[Beignet] [PATCH] GBE: fix the overflow bug in register spilling.

[Zhigang Gong]

Change to use int32 to represent the maxID.

Signed-off-by: Zhigang Gong <zhigang.gong at intel.com>
---
 backend/src/backend/gen_reg_allocation.cpp |   11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/backend/src/backend/gen_reg_allocation.cpp b/backend/src/backend/gen_reg_allocation.cpp
index 726b78c..8243f19 100644
--- a/backend/src/backend/gen_reg_allocation.cpp
+++ b/backend/src/backend/gen_reg_allocation.cpp
@@ -53,19 +53,16 @@ namespace gbe
   };
 
   typedef struct GenRegIntervalKey {
-    GenRegIntervalKey(uint16_t reg, uint16_t maxID) {
-      if (maxID == INT_MAX)
-        maxID = 0xFFFF;
-      GBE_ASSERT(reg <= 0xFFFF && maxID <= 0xFFFF);
-      key = (maxID << 16) | reg;
+    GenRegIntervalKey(uint16_t reg, int32_t maxID) {
+      key = ((uint64_t)maxID << 16) | reg;
     }
     const ir::Register getReg() const {
       return (ir::Register)(key & 0xFFFF);
     }
-    const uint16_t getMaxID() const {
+    const int32_t getMaxID() const {
       return key >> 16;
     }
-    uint32_t key;
+    uint64_t key;
   } GenRegIntervalKey;
 
   struct spillCmp {
-- 
1.7.9.5