AMDGPU: Set element_size in private resource descriptor

Introduce a subtarget feature for this, and leave the default with
the current behavior which assumes up to 16-byte loads/stores can
be used. The field also seems to have the ability to be set to 2 bytes,
but I'm not sure what that would be used for.

llvm-svn: 260651

1 files changed, 19 insertions, 0 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp b/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp
index 913f3f53ff1..2af7a2ccbfe 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp
@@ -593,6 +593,20 @@ void AMDGPUAsmPrinter::EmitProgramInfoSI(const MachineFunction &MF,
   }
 }
 
+// This is supposed to be log2(Size)
+static amd_element_byte_size_t getElementByteSizeValue(unsigned Size) {
+  switch (Size) {
+  case 4:
+    return AMD_ELEMENT_4_BYTES;
+  case 8:
+    return AMD_ELEMENT_8_BYTES;
+  case 16:
+    return AMD_ELEMENT_16_BYTES;
+  default:
+    llvm_unreachable("invalid private_element_size");
+  }
+}
+
 void AMDGPUAsmPrinter::EmitAmdKernelCodeT(const MachineFunction &MF,
                                          const SIProgramInfo &KernelInfo) const {
   const SIMachineFunctionInfo *MFI = MF.getInfo<SIMachineFunctionInfo>();
@@ -606,6 +620,11 @@ void AMDGPUAsmPrinter::EmitAmdKernelCodeT(const MachineFunction &MF,
       (KernelInfo.ComputePGMRSrc2 << 32);
   header.code_properties = AMD_CODE_PROPERTY_IS_PTR64;
 
+
+  AMD_HSA_BITS_SET(header.code_properties,
+                   AMD_CODE_PROPERTY_PRIVATE_ELEMENT_SIZE,
+                   getElementByteSizeValue(STM.getMaxPrivateElementSize()));
+
   if (MFI->hasPrivateSegmentBuffer()) {
     header.code_properties |=
       AMD_CODE_PROPERTY_ENABLE_SGPR_PRIVATE_SEGMENT_BUFFER;