commit 52c5014da099797e9f1f6c90acddf79a68aa85cb
author Sameer Sahasrabuddhe <sameer.sahasrabuddhe@amd.com> Tue Nov 19 14:05:39 2019 +0530
committer Sameer Sahasrabuddhe <sameer.sahasrabuddhe@amd.com> Wed Nov 20 15:53:55 2019 +0530
tree ed25183186a703e2feec5ce7ad864cb41d415237
parent f67534afd6f237d3ec00c207b26579968c3d60e5

[AMDGPU] add support for hostcall buffer pointer as hidden kernel argument

Hostcall is a service that allows a kernel to submit requests to the
host using shared buffers, and block until a response is
received. This will eventually replace the shared buffer currently
used for printf, and repurposes the same hidden kernel argument. This
change introduces a new ValueKind in the HSA metadata to represent the
hostcall buffer.

Differential Revision: https://reviews.llvm.org/D70038

llvm/lib/Target/AMDGPU/AMDGPUHSAMetadataStreamer.cpp

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUHSAMetadataStreamer.cpp b/llvm/lib/Target/AMDGPU/AMDGPUHSAMetadataStreamer.cpp
index 9f5bcd8..511d629 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUHSAMetadataStreamer.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUHSAMetadataStreamer.cpp
@@ -421,7 +421,12 @@
   if (HiddenArgNumBytes >= 32) {
     if (Func.getParent()->getNamedMetadata("llvm.printf.fmts"))
       emitKernelArg(DL, Int8PtrTy, ValueKind::HiddenPrintfBuffer);
-    else
+    else if (Func.getParent()->getFunction("__ockl_hostcall_internal")) {
+      // The printf runtime binding pass should have ensured that hostcall and
+      // printf are not used in the same module.
+      assert(!Func.getParent()->getNamedMetadata("llvm.printf.fmts"));
+      emitKernelArg(DL, Int8PtrTy, ValueKind::HiddenHostcallBuffer);
+    } else
       emitKernelArg(DL, Int8PtrTy, ValueKind::HiddenNone);
   }
 
@@ -854,7 +859,12 @@
   if (HiddenArgNumBytes >= 32) {
     if (Func.getParent()->getNamedMetadata("llvm.printf.fmts"))
       emitKernelArg(DL, Int8PtrTy, "hidden_printf_buffer", Offset, Args);
-    else
+    else if (Func.getParent()->getFunction("__ockl_hostcall_internal")) {
+      // The printf runtime binding pass should have ensured that hostcall and
+      // printf are not used in the same module.
+      assert(!Func.getParent()->getNamedMetadata("llvm.printf.fmts"));
+      emitKernelArg(DL, Int8PtrTy, "hidden_hostcall_buffer", Offset, Args);
+    } else
       emitKernelArg(DL, Int8PtrTy, "hidden_none", Offset, Args);
   }