diff --git a/src/arch/arm/CodeGen.zig b/src/arch/arm/CodeGen.zig index 7de0b6ac22..3b378af581 100644 --- a/src/arch/arm/CodeGen.zig +++ b/src/arch/arm/CodeGen.zig @@ -488,14 +488,10 @@ fn gen(self: *Self) !void { const aligned_total_stack_end = mem.alignForwardGeneric(u32, total_stack_size, self.stack_align); const stack_size = aligned_total_stack_end - self.saved_regs_stack_space; self.max_end_stack = stack_size; - if (Instruction.Operand.fromU32(stack_size)) |op| { - self.mir_instructions.set(sub_reloc, .{ - .tag = .sub, - .data = .{ .rr_op = .{ .rd = .sp, .rn = .sp, .op = op } }, - }); - } else { - return self.failSymbol("TODO ARM: allow larger stacks", .{}); - } + self.mir_instructions.set(sub_reloc, .{ + .tag = .sub_sp_scratch_r0, + .data = .{ .imm32 = stack_size }, + }); _ = try self.addInst(.{ .tag = .dbg_epilogue_begin, diff --git a/src/arch/arm/Emit.zig b/src/arch/arm/Emit.zig index 8770ef1a24..188f5a5cfe 100644 --- a/src/arch/arm/Emit.zig +++ b/src/arch/arm/Emit.zig @@ -11,6 +11,7 @@ const link = @import("../../link.zig"); const Module = @import("../../Module.zig"); const Type = @import("../../type.zig").Type; const ErrorMsg = Module.ErrorMsg; +const Target = std.Target; const assert = std.debug.assert; const DW = std.dwarf; const leb128 = std.leb; @@ -93,6 +94,8 @@ pub fn emitMir( .sub => try emit.mirDataProcessing(inst), .subs => try emit.mirDataProcessing(inst), + .sub_sp_scratch_r0 => try emit.mirSubStackPointer(inst), + .asr => try emit.mirShift(inst), .lsl => try emit.mirShift(inst), .lsr => try emit.mirShift(inst), @@ -190,6 +193,24 @@ fn instructionSize(emit: *Emit, inst: Mir.Inst.Index) usize { .dbg_epilogue_begin, .dbg_prologue_end, => return 0, + + .sub_sp_scratch_r0 => { + const imm32 = emit.mir.instructions.items(.data)[inst].imm32; + + if (imm32 == 0) { + return 0 * 4; + } else if (Instruction.Operand.fromU32(imm32) != null) { + // sub + return 1 * 4; + } else if (Target.arm.featureSetHas(emit.target.cpu.features, .has_v7)) { + // movw; movt; sub + return 3 * 4; + } else { + // mov; orr; orr; orr; sub + return 5 * 4; + } + }, + else => return 4, } } @@ -427,6 +448,37 @@ fn mirDataProcessing(emit: *Emit, inst: Mir.Inst.Index) !void { } } +fn mirSubStackPointer(emit: *Emit, inst: Mir.Inst.Index) !void { + const tag = emit.mir.instructions.items(.tag)[inst]; + const cond = emit.mir.instructions.items(.cond)[inst]; + const imm32 = emit.mir.instructions.items(.data)[inst].imm32; + + switch (tag) { + .sub_sp_scratch_r0 => { + if (imm32 == 0) return; + + const operand = Instruction.Operand.fromU32(imm32) orelse blk: { + const scratch: Register = .r0; + + if (Target.arm.featureSetHas(emit.target.cpu.features, .has_v7)) { + try emit.writeInstruction(Instruction.movw(cond, scratch, @truncate(u16, imm32))); + try emit.writeInstruction(Instruction.movt(cond, scratch, @truncate(u16, imm32 >> 16))); + } else { + try emit.writeInstruction(Instruction.mov(cond, scratch, Instruction.Operand.imm(@truncate(u8, imm32), 0))); + try emit.writeInstruction(Instruction.orr(cond, scratch, scratch, Instruction.Operand.imm(@truncate(u8, imm32 >> 8), 12))); + try emit.writeInstruction(Instruction.orr(cond, scratch, scratch, Instruction.Operand.imm(@truncate(u8, imm32 >> 16), 8))); + try emit.writeInstruction(Instruction.orr(cond, scratch, scratch, Instruction.Operand.imm(@truncate(u8, imm32 >> 24), 4))); + } + + break :blk Instruction.Operand.reg(scratch, Instruction.Operand.Shift.none); + }; + + try emit.writeInstruction(Instruction.sub(cond, .sp, .sp, operand)); + }, + else => unreachable, + } +} + fn mirShift(emit: *Emit, inst: Mir.Inst.Index) !void { const tag = emit.mir.instructions.items(.tag)[inst]; const cond = emit.mir.instructions.items(.cond)[inst]; diff --git a/src/arch/arm/Mir.zig b/src/arch/arm/Mir.zig index 45f89b8120..38cf4da3fd 100644 --- a/src/arch/arm/Mir.zig +++ b/src/arch/arm/Mir.zig @@ -111,6 +111,11 @@ pub const Inst = struct { strh, /// Subtract sub, + /// Pseudo-instruction: Subtract 32-bit immediate from stack + /// + /// r0 can be used by Emit as a scratch register for loading + /// the immediate + sub_sp_scratch_r0, /// Subtract, update condition flags subs, /// Supervisor Call @@ -144,6 +149,10 @@ pub const Inst = struct { /// /// Used by e.g. svc imm24: u24, + /// A 32-bit immediate value. + /// + /// Used by e.g. sub_sp_scratch_r0 + imm32: u32, /// Index into `extra`. Meaning of what can be found there is context-dependent. /// /// Used by e.g. load_memory diff --git a/test/behavior/eval.zig b/test/behavior/eval.zig index fb744612ad..0c07a7b5bb 100644 --- a/test/behavior/eval.zig +++ b/test/behavior/eval.zig @@ -1333,7 +1333,6 @@ test "lazy sizeof is resolved in division" { } test "lazy value is resolved as slice operand" { - if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO const A = struct { a: u32 };