[llvm] Fix Potential bug when handling PHI in AAPointerInfo (PR #97321)
via llvm-commits
llvm-commits at lists.llvm.org
Mon Jul 1 10:16:29 PDT 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-llvm-transforms
Author: Vidush Singhal (vidsinghal)
<details>
<summary>Changes</summary>
If a cycle Info object does not exist, we should return false that an instruction is not cyclic.
for the test:
`llvm/test/Transforms/Attributor/phi_bug_pointer_info.ll`
Debug info Before the fix:
```
Accesses by bin after update:
[8-12] : 1
- 9 - store i32 100, ptr %field2, align 4
- c: i32 100
[32-36] : 1
- 9 - store i32 100, ptr %field8, align 4
- c: i32 100
[2147483647-4294967294] : 1
- 6 - %ret = load i32, ptr %x, align 4
- c: <unknown>
```
Debug info After the fix:
```
Accesses by bin after update:
[8-12] : 2
- 9 - store i32 %0, ptr %field2, align 4
- c: %0 = load i32, ptr %val, align 4
- 6 - %ret = load i32, ptr %x, align 4
- c: <unknown>
[32-36] : 2
- 9 - store i32 %1, ptr %field8, align 4
- c: %1 = load i32, ptr %val2, align 4
- 6 - %ret = load i32, ptr %x, align 4
- c: <unknown>
```
---
Full diff: https://github.com/llvm/llvm-project/pull/97321.diff
3 Files Affected:
- (modified) llvm/lib/Transforms/IPO/AttributorAttributes.cpp (+1-1)
- (added) llvm/test/Transforms/Attributor/phi_bug_pointer_info.ll (+41)
- (modified) llvm/test/Transforms/Attributor/value-simplify-pointer-info.ll (+14-50)
``````````diff
diff --git a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
index c4b9375a53a27..210327a6e8234 100644
--- a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
+++ b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
@@ -214,7 +214,7 @@ ChangeStatus clampStateAndIndicateChange<DerefState>(DerefState &S,
static bool mayBeInCycle(const CycleInfo *CI, const Instruction *I,
bool HeaderOnly, Cycle **CPtr = nullptr) {
if (!CI)
- return true;
+ return false;
auto *BB = I->getParent();
auto *C = CI->getCycle(BB);
if (!C)
diff --git a/llvm/test/Transforms/Attributor/phi_bug_pointer_info.ll b/llvm/test/Transforms/Attributor/phi_bug_pointer_info.ll
new file mode 100644
index 0000000000000..bb423e10f2c72
--- /dev/null
+++ b/llvm/test/Transforms/Attributor/phi_bug_pointer_info.ll
@@ -0,0 +1,41 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-attributes --check-globals --version 2
+; RUN: opt -aa-pipeline=basic-aa -passes=attributor -debug-only=attributor -attributor-manifest-internal -attributor-annotate-decl-cs -S < %s 2>&1 | FileCheck %s
