[PATCH] R600/SI: Fix crash in SIInstrInfo::areLoadsFromSameBasePtr()

[Tom Stellard]

This function assumed that SMRD instructions always have immediate
offsets, which is not always the case.
---
 lib/Target/R600/SIInstrInfo.cpp                | 12 +++++++--
 test/CodeGen/R600/schedule-kernel-arg-loads.ll | 35 ++++++++++++++++++++++++--
 2 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/lib/Target/R600/SIInstrInfo.cpp b/lib/Target/R600/SIInstrInfo.cpp
index 95334c3..c8468f9 100644
--- a/lib/Target/R600/SIInstrInfo.cpp
+++ b/lib/Target/R600/SIInstrInfo.cpp
@@ -120,12 +120,20 @@ bool SIInstrInfo::areLoadsFromSameBasePtr(SDNode *Load0, SDNode *Load1,
     if (Load0->getOperand(0) != Load1->getOperand(0))
       return false;
 
+    const ConstantSDNode *Load0Offset =
+        dyn_cast<ConstantSDNode>(Load0->getOperand(1));
+    const ConstantSDNode *Load1Offset =
+        dyn_cast<ConstantSDNode>(Load1->getOperand(1));
+
+    if (!Load0Offset || !Load1Offset)
+      return false;
+
     // Check chain.
     if (findChainOperand(Load0) != findChainOperand(Load1))
       return false;
 
-    Offset0 = cast<ConstantSDNode>(Load0->getOperand(1))->getZExtValue();
-    Offset1 = cast<ConstantSDNode>(Load1->getOperand(1))->getZExtValue();
+    Offset0 = Load0Offset->getZExtValue();
+    Offset1 = Load1Offset->getZExtValue();
     return true;
   }
 
diff --git a/test/CodeGen/R600/schedule-kernel-arg-loads.ll b/test/CodeGen/R600/schedule-kernel-arg-loads.ll
index f9641fa..6b3e081 100644
--- a/test/CodeGen/R600/schedule-kernel-arg-loads.ll
+++ b/test/CodeGen/R600/schedule-kernel-arg-loads.ll
@@ -1,5 +1,5 @@
-; RUN: llc -march=amdgcn -mcpu=SI -verify-machineinstrs < %s | FileCheck -check-prefix=FUNC -check-prefix=SI %s
-; RUN: llc -march=amdgcn -mcpu=tonga -verify-machineinstrs < %s | FileCheck -check-prefix=FUNC -check-prefix=VI %s
+; RUN: llc -march=amdgcn -mcpu=SI -verify-machineinstrs < %s | FileCheck -check-prefix=FUNC -check-prefix=SI --check-prefix=GCN %s
+; RUN: llc -march=amdgcn -mcpu=tonga -verify-machineinstrs < %s | FileCheck -check-prefix=FUNC -check-prefix=VI --check-prefix=GCN %s
 
 ; FUNC-LABEL: {{^}}cluster_arg_loads:
 ; SI: s_load_dwordx2 s{{\[[0-9]+:[0-9]+\]}}, s{{\[[0-9]+:[0-9]+\]}}, 0x9
@@ -18,3 +18,34 @@ define void @cluster_arg_loads(i32 addrspace(1)* %out0, i32 addrspace(1)* %out1,
   store i32 %y, i32 addrspace(1)* %out1, align 4
   ret void
 }
+
+; Test for a crash in SIInstrInfo::areLoadsFromSameBasePtr() when
+; s_load_dwordx2 has a register offset
+
+; FUNC-LABEL: @same_base_ptr_crash
+; GCN: s_load_dwordx2
+; GCN: s_load_dwordx2
+; GCN: s_load_dwordx2
+; GCN: s_endpgm
+define void @same_base_ptr_crash(i64 addrspace(1)* %out,
+    i64 %arg0, i64 %arg1, i64 %arg2, i64 %arg3, i64 %arg4, i64 %arg5, i64 %arg6, i64 %arg7,
+    i64 %arg8, i64 %arg9, i64 %arg10, i64 %arg11, i64 %arg12, i64 %arg13, i64 %arg14, i64 %arg15,
+    i64 %arg16, i64 %arg17, i64 %arg18, i64 %arg19, i64 %arg20, i64 %arg21, i64 %arg22, i64 %arg23,
+    i64 %arg24, i64 %arg25, i64 %arg26, i64 %arg27, i64 %arg28, i64 %arg29, i64 %arg30, i64 %arg31,
+    i64 %arg32, i64 %arg33, i64 %arg34, i64 %arg35, i64 %arg36, i64 %arg37, i64 %arg38, i64 %arg39,
+    i64 %arg40, i64 %arg41, i64 %arg42, i64 %arg43, i64 %arg44, i64 %arg45, i64 %arg46, i64 %arg47,
+    i64 %arg48, i64 %arg49, i64 %arg50, i64 %arg51, i64 %arg52, i64 %arg53, i64 %arg54, i64 %arg55,
+    i64 %arg56, i64 %arg57, i64 %arg58, i64 %arg59, i64 %arg60, i64 %arg61, i64 %arg62, i64 %arg63,
+    i64 %arg64, i64 %arg65, i64 %arg66, i64 %arg67, i64 %arg68, i64 %arg69, i64 %arg70, i64 %arg71,
+    i64 %arg72, i64 %arg73, i64 %arg74, i64 %arg75, i64 %arg76, i64 %arg77, i64 %arg78, i64 %arg79,
+    i64 %arg80, i64 %arg81, i64 %arg82, i64 %arg83, i64 %arg84, i64 %arg85, i64 %arg86, i64 %arg87,
+    i64 %arg88, i64 %arg89, i64 %arg90, i64 %arg91, i64 %arg92, i64 %arg93, i64 %arg94, i64 %arg95,
+    i64 %arg96, i64 %arg97, i64 %arg98, i64 %arg99, i64 %arg100, i64 %arg101, i64 %arg102, i64 %arg103,
+    i64 %arg104, i64 %arg105, i64 %arg106, i64 %arg107, i64 %arg108, i64 %arg109, i64 %arg110, i64 %arg111,
+    i64 %arg112, i64 %arg113, i64 %arg114, i64 %arg115, i64 %arg116, i64 %arg117, i64 %arg118, i64 %arg119,
+    i64 %arg120, i64 %arg121, i64 %arg122, i64 %arg123, i64 %arg124, i64 %arg125, i64 %arg126) {
+entry:
+  %value = add i64 %arg125, %arg126
+  store i64 %value, i64 addrspace(1)* %out, align 8
+  ret void
+}
-- 
2.0.4