[llvm] 4683ce2 - [InferAttrs] Give strnlen the same attributes as strlen

[Benjamin Kramer via llvm-commits]

Author: Benjamin Kramer
Date: 2021-12-30T20:43:43+01:00
New Revision: 4683ce2cd899b2d682453e173c3466fa270c09f7

URL: https://github.com/llvm/llvm-project/commit/4683ce2cd899b2d682453e173c3466fa270c09f7
DIFF: https://github.com/llvm/llvm-project/commit/4683ce2cd899b2d682453e173c3466fa270c09f7.diff

LOG: [InferAttrs] Give strnlen the same attributes as strlen

This moves the only string function out of the big list of math funcs.
And let's us CSE strnlen calls.

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 580cfd80141e8..bec23a20ac49a 100644
--- a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
@@ -233,6 +233,7 @@ bool llvm::inferLibFuncAttributes(Function &F, const TargetLibraryInfo &TLI) {
 
   switch (TheLibFunc) {
   case LibFunc_strlen:
+  case LibFunc_strnlen:
   case LibFunc_wcslen:
     Changed |= setOnlyReadsMemory(F);
     Changed |= setDoesNotThrow(F);
@@ -1158,7 +1159,6 @@ bool llvm::inferLibFuncAttributes(Function &F, const TargetLibraryInfo &TLI) {
   case LibFunc_sqrt:
   case LibFunc_sqrtf:
   case LibFunc_sqrtl:
-  case LibFunc_strnlen:
   case LibFunc_tan:
   case LibFunc_tanf:
   case LibFunc_tanh:

diff  --git a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
index 7bdb2a1d8e0c4..4fdf32b60923c 100644
--- a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
+++ b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
@@ -921,10 +921,10 @@ declare i8* @strncpy(i8*, i8*, i64)
 ; CHECK: declare noalias i8* @strndup(i8* nocapture readonly, i64 noundef) [[INACCESSIBLEMEMORARGONLY_NOFREE_NOUNWIND_WILLRETURN]]
 declare i8* @strndup(i8*, i64)
 
-; CHECK: declare i64 @strnlen(i8*, i64) [[NOFREE_NOUNWIND_WILLRETURN]]
+; CHECK: declare i64 @strnlen(i8* nocapture, i64) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY_WILLRETURN:#[0-9]+]]
 declare i64 @strnlen(i8*, i64)
 
-; CHECK: declare i8* @strpbrk(i8*, i8* nocapture) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY_WILLRETURN:#[0-9]+]]
+; CHECK: declare i8* @strpbrk(i8*, i8* nocapture) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY_WILLRETURN]]
 declare i8* @strpbrk(i8*, i8*)
 
 ; CHECK: declare i8* @strrchr(i8*, i32) [[ARGMEMONLY_NOFREE_NOUNWIND_READONLY]]