From a978a481bbe66becb01f4955b8e002e6cd59be23 Mon Sep 17 00:00:00 2001
From: Tom Stellard <thomas.stellard@amd.com>
Date: Tue, 20 Jan 2015 17:49:43 +0000
Subject: [PATCH] R600/SI: Don't store scratch buffer frame index in MUBUF
 offset field

We don't have a good way of legalizing this if the frame index offset
is more than the 12-bits, which is size of MUBUF's offset field, so
now we store the frame index in the vaddr field.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226584 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/R600/AMDGPUISelDAGToDAG.cpp | 16 -----
 test/CodeGen/R600/scratch-buffer.ll    | 81 ++++++++++++++++++++++++++
 2 files changed, 81 insertions(+), 16 deletions(-)
 create mode 100644 test/CodeGen/R600/scratch-buffer.ll

diff --git a/lib/Target/R600/AMDGPUISelDAGToDAG.cpp b/lib/Target/R600/AMDGPUISelDAGToDAG.cpp
index eaa506db96c..28b4183d277 100644
--- a/lib/Target/R600/AMDGPUISelDAGToDAG.cpp
+++ b/lib/Target/R600/AMDGPUISelDAGToDAG.cpp
@@ -988,22 +988,6 @@ bool AMDGPUDAGToDAGISel::SelectMUBUFScratch(SDValue Addr, SDValue &Rsrc,
     }
   }
 
-  // (add FI, n0)
-  if ((Addr.getOpcode() == ISD::ADD || Addr.getOpcode() == ISD::OR) &&
-       isa<FrameIndexSDNode>(Addr.getOperand(0))) {
-    VAddr = Addr.getOperand(1);
-    ImmOffset = Addr.getOperand(0);
-    return true;
-  }
-
-  // (FI)
-  if (isa<FrameIndexSDNode>(Addr)) {
-    VAddr = SDValue(CurDAG->getMachineNode(AMDGPU::V_MOV_B32_e32, DL, MVT::i32,
-                                          CurDAG->getConstant(0, MVT::i32)), 0);
-    ImmOffset = Addr;
-    return true;
-  }
-
   // (node)
   VAddr = Addr;
   ImmOffset = CurDAG->getTargetConstant(0, MVT::i16);
diff --git a/test/CodeGen/R600/scratch-buffer.ll b/test/CodeGen/R600/scratch-buffer.ll
new file mode 100644
index 00000000000..cc2a522c9a8
--- /dev/null
+++ b/test/CodeGen/R600/scratch-buffer.ll
@@ -0,0 +1,81 @@
+; RUN: llc -verify-machineinstrs -march=amdgcn -mcpu=SI < %s | FileCheck %s
+
+; When a frame index offset is more than 12-bits, make sure we don't store
+; it in mubuf's offset field.
+
+; CHECK-LABEL: {{^}}legal_offset_fi:
+; CHECK: buffer_store_dword v{{[0-9]+}}, v{{[0-9]+}}, s[{{[0-9]+}}:{{[0-9]+}}], s{{[0-9]+}} offen
+; CHECK: v_mov_b32_e32 [[OFFSET:v[0-9]+]], 0x8000
+; CHECK: buffer_store_dword v{{[0-9]+}}, [[OFFSET]], s[{{[0-9]+}}:{{[0-9]+}}], s{{[0-9]+}} offen{{$}}
+
+define void @legal_offset_fi(i32 addrspace(1)* %out, i32 %cond, i32 %if_offset, i32 %else_offset) {
+entry:
+  %scratch0 = alloca [8192 x i32]
+  %scratch1 = alloca [8192 x i32]
+
+  %scratchptr0 = getelementptr [8192 x i32]* %scratch0, i32 0, i32 0
+  store i32 1, i32* %scratchptr0
+
+  %scratchptr1 = getelementptr [8192 x i32]* %scratch1, i32 0, i32 0
+  store i32 2, i32* %scratchptr1
+
+  %cmp = icmp eq i32 %cond, 0
+  br i1 %cmp, label %if, label %else
+
+if:
+  %if_ptr = getelementptr [8192 x i32]* %scratch0, i32 0, i32 %if_offset
+  %if_value = load i32* %if_ptr
+  br label %done
+
+else:
+  %else_ptr = getelementptr [8192 x i32]* %scratch1, i32 0, i32 %else_offset
+  %else_value = load i32* %else_ptr
+  br label %done
+
+done:
+  %value = phi i32 [%if_value, %if], [%else_value, %else]
+  store i32 %value, i32 addrspace(1)* %out
+  ret void
+
+  ret void
+
+}
+
+; CHECK-LABEL: {{^}}legal_offset_fi_offset
+; CHECK: buffer_store_dword v{{[0-9]+}}, v{{[0-9]+}}, s[{{[0-9]+}}:{{[0-9]+}}], s{{[0-9]+}} offen
+; CHECK: v_add_i32_e32 [[OFFSET:v[0-9]+]], 0x8000
+; CHECK: buffer_store_dword v{{[0-9]+}}, [[OFFSET]], s[{{[0-9]+}}:{{[0-9]+}}], s{{[0-9]+}} offen{{$}}
+
+define void @legal_offset_fi_offset(i32 addrspace(1)* %out, i32 %cond, i32 addrspace(1)* %offsets, i32 %if_offset, i32 %else_offset) {
+entry:
+  %scratch0 = alloca [8192 x i32]
+  %scratch1 = alloca [8192 x i32]
+
+  %offset0 = load i32 addrspace(1)* %offsets
+  %scratchptr0 = getelementptr [8192 x i32]* %scratch0, i32 0, i32 %offset0
+  store i32 %offset0, i32* %scratchptr0
+
+  %offsetptr1 = getelementptr i32 addrspace(1)* %offsets, i32 1
+  %offset1 = load i32 addrspace(1)* %offsetptr1
+  %scratchptr1 = getelementptr [8192 x i32]* %scratch1, i32 0, i32 %offset1
+  store i32 %offset1, i32* %scratchptr1
+
+  %cmp = icmp eq i32 %cond, 0
+  br i1 %cmp, label %if, label %else
+
+if:
+  %if_ptr = getelementptr [8192 x i32]* %scratch0, i32 0, i32 %if_offset
+  %if_value = load i32* %if_ptr
+  br label %done
+
+else:
+  %else_ptr = getelementptr [8192 x i32]* %scratch1, i32 0, i32 %else_offset
+  %else_value = load i32* %else_ptr
+  br label %done
+
+done:
+  %value = phi i32 [%if_value, %if], [%else_value, %else]
+  store i32 %value, i32 addrspace(1)* %out
+  ret void
+}
+
-- 
2.34.1