[Beignet] [PATCH V2] Fix some piglit constant buffer tests fail.

[Yang Rong]

If indirect move's source is scalrar reg, such as using cb[0] in kernel,
should not unpack.

Also change test case compiler_function_constant0 to trigger this bug.

Signed-off-by: Yang Rong <rong.r.yang at intel.com>
---
 backend/src/backend/gen_context.cpp    |    7 ++++++-
 backend/src/backend/gen_register.hpp   |    3 ++-
 kernels/compiler_function_constant0.cl |    2 +-
 utests/compiler_function_constant0.cpp |    6 ++----
 4 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/backend/src/backend/gen_context.cpp b/backend/src/backend/gen_context.cpp
index af651e7..d0c2ff8 100644
--- a/backend/src/backend/gen_context.cpp
+++ b/backend/src/backend/gen_context.cpp
@@ -223,7 +223,12 @@ namespace gbe
   }
 
   void GenContext::emitIndirectMoveInstruction(const SelectionInstruction &insn) {
-    const GenRegister src = GenRegister::unpacked_uw(ra->genReg(insn.src(0)).nr, 0);
+    GenRegister src = ra->genReg(insn.src(0));
+    if(isScalarReg(src.reg()))
+      src = GenRegister::retype(src, GEN_TYPE_UW);
+    else
+      src = GenRegister::unpacked_uw(src.nr, src.subnr);
+
     const GenRegister dst = ra->genReg(insn.dst(0));
     const GenRegister a0 = GenRegister::addr8(0);
     uint32_t simdWidth = p->curr.execWidth;
diff --git a/backend/src/backend/gen_register.hpp b/backend/src/backend/gen_register.hpp
index d772b0d..eb33ae8 100644
--- a/backend/src/backend/gen_register.hpp
+++ b/backend/src/backend/gen_register.hpp
@@ -726,9 +726,10 @@ namespace gbe
     }
 
     static INLINE GenRegister unpacked_uw(uint32_t nr, uint32_t subnr) {
+      GBE_ASSERT((subnr%typeSize(GEN_TYPE_UW)) == 0);
       return GenRegister(GEN_GENERAL_REGISTER_FILE,
                          nr,
-                         subnr,
+                         subnr / typeSize(GEN_TYPE_UW),  //will multiply again in GenRegister, keep unchanged
                          GEN_TYPE_UW,
                          GEN_VERTICAL_STRIDE_16,
                          GEN_WIDTH_8,
diff --git a/kernels/compiler_function_constant0.cl b/kernels/compiler_function_constant0.cl
index f6efcef..363d84e 100644
--- a/kernels/compiler_function_constant0.cl
+++ b/kernels/compiler_function_constant0.cl
@@ -2,5 +2,5 @@ __kernel void
 compiler_function_constant0(__constant short *c0, __constant char *c1, __global int *dst, int value)
 {
   int id = (int)get_global_id(0);
-  dst[id] = value + c0[id%69] + c1[15];
+  dst[id] = value + c0[id%69] + c1[0];
 }
diff --git a/utests/compiler_function_constant0.cpp b/utests/compiler_function_constant0.cpp
index de564f3..c0a8a9d 100644
--- a/utests/compiler_function_constant0.cpp
+++ b/utests/compiler_function_constant0.cpp
@@ -8,7 +8,7 @@ void compiler_function_constant0(void)
   // Setup kernel and buffers
   OCL_CREATE_KERNEL("compiler_function_constant0");
   OCL_CREATE_BUFFER(buf[0], 0, 75 * sizeof(short), NULL);
-  OCL_CREATE_BUFFER(buf[1], 0, 256 * sizeof(char), NULL);
+  OCL_CREATE_BUFFER(buf[1], 0, 1 * sizeof(char), NULL);
   OCL_CREATE_BUFFER(buf[2], 0, n * sizeof(uint32_t), NULL);
   OCL_SET_ARG(0, sizeof(cl_mem), &buf[0]);
   OCL_SET_ARG(1, sizeof(cl_mem), &buf[1]);
@@ -21,9 +21,7 @@ void compiler_function_constant0(void)
   OCL_UNMAP_BUFFER(0);
 
   OCL_MAP_BUFFER(1);
-  for(uint32_t i = 0; i < 256; ++i)
-    ((char *)buf_data[1])[i] = 10;
-  ((char *)buf_data[1])[15] = 15;
+  ((char *)buf_data[1])[0] = 15;
   OCL_UNMAP_BUFFER(1);
 
   // Run the kernel
-- 
1.7.10.4