[llvm] [Attributor] Check range size before constant fold load (PR #151359)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,34 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
+; RUN: opt -S -passes=attributor %s -o - | FileCheck %s
+
+ at g = internal unnamed_addr addrspace(4) constant [3 x i8] c"12\00", align 16
+
+define void @foo(i32 %a, i32 %b, ptr %p) {
+; CHECK-LABEL: define void @foo(
+; CHECK-SAME: i32 [[A:%.*]], i32 [[B:%.*]], ptr nofree nonnull writeonly captures(none) dereferenceable(1) [[P:%.*]]) #[[ATTR0:[0-9]+]] {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i32 [[A]], [[B]]
+; CHECK-NEXT:    br i1 [[CMP]], label %[[L1:.*]], label %[[L2:.*]]
+; CHECK:       [[L1]]:
+; CHECK-NEXT:    br label %[[L3:.*]]
+; CHECK:       [[L2]]:
+; CHECK-NEXT:    br label %[[L3]]
+; CHECK:       [[L3]]:
+; CHECK-NEXT:    [[PHI:%.*]] = phi ptr addrspace(4) [ @g, %[[L1]] ], [ getelementptr inbounds nuw (i8, ptr addrspace(4) @g, i64 1), %[[L2]] ]
+; CHECK-NEXT:    [[LOAD:%.*]] = load i8, ptr addrspace(4) [[PHI]], align 1
+; CHECK-NEXT:    store i8 [[LOAD]], ptr [[P]], align 1
+; CHECK-NEXT:    ret void
+;
+entry:
+  %cmp = icmp ne i32 %a, %b
+  br i1 %cmp, label %l1, label %l2
+l1:
+  br label %l3
+l2:
+  br label %l3
+l3:
+  %phi = phi ptr addrspace(4) [ @g, %l1 ], [ getelementptr inbounds nuw (i8, ptr addrspace(4) @g, i64 1), %l2 ]
+  %load = load i8, ptr addrspace(4) %phi
+  store i8 %load, ptr %p
+  ret void
+}
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arsenm wrote:

Both types of mismatches should still be tested 

https://github.com/llvm/llvm-project/pull/151359