From ee27053db31a89799ae70a4f8c4961259c48b1dd Mon Sep 17 00:00:00 2001 From: Rekai Musuka Date: Sun, 6 Feb 2022 18:48:05 -0400 Subject: [PATCH] chore: remove TODOs and some useless imports --- src/cpu.zig | 1 - src/cpu/arm/block_data_transfer.zig | 2 -- src/cpu/arm/branch.zig | 13 ++++--------- src/cpu/arm/data_processing.zig | 12 ++++++------ src/cpu/arm/half_signed_data_transfer.zig | 9 +++++---- src/cpu/arm/multiply.zig | 2 -- src/cpu/arm/software_interrupt.zig | 2 -- src/cpu/thumb/alu.zig | 18 ++++++++++-------- src/cpu/thumb/data_processing.zig | 2 +- src/cpu/thumb/data_transfer.zig | 2 -- src/cpu/thumb/processing_branch.zig | 2 -- 11 files changed, 26 insertions(+), 39 deletions(-) diff --git a/src/cpu.zig b/src/cpu.zig index 66e457a..688bae8 100644 --- a/src/cpu.zig +++ b/src/cpu.zig @@ -220,7 +220,6 @@ pub const Arm7tdmi = struct { .User, .System => { self.r[13] = self.banked_r[bankedIdx(next) * 2 + 0]; self.r[14] = self.banked_r[bankedIdx(next) * 2 + 1]; - // FIXME: Should we clear out SPSR? }, else => { self.r[13] = self.banked_r[bankedIdx(next) * 2 + 0]; diff --git a/src/cpu/arm/block_data_transfer.zig b/src/cpu/arm/block_data_transfer.zig index 892eeeb..1b66a08 100644 --- a/src/cpu/arm/block_data_transfer.zig +++ b/src/cpu/arm/block_data_transfer.zig @@ -1,5 +1,3 @@ -const std = @import("std"); - const Bus = @import("../../Bus.zig"); const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi; const InstrFn = @import("../../cpu.zig").ArmInstrFn; diff --git a/src/cpu/arm/branch.zig b/src/cpu/arm/branch.zig index 8ca3985..39365f5 100644 --- a/src/cpu/arm/branch.zig +++ b/src/cpu/arm/branch.zig @@ -1,19 +1,16 @@ const std = @import("std"); -const util = @import("../../util.zig"); const Bus = @import("../../Bus.zig"); const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi; const InstrFn = @import("../../cpu.zig").ArmInstrFn; +const u32SignExtend = @import("../../util.zig").u32SignExtend; + pub fn branch(comptime L: bool) InstrFn { return struct { fn inner(cpu: *Arm7tdmi, _: *Bus, opcode: u32) void { - if (L) { - // TODO: Debugging beeg.gba w/ MGBA seems to suggest that I don't do anything here - cpu.r[14] = cpu.r[15]; - } - - cpu.r[15] = cpu.fakePC() +% util.u32SignExtend(24, opcode << 2); + if (L) cpu.r[14] = cpu.r[15]; + cpu.r[15] = cpu.fakePC() +% u32SignExtend(24, opcode << 2); } }.inner; } @@ -21,7 +18,5 @@ pub fn branch(comptime L: bool) InstrFn { pub fn branchAndExchange(cpu: *Arm7tdmi, _: *Bus, opcode: u32) void { const rn = opcode & 0xF; cpu.cpsr.t.write(cpu.r[rn] & 1 == 1); - - // TODO: Is this how I should do it? cpu.r[15] = cpu.r[rn] & 0xFFFF_FFFE; } diff --git a/src/cpu/arm/data_processing.zig b/src/cpu/arm/data_processing.zig index aa40bd2..a2486d9 100644 --- a/src/cpu/arm/data_processing.zig +++ b/src/cpu/arm/data_processing.zig @@ -1,10 +1,10 @@ -const std = @import("std"); - -const shifter = @import("../barrel_shifter.zig"); const Bus = @import("../../Bus.zig"); const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi; const InstrFn = @import("../../cpu.zig").ArmInstrFn; +const rotateRight = @import("../barrel_shifter.zig").rotateRight; +const execute = @import("../barrel_shifter.zig").execute; + pub fn dataProcessing(comptime I: bool, comptime S: bool, comptime instrKind: u4) InstrFn { return struct { fn inner(cpu: *Arm7tdmi, _: *Bus, opcode: u32) void { @@ -20,9 +20,9 @@ pub fn dataProcessing(comptime I: bool, comptime S: bool, comptime instrKind: u4 var op2: u32 = undefined; if (I) { const amount = @truncate(u8, (opcode >> 8 & 0xF) << 1); - op2 = shifter.rotateRight(S, &cpu.cpsr, opcode & 0xFF, amount); + op2 = rotateRight(S, &cpu.cpsr, opcode & 0xFF, amount); } else { - op2 = shifter.execute(S, cpu, opcode); + op2 = execute(S, cpu, opcode); } // Undo special condition from above @@ -275,7 +275,7 @@ fn setTestOpFlags(comptime S: bool, cpu: *Arm7tdmi, opcode: u32, result: u32) vo cpu.cpsr.n.write(result >> 31 & 1 == 1); cpu.cpsr.z.write(result == 0); // Barrel Shifter should always calc CPSR C in TST - if (!S) _ = shifter.execute(true, cpu, opcode); + if (!S) _ = execute(true, cpu, opcode); } fn undefinedTestBehaviour(cpu: *Arm7tdmi) void { diff --git a/src/cpu/arm/half_signed_data_transfer.zig b/src/cpu/arm/half_signed_data_transfer.zig index 6e3bf86..b089adb 100644 --- a/src/cpu/arm/half_signed_data_transfer.zig +++ b/src/cpu/arm/half_signed_data_transfer.zig @@ -1,10 +1,11 @@ const std = @import("std"); -const util = @import("../../util.zig"); const Bus = @import("../../Bus.zig"); const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi; const InstrFn = @import("../../cpu.zig").ArmInstrFn; +const u32SignExtend = @import("../../util.zig").u32SignExtend; + pub fn halfAndSignedDataTransfer(comptime P: bool, comptime U: bool, comptime I: bool, comptime W: bool, comptime L: bool) InstrFn { return struct { fn inner(cpu: *Arm7tdmi, bus: *Bus, opcode: u32) void { @@ -41,14 +42,14 @@ pub fn halfAndSignedDataTransfer(comptime P: bool, comptime U: bool, comptime I: }, 0b10 => { // LDRSB - result = util.u32SignExtend(8, bus.read8(address)); + result = u32SignExtend(8, bus.read8(address)); }, 0b11 => { // LDRSH const value = if (address & 1 == 1) blk: { - break :blk util.u32SignExtend(8, bus.read8(address)); + break :blk u32SignExtend(8, bus.read8(address)); } else blk: { - break :blk util.u32SignExtend(16, bus.read16(address)); + break :blk u32SignExtend(16, bus.read16(address)); }; result = std.math.rotr(u32, value, 8 * (address & 1)); diff --git a/src/cpu/arm/multiply.zig b/src/cpu/arm/multiply.zig index 64fc72e..df03a75 100644 --- a/src/cpu/arm/multiply.zig +++ b/src/cpu/arm/multiply.zig @@ -1,5 +1,3 @@ -const std = @import("std"); - const Bus = @import("../../Bus.zig"); const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi; const InstrFn = @import("../../cpu.zig").ArmInstrFn; diff --git a/src/cpu/arm/software_interrupt.zig b/src/cpu/arm/software_interrupt.zig index f40e8a4..fb41864 100644 --- a/src/cpu/arm/software_interrupt.zig +++ b/src/cpu/arm/software_interrupt.zig @@ -1,5 +1,3 @@ -const std = @import("std"); - const Bus = @import("../../Bus.zig"); const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi; const InstrFn = @import("../../cpu.zig").ArmInstrFn; diff --git a/src/cpu/thumb/alu.zig b/src/cpu/thumb/alu.zig index 4a8bf86..f7921e8 100644 --- a/src/cpu/thumb/alu.zig +++ b/src/cpu/thumb/alu.zig @@ -1,9 +1,6 @@ -const std = @import("std"); - const Bus = @import("../../Bus.zig"); const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi; const InstrFn = @import("../../cpu.zig").ThumbInstrFn; -const shifter = @import("../barrel_shifter.zig"); const adc = @import("../arm/data_processing.zig").adc; const sbc = @import("../arm/data_processing.zig").sbc; @@ -13,6 +10,11 @@ const cmn = @import("../arm/data_processing.zig").cmn; const setTestOpFlags = @import("../arm/data_processing.zig").setTestOpFlags; const setLogicOpFlags = @import("../arm/data_processing.zig").setLogicOpFlags; +const logicalLeft = @import("../barrel_shifter.zig").logicalLeft; +const logicalRight = @import("../barrel_shifter.zig").logicalRight; +const arithmeticRight = @import("../barrel_shifter.zig").arithmeticRight; +const rotateRight = @import("../barrel_shifter.zig").rotateRight; + pub fn format4(comptime op: u4) InstrFn { return struct { fn inner(cpu: *Arm7tdmi, _: *Bus, opcode: u16) void { @@ -35,19 +37,19 @@ pub fn format4(comptime op: u4) InstrFn { }, 0x2 => { // LSL - const result = shifter.logicalLeft(true, &cpu.cpsr, cpu.r[rd], @truncate(u8, cpu.r[rs])); + const result = logicalLeft(true, &cpu.cpsr, cpu.r[rd], @truncate(u8, cpu.r[rs])); cpu.r[rd] = result; setLogicOpFlags(true, cpu, result); }, 0x3 => { // LSR - const result = shifter.logicalRight(true, &cpu.cpsr, cpu.r[rd], @truncate(u8, cpu.r[rs])); + const result = logicalRight(true, &cpu.cpsr, cpu.r[rd], @truncate(u8, cpu.r[rs])); cpu.r[rd] = result; setLogicOpFlags(true, cpu, result); }, 0x4 => { // ASR - const result = shifter.arithmeticRight(true, &cpu.cpsr, cpu.r[rd], @truncate(u8, cpu.r[rs])); + const result = arithmeticRight(true, &cpu.cpsr, cpu.r[rd], @truncate(u8, cpu.r[rs])); cpu.r[rd] = result; setLogicOpFlags(true, cpu, result); }, @@ -61,14 +63,14 @@ pub fn format4(comptime op: u4) InstrFn { }, 0x7 => { // ROR - const result = shifter.rotateRight(true, &cpu.cpsr, cpu.r[rd], @truncate(u8, cpu.r[rs])); + const result = rotateRight(true, &cpu.cpsr, cpu.r[rd], @truncate(u8, cpu.r[rs])); cpu.r[rd] = result; setLogicOpFlags(true, cpu, result); }, 0x8 => { // TST const result = cpu.r[rd] & cpu.r[rs]; - setLogicOpFlags(true, cpu, result); // FIXME: Barrel Shifter? + setLogicOpFlags(true, cpu, result); }, 0x9 => { // NEG diff --git a/src/cpu/thumb/data_processing.zig b/src/cpu/thumb/data_processing.zig index d8c0b72..2cb53e3 100644 --- a/src/cpu/thumb/data_processing.zig +++ b/src/cpu/thumb/data_processing.zig @@ -101,7 +101,7 @@ pub fn format12(comptime isSP: bool, comptime rd: u3) InstrFn { // ADD const left = if (isSP) cpu.r[13] else (cpu.r[15] + 2) & 0xFFFF_FFFD; const right = (opcode & 0xFF) << 2; - const result = left + right; // TODO: What about overflows? + const result = left + right; cpu.r[rd] = result; } }.inner; diff --git a/src/cpu/thumb/data_transfer.zig b/src/cpu/thumb/data_transfer.zig index 786dd67..15ed733 100644 --- a/src/cpu/thumb/data_transfer.zig +++ b/src/cpu/thumb/data_transfer.zig @@ -9,8 +9,6 @@ pub fn format6(comptime rd: u3) InstrFn { fn inner(cpu: *Arm7tdmi, bus: *Bus, opcode: u16) void { // LDR const offset = (opcode & 0xFF) << 2; - - // FIXME: Should this overflow? cpu.r[rd] = bus.read32((cpu.r[15] + 2 & 0xFFFF_FFFD) + offset); } }.inner; diff --git a/src/cpu/thumb/processing_branch.zig b/src/cpu/thumb/processing_branch.zig index 20b2493..52faf15 100644 --- a/src/cpu/thumb/processing_branch.zig +++ b/src/cpu/thumb/processing_branch.zig @@ -1,5 +1,3 @@ -const std = @import("std"); - const Bus = @import("../../Bus.zig"); const Arm7tdmi = @import("../../cpu.zig").Arm7tdmi; const InstrFn = @import("../../cpu.zig").ThumbInstrFn;