[compiler-rt] c13ac9c - [Compiler-rt] Fix wrong assignment in compiler_rt (#164713)

[via llvm-commits]

Author: Mikołaj Piróg
Date: 2025-10-23T16:04:41Z
New Revision: c13ac9cadf1f9b4fa886b82d1e84a5feb0439023

URL: https://github.com/llvm/llvm-project/commit/c13ac9cadf1f9b4fa886b82d1e84a5feb0439023
DIFF: https://github.com/llvm/llvm-project/commit/c13ac9cadf1f9b4fa886b82d1e84a5feb0439023.diff

LOG: [Compiler-rt] Fix wrong assignment in compiler_rt (#164713)

The `INTEL_CLEARWATERFOREST` belongs to `ProcessorTypes` enum, but it
was assigned to `Subtype` value, leading to cpu_specific/cpu_dispatch
not recognizing CWF. The type for `Subtype` and `Type` are changed to
respective enums to guard against these sort of errors in the future

Added: 
    

Modified: 
    compiler-rt/lib/builtins/cpu_model/x86.c

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/builtins/cpu_model/x86.c b/compiler-rt/lib/builtins/cpu_model/x86.c
index 7ddfaa3e3ed6c..d9ff116cdc292 100644
--- a/compiler-rt/lib/builtins/cpu_model/x86.c
+++ b/compiler-rt/lib/builtins/cpu_model/x86.c
@@ -36,14 +36,14 @@ enum VendorSignatures {
   SIG_AMD = 0x68747541,   // Auth
 };
 
-enum ProcessorVendors {
+enum ProcessorVendors : unsigned int {
   VENDOR_INTEL = 1,
   VENDOR_AMD,
   VENDOR_OTHER,
   VENDOR_MAX
 };
 
-enum ProcessorTypes {
+enum ProcessorTypes : unsigned int {
   INTEL_BONNELL = 1,
   INTEL_CORE2,
   INTEL_COREI7,
@@ -319,11 +319,9 @@ static void detectX86FamilyModel(unsigned EAX, unsigned *Family,
 
 #define testFeature(F) (Features[F / 32] & (1 << (F % 32))) != 0
 
-static const char *getIntelProcessorTypeAndSubtype(unsigned Family,
-                                                   unsigned Model,
-                                                   const unsigned *Features,
-                                                   unsigned *Type,
-                                                   unsigned *Subtype) {
+static const char *getIntelProcessorTypeAndSubtype(
+    unsigned Family, unsigned Model, const unsigned *Features,
+    enum ProcessorTypes *Type, enum ProcessorSubtypes *Subtype) {
   // We select CPU strings to match the code in Host.cpp, but we don't use them
   // in compiler-rt.
   const char *CPU = 0;
@@ -616,8 +614,7 @@ static const char *getIntelProcessorTypeAndSubtype(unsigned Family,
     // Clearwaterforest:
     case 0xdd:
       CPU = "clearwaterforest";
-      *Type = INTEL_COREI7;
-      *Subtype = INTEL_CLEARWATERFOREST;
+      *Type = INTEL_CLEARWATERFOREST;
       break;
 
     case 0x57:
@@ -667,11 +664,9 @@ static const char *getIntelProcessorTypeAndSubtype(unsigned Family,
   return CPU;
 }
 
-static const char *getAMDProcessorTypeAndSubtype(unsigned Family,
-                                                 unsigned Model,
-                                                 const unsigned *Features,
-                                                 unsigned *Type,
-                                                 unsigned *Subtype) {
+static const char *getAMDProcessorTypeAndSubtype(
+    unsigned Family, unsigned Model, const unsigned *Features,
+    enum ProcessorTypes *Type, enum ProcessorSubtypes *Subtype) {
   const char *CPU = 0;
 
   switch (Family) {
@@ -1162,11 +1157,14 @@ __attribute__((visibility("hidden")))
 #endif
 struct __processor_model {
   unsigned int __cpu_vendor;
-  unsigned int __cpu_type;
-  unsigned int __cpu_subtype;
+  enum ProcessorTypes __cpu_type;
+  enum ProcessorSubtypes __cpu_subtype;
   unsigned int __cpu_features[1];
 } __cpu_model = {0, 0, 0, {0}};
 
+static_assert(sizeof(__cpu_model) == 16,
+              "Wrong size of __cpu_model will result in ABI break");
+
 #ifndef _WIN32
 __attribute__((visibility("hidden")))
 #endif