECK:      auipc t1, f
-// CHECK-NEXT: jalr zero, -0x18(t1) # TAILCALL  # Offset: 8
+// CHECK-NEXT: jr -0x18(t1) # TAILCALL  # Offset: 8
 
 // CHECK-LABEL: Binary Function "compressed_tail" after building cfg {
 // CHECK:      jr a0 # TAILCALL  # Offset: 0

bolt/test/RISCV/relax.s

@@ -5,9 +5,9 @@
 // RUN: llvm-objdump -d %t.bolt | FileCheck --check-prefix=OBJDUMP %s
 
 // CHECK:      Binary Function "_start" after building cfg {
-// CHECK:      jal ra, near_f
+// CHECK:      jal near_f
 // CHECK-NEXT: auipc ra, far_f
-// CHECK-NEXT: jalr ra, 0xc(ra)
+// CHECK-NEXT: jalr 0xc(ra)
 // CHECK-NEXT: j near_f
 
 // CHECK:      Binary Function "_start" after fix-riscv-calls {

bolt/test/RISCV/reloc-branch.s

@@ -7,7 +7,7 @@
   .p2align 1
 // CHECK: Binary Function "_start" after building cfg {
 _start:
-// CHECK: beq zero, zero, .Ltmp0
+// CHECK: beqz zero, .Ltmp0
   beq zero, zero, 1f
   nop
 // CHECK: .Ltmp0

bolt/test/RISCV/reloc-jal.s

@@ -14,7 +14,7 @@ f:
   .globl _start
   .p2align 1
 _start:
-// CHECK: jal ra, f
+// CHECK: jal f
   jal ra, f
   ret
   .size _start, .-_start