[llvm] [clang] [lld] [FuncAttrs] Deduce `noundef` attributes for return values (PR #76553)

2024-01-01 Thread Nikita Popov via cfe-commits 

nikic wrote:

Yeah, we should skip this inference for functions with the sanitize_memory 
attribute.

https://github.com/llvm/llvm-project/pull/76553
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[llvm] [clang] [lld] [FuncAttrs] Deduce `noundef` attributes for return values (PR #76553)

2024-01-01 Thread Yingwei Zheng via cfe-commits 

dtcxzyw wrote:

> Can you please fix or revert 
> https://lab.llvm.org/buildbot/#/builders/74/builds/24592 ?

Thank you for reporting this! I will check the error log.


https://github.com/llvm/llvm-project/pull/76553
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[llvm] [clang] [lld] [FuncAttrs] Deduce `noundef` attributes for return values (PR #76553)

2024-01-01 Thread Vitaly Buka via cfe-commits 

vitalybuka wrote:

Another problem is that there was assumption that definition and declaration 
will be consistent, for msan is a part of ABI.
Clang will generate them consistently for all modules, with declaration and 
definition of the function.

Is possible that after this patch some definitions will get noundef, but 
declarations in other modules will still have none? If that is so, it breaks 
msan.

https://github.com/llvm/llvm-project/pull/76553
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[llvm] [clang] [lld] [FuncAttrs] Deduce `noundef` attributes for return values (PR #76553)

2024-01-01 Thread Vitaly Buka via cfe-commits 

vitalybuka wrote:

```
This patch deduces noundef attributes for return values.
IIUC, a function returns noundef values iff all of its return values are 
guaranteed not to be undef or poison.
```

https://github.com/llvm/llvm-project/pull/76553
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[llvm] [clang] [lld] [FuncAttrs] Deduce `noundef` attributes for return values (PR #76553)

2023-12-31 Thread Yingwei Zheng via cfe-commits 

https://github.com/dtcxzyw closed 
https://github.com/llvm/llvm-project/pull/76553
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[llvm] [clang] [lld] [FuncAttrs] Deduce `noundef` attributes for return values (PR #76553)

2023-12-31 Thread Yingwei Zheng via cfe-commits 

https://github.com/dtcxzyw edited 
https://github.com/llvm/llvm-project/pull/76553
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[llvm] [clang] [lld] [FuncAttrs] Deduce `noundef` attributes for return values (PR #76553)

2023-12-31 Thread Nikita Popov via cfe-commits 

https://github.com/nikic approved this pull request.

LGTM, assuming Linux CI passes now.

https://github.com/llvm/llvm-project/pull/76553
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[llvm] [clang] [lld] [FuncAttrs] Deduce `noundef` attributes for return values (PR #76553)

2023-12-31 Thread Yingwei Zheng via cfe-commits 

dtcxzyw wrote:

> There are lld test failures.

Done.

https://github.com/llvm/llvm-project/pull/76553
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[llvm] [clang] [lld] [FuncAttrs] Deduce `noundef` attributes for return values (PR #76553)

2023-12-31 Thread Yingwei Zheng via cfe-commits 

https://github.com/dtcxzyw updated 
https://github.com/llvm/llvm-project/pull/76553

>From 30dcc33c4ea3ab50397a7adbe85fe977d4a400bd Mon Sep 17 00:00:00 2001
From: Yingwei Zheng 
Date: Fri, 29 Dec 2023 14:27:22 +0800
Subject: [PATCH 1/2] [FuncAttrs] Add pre-commit tests. NFC.

---
 llvm/test/Transforms/FunctionAttrs/noundef.ll | 145 ++
 1 file changed, 145 insertions(+)
 create mode 100644 llvm/test/Transforms/FunctionAttrs/noundef.ll

