| author |  Devin J. Pohly <djpohly@gmail.com> 2026-06-07 03:03:17-05:00 |
| committer |  Andrew Kelley <andrew@ziglang.org> 2026-06-10 20:52:33-07:00 |
| log | 41d08843ffd59e0ae1396dbf958bdd11257f384a |
| tree | 43441731c1ad5a3718a5f6b725293a1e62090c03 |
| parent | 3a8097ffd4a6370e8188767c6fff409e02186f72 |
x86_64 backend: fix signed enum switch
Once the switch condition is been shifted up so the minimum value is 0,
it makes sense to treat its type as the unsigned version of its original
type.
Fixes #356512 files changed, 19 insertions(+), 1 deletions(-)
src- codegen
- x86_64
- test
- behavior
src/codegen/x86_64/CodeGen.zig+1-1
| ... | @@ -176662,7 +176662,7 @@ fn lowerSwitchBr( | ... | @@ -176662,7 +176662,7 @@ fn lowerSwitchBr( |
| 176662 | }; | 176662 | }; |
| 176663 | const condition_index_lock = cg.register_manager.lockReg(condition_index_reg); | 176663 | const condition_index_lock = cg.register_manager.lockReg(condition_index_reg); |
| 176664 | defer if (condition_index_lock) |lock| cg.register_manager.unlockReg(lock); | 176664 | defer if (condition_index_lock) |lock| cg.register_manager.unlockReg(lock); |
| 176665 | try cg.truncateRegister(condition_ty, condition_index_reg); | 176665 | try cg.truncateRegister(unsigned_condition_ty, condition_index_reg); |
| 176666 | const ptr_size = @divExact(cg.target.ptrBitWidth(), 8); | 176666 | const ptr_size = @divExact(cg.target.ptrBitWidth(), 8); |
| 176667 | try cg.asmMemory(.{ ._mp, .j }, .{ | 176667 | try cg.asmMemory(.{ ._mp, .j }, .{ |
| 176668 | .base = .table, | 176668 | .base = .table, |
test/behavior/enum.zig+18
| ... | @@ -1313,6 +1313,24 @@ test "switch on an extern enum with negative value" { | ... | @@ -1313,6 +1313,24 @@ test "switch on an extern enum with negative value" { |
| 1313 | } | 1313 | } |
| 1314 | } | 1314 | } |
| 1315 | 1315 | ||
| 1316 | test "switch on an enum with small signed tag type" { | ||
| 1317 | const E = enum(i3) { | ||
| 1318 | y = -2, | ||
| 1319 | z = -1, | ||
| 1320 | a = 0, | ||
| 1321 | b = 1, | ||
| 1322 | c = 2, | ||
| 1323 | }; | ||
| 1324 | |||
| 1325 | var runtime: E = .c; | ||
| 1326 | _ = &runtime; | ||
| 1327 | const result: u8 = switch (runtime) { | ||
| 1328 | .y, .z, .a, .b => 0, | ||
| 1329 | .c => 1, | ||
| 1330 | }; | ||
| 1331 | try expect(result == 1); | ||
| 1332 | } | ||
| 1333 | |||
| 1316 | test "Non-exhaustive enum with nonstandard int size behaves correctly" { | 1334 | test "Non-exhaustive enum with nonstandard int size behaves correctly" { |
| 1317 | const E = enum(u15) { _ }; | 1335 | const E = enum(u15) { _ }; |
| 1318 | try expect(@sizeOf(E) == @sizeOf(u15)); | 1336 | try expect(@sizeOf(E) == @sizeOf(u15)); |