x86_64: add wrapper for .jmp_reloc

src/arch/x86_64/CodeGen.zig

@@ -423,6 +423,14 @@ fn asmCmovccRegisterRegister(self: *Self, reg1: Register, reg2: Register, cc: bi
     });
 }
 
+fn asmJmpReloc(self: *Self, target: Mir.Inst.Index) !Mir.Inst.Index {
+    return self.addInst(.{
+        .tag = .jmp_reloc,
+        .ops = undefined,
+        .data = .{ .inst = target },
+    });
+}
+
 fn asmNone(self: *Self, tag: Mir.Inst.Tag) !void {
     _ = try self.addInst(.{
         .tag = tag,
@@ -4145,11 +4153,7 @@ fn airRet(self: *Self, inst: Air.Inst.Index) !void {
     // TODO when implementing defer, this will need to jump to the appropriate defer expression.
     // TODO optimization opportunity: figure out when we can emit this as a 2 byte instruction
     // which is available if the jump is 127 bytes or less forward.
-    const jmp_reloc = try self.addInst(.{
-        .tag = .jmp_reloc,
-        .ops = .inst,
-        .data = .{ .inst = undefined },
-    });
+    const jmp_reloc = try self.asmJmpReloc(undefined);
     try self.exitlude_jump_relocs.append(self.gpa, jmp_reloc);
     return self.finishAir(inst, .dead, .{ un_op, .none, .none });
 }
@@ -4181,11 +4185,7 @@ fn airRetLoad(self: *Self, inst: Air.Inst.Index) !void {
     // TODO when implementing defer, this will need to jump to the appropriate defer expression.
     // TODO optimization opportunity: figure out when we can emit this as a 2 byte instruction
     // which is available if the jump is 127 bytes or less forward.
-    const jmp_reloc = try self.addInst(.{
-        .tag = .jmp_reloc,
-        .ops = .inst,
-        .data = .{ .inst = undefined },
-    });
+    const jmp_reloc = try self.asmJmpReloc(undefined);
     try self.exitlude_jump_relocs.append(self.gpa, jmp_reloc);
     return self.finishAir(inst, .dead, .{ un_op, .none, .none });
 }
@@ -4722,11 +4722,7 @@ fn airLoop(self: *Self, inst: Air.Inst.Index) !void {
     const body = self.air.extra[loop.end..][0..loop.data.body_len];
     const jmp_target = @intCast(u32, self.mir_instructions.len);
     try self.genBody(body);
-    _ = try self.addInst(.{
-        .tag = .jmp_reloc,
-        .ops = .inst,
-        .data = .{ .inst = jmp_target },
-    });
+    _ = try self.asmJmpReloc(jmp_target);
     return self.finishAirBookkeeping();
 }
 
@@ -5062,11 +5058,7 @@ fn brVoid(self: *Self, block: Air.Inst.Index) !void {
     // Emit a jump with a relocation. It will be patched up after the block ends.
     try block_data.relocs.ensureUnusedCapacity(self.gpa, 1);
     // Leave the jump offset undefined
-    const jmp_reloc = try self.addInst(.{
-        .tag = .jmp_reloc,
-        .ops = .inst,
-        .data = .{ .inst = undefined },
-    });
+    const jmp_reloc = try self.asmJmpReloc(undefined);
     block_data.relocs.appendAssumeCapacity(jmp_reloc);
 }
 
@@ -5656,13 +5648,7 @@ fn genInlineMemcpy(
     }), tmp_reg.to8());
     try self.asmRegisterImmediate(.add, index_reg, Immediate.u(1));
     try self.asmRegisterImmediate(.sub, count_reg, Immediate.u(1));
-
-    _ = try self.addInst(.{
-        .tag = .jmp_reloc,
-        .ops = .inst,
-        .data = .{ .inst = loop_start },
-    });
-
+    _ = try self.asmJmpReloc(loop_start);
     try self.performReloc(loop_reloc);
 }
 
@@ -5750,13 +5736,7 @@ fn genInlineMemset(
     }
 
     try self.asmRegisterImmediate(.sub, index_reg, Immediate.u(1));
-
-    _ = try self.addInst(.{
-        .tag = .jmp_reloc,
-        .ops = .inst,
-        .data = .{ .inst = loop_start },
-    });
-
+    _ = try self.asmJmpReloc(loop_start);
     try self.performReloc(loop_reloc);
 }
 

src/arch/x86_64/Emit.zig

@@ -410,23 +410,17 @@ fn mirJcc(emit: *Emit, inst: Mir.Inst.Index) InnerError!void {
 }
 
 fn mirJmpReloc(emit: *Emit, inst: Mir.Inst.Index) InnerError!void {
-    const ops = emit.mir.instructions.items(.ops)[inst];
-    switch (ops) {
-        .inst => {
-            const target = emit.mir.instructions.items(.data)[inst].inst;
-            const source = emit.code.items.len;
-            try emit.encode(.jmp, .{
-                .op1 = .{ .imm = Immediate.s(0) },
-            });
-            try emit.relocs.append(emit.bin_file.allocator, .{
-                .source = source,
-                .target = target,
-                .offset = emit.code.items.len - 4,
-                .length = 5,
-            });
-        },
-        else => unreachable,
-    }
+    const target = emit.mir.instructions.items(.data)[inst].inst;
+    const source = emit.code.items.len;
+    try emit.encode(.jmp, .{
+        .op1 = .{ .imm = Immediate.s(0) },
+    });
+    try emit.relocs.append(emit.bin_file.allocator, .{
+        .source = source,
+        .target = target,
+        .offset = emit.code.items.len - 4,
+        .length = 5,
+    });
 }
 
 fn mirCallExtern(emit: *Emit, inst: Mir.Inst.Index) InnerError!void {

src/arch/x86_64/Mir.zig

@@ -140,6 +140,7 @@ pub const Inst = struct {
         mov_moffs,
 
         /// Jump with relocation to another local MIR instruction
+        /// Uses `inst` payload.
         jmp_reloc,
 
         /// Call to an extern symbol via linker relocation.
@@ -242,9 +243,6 @@ pub const Inst = struct {
         /// Memory moffs, rax.
         /// Uses `payload` with extra data of type `MemoryMoffs`.
         moffs_rax,
-        /// Lea into register with linker relocation.
-        /// Uses `payload` payload with data of type `LeaRegisterReloc`.
-        lea_r_reloc,
         /// References another Mir instruction directly.
         /// Uses `inst` payload.
         inst,