| author |  Jakub Konka <kubkon@jakubkonka.com> 2023-11-02 13:21:25+01:00 |
| committer | Jakub Konka <kubkon@jakubkonka.com> 2023-11-04 09:11:37+01:00 |
| log | d2c4597eb5fcaba07f15c22092fc8c42c8b70ee3 |
| tree | 9f2909dba23d0bdb715ecdcb7e0889be3a5170ac |
| parent | ccb2afacc00264897cc474befc13f36239c91b03 |
x86_64: rewrite .got.zig movs to standard loads when emitting objects
2 files changed, 26 insertions(+), 7 deletions(-)
src/arch/x86_64/Emit.zig+4-3
| ... | ... | @@ -85,14 +85,15 @@ pub fn emitMir(emit: *Emit) Error!void { |
| 85 | 85 | @tagName(emit.lower.bin_file.tag), |
| 86 | 86 | }), |
| 87 | 87 | .linker_reloc => |data| if (emit.lower.bin_file.cast(link.File.Elf)) |elf_file| { |
| 88 | const is_obj = emit.lower.bin_file.options.effectiveOutputMode() == .Obj; | |
| 88 | 89 | const atom = elf_file.symbol(data.atom_index).atom(elf_file).?; |
| 89 | 90 | const sym_index = elf_file.zigObjectPtr().?.symbol(data.sym_index); |
| 90 | 91 | const sym = elf_file.symbol(sym_index); |
| 91 | if (sym.flags.needs_zig_got and emit.lower.bin_file.options.effectiveOutputMode() != .Obj) { | |
| 92 | if (sym.flags.needs_zig_got and !is_obj) { | |
| 92 | 93 | _ = try sym.getOrCreateZigGotEntry(sym_index, elf_file); |
| 93 | 94 | } |
| 94 | 95 | if (emit.lower.bin_file.options.pic) { |
| 95 | const r_type: u32 = if (sym.flags.needs_zig_got) | |
| 96 | const r_type: u32 = if (sym.flags.needs_zig_got and !is_obj) | |
| 96 | 97 | link.File.Elf.R_X86_64_ZIG_GOTPCREL |
| 97 | 98 | else if (sym.flags.needs_got) |
| 98 | 99 | std.elf.R_X86_64_GOTPCREL |
| ... | ... | @@ -104,7 +105,7 @@ pub fn emitMir(emit: *Emit) Error!void { |
| 104 | 105 | .r_addend = -4, |
| 105 | 106 | }); |
| 106 | 107 | } else { |
| 107 | const r_type: u32 = if (sym.flags.needs_zig_got) | |
| 108 | const r_type: u32 = if (sym.flags.needs_zig_got and !is_obj) | |
| 108 | 109 | link.File.Elf.R_X86_64_ZIG_GOT32 |
| 109 | 110 | else if (sym.flags.needs_got) |
| 110 | 111 | std.elf.R_X86_64_GOT32 |
src/arch/x86_64/Lower.zig+22-4
| ... | ... | @@ -319,6 +319,15 @@ fn reloc(lower: *Lower, target: Reloc.Target) Immediate { |
| 319 | 319 | } |
| 320 | 320 | |
| 321 | 321 | fn emit(lower: *Lower, prefix: Prefix, mnemonic: Mnemonic, ops: []const Operand) Error!void { |
| 322 | const needsZigGot = struct { | |
| 323 | fn needsZigGot(sym: bits.Symbol, ctx: *link.File) bool { | |
| 324 | const elf_file = ctx.cast(link.File.Elf).?; | |
| 325 | const sym_index = elf_file.zigObjectPtr().?.symbol(sym.sym_index); | |
| 326 | return elf_file.symbol(sym_index).flags.needs_zig_got; | |
| 327 | } | |
| 328 | }.needsZigGot; | |
| 329 | ||
| 330 | const is_obj = lower.bin_file.options.effectiveOutputMode() == .Obj; | |
| 322 | 331 | var emit_prefix = prefix; |
| 323 | 332 | var emit_mnemonic = mnemonic; |
| 324 | 333 | var emit_ops_storage: [4]Operand = undefined; |
| ... | ... | @@ -334,7 +343,13 @@ fn emit(lower: *Lower, prefix: Prefix, mnemonic: Mnemonic, ops: []const Operand) |
| 334 | 343 | assert(mem_op.sib.scale_index.scale == 0); |
| 335 | 344 | _ = lower.reloc(.{ .linker_reloc = sym }); |
| 336 | 345 | break :op if (lower.bin_file.options.pic) switch (mnemonic) { |
| 337 | .mov, .lea => .{ .mem = Memory.rip(mem_op.sib.ptr_size, 0) }, | |
| 346 | .lea => { | |
| 347 | break :op .{ .mem = Memory.rip(mem_op.sib.ptr_size, 0) }; | |
| 348 | }, | |
| 349 | .mov => { | |
| 350 | if (is_obj and needsZigGot(sym, lower.bin_file)) emit_mnemonic = .lea; | |
| 351 | break :op .{ .mem = Memory.rip(mem_op.sib.ptr_size, 0) }; | |
| 352 | }, | |
| 338 | 353 | else => unreachable, |
| 339 | 354 | } else switch (mnemonic) { |
| 340 | 355 | .call => .{ .mem = Memory.sib(mem_op.sib.ptr_size, .{ |
| ... | ... | @@ -344,9 +359,12 @@ fn emit(lower: *Lower, prefix: Prefix, mnemonic: Mnemonic, ops: []const Operand) |
| 344 | 359 | emit_mnemonic = .mov; |
| 345 | 360 | break :op .{ .imm = Immediate.s(0) }; |
| 346 | 361 | }, |
| 347 | .mov => .{ .mem = Memory.sib(mem_op.sib.ptr_size, .{ | |
| 348 | .base = .{ .reg = .ds }, | |
| 349 | }) }, | |
| 362 | .mov => { | |
| 363 | if (is_obj and needsZigGot(sym, lower.bin_file)) emit_mnemonic = .lea; | |
| 364 | break :op .{ .mem = Memory.sib(mem_op.sib.ptr_size, .{ | |
| 365 | .base = .{ .reg = .ds }, | |
| 366 | }) }; | |
| 367 | }, | |
| 350 | 368 | else => unreachable, |
| 351 | 369 | }; |
| 352 | 370 | }, |