From f4ffde64fe950d5ec102817e2fa84219f872c349 Mon Sep 17 00:00:00 2001
From: Yichao Yu <yyc1992@gmail.com>
Date: Fri, 26 Jun 2015 22:04:46 -0400
Subject: [PATCH] Make size and offset in jl_fielddesc_t 32bit length

---
 src/alloc.c |  5 +++--
 src/julia.h | 10 +++++-----
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/src/alloc.c b/src/alloc.c
index 522bbba61d5d0..2ff8912660391 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -577,11 +577,12 @@ void jl_compute_field_offsets(jl_datatype_t *st)
             if (al > alignm)
                 alignm = al;
         }
-        if (__unlikely(sz > JL_FIELD_MAX_OFFSET))
-            jl_throw(jl_overflow_exception);
         st->fields[i].offset = sz;
         st->fields[i].size = fsz;
         sz += fsz;
+        if (__unlikely(sz >= JL_FIELD_MAX_SIZE)) {
+            jl_throw(jl_overflow_exception);
+        }
     }
     st->alignment = alignm;
     st->size = LLT_ALIGN(sz, alignm);
diff --git a/src/julia.h b/src/julia.h
index bcfb3b1df71bf..b2d65cc301881 100644
--- a/src/julia.h
+++ b/src/julia.h
@@ -253,13 +253,13 @@ typedef struct {
 } jl_uniontype_t;
 
 typedef struct {
-    uint16_t offset;   // offset relative to data start, excluding type tag
-    uint16_t size:15;
-    uint16_t isptr:1;
+    uint32_t offset;   // offset relative to data start, excluding type tag
+    uint32_t size:31;
+    uint32_t isptr:1;
 } jl_fielddesc_t;
 
-#define JL_FIELD_MAX_OFFSET ((1ul << 16) - 1ul)
-#define JL_FIELD_MAX_SIZE ((1ul << 15) - 1ul)
+// For both field size and total size
+#define JL_FIELD_MAX_SIZE ((((uint32_t)1) << 31) - 1)
 
 typedef struct _jl_datatype_t {
     JL_DATA_TYPE