AMDGPU/SI: Set correct value for amd_kernel_code_t::kernarg_segment_alignment

Reviewers: arsenm

Subscribers: kzhuravl, wdng, nhaehnle, yaxunl, llvm-commits, tony-tye

Differential Revision: https://reviews.llvm.org/D27416

llvm-svn: 288852

2 files changed, 9 insertions, 0 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp b/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp
index d836a8ea024..2390fc9b3db 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp
@@ -763,6 +763,11 @@ void AMDGPUAsmPrinter::EmitAmdKernelCodeT(const MachineFunction &MF,
   header.reserved_vgpr_first = KernelInfo.ReservedVGPRFirst;
   header.reserved_vgpr_count = KernelInfo.ReservedVGPRCount;
 
+  // These alignment values are specified in powers of two, so alignment =
+  // 2^n.  The minimum alignment is 2^4 = 16.
+  header.kernarg_segment_alignment = std::max((size_t)4,
+      countTrailingZeros(MFI->getMaxKernArgAlign()));
+
   if (STM.debuggerEmitPrologue()) {
     header.debug_wavefront_private_segment_offset_sgpr =
       KernelInfo.DebuggerWavefrontPrivateSegmentOffsetSGPR;
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUMachineFunction.h b/llvm/lib/Target/AMDGPU/AMDGPUMachineFunction.h
index 0c8b79d496d..5d0640b816f 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUMachineFunction.h
+++ b/llvm/lib/Target/AMDGPU/AMDGPUMachineFunction.h
@@ -50,6 +50,10 @@ public:
     return KernArgSize;
   }
 
+  unsigned getMaxKernArgAlign() const {
+    return MaxKernArgAlign;
+  }
+
   void setABIArgOffset(unsigned NewOffset) {
     ABIArgOffset = NewOffset;
   }