[AMDGPU] Add test

Summary:
Add test checking that the redundant immediate MOV instruction
(by-product of handling phi nodes) is not found in the generated code.

Reviewers: arsenm, anton-afanasyev, craig.topper, rtereshin, bogner

Reviewed By: arsenm

Subscribers: kzhuravl, yaxunl, dstuttard, tpr, t-tye, wdng, jvesely, nhaehnle, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63860

llvm-svn: 370634

llvm/test/CodeGen/AMDGPU/cse-phi-incoming-val.ll

@@ -0,0 +1,41 @@
+; RUN: llc < %s -mtriple=amdgcn--amdpal -mcpu=gfx900 -verify-machineinstrs | FileCheck %s
+
+; Check that the redundant immediate MOV instruction
+; (by-product of handling phi nodes) is not found
+; in the generated code.
+
+; CHECK-LABEL: {{^}}mov_opt:
+; CHECK: v_mov_b32_e32 {{v[0-9]+}}, 1.0
+; CHECK: %bb.1:
+; CHECK-NOT: v_mov_b32_e32 {{v[0-9]+}}, 1.0
+; CHECK: BB0_2:
+
+define amdgpu_ps void @mov_opt(i32 %arg, i32 inreg %arg1, i32 inreg %arg2) local_unnamed_addr #0 {
+bb:
+  %tmp = icmp eq i32 %arg1, 0
+  br i1 %tmp, label %bb3, label %bb10
+
+bb3:                                              ; preds = %bb
+  %tmp4 = icmp eq i32 %arg2, 0
+  br i1 %tmp4, label %bb5, label %bb10
+
+bb5:                                              ; preds = %bb3
+  %tmp6 = getelementptr <{ [4294967295 x i32] }>, <{ [4294967295 x i32] }> addrspace(6)* null, i32 0, i32 0, i32 %arg
+  %tmp7 = load i32, i32 addrspace(6)* %tmp6
+  %tmp8 = icmp eq i32 %tmp7, 1
+  br i1 %tmp8, label %bb10, label %bb9
+
+bb9:                                              ; preds = %bb5
+  br label %bb10
+
+bb10:                                             ; preds = %bb9, %bb5, %bb3, %bb
+  %tmp11 = phi float [ 1.000000e+00, %bb3 ], [ 0.000000e+00, %bb9 ], [ 1.000000e+00, %bb ], [ undef, %bb5 ]
+  call void @llvm.amdgcn.exp.f32(i32 immarg 40, i32 immarg 15, float %tmp11, float undef, float undef, float undef, i1 immarg false, i1 immarg false) #0
+  ret void
+}
+
+; Function Attrs: inaccessiblememonly nounwind
+declare void @llvm.amdgcn.exp.f32(i32 immarg, i32 immarg, float, float, float, float, i1 immarg, i1 immarg) #1
+
+attributes #0 = { nounwind }
+attributes #1 = { inaccessiblememonly nounwind }