From ce21a784a4bccc66d555b337ebdf98454aaa652f Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Mon, 13 Apr 2020 12:49:42 +0200
Subject: [PATCH] stage1: More fixes for BE targets

* Fix packed struct alignment
* Adjust some tests
---
 src/codegen.cpp                  | 12 +++++++-----
 test/stage1/behavior/ptrcast.zig | 10 +++++++---
 test/stage1/behavior/struct.zig  |  7 +++++--
 3 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/src/codegen.cpp b/src/codegen.cpp
index 23ab2a130e..1a091584b4 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -7265,7 +7265,8 @@ check: switch (const_val->special) {
                             LLVMTypeRef field_ty = LLVMStructGetTypeAtIndex(get_llvm_type(g, type_entry),
                                     (unsigned)type_struct_field->gen_index);
                             const size_t size_in_bytes = LLVMStoreSizeOfType(g->target_data_ref, field_ty);
-                            LLVMTypeRef big_int_type_ref = LLVMIntType(size_in_bytes * 8);
+                            const size_t size_in_bits = size_in_bytes * 8;
+                            LLVMTypeRef big_int_type_ref = LLVMIntType(size_in_bits);
                             LLVMValueRef val = LLVMConstInt(big_int_type_ref, 0, false);
                             size_t used_bits = 0;
                             for (size_t i = src_field_index; i < src_field_index_end; i += 1) {
@@ -7278,16 +7279,17 @@ check: switch (const_val->special) {
                                 uint32_t packed_bits_size = type_size_bits(g, it_field->type_entry);
                                 if (is_big_endian) {
                                     LLVMValueRef shift_amt = LLVMConstInt(big_int_type_ref,
-                                            packed_bits_size, false);
-                                    val = LLVMConstShl(val, shift_amt);
-                                    val = LLVMConstOr(val, child_val);
+                                        size_in_bits - used_bits - packed_bits_size, false);
+                                    LLVMValueRef child_val_shifted = LLVMConstShl(child_val, shift_amt);
+                                    val = LLVMConstOr(val, child_val_shifted);
                                 } else {
                                     LLVMValueRef shift_amt = LLVMConstInt(big_int_type_ref, used_bits, false);
                                     LLVMValueRef child_val_shifted = LLVMConstShl(child_val, shift_amt);
                                     val = LLVMConstOr(val, child_val_shifted);
-                                    used_bits += packed_bits_size;
                                 }
+                                used_bits += packed_bits_size;
                             }
+                            assert(size_in_bits >= used_bits);
                             if (LLVMGetTypeKind(field_ty) != LLVMArrayTypeKind) {
                                 assert(LLVMGetTypeKind(field_ty) == LLVMIntegerTypeKind);
                                 fields[type_struct_field->gen_index] = val;
diff --git a/test/stage1/behavior/ptrcast.zig b/test/stage1/behavior/ptrcast.zig
index 3925325e61..26e9545248 100644
--- a/test/stage1/behavior/ptrcast.zig
+++ b/test/stage1/behavior/ptrcast.zig
@@ -1,5 +1,5 @@
-const builtin = @import("builtin");
 const std = @import("std");
+const builtin = std.builtin;
 const expect = std.testing.expect;
 
 test "reinterpret bytes as integer with nonzero offset" {
@@ -36,8 +36,12 @@ fn testReinterpretBytesAsExternStruct() void {
 }
 
 test "reinterpret struct field at comptime" {
-    const numLittle = comptime Bytes.init(0x12345678);
-    expect(std.mem.eql(u8, &[_]u8{ 0x78, 0x56, 0x34, 0x12 }, &numLittle.bytes));
+    const numNative = comptime Bytes.init(0x12345678);
+    if (builtin.endian != .Little) {
+        expect(std.mem.eql(u8, &[_]u8{ 0x12, 0x34, 0x56, 0x78 }, &numNative.bytes));
+    } else {
+        expect(std.mem.eql(u8, &[_]u8{ 0x78, 0x56, 0x34, 0x12 }, &numNative.bytes));
+    }
 }
 
 const Bytes = struct {
diff --git a/test/stage1/behavior/struct.zig b/test/stage1/behavior/struct.zig
index 0365991ed3..1203399a24 100644
--- a/test/stage1/behavior/struct.zig
+++ b/test/stage1/behavior/struct.zig
@@ -1,8 +1,8 @@
 const std = @import("std");
+const builtin = std.builtin;
 const expect = std.testing.expect;
 const expectEqual = std.testing.expectEqual;
 const expectEqualSlices = std.testing.expectEqualSlices;
-const builtin = @import("builtin");
 const maxInt = std.math.maxInt;
 const StructWithNoFields = struct {
     fn add(a: i32, b: i32) i32 {
@@ -407,7 +407,10 @@ const Bitfields = packed struct {
 };
 
 test "native bit field understands endianness" {
-    var all: u64 = 0x7765443322221111;
+    var all: u64 = if (builtin.endian != .Little)
+        0x1111222233445677
+    else
+        0x7765443322221111;
     var bytes: [8]u8 = undefined;
     @memcpy(&bytes, @ptrCast([*]u8, &all), 8);
     var bitfields = @ptrCast(*Bitfields, &bytes).*;