[flang-commits] [flang] [flang] Add ability to have special allocator for descriptor data (PR #100690)

[Peter Klausler via flang-commits]

Valentin Clement =?utf-8?b?KOODkOODrOODsw=?=,Valentin Clement
 <clementval at gmail.com>,Valentin Clement =?utf-8?b?KOODkOODrOODsw=?=,
Valentin Clement =?utf-8?b?KOODkOODrOODsw=?=,Valentin Clement
 <clementval at gmail.com>,Valentin Clement <clementval at gmail.com>
Message-ID:
In-Reply-To: <llvm.org/llvm/llvm-project/pull/100690 at github.com>


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@@ -420,6 +420,27 @@ class Descriptor {
 
   void Dump(FILE * = stdout) const;
 
+// Number of bits used to encode the addendum presence flag.
+#define _CFI_ADDENDUM_BITS 1
+// Value of the addendum presence flag.
+#define _CFI_ADDENDUM_FLAG 1
+// Allocator index mask.
+#define _CFI_ALLOCATOR_IDX_MASK 0b00001110
+
+  RT_API_ATTRS inline bool HasAddendum() const {
+    return raw_.extra & _CFI_ADDENDUM_FLAG;
+  }
+  RT_API_ATTRS inline void SetHasAddendum() {
+    raw_.extra |= _CFI_ADDENDUM_FLAG;
+  }
+  RT_API_ATTRS inline int GetAllocIdx() const {
+    return (raw_.extra & _CFI_ALLOCATOR_IDX_MASK) >> _CFI_ADDENDUM_BITS;
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klausler wrote:

One last tweak, then I think I'm done: please rename _CFI_ADDENDUM_BITS, at least as it is used here, to something that signifies that it's the shift count for the ALLOCATOR_IDX field.  That will make these two member functions independent of any assumption that the ALLOCATOR_IDX field has to be adjacent to the addendum flag and that both are right-justified.

https://github.com/llvm/llvm-project/pull/100690