diff --git a/llvm/test/Transforms/FunctionAttrs/noundef.ll 
b/llvm/test/Transforms/FunctionAttrs/noundef.ll
new file mode 100644
index 00..9eca495e111e8f
--- /dev/null
+++ b/llvm/test/Transforms/FunctionAttrs/noundef.ll
@@ -0,0 +1,145 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py 
UTC_ARGS: --version 4
+; RUN: opt < %s -passes='function-attrs' -S | FileCheck %s
+
+define i32 @test_ret_constant() {
+; CHECK-LABEL: define i32 @test_ret_constant(
+; CHECK-SAME: ) #[[ATTR0:[0-9]+]] {
+; CHECK-NEXT:ret i32 0
+;
+  ret i32 0
+}
+
+define i32 @test_ret_poison() {
+; CHECK-LABEL: define i32 @test_ret_poison(
+; CHECK-SAME: ) #[[ATTR0]] {
+; CHECK-NEXT:ret i32 poison
+;
+  ret i32 poison
+}
+
+define i32 @test_ret_undef() {
+; CHECK-LABEL: define i32 @test_ret_undef(
+; CHECK-SAME: ) #[[ATTR0]] {
+; CHECK-NEXT:ret i32 undef
+;
+  ret i32 undef
+}
+
+define i32 @test_ret_param(i32 %x) {
+; CHECK-LABEL: define i32 @test_ret_param(
+; CHECK-SAME: i32 returned [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:ret i32 [[X]]
+;
+  ret i32 %x
+}
+
+define i32 @test_ret_noundef_param(i32 noundef %x) {
+; CHECK-LABEL: define i32 @test_ret_noundef_param(
+; CHECK-SAME: i32 noundef returned [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:ret i32 [[X]]
+;
+  ret i32 %x
+}
+
+define i32 @test_ret_noundef_expr(i32 noundef %x) {
+; CHECK-LABEL: define i32 @test_ret_noundef_expr(
+; CHECK-SAME: i32 noundef [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:[[Y:%.*]] = add i32 [[X]], 1
+; CHECK-NEXT:ret i32 [[Y]]
+;
+  %y = add i32 %x, 1
+  ret i32 %y
+}
+
+define i32 @test_ret_create_poison_expr(i32 noundef %x) {
+; CHECK-LABEL: define i32 @test_ret_create_poison_expr(
+; CHECK-SAME: i32 noundef [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:[[Y:%.*]] = add nsw i32 [[X]], 1
+; CHECK-NEXT:ret i32 [[Y]]
+;
+  %y = add nsw i32 %x, 1
+  ret i32 %y
+}
+
+define i32 @test_ret_freezed(i32 noundef %x) {
+; CHECK-LABEL: define i32 @test_ret_freezed(
+; CHECK-SAME: i32 noundef [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:[[Y:%.*]] = add nsw i32 [[X]], 1
+; CHECK-NEXT:[[Z:%.*]] = freeze i32 [[Y]]
+; CHECK-NEXT:ret i32 [[Z]]
+;
+  %y = add nsw i32 %x, 1
+  %z = freeze i32 %y
+  ret i32 %z
+}
+
+define i32 @test_ret_control_flow(i32 noundef %x) {
+; CHECK-LABEL: define i32 @test_ret_control_flow(
+; CHECK-SAME: i32 noundef [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:[[COND:%.*]] = icmp eq i32 [[X]], 0
+; CHECK-NEXT:br i1 [[COND]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK:   if.then:
+; CHECK-NEXT:ret i32 2
+; CHECK:   if.else:
+; CHECK-NEXT:[[RET:%.*]] = add i32 [[X]], 1
+; CHECK-NEXT:ret i32 [[RET]]
+;
+  %cond = icmp eq i32 %x, 0
+  br i1 %cond, label %if.then, label %if.else
+if.then:
+  ret i32 2
+if.else:
+  %ret = add i32 %x, 1
+  ret i32 %ret
+}
+
+define i32 @test_ret_control_flow_may_poison(i32 noundef %x) {
+; CHECK-LABEL: define i32 @test_ret_control_flow_may_poison(
+; CHECK-SAME: i32 noundef [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:[[COND:%.*]] = icmp eq i32 [[X]], 0
+; CHECK-NEXT:br i1 [[COND]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK:   if.then:
+; CHECK-NEXT:ret i32 2
+; CHECK:   if.else:
+; CHECK-NEXT:[[RET:%.*]] = add nsw i32 [[X]], 1
+; CHECK-NEXT:ret i32 [[RET]]
+;
+  %cond = icmp eq i32 %x, 0
+  br i1 %cond, label %if.then, label %if.else
+if.then:
+  ret i32 2
+if.else:
+  %ret = add nsw i32 %x, 1
+  ret i32 %ret
+}
+
+; TODO: use context-sensitive analysis
+define i32 @test_ret_control_flow_never_poison(i32 noundef %x) {
+; CHECK-LABEL: define i32 @test_ret_control_flow_never_poison(
+; CHECK-SAME: i32 noundef [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:[[COND:%.*]] = icmp eq i32 [[X]], 2147483647
+; CHECK-NEXT:br i1 [[COND]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK:   if.then:
+; CHECK-NEXT:ret i32 2
+; CHECK:   if.else:
+; CHECK-NEXT:[[RET:%.*]] = add nsw i32 [[X]], 1
+; CHECK-NEXT:ret i32 [[RET]]
+;
+  %cond = icmp eq i32 %x, 2147483647
+  br i1 %cond, label %if.then, label %if.else
+if.then:
+  ret i32 2
+if.else:
+  %ret = add nsw i32 %x, 1
+  ret i32 %ret
+}
+
+define i32 @test_noundef_prop() {
+; CHECK-LABEL: define i32 @test_noundef_prop(
+; CHECK-SAME: ) #[[ATTR0]] {
+; CHECK-NEXT:[[RET:%.*]] = call i32 @test_ret_constant()
+; CHECK-NEXT:ret i32 [[RET]]
+;
+  %ret = call i32 @test_ret_constant()
+  ret i32 %ret
+}

