AMDGPU/GlobalISel: Add some more tests for add3 folding

These currently fail to form add3 due to the pointer type, but they
should be handle.

Author: arsenm

llvm/test/CodeGen/AMDGPU/GlobalISel/inst-select-pattern-add3.mir

@@ -130,3 +130,90 @@ body: |
     S_ENDPGM 0, implicit %4, implicit %3
 ...
 
+---
+
+name:            add_p3_vgpr_vgpr_vgpr
+legalized:       true
+regBankSelected: true
+tracksRegLiveness: true
+
+body: |
+  bb.0:
+    liveins: $vgpr0, $vgpr1, $vgpr2
+
+    ; GFX8-LABEL: name: add_p3_vgpr_vgpr_vgpr
+    ; GFX8: liveins: $vgpr0, $vgpr1, $vgpr2
+    ; GFX8: [[COPY:%[0-9]+]]:vgpr_32 = COPY $vgpr0
+    ; GFX8: [[COPY1:%[0-9]+]]:vgpr_32 = COPY $vgpr1
+    ; GFX8: [[COPY2:%[0-9]+]]:vgpr_32 = COPY $vgpr2
+    ; GFX8: %3:vgpr_32, dead %6:sreg_64_xexec = V_ADD_I32_e64 [[COPY]], [[COPY1]], 0, implicit $exec
+    ; GFX8: %4:vgpr_32, dead %5:sreg_64_xexec = V_ADD_I32_e64 %3, [[COPY2]], 0, implicit $exec
+    ; GFX8: S_ENDPGM 0, implicit %4
+    ; GFX9-LABEL: name: add_p3_vgpr_vgpr_vgpr
+    ; GFX9: liveins: $vgpr0, $vgpr1, $vgpr2
+    ; GFX9: [[COPY:%[0-9]+]]:vgpr_32 = COPY $vgpr0
+    ; GFX9: [[COPY1:%[0-9]+]]:vgpr_32 = COPY $vgpr1
+    ; GFX9: [[COPY2:%[0-9]+]]:vgpr_32 = COPY $vgpr2
+    ; GFX9: [[V_ADD_U32_e64_:%[0-9]+]]:vgpr_32 = V_ADD_U32_e64 [[COPY]], [[COPY1]], 0, implicit $exec
+    ; GFX9: [[V_ADD_U32_e64_1:%[0-9]+]]:vgpr_32 = V_ADD_U32_e64 [[V_ADD_U32_e64_]], [[COPY2]], 0, implicit $exec
+    ; GFX9: S_ENDPGM 0, implicit [[V_ADD_U32_e64_1]]
+    ; GFX10-LABEL: name: add_p3_vgpr_vgpr_vgpr
+    ; GFX10: liveins: $vgpr0, $vgpr1, $vgpr2
+    ; GFX10: $vcc_hi = IMPLICIT_DEF
+    ; GFX10: [[COPY:%[0-9]+]]:vgpr_32 = COPY $vgpr0
+    ; GFX10: [[COPY1:%[0-9]+]]:vgpr_32 = COPY $vgpr1
+    ; GFX10: [[COPY2:%[0-9]+]]:vgpr_32 = COPY $vgpr2
+    ; GFX10: [[V_ADD_U32_e64_:%[0-9]+]]:vgpr_32 = V_ADD_U32_e64 [[COPY]], [[COPY1]], 0, implicit $exec
+    ; GFX10: [[V_ADD_U32_e64_1:%[0-9]+]]:vgpr_32 = V_ADD_U32_e64 [[V_ADD_U32_e64_]], [[COPY2]], 0, implicit $exec
+    ; GFX10: S_ENDPGM 0, implicit [[V_ADD_U32_e64_1]]
+    %0:vgpr(p3) = COPY $vgpr0
+    %1:vgpr(s32) = COPY $vgpr1
