From 15921d032cfff6994289d1f299bef168f0a49a4e Mon Sep 17 00:00:00 2001
From: gingerBill <bill@gingerbill.org>
Date: Sun, 12 Sep 2021 16:45:57 +0100
Subject: [PATCH] Correct endianness on slicing

---
 src/llvm_backend_expr.cpp    |  9 ++++++---
 src/llvm_backend_utility.cpp | 11 +++++++++++
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/src/llvm_backend_expr.cpp b/src/llvm_backend_expr.cpp
index 8189aec68..a4b4564c0 100644
--- a/src/llvm_backend_expr.cpp
+++ b/src/llvm_backend_expr.cpp
@@ -888,7 +888,6 @@ lbValue lb_build_binary_expr(lbProcedure *p, Ast *expr) {
 	return {};
 }
 
-
 lbValue lb_emit_conv(lbProcedure *p, lbValue value, Type *t) {
 	lbModule *m = p->module;
 	t = reduce_tuple_to_single_type(t);
@@ -2981,8 +2980,12 @@ lbAddr lb_build_addr(lbProcedure *p, Ast *expr) {
 		lbValue low  = lb_const_int(p->module, t_int, 0);
 		lbValue high = {};
 
-		if (se->low  != nullptr) low  = lb_build_expr(p, se->low);
-		if (se->high != nullptr) high = lb_build_expr(p, se->high);
+		if (se->low  != nullptr) {
+			low = lb_correct_endianness(p, lb_build_expr(p, se->low));
+		}
+		if (se->high != nullptr) {
+			high = lb_correct_endianness(p, lb_build_expr(p, se->high));
+		}
 
 		bool no_indices = se->low == nullptr && se->high == nullptr;
 
diff --git a/src/llvm_backend_utility.cpp b/src/llvm_backend_utility.cpp
index 6f08ddf5f..db3cb443e 100644
--- a/src/llvm_backend_utility.cpp
+++ b/src/llvm_backend_utility.cpp
@@ -38,6 +38,16 @@ bool lb_is_type_aggregate(Type *t) {
 }
 
 
+lbValue lb_correct_endianness(lbProcedure *p, lbValue value) {
+	Type *src = core_type(value.type);
+	GB_ASSERT(is_type_integer(src) || is_type_float(src));
+	if (is_type_different_to_arch_endianness(src)) {
+		Type *platform_src_type = integer_endian_type_to_platform_type(src);
+		value = lb_emit_byte_swap(p, value, platform_src_type);
+	}
+	return value;
+}
+
 void lb_mem_zero_ptr_internal(lbProcedure *p, LLVMValueRef ptr, LLVMValueRef len, unsigned alignment) {
 	bool is_inlinable = false;
 
@@ -1125,6 +1135,7 @@ lbValue lb_emit_array_epi(lbProcedure *p, lbValue s, isize index) {
 }
 
 lbValue lb_emit_ptr_offset(lbProcedure *p, lbValue ptr, lbValue index) {
+	index = lb_correct_endianness(p, index);
 	LLVMValueRef indices[1] = {index.value};
 	lbValue res = {};
 	res.type = ptr.type;