[llvm] [GlobalIsel] Combine integers (PR #92879)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,199 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -mtriple aarch64 -run-pass=aarch64-prelegalizer-combiner -verify-machineinstrs %s -o - | FileCheck %s
+# REQUIRES: asserts
+
+
+---
+name:   ZeroMinusAPlusB
+body:             |
+  bb.0:
+    liveins: $w0, $w1
+
+    ; CHECK-LABEL: name: ZeroMinusAPlusB
+    ; CHECK: liveins: $w0, $w1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %a:_(s32) = COPY $w0
+    ; CHECK-NEXT: %b:_(s32) = COPY $w0
+    ; CHECK-NEXT: %add:_(s32) = G_SUB %b, %a
+    ; CHECK-NEXT: $w0 = COPY %add(s32)
+    ; CHECK-NEXT: RET_ReallyLR implicit $w0
+    %x:_(s32) = COPY $w0
+    %a:_(s32) = COPY $w0
+    %b:_(s32) = COPY $w0
+    %zero:_(s32) = G_CONSTANT i32 0
+    %sub:_(s32) = G_SUB %zero, %a
+    %add:_(s32) = G_ADD %sub, %b
+    $w0 = COPY %add
+    RET_ReallyLR implicit $w0
+
+...
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arsenm wrote:

Test the multi-use intermediate cases 

https://github.com/llvm/llvm-project/pull/92879