[llvm] [GlobalISel] Fold Add Shift combine from SelectionDAG (PR #177371)

[Matt Arsenault via llvm-commits]

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@@ -1934,11 +1934,15 @@ def add_shl_neg_frags : GICombinePatFrag<
     (pattern (G_CONSTANT $zero, 0),
              (G_SUB $neg_y, $zero, $y),
              (G_SHL $shl_neg, $neg_y, $n),
-             (G_ADD $dst, $x, $shl_neg)),
+             (G_ADD $dst, $x, $shl_neg),
+             [{ return MRI.hasOneNonDBGUse(${shl_neg}.getReg()) &&
+                       MRI.hasOneNonDBGUse(${neg_y}.getReg()); }]),
     (pattern (G_CONSTANT $zero, 0),
              (G_SUB $neg_y, $zero, $y),
              (G_SHL $shl_neg, $neg_y, $n),
-             (G_ADD $dst, $shl_neg, $x))
+             (G_ADD $dst, $shl_neg, $x),
+             [{ return MRI.hasOneNonDBGUse(${shl_neg}.getReg()) &&
+                       MRI.hasOneNonDBGUse(${neg_y}.getReg()); }])
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arsenm wrote:

This one isn't tested with multiple uses?

https://github.com/llvm/llvm-project/pull/177371