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stage2 codegen: Set MCValue of register arguments to their stack copy

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joachimschmidt557 2021-04-09 18:02:22 +02:00
parent c676c21824
commit a6ddc12b33
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1 changed files with 53 additions and 27 deletions
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80
src/codegen.zig
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@ -1681,22 +1681,34 @@ fn Function(comptime arch: std.Target.Cpu.Arch) type {
switch (mcv) {
.register => |reg| {
// Copy arg to stack for better debugging
const ty = inst.base.ty;
const abi_size = math.cast(u32, ty.abiSize(self.target.*)) catch {
return self.fail(inst.base.src, "type '{}' too big to fit into stack frame", .{ty});
};
const abi_align = ty.abiAlignment(self.target.*);
const stack_offset = try self.allocMem(&inst.base, abi_size, abi_align);
try self.genSetStack(inst.base.src, ty, stack_offset, MCValue{ .register = reg });
const adjusted_stack_offset = math.negateCast(stack_offset + abi_size) catch {
return self.fail(inst.base.src, "Stack offset too large for arguments", .{});
};
switch (self.debug_output) {
.dwarf => |dbg_out| {
try dbg_out.dbg_info.ensureCapacity(dbg_out.dbg_info.items.len + 3);
dbg_out.dbg_info.appendAssumeCapacity(link.File.Elf.abbrev_parameter);
dbg_out.dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT_location, DW.FORM_exprloc
1, // ULEB128 dwarf expression length
reg.dwarfLocOp(),
});
try dbg_out.dbg_info.ensureCapacity(dbg_out.dbg_info.items.len + 5 + name_with_null.len);
try self.addDbgInfoTypeReloc(inst.base.ty); // DW.AT_type, DW.FORM_ref4
dbg_out.dbg_info.appendSliceAssumeCapacity(name_with_null); // DW.AT_name, DW.FORM_string
},
.none => {},
}
},
.stack_offset => |offset| {
switch (self.debug_output) {
.dwarf => |dbg_out| {
switch (arch) {
.arm, .armeb => {
const ty = inst.base.ty;
const abi_size = math.cast(u32, ty.abiSize(self.target.*)) catch {
return self.fail(inst.base.src, "type '{}' too big to fit into stack frame", .{ty});
};
const adjusted_stack_offset = math.negateCast(offset + abi_size) catch {
return self.fail(inst.base.src, "Stack offset too large for arguments", .{});
};
try dbg_out.dbg_info.append(link.File.Elf.abbrev_parameter);
// Get length of the LEB128 stack offset
@ -1708,19 +1720,13 @@ fn Function(comptime arch: std.Target.Cpu.Arch) type {
try leb128.writeULEB128(dbg_out.dbg_info.writer(), counting_writer.bytes_written + 1);
try dbg_out.dbg_info.append(DW.OP_breg11);
try leb128.writeILEB128(dbg_out.dbg_info.writer(), adjusted_stack_offset);
try dbg_out.dbg_info.ensureCapacity(dbg_out.dbg_info.items.len + 5 + name_with_null.len);
try self.addDbgInfoTypeReloc(inst.base.ty); // DW.AT_type, DW.FORM_ref4
dbg_out.dbg_info.appendSliceAssumeCapacity(name_with_null); // DW.AT_name, DW.FORM_string
},
else => {
try dbg_out.dbg_info.ensureCapacity(dbg_out.dbg_info.items.len + 3);
dbg_out.dbg_info.appendAssumeCapacity(link.File.Elf.abbrev_parameter);
dbg_out.dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT_location, DW.FORM_exprloc
1, // ULEB128 dwarf expression length
reg.dwarfLocOp(),
});
},
else => {},
}
try dbg_out.dbg_info.ensureCapacity(dbg_out.dbg_info.items.len + 5 + name_with_null.len);
try self.addDbgInfoTypeReloc(inst.base.ty); // DW.AT_type, DW.FORM_ref4
dbg_out.dbg_info.appendSliceAssumeCapacity(name_with_null); // DW.AT_name, DW.FORM_string
},
.none => {},
}
@ -1738,19 +1744,39 @@ fn Function(comptime arch: std.Target.Cpu.Arch) type {
}
const result = self.args[arg_index];
try self.genArgDbgInfo(inst, result);
const mcv = switch (arch) {
// TODO support stack-only registers on all target architectures
.arm, .armeb, .aarch64, .aarch64_32, .aarch64_be => switch (result) {
// Copy registers to the stack
.register => |reg| blk: {
const ty = inst.base.ty;
const abi_size = math.cast(u32, ty.abiSize(self.target.*)) catch {
return self.fail(inst.base.src, "type '{}' too big to fit into stack frame", .{ty});
};
const abi_align = ty.abiAlignment(self.target.*);
const stack_offset = try self.allocMem(&inst.base, abi_size, abi_align);
try self.genSetStack(inst.base.src, ty, stack_offset, MCValue{ .register = reg });
break :blk MCValue{ .stack_offset = stack_offset };
},
else => result,
},
else => result,
};
try self.genArgDbgInfo(inst, mcv);
if (inst.base.isUnused())
return MCValue.dead;
switch (result) {
switch (mcv) {
.register => |reg| {
try self.register_manager.registers.ensureCapacity(self.gpa, self.register_manager.registers.count() + 1);
self.register_manager.getRegAssumeFree(toCanonicalReg(reg), &inst.base);
},
else => {},
}
return result;
return mcv;
}
fn genBreakpoint(self: *Self, src: LazySrcLoc) !MCValue {
@ -2257,7 +2283,7 @@ fn Function(comptime arch: std.Target.Cpu.Arch) type {
const rhs = try self.resolveInst(inst.rhs);
const src_mcv = rhs;
const dst_mcv = if (lhs != .register) try self.copyToNewRegister(&inst.base, lhs) else lhs;
const dst_mcv = if (lhs != .register) try self.copyToNewRegister(inst.lhs, lhs) else lhs;
try self.genArmBinOpCode(inst.base.src, dst_mcv.register, dst_mcv, src_mcv, .cmp_eq);
const info = inst.lhs.ty.intInfo(self.target.*);