- Fix alignment for uint128 to 16 with WASM targets.

- Incorrect assert in struct alignment checking #2841
- Packed structs sometimes not lowered as such.

lib/std/core/env.c3

@@ -154,12 +154,13 @@ const bool FREEBSD = LIBC && OS_TYPE == FREEBSD;
 const bool NETBSD = LIBC && OS_TYPE == NETBSD;
 const bool BSD_FAMILY = env::FREEBSD || env::OPENBSD || env::NETBSD;
 const bool WASI = LIBC && OS_TYPE == WASI;
+const bool WASM = ARCH_TYPE == ArchType.WASM32 || ARCH_TYPE == ArchType.WASM64;
 const bool ANDROID = LIBC && OS_TYPE == ANDROID;
 const bool WASM_NOLIBC @builtin @deprecated("Use 'FREESTANDING_WASM' instead") = !LIBC && ARCH_TYPE == ArchType.WASM32 || ARCH_TYPE == ArchType.WASM64;
 const bool FREESTANDING_PE32 = NO_LIBC && OS_TYPE == WIN32;
 const bool FREESTANDING_MACHO = NO_LIBC && OS_TYPE == MACOS;
 const bool FREESTANDING_ELF = NO_LIBC && !env::FREESTANDING_PE32 && !env::FREESTANDING_MACHO && !env::FREESTANDING_WASM;
-const bool FREESTANDING_WASM = NO_LIBC && (ARCH_TYPE == ArchType.WASM32 || ARCH_TYPE == ArchType.WASM64);
+const bool FREESTANDING_WASM = NO_LIBC && WASM;
 const bool FREESTANDING = env::FREESTANDING_PE32 || env::FREESTANDING_MACHO || env::FREESTANDING_ELF || env::FREESTANDING_WASM;
 const bool ADDRESS_SANITIZER = $$ADDRESS_SANITIZER;
 const bool MEMORY_SANITIZER = $$MEMORY_SANITIZER;

lib/std/core/mem.c3

@@ -7,7 +7,7 @@ import std::os::posix, std::os::win32;
 import std::math;
 
 const MAX_MEMORY_ALIGNMENT = 0x1000_0000;
-const DEFAULT_MEM_ALIGNMENT = (void*.alignof) * 2;
+const DEFAULT_MEM_ALIGNMENT = env::WASM ? 16 : (void*.alignof) * 2;
 const ulong KB = 1024;
 const ulong MB = KB * 1024;
 const ulong GB = MB * 1024;

releasenotes.md

@@ -134,6 +134,9 @@
 - Lowering of optional in && was incorrect #2843
 - Resolving &X.b when X is a const incorrectly checked for runtime constness #2842
 - Alignment param on $$unaligned_* not checked for zero #2844
+- Fix alignment for uint128 to 16 with WASM targets.
+- Incorrect assert in struct alignment checking #2841
+- Packed structs sometimes not lowered as such.
 
 ### Stdlib changes
 - Add `ThreadPool` join function to wait for all threads to finish in the pool without destroying the threads.

src/compiler/llvm_codegen_type.c

@@ -49,6 +49,7 @@ static inline LLVMTypeRef llvm_type_from_decl(GenContext *c, Decl *decl)
 				vec_add(types, llvm_const_padding_type(c, decl->strukt.padding));
 			}
 			LLVMStructSetBody(type, types, vec_size(types), decl->is_packed);
+			ASSERT_SPAN(decl, llvm_abi_size(c, type) == type_size(decl->type));
 			return type;
 		}
 		case DECL_UNION:

src/compiler/sema_decls.c

@@ -679,7 +679,7 @@ static bool sema_analyse_struct_members(SemaContext *context, Decl *decl)
 	}
 	if (is_unaligned && size > offset)
 	{
-		ASSERT(!decl->strukt.padding);
+		ASSERT(!decl->strukt.padding || decl->strukt.padding == size - offset);
 		decl->strukt.padding = size - offset;
 	}
 
@@ -703,7 +703,7 @@ static bool sema_analyse_struct_members(SemaContext *context, Decl *decl)
 		}
 	}
 
