Skip to content

Conversation

@melver
Copy link
Contributor

@melver melver commented Jun 19, 2025

While pvalloc() is a legacy POSIX function, it remains widely available in common C libraries like glibc.

Model pvalloc() in TargetLibraryInfo, allowing LLVM to correctly infer its attributes.

@llvmbot llvmbot added llvm:analysis Includes value tracking, cost tables and constant folding llvm:transforms labels Jun 19, 2025
@llvmbot
Copy link
Member

llvmbot commented Jun 19, 2025

@llvm/pr-subscribers-llvm-analysis

@llvm/pr-subscribers-llvm-transforms

Author: Marco Elver (melver)

Changes

While pvalloc() is a legacy POSIX function, it remains widely available in common C libraries like glibc.

Model pvalloc() in TargetLibraryInfo, allowing LLVM to correctly infer its attributes.


Full diff: https://github.com/llvm/llvm-project/pull/144949.diff

6 Files Affected:

  • (modified) llvm/include/llvm/Analysis/TargetLibraryInfo.def (+5)
  • (modified) llvm/lib/Analysis/TargetLibraryInfo.cpp (+1)
  • (modified) llvm/lib/Transforms/Utils/BuildLibCalls.cpp (+1)
  • (modified) llvm/test/Transforms/InferFunctionAttrs/annotate.ll (+3)
  • (modified) llvm/test/tools/llvm-tli-checker/ps4-tli-check.yaml (+2-2)
  • (modified) llvm/unittests/Analysis/TargetLibraryInfoTest.cpp (+1)
diff --git a/llvm/include/llvm/Analysis/TargetLibraryInfo.def b/llvm/include/llvm/Analysis/TargetLibraryInfo.def
index db566b8ee610e..014988299d37f 100644
--- a/llvm/include/llvm/Analysis/TargetLibraryInfo.def
+++ b/llvm/include/llvm/Analysis/TargetLibraryInfo.def
@@ -2046,6 +2046,11 @@ TLI_DEFINE_ENUM_INTERNAL(puts)
 TLI_DEFINE_STRING_INTERNAL("puts")
 TLI_DEFINE_SIG_INTERNAL(Int, Ptr)
 
+/// void *pvalloc(size_t size);
+TLI_DEFINE_ENUM_INTERNAL(pvalloc)
+TLI_DEFINE_STRING_INTERNAL("pvalloc")
+TLI_DEFINE_SIG_INTERNAL(Ptr, SizeT)
+
 /// ssize_t pwrite(int fildes, const void *buf, size_t nbyte, off_t offset);
 TLI_DEFINE_ENUM_INTERNAL(pwrite)
 TLI_DEFINE_STRING_INTERNAL("pwrite")
diff --git a/llvm/lib/Analysis/TargetLibraryInfo.cpp b/llvm/lib/Analysis/TargetLibraryInfo.cpp
index c8b568354965d..8fe56b2faeba4 100644
--- a/llvm/lib/Analysis/TargetLibraryInfo.cpp
+++ b/llvm/lib/Analysis/TargetLibraryInfo.cpp
@@ -814,6 +814,7 @@ static void initializeLibCalls(TargetLibraryInfoImpl &TLI, const Triple &T,
     TLI.setUnavailable(LibFunc_pclose);
     TLI.setUnavailable(LibFunc_popen);
     TLI.setUnavailable(LibFunc_pread);
+    TLI.setUnavailable(LibFunc_pvalloc);
     TLI.setUnavailable(LibFunc_pwrite);
     TLI.setUnavailable(LibFunc_read);
     TLI.setUnavailable(LibFunc_readlink);
diff --git a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
index a5f6047b0b7ae..e36b9ee380fc4 100644
--- a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
@@ -512,6 +512,7 @@ bool llvm::inferNonMandatoryLibFuncAttrs(Function &F,
     Changed |= setAllocKind(F, AllocFnKind::Alloc | AllocFnKind::Uninitialized | AllocFnKind::Aligned);
     [[fallthrough]];
   case LibFunc_valloc:
+  case LibFunc_pvalloc:
   case LibFunc_malloc:
   case LibFunc_vec_malloc:
     Changed |= setAllocFamily(F, TheLibFunc == LibFunc_vec_malloc ? "vec_malloc"
diff --git a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
index 9e56b01c6b315..d39ae37706173 100644
--- a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
+++ b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
@@ -812,6 +812,9 @@ declare i32 @putchar_unlocked(i32)
 ; CHECK: declare noundef i32 @puts(ptr noundef readonly captures(none)) [[NOFREE_NOUNWIND]]
 declare i32 @puts(ptr)
 