+; RUN: opt -aa-pipeline=basic-aa -passes=attributor-cgscc -debug-only=attributor -attributor-manifest-internal -attributor-annotate-decl-cs -S < %s 2>&1 | FileCheck %s
+; REQUIRES: asserts
+
+
+ at globalBytes = internal global [1024 x i8] zeroinitializer
+
+; CHECK: Accesses by bin after update:
+; CHECK: [8-12] : 2
+; CHECK: - 9 - store i32 %0, ptr %field2, align 4
+; CHECK: - c: %0 = load i32, ptr %val, align 4
+; CHECK: - 6 - %ret = load i32, ptr %x, align 4
+; CHECK: - c: <unknown>
+; CHECK: [32-36] : 2
+; CHECK: - 9 - store i32 %1, ptr %field8, align 4
+; CHECK: - c: %1 = load i32, ptr %val2, align 4
+; CHECK: - 6 - %ret = load i32, ptr %x, align 4
+; CHECK: - c: <unknown>
+define dso_local i32 @phi_different_offsets(ptr nocapture %val, ptr nocapture %val2, i1 %cmp) {
+entry:
+ br i1 %cmp, label %then, label %else
+
+then:
+ %field2 = getelementptr i32, ptr @globalBytes, i32 2
+ %1 = load i32, ptr %val
+ store i32 %1, ptr %field2
+ br label %end
+
+else:
+ %field8 = getelementptr i32, ptr @globalBytes, i32 8
+ %2 = load i32, ptr %val2
+ store i32 %2, ptr %field8
+ br label %end
+
+end:
+ %x = phi ptr [ %field2, %then ], [ %field8, %else ]
+ %ret = load i32, ptr %x
+ ret i32 %ret
+
+}
diff --git a/llvm/test/Transforms/Attributor/value-simplify-pointer-info.ll b/llvm/test/Transforms/Attributor/value-simplify-pointer-info.ll
index 7a35b5c856097..1dce6e105bf29 100644
--- a/llvm/test/Transforms/Attributor/value-simplify-pointer-info.ll
+++ b/llvm/test/Transforms/Attributor/value-simplify-pointer-info.ll
@@ -2092,47 +2092,35 @@ end:
; FIXME: This function returns 1.
define i8 @phi_no_store_1() {
;
-; TUNIT: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn
+; TUNIT: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(write)
; TUNIT-LABEL: define {{[^@]+}}@phi_no_store_1
-; TUNIT-SAME: () #[[ATTR3]] {
+; TUNIT-SAME: () #[[ATTR5]] {
; TUNIT-NEXT: entry:
; TUNIT-NEXT: br label [[LOOP:%.*]]
; TUNIT: loop:
; TUNIT-NEXT: [[P:%.*]] = phi ptr [ @a1, [[ENTRY:%.*]] ], [ [[G:%.*]], [[LOOP]] ]
; TUNIT-NEXT: [[I:%.*]] = phi i8 [ 0, [[ENTRY]] ], [ [[O:%.*]], [[LOOP]] ]
-; TUNIT-NEXT: store i8 1, ptr [[P]], align 1
; TUNIT-NEXT: [[G]] = getelementptr i8, ptr [[P]], i64 1
; TUNIT-NEXT: [[O]] = add nsw i8 [[I]], 1
; TUNIT-NEXT: [[C:%.*]] = icmp eq i8 [[O]], 3
; TUNIT-NEXT: br i1 [[C]], label [[END:%.*]], label [[LOOP]]
; TUNIT: end:
-; TUNIT-NEXT: [[S11:%.*]] = getelementptr i8, ptr @a1, i64 2
-; TUNIT-NEXT: [[L11:%.*]] = load i8, ptr [[S11]], align 2
-; TUNIT-NEXT: [[S12:%.*]] = getelementptr i8, ptr @a1, i64 3
-; TUNIT-NEXT: [[L12:%.*]] = load i8, ptr [[S12]], align 1
-; TUNIT-NEXT: [[ADD:%.*]] = add i8 [[L11]], [[L12]]