>From fe11127cd7e9ed4669243502eda5991504b9809a Mon Sep 17 00:00:00 2001
From: Yingwei Zheng

[llvm] [clang] [lld] [FuncAttrs] Deduce `noundef` attributes for return values (PR #76553)

2023-12-31 Thread Yingwei Zheng via cfe-commits 

https://github.com/dtcxzyw updated 
https://github.com/llvm/llvm-project/pull/76553

>From 30dcc33c4ea3ab50397a7adbe85fe977d4a400bd Mon Sep 17 00:00:00 2001
From: Yingwei Zheng 
Date: Fri, 29 Dec 2023 14:27:22 +0800
Subject: [PATCH 1/2] [FuncAttrs] Add pre-commit tests. NFC.

---
 llvm/test/Transforms/FunctionAttrs/noundef.ll | 145 ++
 1 file changed, 145 insertions(+)
 create mode 100644 llvm/test/Transforms/FunctionAttrs/noundef.ll

diff --git a/llvm/test/Transforms/FunctionAttrs/noundef.ll 
b/llvm/test/Transforms/FunctionAttrs/noundef.ll
new file mode 100644
index 00..9eca495e111e8f
--- /dev/null
+++ b/llvm/test/Transforms/FunctionAttrs/noundef.ll
@@ -0,0 +1,145 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py 
UTC_ARGS: --version 4
+; RUN: opt < %s -passes='function-attrs' -S | FileCheck %s
+
+define i32 @test_ret_constant() {
+; CHECK-LABEL: define i32 @test_ret_constant(
+; CHECK-SAME: ) #[[ATTR0:[0-9]+]] {
+; CHECK-NEXT:ret i32 0
+;
+  ret i32 0
+}
+
+define i32 @test_ret_poison() {
+; CHECK-LABEL: define i32 @test_ret_poison(
+; CHECK-SAME: ) #[[ATTR0]] {
+; CHECK-NEXT:ret i32 poison
+;
+  ret i32 poison
+}
+
+define i32 @test_ret_undef() {
+; CHECK-LABEL: define i32 @test_ret_undef(
+; CHECK-SAME: ) #[[ATTR0]] {
+; CHECK-NEXT:ret i32 undef
+;
+  ret i32 undef
+}
+
+define i32 @test_ret_param(i32 %x) {
+; CHECK-LABEL: define i32 @test_ret_param(
+; CHECK-SAME: i32 returned [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:ret i32 [[X]]
+;
+  ret i32 %x
+}
+
+define i32 @test_ret_noundef_param(i32 noundef %x) {
+; CHECK-LABEL: define i32 @test_ret_noundef_param(
+; CHECK-SAME: i32 noundef returned [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:ret i32 [[X]]
+;
+  ret i32 %x
+}
+
+define i32 @test_ret_noundef_expr(i32 noundef %x) {
+; CHECK-LABEL: define i32 @test_ret_noundef_expr(
+; CHECK-SAME: i32 noundef [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:[[Y:%.*]] = add i32 [[X]], 1
+; CHECK-NEXT:ret i32 [[Y]]
+;
+  %y = add i32 %x, 1
+  ret i32 %y
+}
+
+define i32 @test_ret_create_poison_expr(i32 noundef %x) {
+; CHECK-LABEL: define i32 @test_ret_create_poison_expr(
+; CHECK-SAME: i32 noundef [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:[[Y:%.*]] = add nsw i32 [[X]], 1
+; CHECK-NEXT:ret i32 [[Y]]
+;
+  %y = add nsw i32 %x, 1
+  ret i32 %y
+}
+