+; CHECK: declare noalias noundef ptr @pvalloc(i64 noundef) [[INACCESSIBLEMEMONLY_NOFREE_NOUNWIND_WILLRETURN_ALLOCKIND_ALLOCUNINIT_ALLOCSIZE0_FAMILY_MALLOC]]
+declare ptr @pvalloc(i64)
+
 ; CHECK: declare noundef i64 @pwrite(i32 noundef, ptr noundef readonly captures(none), i64 noundef, i64 noundef) [[NOFREE]]
 declare i64 @pwrite(i32, ptr, i64, i64)
 
diff --git a/llvm/test/tools/llvm-tli-checker/ps4-tli-check.yaml b/llvm/test/tools/llvm-tli-checker/ps4-tli-check.yaml
index 2d23b15d74b17..51a5a63ba370c 100644
--- a/llvm/test/tools/llvm-tli-checker/ps4-tli-check.yaml
+++ b/llvm/test/tools/llvm-tli-checker/ps4-tli-check.yaml
@@ -54,10 +54,10 @@
 ## the exact count first; the two directives should add up to that.
 ## Yes, this means additions to TLI will fail this test, but the argument
 ## to -COUNT can't be an expression.
-# AVAIL: TLI knows 523 symbols, 289 available
+# AVAIL: TLI knows 524 symbols, 289 available
 # AVAIL-COUNT-289: {{^}} available
 # AVAIL-NOT:       {{^}} available
-# UNAVAIL-COUNT-234: not available
+# UNAVAIL-COUNT-235: not available
 # UNAVAIL-NOT:       not available
 
 ## This is a large file so it's worth telling lit to stop here.
diff --git a/llvm/unittests/Analysis/TargetLibraryInfoTest.cpp b/llvm/unittests/Analysis/TargetLibraryInfoTest.cpp
index 97722483aefe0..2f1bcbae4fc50 100644
--- a/llvm/unittests/Analysis/TargetLibraryInfoTest.cpp
+++ b/llvm/unittests/Analysis/TargetLibraryInfoTest.cpp
@@ -315,6 +315,7 @@ TEST_F(TargetLibraryInfoTest, ValidProto) {
       "declare i32 @putchar(i32)\n"
       "declare i32 @putchar_unlocked(i32)\n"
       "declare i32 @puts(i8*)\n"
+      "declare i8* @pvalloc(i64)\n"
       "declare void @qsort(i8*, i64, i64, i32 (i8*, i8*)*)\n"
       "declare i64 @readlink(i8*, i8*, i64)\n"
       "declare i8* @realloc(i8*, i64)\n"

@melver melver requested a review from nikic June 23, 2025 07:10
While pvalloc() is a legacy POSIX function, it remains widely available
in common C libraries like glibc.

Model pvalloc() in TargetLibraryInfo, allowing LLVM to correctly infer
its attributes.
@melver melver requested a review from nikic June 23, 2025 08:38
@melver melver merged commit 0662045 into llvm:main Jun 23, 2025
7 checks passed
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

llvm:analysis Includes value tracking, cost tables and constant folding llvm:transforms

Projects

None yet

Development

Successfully merging this pull request may close these issues.

3 participants