From 91750e2f1b512a1a460065e6db8cb43101cb4f90 Mon Sep 17 00:00:00 2001 From: jakubtomsu <66876057+jakubtomsu@users.noreply.github.com> Date: Sat, 18 Oct 2025 16:11:47 +0200 Subject: [PATCH 1/2] prefer Type pointer over LLVMTypeRef when doing a struct_field_remapping lookup --- src/llvm_backend_utility.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/llvm_backend_utility.cpp b/src/llvm_backend_utility.cpp index 182928247..4a760c594 100644 --- a/src/llvm_backend_utility.cpp +++ b/src/llvm_backend_utility.cpp @@ -981,9 +981,9 @@ gb_internal lbStructFieldRemapping lb_get_struct_remapping(lbModule *m, Type *t) mutex_lock(&m->types_mutex); - auto *field_remapping = map_get(&m->struct_field_remapping, cast(void *)struct_type); + auto *field_remapping = map_get(&m->struct_field_remapping, cast(void *)t); if (field_remapping == nullptr) { - field_remapping = map_get(&m->struct_field_remapping, cast(void *)t); + field_remapping = map_get(&m->struct_field_remapping, cast(void *)struct_type); } mutex_unlock(&m->types_mutex); From c21453acc598ca1ec755d6e88c9c7f0e1db51da6 Mon Sep 17 00:00:00 2001 From: jakubtomsu <66876057+jakubtomsu@users.noreply.github.com> Date: Sat, 18 Oct 2025 16:18:58 +0200 Subject: [PATCH 2/2] comment --- src/llvm_backend_utility.cpp | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/llvm_backend_utility.cpp b/src/llvm_backend_utility.cpp index 4a760c594..c7b4170e9 100644 --- a/src/llvm_backend_utility.cpp +++ b/src/llvm_backend_utility.cpp @@ -981,6 +981,9 @@ gb_internal lbStructFieldRemapping lb_get_struct_remapping(lbModule *m, Type *t) mutex_lock(&m->types_mutex); + // NOTE(jakub): It's very important to check the type pointer first, + // because two disctinct but similar structs can end up with the same LLVMTypeRef after interning. + // (For example struct{u16,u8} looks identical to LLVM as struct{u16,u8,u8} once padding fields are inserted.) auto *field_remapping = map_get(&m->struct_field_remapping, cast(void *)t); if (field_remapping == nullptr) { field_remapping = map_get(&m->struct_field_remapping, cast(void *)struct_type);