Commit b698168664

Andrew Kelley <andrew@ziglang.org>
2022-07-03 22:33:09
stage2: update vector alignment logic
This follows LLVM14's lead on vector alignment, which computes byte count based on the length premultiplied by bits. This commit also disables behavior tests regressed by LLVM 14, only for stage1. stage2 fortunately does not trip the regression.
master
1 parent 15f111a
Changed files (2)
src
type.zig
test
behavior
vector.zig
src/type.zig
@@ -2909,8 +2909,8 @@ pub const Type = extern union {
             .vector => {
                 const len = ty.arrayLen();
                 const bits = try bitSizeAdvanced(ty.elemType(), target, sema_kit);
-                const bytes = (bits + 7) / 8;
-                const alignment = std.math.ceilPowerOfTwoAssert(u64, bytes * len);
+                const bytes = ((bits * len) + 7) / 8;
+                const alignment = std.math.ceilPowerOfTwoAssert(u64, bytes);
                 return AbiAlignmentAdvanced{ .scalar = @intCast(u32, alignment) };
             },
test/behavior/vector.zig
@@ -5,6 +5,12 @@ const math = std.math;
 const expect = std.testing.expect;
 
 test "implicit cast vector to array - bool" {
+    if (builtin.zig_backend == .stage1) {
+        // Regressed in LLVM 14:
+        // https://github.com/llvm/llvm-project/issues/55522
+        return error.SkipZigTest;
+    }
+
     if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
     if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
     if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
@@ -391,6 +397,12 @@ test "initialize vector which is a struct field" {
 }
 
 test "vector comparison operators" {
+    if (builtin.zig_backend == .stage1) {
+        // Regressed in LLVM 14:
+        // https://github.com/llvm/llvm-project/issues/55522
+        return error.SkipZigTest;
+    }
+
     if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
     if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
     if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
@@ -1051,7 +1063,7 @@ test "@shlWithOverflow" {
 
 test "alignment of vectors" {
     try expect(@alignOf(@Vector(2, u8)) == 2);
-    try expect(@alignOf(@Vector(2, u1)) == 2);
+    try expect(@alignOf(@Vector(2, u1)) == 1);
     try expect(@alignOf(@Vector(1, u1)) == 1);
     try expect(@alignOf(@Vector(2, u16)) == 4);
 }