[llvm] 0496eda - [BuildLibCalls] Add additional attrs to memcpy_chk.

[Florian Hahn via llvm-commits]

Author: Florian Hahn
Date: 2021-12-02T09:50:14Z
New Revision: 0496edad49939b655435ad71ffda9e366c7c3dc6

URL: https://github.com/llvm/llvm-project/commit/0496edad49939b655435ad71ffda9e366c7c3dc6
DIFF: https://github.com/llvm/llvm-project/commit/0496edad49939b655435ad71ffda9e366c7c3dc6.diff

LOG: [BuildLibCalls] Add additional attrs to memcpy_chk.

`memcpy_chk` can be treated like `memcpy`, with the exception that it
may not return (if it aborts the program).

See D114793 for a similar patch for `memset_chk`.

Reviewed By: xbolva00

Differential Revision: https://reviews.llvm.org/D114863

Added: 
    

Modified: 
    llvm/lib/Transforms/Utils/BuildLibCalls.cpp
    llvm/test/Transforms/InferFunctionAttrs/annotate.ll

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
index 5b05a87f86913..7b1919573e831 100644
--- a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
@@ -452,18 +452,17 @@ bool llvm::inferLibFuncAttributes(Function &F, const TargetLibraryInfo &TLI) {
     return Changed;
   case LibFunc_mempcpy:
   case LibFunc_memccpy:
+    Changed |= setWillReturn(F);
+    LLVM_FALLTHROUGH;
+  case LibFunc_memcpy_chk:
     Changed |= setDoesNotThrow(F);
     Changed |= setOnlyAccessesArgMemory(F);
-    Changed |= setWillReturn(F);
     Changed |= setDoesNotAlias(F, 0);
     Changed |= setOnlyWritesMemory(F, 0);
     Changed |= setDoesNotAlias(F, 1);
     Changed |= setDoesNotCapture(F, 1);
     Changed |= setOnlyReadsMemory(F, 1);
     return Changed;
-  case LibFunc_memcpy_chk:
-    Changed |= setDoesNotThrow(F);
-    return Changed;
   case LibFunc_memalign:
     Changed |= setOnlyAccessesInaccessibleMemory(F);
     Changed |= setRetNoUndef(F);

diff  --git a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
index 22101498ff40a..40306356594ff 100644
--- a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
+++ b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
@@ -631,7 +631,7 @@ declare i32 @memcmp(i8*, i8*, i64)
 ; CHECK: declare i8* @memcpy(i8* noalias returned writeonly, i8* noalias nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_WILLRETURN]]
 declare i8* @memcpy(i8*, i8*, i64)
 
-; CHECK: declare i8* @__memcpy_chk(i8*, i8*, i64, i64) [[NOFREE_NOUNWIND]]
+; CHECK: declare i8* @__memcpy_chk(i8* noalias writeonly, i8* noalias nocapture readonly, i64, i64) [[ARGMEMONLY_NOFREE_NOUNWIND:#[0-9]+]]
 declare i8* @__memcpy_chk(i8*, i8*, i64, i64)
 
 ; CHECK: declare i8* @mempcpy(i8* noalias writeonly, i8* noalias nocapture readonly, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_WILLRETURN]]
@@ -643,7 +643,7 @@ declare i8* @memmove(i8*, i8*, i64)
 ; CHECK: declare i8* @memset(i8* writeonly, i32, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_WILLRETURN:#[0-9]+]]
 declare i8* @memset(i8*, i32, i64)
 
-; CHECK: declare i8* @__memset_chk(i8* writeonly, i32, i64, i64) [[ARGMEMONLY_NOFREE_NOUNWIND:#[0-9]+]]
+; CHECK: declare i8* @__memset_chk(i8* writeonly, i32, i64, i64) [[ARGMEMONLY_NOFREE_NOUNWIND]]
 declare i8* @__memset_chk(i8*, i32, i64, i64)
 
 ; CHECK: declare noundef i32 @mkdir(i8* nocapture noundef readonly, i16 noundef zeroext) [[NOFREE_NOUNWIND]]