[Libclc-dev] [PATCH 2/4] mem_fence() support for R600 targets

[Hilloulin Damien]

  This patch introduces three new intrinsics and therefore
  must be used in conjunction with the patches to the LLVM backend. It 
adds the
  mem_fence built-in function, and an implementation for r600 using the 
newly
  introduced LLVM intrinsics. (It is mainly copy-paste from 
barrier_impl.ll but
  if flags equals 0, we do nothing).

Signed-off-by: Damien Hilloulin <damien.hilloulin at supelec.fr>
---
  generic/include/clc/clc.h                          |  3 ++
  .../include/clc/explicitmemoryfence/mem_fence.h    |  1 +
  r600/lib/SOURCES                                   |  1 +
  r600/lib/explicitmemoryfence/mem_fence_impl.ll     | 44 
++++++++++++++++++++++
  4 files changed, 49 insertions(+)
  create mode 100644 generic/include/clc/explicitmemoryfence/mem_fence.h
  create mode 100644 r600/lib/explicitmemoryfence/mem_fence_impl.ll

diff --git a/generic/include/clc/clc.h b/generic/include/clc/clc.h
index 84b25ac..13d9c11 100644
--- a/generic/include/clc/clc.h
+++ b/generic/include/clc/clc.h
@@ -126,6 +126,9 @@
  #include <clc/synchronization/cl_mem_fence_flags.h>
  #include <clc/synchronization/barrier.h>

+/* 6.11.9 Explicit memory fence Functions */
+#include <clc/explicitmemoryfence/mem_fence.h>
+
  /* 6.11.10 Async Copy and Prefetch Functions */
  #include <clc/async/prefetch.h>

diff --git a/generic/include/clc/explicitmemoryfence/mem_fence.h 
b/generic/include/clc/explicitmemoryfence/mem_fence.h
new file mode 100644
index 0000000..15f4b39
--- /dev/null
+++ b/generic/include/clc/explicitmemoryfence/mem_fence.h
@@ -0,0 +1 @@
+_CLC_DECL void mem_fence(cl_mem_fence_flags flags);
diff --git a/r600/lib/SOURCES b/r600/lib/SOURCES
index ba56605..1a38b76 100644
--- a/r600/lib/SOURCES
+++ b/r600/lib/SOURCES
@@ -1,4 +1,5 @@
  atomic/atomic.cl
+explicitmemoryfence/mem_fence_impl.ll
  math/nextafter.cl
  workitem/get_num_groups.ll
  workitem/get_group_id.ll
diff --git a/r600/lib/explicitmemoryfence/mem_fence_impl.ll 
b/r600/lib/explicitmemoryfence/mem_fence_impl.ll
new file mode 100644
index 0000000..b04be89
--- /dev/null
+++ b/r600/lib/explicitmemoryfence/mem_fence_impl.ll
@@ -0,0 +1,44 @@
+declare i32 @__clc_clk_local_mem_fence() nounwind alwaysinline
+declare i32 @__clc_clk_global_mem_fence() nounwind alwaysinline
+declare void @llvm.AMDGPU.mem_fence.local() nounwind noduplicate
+declare void @llvm.AMDGPU.mem_fence.global() nounwind noduplicate
+declare void @llvm.AMDGPU.mem_fence.localglobal() nounwind noduplicate
+
+define void @mem_fence(i32 %flags) nounwind noduplicate alwaysinline {
+
+;flags_masking:
+  %CLK_LOCAL_MEM_FENCE = call i32 @__clc_clk_local_mem_fence()
+  %CLK_GLOBAL_MEM_FENCE = call i32 @__clc_clk_global_mem_fence()
+  %CLK_LOCAL_GLOBAL_MEM_FENCE = or i32 %CLK_LOCAL_MEM_FENCE, 
%CLK_GLOBAL_MEM_FENCE
+  %FLAGS_MEM_FENCE_LOCAL_MASKED = and i32 %flags, %CLK_LOCAL_MEM_FENCE
+  %FLAGS_MEM_FENCE_GLOBAL_MASKED = and i32 %flags, %CLK_GLOBAL_MEM_FENCE
+
+;mem_fence_local_and_global_test:
+  %MEM_FENCE_LOCAL_AND_GLOBAL_TEST_RESULT = icmp eq i32 %flags, 
%CLK_LOCAL_GLOBAL_MEM_FENCE
+  br i1 %MEM_FENCE_LOCAL_AND_GLOBAL_TEST_RESULT, label 
%mem_fence_local_and_global, label %mem_fence_local_test
+
+mem_fence_local_and_global:
+  call void @llvm.AMDGPU.mem_fence.localglobal() noduplicate
+  br label %done
+
+mem_fence_local_test:
+  %MEM_FENCE_LOCAL_TEST_RESULT = icmp ne i32 
%FLAGS_MEM_FENCE_LOCAL_MASKED, 0
+  br i1 %MEM_FENCE_LOCAL_TEST_RESULT, label %mem_fence_local, label 
%mem_fence_global_test
+
+mem_fence_local:
+  call void @llvm.AMDGPU.mem_fence.local() noduplicate
+  br label %done
+
+mem_fence_global_test:
+  %MEM_FENCE_GLOBAL_TEST_RESULT = icmp ne i32 
%FLAGS_MEM_FENCE_GLOBAL_MASKED, 0
+  br i1 %MEM_FENCE_GLOBAL_TEST_RESULT, label %mem_fence_global, label %done
+
+mem_fence_global:
+  call void @llvm.AMDGPU.mem_fence.global() noduplicate
+  br label %done
+
+; nothing to do if flags equals 0
+
+done:
+  ret void
+}
-- 
1.9.1