-; TUNIT-NEXT: ret i8 [[ADD]]
+; TUNIT-NEXT: ret i8 0
;
-; CGSCC: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn
+; CGSCC: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(write)
; CGSCC-LABEL: define {{[^@]+}}@phi_no_store_1
-; CGSCC-SAME: () #[[ATTR5]] {
+; CGSCC-SAME: () #[[ATTR6]] {
; CGSCC-NEXT: entry:
; CGSCC-NEXT: br label [[LOOP:%.*]]
; CGSCC: loop:
; CGSCC-NEXT: [[P:%.*]] = phi ptr [ @a1, [[ENTRY:%.*]] ], [ [[G:%.*]], [[LOOP]] ]
; CGSCC-NEXT: [[I:%.*]] = phi i8 [ 0, [[ENTRY]] ], [ [[O:%.*]], [[LOOP]] ]
-; CGSCC-NEXT: store i8 1, ptr [[P]], align 1
; CGSCC-NEXT: [[G]] = getelementptr i8, ptr [[P]], i64 1
; CGSCC-NEXT: [[O]] = add nsw i8 [[I]], 1
; CGSCC-NEXT: [[C:%.*]] = icmp eq i8 [[O]], 3
; CGSCC-NEXT: br i1 [[C]], label [[END:%.*]], label [[LOOP]]
; CGSCC: end:
-; CGSCC-NEXT: [[S11:%.*]] = getelementptr i8, ptr @a1, i64 2
-; CGSCC-NEXT: [[L11:%.*]] = load i8, ptr [[S11]], align 2
-; CGSCC-NEXT: [[S12:%.*]] = getelementptr i8, ptr @a1, i64 3
-; CGSCC-NEXT: [[L12:%.*]] = load i8, ptr [[S12]], align 1
-; CGSCC-NEXT: [[ADD:%.*]] = add i8 [[L11]], [[L12]]
-; CGSCC-NEXT: ret i8 [[ADD]]
+; CGSCC-NEXT: ret i8 0
;
entry:
br label %loop
@@ -2172,9 +2160,7 @@ define i8 @phi_no_store_2() {
; TUNIT: end:
; TUNIT-NEXT: [[S21:%.*]] = getelementptr i8, ptr @a2, i64 2
; TUNIT-NEXT: [[L21:%.*]] = load i8, ptr [[S21]], align 2
-; TUNIT-NEXT: [[S22:%.*]] = getelementptr i8, ptr @a2, i64 3
-; TUNIT-NEXT: [[L22:%.*]] = load i8, ptr [[S22]], align 1
-; TUNIT-NEXT: [[ADD:%.*]] = add i8 [[L21]], [[L22]]
+; TUNIT-NEXT: [[ADD:%.*]] = add i8 [[L21]], 0
; TUNIT-NEXT: ret i8 [[ADD]]
;
; CGSCC: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn
@@ -2193,9 +2179,7 @@ define i8 @phi_no_store_2() {
; CGSCC: end:
; CGSCC-NEXT: [[S21:%.*]] = getelementptr i8, ptr @a2, i64 2
; CGSCC-NEXT: [[L21:%.*]] = load i8, ptr [[S21]], align 2
-; CGSCC-NEXT: [[S22:%.*]] = getelementptr i8, ptr @a2, i64 3
-; CGSCC-NEXT: [[L22:%.*]] = load i8, ptr [[S22]], align 1
-; CGSCC-NEXT: [[ADD:%.*]] = add i8 [[L21]], [[L22]]
+; CGSCC-NEXT: [[ADD:%.*]] = add i8 [[L21]], 0
; CGSCC-NEXT: ret i8 [[ADD]]
;
entry:
@@ -2218,57 +2202,37 @@ end:
}
define i8 @phi_no_store_3() {
-; TUNIT: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn
+; TUNIT: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(write)
; TUNIT-LABEL: define {{[^@]+}}@phi_no_store_3
-; TUNIT-SAME: () #[[ATTR3]] {
+; TUNIT-SAME: () #[[ATTR5]] {
; TUNIT-NEXT: entry:
; TUNIT-NEXT: [[S30:%.*]] = getelementptr i8, ptr @a3, i64 3
-; TUNIT-NEXT: store i8 0, ptr [[S30]], align 1