-	decl->is_packed = is_unaligned;
+	decl->is_packed |= is_unaligned;
 	// Strip padding if we are aligned.
 	if (!decl->is_packed && is_naturally_aligned)
 	{

src/compiler/target.c

@@ -1683,9 +1683,7 @@ static AlignData os_target_alignment_of_int(OsType os, ArchType arch, uint32_t b
 		case ARCH_TYPE_PPC64:
 		case ARCH_TYPE_PPC:
 		case ARCH_TYPE_PPC64LE:
-		case ARCH_TYPE_WASM64:
 		case ARCH_TYPE_RISCV32:
-		case ARCH_TYPE_WASM32:
 		case ARCH_TYPE_XTENSA:
 			return (AlignData) { MIN(64u, bits), MIN(64u, bits) };
 		case ARCH_TYPE_X86_64:
@@ -1694,6 +1692,8 @@ static AlignData os_target_alignment_of_int(OsType os, ArchType arch, uint32_t b
 #else
 			FALLTHROUGH;
 #endif
+		case ARCH_TYPE_WASM64:
+		case ARCH_TYPE_WASM32:
 		case ARCH_TYPE_RISCV64:
 			return (AlignData) { bits, bits };
 		case ARCH_TYPE_AARCH64:

test/test_suite/struct/struct_pack_and_align.c3t

@@ -58,7 +58,7 @@ fn int test5(ichar x)
     return y.foo + y.bar;
 }
 
-// { i32, i16, i16 }
+// <{ i32, i16, i16 }>
 struct Foo6 @packed
 {
     int a;
@@ -76,16 +76,15 @@ Foo6 foo6 = { 1, 2, 3 };
 %Foo3 = type <{ i8, i64, [7 x i8] }>
 %Foo4 = type <{ i8, i64 }>
 %Foo5 = type { i32, [12 x i8], i8, [15 x i8] }
-%Foo6 = type { i32, i16, i16 }
+%Foo6 = type <{ i32, i16, i16 }>
 
 @struct2.foo1 = local_unnamed_addr global %Foo1 <{ i64 1, i8 2, [3 x i8] undef }>, align 4
 @struct2.foo2 = local_unnamed_addr global %Foo2 <{ i8 1, i64 2, [3 x i8] undef }>, align 4
 @struct2.foo3 = local_unnamed_addr global %Foo3 <{ i8 1, i64 2, [7 x i8] undef }>, align 8
 @struct2.foo4 = local_unnamed_addr global %Foo4 <{ i8 1, i64 2 }>, align 1
 @struct2.foo5 = local_unnamed_addr global %Foo5 { i32 1, [12 x i8] undef, i8 2, [15 x i8] undef }, align 16
-@struct2.foo6 = local_unnamed_addr global %Foo6 { i32 1, i16 2, i16 3 }, align 1
+@struct2.foo6 = local_unnamed_addr global %Foo6 <{ i32 1, i16 2, i16 3 }>, align 1
 
-; Function Attrs:
 define i32 @struct2.test5(i8 signext %0) #0 {
 entry:
   %y = alloca %Foo5, align 16

test/test_suite/struct/struct_pack_error.c3t

@@ -36,7 +36,7 @@ fn void main()
 /* #expect: test.ll
 
 %Client = type <{ i32, %MsgHeader, i16, [2 x i8], %"ElasticArray{ulong, 1}" }>
-%MsgHeader = type { i64 }
+%MsgHeader = type <{ i64 }>
 %"ElasticArray{ulong, 1}" = type { i64, [1 x i64] }
 
 define void @test.main() #0 {

test/test_suite/struct/struct_packed.c3t

@@ -0,0 +1,35 @@
+// #target: macos-x64
+module test;
+struct Foo3 @align(8)
+{
+	char foo;
+	Foo6 bar;
+}
+struct Foo6 @packed
+{
+	short c;
+}
+
+fn int main()
+{
+	Foo3 x;
+	return 0;
+}
+
+/* #expect: test.ll
+
+%Foo3 = type <{ i8, %Foo6, [5 x i8] }>
+%Foo6 = type <{ i16 }>
+
+@"$ct.test.Foo3" = linkonce global %.introspect { i8 10, i64 0, ptr null, i64 8, i64 0, i64 2, [0 x i64] zeroinitializer }, align 8
+@"$ct.test.Foo6" = linkonce global %.introspect { i8 10, i64 0, ptr null, i64 2, i64 0, i64 1, [0 x i64] zeroinitializer }, align 8
+
+define i32 @main() #0 {
+entry:
+  %x = alloca %Foo3, align 8
+  store i8 0, ptr %x, align 8
+  %ptradd = getelementptr inbounds i8, ptr %x, i64 1
+  store i16 0, ptr %ptradd, align 1
+  ret i32 0
+}
+