[PATCH] D100879: [Clang] Propagate guaranteed alignment for malloc and others
Dávid Bolvanský via Phabricator via cfe-commits
cfe-commits at lists.llvm.org
Wed Apr 21 05:15:50 PDT 2021
xbolva00 updated this revision to Diff 339192.
xbolva00 added a comment.
Fixed small typo in tests.
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D100879/new/
https://reviews.llvm.org/D100879
Files:
clang/lib/CodeGen/CGCall.cpp
clang/test/CodeGen/alloc-fns-alignment.c
Index: clang/test/CodeGen/alloc-fns-alignment.c
===================================================================
--- /dev/null
+++ clang/test/CodeGen/alloc-fns-alignment.c
@@ -0,0 +1,35 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm < %s | FileCheck %s --check-prefix=ALIGN16
+// RUN: %clang_cc1 -triple x86_64-windows-msvc -emit-llvm < %s | FileCheck %s --check-prefix=ALIGN16
+// RUN: %clang_cc1 -triple i386-apple-darwin -emit-llvm < %s | FileCheck %s --check-prefix=ALIGN16
+// RUN: %clang_cc1 -triple i386-unknown-linux-gnu -emit-llvm < %s | FileCheck %s --check-prefix=ALIGN8
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fno-builtin-malloc -emit-llvm < %s | FileCheck %s --check-prefix=NOBUILTIN-MALLOC
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fno-builtin-calloc -emit-llvm < %s | FileCheck %s --check-prefix=NOBUILTIN-CALLOC
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fno-builtin-realloc -emit-llvm < %s | FileCheck %s --check-prefix=NOBUILTIN-REALLOC
+
+typedef __SIZE_TYPE__ size_t;
+
+void *malloc(size_t);
+void *calloc(size_t, size_t);
+void *realloc(void *, size_t);
+
+void *malloc_test(size_t n) {
+ return malloc(n);
+}
+
+void *calloc_test(size_t n) {
+ return calloc(1, n);
+}
+
+void *raalloc_test(void *p, size_t n) {
+ return realloc(p, n);
+}
+
+// ALIGN16: align 16 i8* @malloc
+// ALIGN16: align 16 i8* @calloc
+// ALIGN16: align 16 i8* @realloc
+// ALIGN8: align 8 i8* @malloc
+// ALIGN8: align 8 i8* @calloc
+// ALIGN8: align 8 i8* @realloc
+// NOBUILTIN-MALLOC: declare i8* @malloc
+// NOBUILTIN-CALLOC: declare i8* @calloc
+// NOBUILTIN-REALLOC: declare i8* @realloc
Index: clang/lib/CodeGen/CGCall.cpp
===================================================================
--- clang/lib/CodeGen/CGCall.cpp
+++ clang/lib/CodeGen/CGCall.cpp
@@ -2048,6 +2048,24 @@
// allows it to work on indirect virtual function calls.
if (AttrOnCallSite && TargetDecl->hasAttr<NoMergeAttr>())
FuncAttrs.addAttribute(llvm::Attribute::NoMerge);
+
+ // Add known guaranteed alignment for allocation functions
+ if (unsigned BuiltinID = Fn->getBuiltinID()) {
+ switch (BuiltinID) {
+ case Builtin::BIaligned_alloc:
+ case Builtin::BIcalloc:
+ case Builtin::BImalloc:
+ case Builtin::BImemalign:
+ case Builtin::BIrealloc:
+ case Builtin::BIstrdup:
+ case Builtin::BIstrndup:
+ RetAttrs.addAlignmentAttr(Context.getTargetInfo().getNewAlign() /
+ Context.getTargetInfo().getCharWidth());
+ break;
+ default:
+ break;
+ }
+ }
}
// 'const', 'pure' and 'noalias' attributed functions are also nounwind.
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