AMDGPU: Fix crash when scheduling non-memory SMRD instructions

[nhaehnle]

Summary

Fixes piglit spec/arb_shader_clock/execution/*

[arsenm]

LGTM

llvm/trunk/lib/Target/AMDGPU/SIInstrInfo.cpp

if (AMDGPU::getNamedOperandIdx(Opc0, AMDGPU::OpName::data1) != -1 ||
       return false;
 
     Offset0 = cast<ConstantSDNode>(Load0->getOperand(2))->getZExtValue();
     Offset1 = cast<ConstantSDNode>(Load1->getOperand(2))->getZExtValue();
     return true;
   }
 
   if (isSMRD(Opc0) && isSMRD(Opc1)) {
+    // Skip time and cache invalidation instructions.
+    if (AMDGPU::getNamedOperandIdx(Opc0, AMDGPU::OpName::sbase) == -1 ||
+        AMDGPU::getNamedOperandIdx(Opc1, AMDGPU::OpName::sbase) == -1)
+      return false;
+
     assert(getNumOperandsNoGlue(Load0) == getNumOperandsNoGlue(Load1));
 
     // Check base reg.
     if (Load0->getOperand(0) != Load1->getOperand(0))
       return false;
 
     const ConstantSDNode *Load0Offset =
         dyn_cast<ConstantSDNode>(Load0->getOperand(1));

llvm/trunk/test/CodeGen/AMDGPU/readcyclecounter.ll

define amdgpu_kernel void @test_readcyclecounter(i64 addrspace(1)* %out) #0 {
   %cycle0 = call i64 @llvm.readcyclecounter()
   store volatile i64 %cycle0, i64 addrspace(1)* %out
 
   %cycle1 = call i64 @llvm.readcyclecounter()
   store volatile i64 %cycle1, i64 addrspace(1)* %out
   ret void
 }
 
+; This test used to crash in ScheduleDAG.
+;
+; GCN-LABEL: {{^}}test_readcyclecounter_smem:
+; SI-DAG: s_memtime
+; VI-DAG: s_memrealtime
+; GCN-DAG: s_load_dword
+define amdgpu_cs i32 @test_readcyclecounter_smem(i64 addrspace(2)* inreg %in) #0 {
+  %cycle0 = call i64 @llvm.readcyclecounter()
+  %in.v = load i64, i64 addrspace(2)* %in
+  %r.64 = add i64 %cycle0, %in.v
+  %r.32 = trunc i64 %r.64 to i32
+  ret i32 %r.32
+}
+
 attributes #0 = { nounwind }