[llvm] [GlobalIsel][AArch64] Add ADDO combine to the postlegalizer combiner (PR #101327)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,73 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 2
+# RUN: llc -mtriple aarch64 -run-pass=legalizer,aarch64-postlegalizer-combiner -verify-machineinstrs %s -o - | FileCheck %s
+
+---
+name:            add_s128_unknown_bits
+body:             |
+  bb.0:
+    liveins: $q0, $q1
+    ; CHECK-LABEL: name: add_s128_unknown_bits
+    ; CHECK: liveins: $q0, $q1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %lhs:_(s128) = COPY $q0
+    ; CHECK-NEXT: %rhs:_(s128) = COPY $q1
+    ; CHECK-NEXT: [[UV:%[0-9]+]]:_(s64), [[UV1:%[0-9]+]]:_(s64) = G_UNMERGE_VALUES %lhs(s128)
+    ; CHECK-NEXT: [[UV2:%[0-9]+]]:_(s64), [[UV3:%[0-9]+]]:_(s64) = G_UNMERGE_VALUES %rhs(s128)
+    ; CHECK-NEXT: [[UADDO:%[0-9]+]]:_(s64), [[UADDO1:%[0-9]+]]:_(s32) = G_UADDO [[UV]], [[UV2]]
+    ; CHECK-NEXT: [[UADDE:%[0-9]+]]:_(s64), [[UADDE1:%[0-9]+]]:_(s32) = G_UADDE [[UV1]], [[UV3]], [[UADDO1]]
+    ; CHECK-NEXT: %res:_(s128) = G_MERGE_VALUES [[UADDO]](s64), [[UADDE]](s64)
+    ; CHECK-NEXT: $q0 = COPY %res(s128)
+    %lhs:_(s128) = COPY $q0
+    %rhs:_(s128) = COPY $q1
+    %res:_(s128) = G_ADD %lhs, %rhs
+    $q0 = COPY %res(s128)
+...
+
+---
+name:            add_s128_low64_known_nonzero
+body:             |
+  bb.0:
+    liveins: $q0, $q1
+    ; CHECK-LABEL: name: add_s128_low64_known_nonzero
+    ; CHECK: liveins: $q0, $q1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %a:_(s128) = COPY $q0
+    ; CHECK-NEXT: %rhs:_(s128) = COPY $q1
+    ; CHECK-NEXT: [[C:%[0-9]+]]:_(s64) = G_CONSTANT i64 -1
+    ; CHECK-NEXT: [[UV:%[0-9]+]]:_(s64), [[UV1:%[0-9]+]]:_(s64) = G_UNMERGE_VALUES %a(s128)
+    ; CHECK-NEXT: [[UV2:%[0-9]+]]:_(s64), [[UV3:%[0-9]+]]:_(s64) = G_UNMERGE_VALUES %rhs(s128)
+    ; CHECK-NEXT: [[UADDO:%[0-9]+]]:_(s64), [[UADDO1:%[0-9]+]]:_(s32) = G_UADDO [[UV2]], [[C]]
+    ; CHECK-NEXT: [[UADDE:%[0-9]+]]:_(s64), [[UADDE1:%[0-9]+]]:_(s32) = G_UADDE [[UV1]], [[UV3]], [[UADDO1]]
+    ; CHECK-NEXT: %res:_(s128) = G_MERGE_VALUES [[UADDO]](s64), [[UADDE]](s64)
+    ; CHECK-NEXT: $q0 = COPY %res(s128)
+    %a:_(s128) = COPY $q0
+    %rhs:_(s128) = COPY $q1
+    %mask:_(s128) = G_CONSTANT i128 18446744073709551615
+    %lhs:_(s128) = G_OR %a, %mask
+    %res:_(s128) = G_ADD %lhs, %rhs
+    $q0 = COPY %res(s128)
+...
+
+---
+name:            add_s128_low64_known_zero
+body:             |
+  bb.0:
+    liveins: $q0, $q1
+    ; CHECK-LABEL: name: add_s128_low64_known_zero
+    ; CHECK: liveins: $q0, $q1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %a:_(s128) = COPY $q0
+    ; CHECK-NEXT: %rhs:_(s128) = COPY $q1
+    ; CHECK-NEXT: [[UV:%[0-9]+]]:_(s64), [[UV1:%[0-9]+]]:_(s64) = G_UNMERGE_VALUES %a(s128)
+    ; CHECK-NEXT: [[UV2:%[0-9]+]]:_(s64), [[UV3:%[0-9]+]]:_(s64) = G_UNMERGE_VALUES %rhs(s128)
+    ; CHECK-NEXT: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
+    ; CHECK-NEXT: [[UADDE:%[0-9]+]]:_(s64), [[UADDE1:%[0-9]+]]:_(s32) = G_UADDE [[UV1]], [[UV3]], [[C]]
+    ; CHECK-NEXT: %res:_(s128) = G_MERGE_VALUES [[UV2]](s64), [[UADDE]](s64)
+    ; CHECK-NEXT: $q0 = COPY %res(s128)
+    %a:_(s128) = COPY $q0
+    %rhs:_(s128) = COPY $q1
+    %mask:_(s128) = G_CONSTANT i128 -18446744073709551616
+    %lhs:_(s128) = G_AND %a, %mask
+    %res:_(s128) = G_ADD %lhs, %rhs
+    $q0 = COPY %res(s128)
+...
----------------
arsenm wrote:

Can you include an end to end IR test that shows an improvement? 

https://github.com/llvm/llvm-project/pull/101327