; TUNIT-NEXT: br label [[LOOP:%.*]]
; TUNIT: loop:
; TUNIT-NEXT: [[P:%.*]] = phi ptr [ @a3, [[ENTRY:%.*]] ], [ [[G:%.*]], [[LOOP]] ]
; TUNIT-NEXT: [[I:%.*]] = phi i8 [ 0, [[ENTRY]] ], [ [[O:%.*]], [[LOOP]] ]
-; TUNIT-NEXT: store i8 1, ptr [[P]], align 1
; TUNIT-NEXT: [[G]] = getelementptr i8, ptr @a3, i64 2
; TUNIT-NEXT: [[O]] = add nsw i8 [[I]], 1
; TUNIT-NEXT: [[C:%.*]] = icmp eq i8 [[O]], 7
; TUNIT-NEXT: br i1 [[C]], label [[END:%.*]], label [[LOOP]]
; TUNIT: end:
-; TUNIT-NEXT: [[S31:%.*]] = getelementptr i8, ptr @a3, i64 2
-; TUNIT-NEXT: [[L31:%.*]] = load i8, ptr [[S31]], align 2
-; TUNIT-NEXT: [[S32:%.*]] = getelementptr i8, ptr @a3, i64 3
-; TUNIT-NEXT: [[L32:%.*]] = load i8, ptr [[S32]], align 1
-; TUNIT-NEXT: [[ADD:%.*]] = add i8 [[L31]], [[L32]]
-; TUNIT-NEXT: [[S34:%.*]] = getelementptr i8, ptr @a3, i64 4
-; TUNIT-NEXT: [[L34:%.*]] = load i8, ptr [[S34]], align 4
-; TUNIT-NEXT: [[ADD2:%.*]] = add i8 [[ADD]], [[L34]]
-; TUNIT-NEXT: ret i8 [[ADD2]]
+; TUNIT-NEXT: ret i8 poison
;
-; CGSCC: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn
+; CGSCC: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(write)
; CGSCC-LABEL: define {{[^@]+}}@phi_no_store_3
-; CGSCC-SAME: () #[[ATTR5]] {
+; CGSCC-SAME: () #[[ATTR6]] {
; CGSCC-NEXT: entry:
; CGSCC-NEXT: [[S30:%.*]] = getelementptr i8, ptr @a3, i64 3
-; CGSCC-NEXT: store i8 0, ptr [[S30]], align 1
; CGSCC-NEXT: br label [[LOOP:%.*]]
; CGSCC: loop:
; CGSCC-NEXT: [[P:%.*]] = phi ptr [ @a3, [[ENTRY:%.*]] ], [ [[G:%.*]], [[LOOP]] ]
; CGSCC-NEXT: [[I:%.*]] = phi i8 [ 0, [[ENTRY]] ], [ [[O:%.*]], [[LOOP]] ]
-; CGSCC-NEXT: store i8 1, ptr [[P]], align 1
; CGSCC-NEXT: [[G]] = getelementptr i8, ptr @a3, i64 2
; CGSCC-NEXT: [[O]] = add nsw i8 [[I]], 1
; CGSCC-NEXT: [[C:%.*]] = icmp eq i8 [[O]], 7
; CGSCC-NEXT: br i1 [[C]], label [[END:%.*]], label [[LOOP]]
; CGSCC: end:
-; CGSCC-NEXT: [[S31:%.*]] = getelementptr i8, ptr @a3, i64 2
-; CGSCC-NEXT: [[L31:%.*]] = load i8, ptr [[S31]], align 2
-; CGSCC-NEXT: [[S32:%.*]] = getelementptr i8, ptr @a3, i64 3
-; CGSCC-NEXT: [[L32:%.*]] = load i8, ptr [[S32]], align 1
-; CGSCC-NEXT: [[ADD:%.*]] = add i8 [[L31]], [[L32]]
-; CGSCC-NEXT: [[S34:%.*]] = getelementptr i8, ptr @a3, i64 4
-; CGSCC-NEXT: [[L34:%.*]] = load i8, ptr [[S34]], align 4
-; CGSCC-NEXT: [[ADD2:%.*]] = add i8 [[ADD]], [[L34]]
-; CGSCC-NEXT: ret i8 [[ADD2]]
+; CGSCC-NEXT: ret i8 poison
;
entry:
%s30 = getelementptr i8, ptr @a3, i64 3
``````````
</details>
https://github.com/llvm/llvm-project/pull/97321
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