+define i32 @test_ret_freezed(i32 noundef %x) {
+; CHECK-LABEL: define i32 @test_ret_freezed(
+; CHECK-SAME: i32 noundef [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:[[Y:%.*]] = add nsw i32 [[X]], 1
+; CHECK-NEXT:[[Z:%.*]] = freeze i32 [[Y]]
+; CHECK-NEXT:ret i32 [[Z]]
+;
+  %y = add nsw i32 %x, 1
+  %z = freeze i32 %y
+  ret i32 %z
+}
+
+define i32 @test_ret_control_flow(i32 noundef %x) {
+; CHECK-LABEL: define i32 @test_ret_control_flow(
+; CHECK-SAME: i32 noundef [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:[[COND:%.*]] = icmp eq i32 [[X]], 0
+; CHECK-NEXT:br i1 [[COND]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK:   if.then:
+; CHECK-NEXT:ret i32 2
+; CHECK:   if.else:
+; CHECK-NEXT:[[RET:%.*]] = add i32 [[X]], 1
+; CHECK-NEXT:ret i32 [[RET]]
+;
+  %cond = icmp eq i32 %x, 0
+  br i1 %cond, label %if.then, label %if.else
+if.then:
+  ret i32 2
+if.else:
+  %ret = add i32 %x, 1
+  ret i32 %ret
+}
+
+define i32 @test_ret_control_flow_may_poison(i32 noundef %x) {
+; CHECK-LABEL: define i32 @test_ret_control_flow_may_poison(
+; CHECK-SAME: i32 noundef [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:[[COND:%.*]] = icmp eq i32 [[X]], 0
+; CHECK-NEXT:br i1 [[COND]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK:   if.then:
+; CHECK-NEXT:ret i32 2
+; CHECK:   if.else:
+; CHECK-NEXT:[[RET:%.*]] = add nsw i32 [[X]], 1
+; CHECK-NEXT:ret i32 [[RET]]
+;
+  %cond = icmp eq i32 %x, 0
+  br i1 %cond, label %if.then, label %if.else
+if.then:
+  ret i32 2
+if.else:
+  %ret = add nsw i32 %x, 1
+  ret i32 %ret
+}
+
+; TODO: use context-sensitive analysis
+define i32 @test_ret_control_flow_never_poison(i32 noundef %x) {
+; CHECK-LABEL: define i32 @test_ret_control_flow_never_poison(
+; CHECK-SAME: i32 noundef [[X:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT:[[COND:%.*]] = icmp eq i32 [[X]], 2147483647
+; CHECK-NEXT:br i1 [[COND]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK:   if.then:
+; CHECK-NEXT:ret i32 2
+; CHECK:   if.else:
+; CHECK-NEXT:[[RET:%.*]] = add nsw i32 [[X]], 1
+; CHECK-NEXT:ret i32 [[RET]]
+;
+  %cond = icmp eq i32 %x, 2147483647
+  br i1 %cond, label %if.then, label %if.else
+if.then:
+  ret i32 2
+if.else:
+  %ret = add nsw i32 %x, 1
+  ret i32 %ret
+}
+
+define i32 @test_noundef_prop() {
+; CHECK-LABEL: define i32 @test_noundef_prop(
+; CHECK-SAME: ) #[[ATTR0]] {
+; CHECK-NEXT:[[RET:%.*]] = call i32 @test_ret_constant()
+; CHECK-NEXT:ret i32 [[RET]]
+;
+  %ret = call i32 @test_ret_constant()
+  ret i32 %ret
+}

>From 46188dfe1a8069c94fc4628660889e070e6a82cb Mon Sep 17 00:00:00 2001
From: Yingwei Zheng