[llvm] [CodeGenPrepare] Check types when unmerging GEPs across indirect branches (PR #68587)

[Nikita Popov via llvm-commits]

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@@ -0,0 +1,51 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 3
+; RUN: opt -S -codegenprepare %s -o - | FileCheck %s
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+%struct.Blub = type { i8, i8, ptr }
+
+ at indirectBrPtr = external hidden global ptr
+
+define dso_local noundef ptr @testFunc(ptr noundef readonly %array, i1 %skip) {
+; CHECK-LABEL: define dso_local noundef ptr @testFunc(
+; CHECK-SAME: ptr noundef readonly [[ARRAY:%.*]], i1 [[SKIP:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br i1 [[SKIP]], label [[LOOPHEADER:%.*]], label [[ENDBLOCK_CLONE:%.*]]
+; CHECK:       loopHeader:
+; CHECK-NEXT:    [[CURRENTARRAYELEMENT:%.*]] = phi ptr [ [[ARRAY]], [[ENTRY:%.*]] ], [ [[NEXTARRAYELEMENT:%.*]], [[LOOPFOOTER:%.*]] ]
+; CHECK-NEXT:    [[ELEMENTVALUEPTR:%.*]] = getelementptr inbounds i8, ptr [[CURRENTARRAYELEMENT]], i64 1
+; CHECK-NEXT:    [[ELEMENTVALUE:%.*]] = load i8, ptr [[ELEMENTVALUEPTR]], align 1
+; CHECK-NEXT:    indirectbr ptr @indirectBrPtr, [label [[LOOPFOOTER]], label %endBlock]
+; CHECK:       loopFooter:
+; CHECK-NEXT:    [[ISGOODVALUE:%.*]] = icmp eq i8 [[ELEMENTVALUE]], 0
+; CHECK-NEXT:    [[NEXTARRAYELEMENT]] = getelementptr inbounds [[STRUCT_BLUB:%.*]], ptr [[CURRENTARRAYELEMENT]], i64 1
+; CHECK-NEXT:    br i1 [[ISGOODVALUE]], label [[LOOPHEADER]], label [[ENDBLOCK_CLONE]]
+; CHECK:       endBlock:
+; CHECK-NEXT:    br label [[DOTSPLIT:%.*]]
+; CHECK:       .split:
+; CHECK-NEXT:    [[MERGE:%.*]] = phi ptr [ [[ELEMENTVALUEPTR]], [[ENDBLOCK:%.*]] ], [ [[RETVAL_CLONE:%.*]], [[ENDBLOCK_CLONE]] ]
+; CHECK-NEXT:    ret ptr [[MERGE]]
+; CHECK:       endBlock.clone:
+; CHECK-NEXT:    [[RETVAL_CLONE]] = phi ptr [ [[ARRAY]], [[ENTRY]] ], [ [[ELEMENTVALUEPTR]], [[LOOPFOOTER]] ]
+; CHECK-NEXT:    br label [[DOTSPLIT]]
+;
+entry:
+  br i1 %skip, label %loopHeader, label %endBlock
+
+loopHeader:                                                ; preds = %2, %1
----------------
nikic wrote:

Can drop these `; preds` comments, especially as they don't match the actual block names.

https://github.com/llvm/llvm-project/pull/68587