[llvm] [Attributor] Change allocation size and load/store offsets using AAPointerInfo for Alloca instructions and keep track of instructions causing an Access (PR #72029)

[Shilei Tian via llvm-commits]

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@@ -10,11 +10,11 @@ define void @foo(ptr %ptr) {
 ; TUNIT-LABEL: define {{[^@]+}}@foo
 ; TUNIT-SAME: (ptr nofree readnone captures(none) [[PTR:%.*]]) #[[ATTR0:[0-9]+]] {
 ; TUNIT-NEXT:  entry:
-; TUNIT-NEXT:    [[TMP0:%.*]] = alloca [[STRUCT_TEST_A:%.*]], align 8
+; TUNIT-NEXT:    [[TMP0:%.*]] = alloca [8 x i8], align 1
 ; TUNIT-NEXT:    br label [[CALL_BR:%.*]]
 ; TUNIT:       call.br:
-; TUNIT-NEXT:    [[TMP1:%.*]] = getelementptr inbounds [[STRUCT_TEST_A]], ptr [[TMP0]], i64 0, i32 2
-; TUNIT-NEXT:    tail call void @bar(ptr noalias nofree noundef nonnull readonly byval([[STRUCT_TEST_A]]) align 8 captures(none) dereferenceable(24) [[TMP0]]) #[[ATTR2:[0-9]+]]
+; TUNIT-NEXT:    [[NEWGEP:%.*]] = getelementptr [8 x i8], ptr [[TMP0]], i64 0
+; TUNIT-NEXT:    tail call void @bar(ptr noalias nofree noundef nonnull readonly byval([[STRUCT_TEST_A:%.*]]) align 8 captures(none) dereferenceable(24) [[TMP0]]) #[[ATTR2:[0-9]+]]
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shiltian wrote:

Also, consider adding tests like `{i32, i32, %struct...}` and only actually use the nested struct. In this case, the alignment would be trickier.

https://github.com/llvm/llvm-project/pull/72029