+    %2:vgpr(s32) = COPY $vgpr2
+    %3:vgpr(p3) = G_PTR_ADD %0, %1
+    %4:vgpr(p3) = G_PTR_ADD %3, %2
+    S_ENDPGM 0, implicit %4
+...
+
+---
+
+name:            add_p5_vgpr_vgpr_vgpr
+legalized:       true
+regBankSelected: true
+tracksRegLiveness: true
+
+body: |
+  bb.0:
+    liveins: $vgpr0, $vgpr1, $vgpr2
+
+    ; GFX8-LABEL: name: add_p5_vgpr_vgpr_vgpr
+    ; GFX8: liveins: $vgpr0, $vgpr1, $vgpr2
+    ; GFX8: [[COPY:%[0-9]+]]:vgpr_32 = COPY $vgpr0
+    ; GFX8: [[COPY1:%[0-9]+]]:vgpr_32 = COPY $vgpr1
+    ; GFX8: [[COPY2:%[0-9]+]]:vgpr_32 = COPY $vgpr2
+    ; GFX8: %3:vgpr_32, dead %6:sreg_64_xexec = V_ADD_I32_e64 [[COPY]], [[COPY1]], 0, implicit $exec
+    ; GFX8: %4:vgpr_32, dead %5:sreg_64_xexec = V_ADD_I32_e64 %3, [[COPY2]], 0, implicit $exec
+    ; GFX8: S_ENDPGM 0, implicit %4
+    ; GFX9-LABEL: name: add_p5_vgpr_vgpr_vgpr
+    ; GFX9: liveins: $vgpr0, $vgpr1, $vgpr2
+    ; GFX9: [[COPY:%[0-9]+]]:vgpr_32 = COPY $vgpr0
+    ; GFX9: [[COPY1:%[0-9]+]]:vgpr_32 = COPY $vgpr1
+    ; GFX9: [[COPY2:%[0-9]+]]:vgpr_32 = COPY $vgpr2
+    ; GFX9: [[V_ADD_U32_e64_:%[0-9]+]]:vgpr_32 = V_ADD_U32_e64 [[COPY]], [[COPY1]], 0, implicit $exec
+    ; GFX9: [[V_ADD_U32_e64_1:%[0-9]+]]:vgpr_32 = V_ADD_U32_e64 [[V_ADD_U32_e64_]], [[COPY2]], 0, implicit $exec
+    ; GFX9: S_ENDPGM 0, implicit [[V_ADD_U32_e64_1]]
+    ; GFX10-LABEL: name: add_p5_vgpr_vgpr_vgpr
+    ; GFX10: liveins: $vgpr0, $vgpr1, $vgpr2
+    ; GFX10: $vcc_hi = IMPLICIT_DEF
+    ; GFX10: [[COPY:%[0-9]+]]:vgpr_32 = COPY $vgpr0
+    ; GFX10: [[COPY1:%[0-9]+]]:vgpr_32 = COPY $vgpr1
+    ; GFX10: [[COPY2:%[0-9]+]]:vgpr_32 = COPY $vgpr2
+    ; GFX10: [[V_ADD_U32_e64_:%[0-9]+]]:vgpr_32 = V_ADD_U32_e64 [[COPY]], [[COPY1]], 0, implicit $exec
+    ; GFX10: [[V_ADD_U32_e64_1:%[0-9]+]]:vgpr_32 = V_ADD_U32_e64 [[V_ADD_U32_e64_]], [[COPY2]], 0, implicit $exec
+    ; GFX10: S_ENDPGM 0, implicit [[V_ADD_U32_e64_1]]
+    %0:vgpr(p5) = COPY $vgpr0
+    %1:vgpr(s32) = COPY $vgpr1
+    %2:vgpr(s32) = COPY $vgpr2
+    %3:vgpr(p5) = G_PTR_ADD %0, %1
+    %4:vgpr(p5) = G_PTR_ADD %3, %2
+    S_ENDPGM 0, implicit %4
+...