[openmp][amdgpu][nfc] Simplify implicit args handling

Removes a +x/-x pair on the only store/load of a variable
and deletes some nearby dead code. Also reduces the size of the implicit
struct to reflect the code currently emitted by clang.

Differential Revision: https://reviews.llvm.org/D114270

3 files changed, 10 insertions, 45 deletions

diff --git a/openmp/libomptarget/plugins/amdgpu/impl/internal.h b/openmp/libomptarget/plugins/amdgpu/impl/internal.h
index 8bca165dd5ae..bdac98c1e101 100644
--- a/openmp/libomptarget/plugins/amdgpu/impl/internal.h
+++ b/openmp/libomptarget/plugins/amdgpu/impl/internal.h
@@ -38,13 +38,11 @@ typedef struct impl_implicit_args_s {
   unsigned long offset_y;
   unsigned long offset_z;
   unsigned long hostcall_ptr;
-  char num_gpu_queues;
-  unsigned long gpu_queue_ptr;
-  char num_cpu_queues;
-  unsigned long cpu_worker_signals;
-  unsigned long cpu_queue_ptr;
-  unsigned long kernarg_template_ptr;
+  unsigned long unused0;
+  unsigned long unused1;
+  unsigned long unused2;
 } impl_implicit_args_t;
+static_assert(sizeof(impl_implicit_args_t) == 56, "");
 
 // ---------------------- Kernel Start -------------
 typedef struct atl_kernel_info_s {
@@ -57,9 +55,6 @@ typedef struct atl_kernel_info_s {
   uint32_t vgpr_spill_count;
   uint32_t kernel_segment_size;
   uint32_t num_args;
-  std::vector<uint64_t> arg_alignments;
-  std::vector<uint64_t> arg_offsets;
-  std::vector<uint64_t> arg_sizes;
 } atl_kernel_info_t;
 
 typedef struct atl_symbol_info_s {
diff --git a/openmp/libomptarget/plugins/amdgpu/impl/system.cpp b/openmp/libomptarget/plugins/amdgpu/impl/system.cpp
index 9151da95d6e4..4d661dc38100 100644
--- a/openmp/libomptarget/plugins/amdgpu/impl/system.cpp
+++ b/openmp/libomptarget/plugins/amdgpu/impl/system.cpp
@@ -62,26 +62,16 @@ public:
   };
 
   KernelArgMD()
-      : name_(std::string()), typeName_(std::string()), size_(0), offset_(0),
-        align_(0), valueKind_(ValueKind::Unknown) {}
+      : name_(std::string()),  size_(0), offset_(0),
+        valueKind_(ValueKind::Unknown) {}
 
   // fields
   std::string name_;
-  std::string typeName_;
   uint32_t size_;
   uint32_t offset_;
-  uint32_t align_;
   ValueKind valueKind_;
 };
 
-class KernelMD {
-public:
-  KernelMD() : kernargSegmentSize_(0ull) {}
-
-  // fields
-  uint64_t kernargSegmentSize_;
-};
-
 static const std::map<std::string, KernelArgMD::ValueKind> ArgValueKind = {
     // v3
     //    {"by_value", KernelArgMD::ValueKind::ByValue},
@@ -320,10 +310,6 @@ int populate_kernelArgMD(msgpack::byte_range args_element,
       foronly_string(value, [&](size_t N, const unsigned char *str) {
         kernelarg->name_ = std::string(str, str + N);
       });
-    } else if (message_is_string(key, ".type_name")) {
-      foronly_string(value, [&](size_t N, const unsigned char *str) {
-        kernelarg->typeName_ = std::string(str, str + N);
-      });
     } else if (message_is_string(key, ".size")) {
       foronly_unsigned(value, [&](uint64_t x) { kernelarg->size_ = x; });
     } else if (message_is_string(key, ".offset")) {
@@ -395,7 +381,7 @@ static hsa_status_t get_code_object_custom_metadata(
       return HSA_STATUS_ERROR_INVALID_CODE_OBJECT;
     }
 
-    atl_kernel_info_t info = {0, 0, 0, 0, 0, 0, 0, 0, 0, {}, {}, {}};
+    atl_kernel_info_t info = {0, 0, 0, 0, 0, 0, 0, 0, 0};
 
     uint64_t sgpr_count, vgpr_count, sgpr_spill_count, vgpr_spill_count;
     msgpack_errors += map_lookup_uint64_t(element, ".sgpr_count", &sgpr_count);
@@ -479,13 +465,10 @@ static hsa_status_t get_code_object_custom_metadata(
                  "iterate args map in kernel args metadata");
           return HSA_STATUS_ERROR_INVALID_CODE_OBJECT;
         }
-        // populate info with sizes and offsets
-        info.arg_sizes.push_back(lcArg.size_);
         // v3 has offset field and not align field
         size_t new_offset = lcArg.offset_;
         size_t padding = new_offset - offset;
         offset = new_offset;
-        info.arg_offsets.push_back(lcArg.offset_);
         DP("Arg[%lu] \"%s\" (%u, %u)\n", i, lcArg.name_.c_str(), lcArg.size_,
            lcArg.offset_);
         offset += lcArg.size_;
@@ -501,12 +484,9 @@ static hsa_status_t get_code_object_custom_metadata(
       }
     }
 
-    // add size of implicit args, e.g.: offset x, y and z and pipe pointer, but
-    // do not count the compiler set implicit args, but set your own implicit
-    // args by discounting the compiler set implicit args
+    // TODO: Probably don't want this arithmetic 
     info.kernel_segment_size =
-        (hasHiddenArgs ? kernel_explicit_args_size : kernel_segment_size) +
-        sizeof(impl_implicit_args_t);
+        (hasHiddenArgs ? kernel_explicit_args_size : kernel_segment_size);
     DP("[%s: kernarg seg size] (%lu --> %u)\n", kernelName.c_str(),
        kernel_segment_size, info.kernel_segment_size);
 
diff --git a/openmp/libomptarget/plugins/amdgpu/src/rtl.cpp b/openmp/libomptarget/plugins/amdgpu/src/rtl.cpp
index 906b856c6311..71321be3e83c 100644
--- a/openmp/libomptarget/plugins/amdgpu/src/rtl.cpp
+++ b/openmp/libomptarget/plugins/amdgpu/src/rtl.cpp
@@ -1631,22 +1631,12 @@ __tgt_target_table *__tgt_rtl_load_binary_locked(int32_t device_id,
       auto It = KernelInfoMap.find(kernelStr);
       if (It != KernelInfoMap.end()) {
         atl_kernel_info_t info = It->second;
-        // return the size for non-implicit args
-        kernarg_segment_size =
-            info.kernel_segment_size - sizeof(impl_implicit_args_t);
+        kernarg_segment_size = info.kernel_segment_size;
       } else {
         err = HSA_STATUS_ERROR;
       }
     }
 
-    // each arg is a void * in this openmp implementation
-    uint32_t arg_num = kernarg_segment_size / sizeof(void *);
-    std::vector<size_t> arg_sizes(arg_num);
-    for (std::vector<size_t>::iterator it = arg_sizes.begin();
-         it != arg_sizes.end(); it++) {
-      *it = sizeof(void *);
-    }
-
     // default value GENERIC (in case symbol is missing from cubin file)
     llvm::omp::OMPTgtExecModeFlags ExecModeVal =
         llvm::omp::OMPTgtExecModeFlags::OMP_TGT_EXEC_MODE_GENERIC;