[llvm] Reland "Redesign Straight-Line Strength Reduction (SLSR) (#162930)" (PR #169614)

[Artem Belevich via llvm-commits]

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@@ -8,7 +8,7 @@ target datalayout = "e-i64:64-v16:16-v32:32-n16:32:64"
 define void @path_compression(i32 %a, ptr %base, i16 %r, i1 %cond) {
 ; CHECK-LABEL: @path_compression(
 ; CHECK: [[I:%.*]] = sext i32 %a to i64
-; CHECK: [[GEP1:%.*]] = getelementptr inbounds %struct.A, ptr %base, i64 [[I]]
+; CHECK: [[GEP1:%.*]] = getelementptr %struct.A, ptr %base, i64 [[I]]
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Artem-B wrote:

We don't seem to change anything else in that GEP instruction. Did we really rewrite it?
Original IR appears to be unchanged modulo the `inbounds`:
```
  %1 = sext i32 %a to i64
  %getElem1 = getelementptr inbounds %struct.A, ptr %base, i64 %1
```

Is it possible that we're rewriting only some of the instructions in `DropPoisonGeneratingInsts`? If that's the case, should the attributes be dropped only on the actually rewritten isntructions?


https://github.com/llvm/llvm-project/pull/169614