Commit e03ec51b4b47c6730462bed3f8d703767a7b33d9 | zig

author	Koakuma <koachan@protonmail.com> 2022-04-21 05:29:15+07:00
committer	Jakub Konka <kubkon@jakubkonka.com> 2022-05-05 19:34:04+02:00
log	e03ec51b4b47c6730462bed3f8d703767a7b33d9
tree	0d26e76ef15620d344568e05f9868accfb70ee7e
parent	a00d69ea4a8c6e21ca99daa10d3b324609f3ef24

1 files changed, 17 insertions(+), 1 deletions(-)

src/arch/sparcv9/CodeGen.zig+17-1

 @@ -394,7 +394,11 @@ fn gen(self: *Self) !void {
             },
         });
-        // TODO Find a way to fill this slot
+        // Branches in SPARC have a delay slot, that is, the instruction
+        // following it will unconditionally be executed.
+        // See: Section 3.2.3 Control Transfer in SPARCv9 manual.
+        // See also: https://arcb.csc.ncsu.edu/~mueller/codeopt/codeopt00/notes/delaybra.html
+        // TODO Find a way to fill this delay slot
         // nop
         _ = try self.addInst(.{
             .tag = .nop,
 @@ -895,6 +899,12 @@ fn airCall(self: *Self, inst: Air.Inst.Index, modifier: std.builtin.CallOptions.
                         },
                     },
                 });
+                // TODO Find a way to fill this delay slot
+                _ = try self.addInst(.{
+                    .tag = .nop,
+                    .data = .{ .nop = {} },
+                });
             } else if (func_value.castTag(.extern_fn)) |_| {
                 return self.fail("TODO implement calling extern functions", .{});
             } else {
 @@ -917,6 +927,12 @@ fn airCall(self: *Self, inst: Air.Inst.Index, modifier: std.builtin.CallOptions.
                 },
             },
         });
+        // TODO Find a way to fill this delay slot
+        _ = try self.addInst(.{
+            .tag = .nop,
+            .data = .{ .nop = {} },
+        });
     }
     const result = info.return_value;